Revision of the genus Hydroides (Annelida: Serpulidae) from Australia.

PubMed

Sun, Yanan; Wong, Eunice; ten Hove, Harry A; Hutchings, Pat A; Williamson, Jane E; Kupriyanova, Elena K

2015-09-01

Hydroides Gunnerus, 1768 is the largest and one of the economically most important genera of calcareous tubeworms (Serpulidae, Annelida) that includes a number of notorious fouling and bioinvading species. Although the representatives of the genus are typically found in shallow waters of tropical and subtropical areas worldwide, the species composition of the genus in Australia has never been revised. We conducted the first detailed regional taxonomic revision of Hydroides species based both on the historical collections from Australian museums (Australian Museum, Museum Victoria, South Australian Museum, Western Australian Museum, Queensland Museum, and Museum and Art Gallery of Northern Territory) and newly collected material from New South Wales, Victoria, Queensland, Northern Territory, and Western Australia. In total, 25 species are currently considered valid in Australia, including three new species: H. amri n. sp. from NSW, SA, and Vic (previously referred to as H. cf. brachyacantha), as well as H. glasbyi n. sp. and H. qiui n. sp., both from NT, and two new records of H. furcifera and H. multispinosa for Australia. We have synonymised H. spiratubus with H. albiceps, and H. spiculitubus with H. tambalagamensis in this study. The status of the taxon H. cf. recta remains undecided. An identification key and diagnoses accompanied by original high-quality photographs for all species recorded in Australia are provided. Application of molecular genetics is needed to resolve the status of some problematic species.

Elisesione, a new name for Wesenbergia Hartman, 1955, and the description of a new species (Annelida, Hesionidae).

PubMed

Salazar-Vallejo, Sergio I

2016-01-01

Wesenbergia Hartman, 1955 (Annelida, Hesionidae) is both preoccupied and a junior homonym of Wesenbergia Kryger, 1943 (Hymenoptera, Pteromalidae), and must be renamed. Elisesione nom. n. is proposed as a replacement name, derived from the combination of the first name of the discoverer, Elise Wesenberg-Lund, and Hesione Savigny in Lamarck, 1818. Elisesione mezianei sp. n. , is described from the Wallis and Futuna islands (southwest Pacific). A key to separate Elisesione mezianei sp. n. from its congener Elisesione problematica (Wesenberg-Lund, 1950) is included; further, the record of Elisesione problematica for Japan should be regarded as a distinct species because it has palps shorter than antennae (subequal in the type species), and shorter neurochaetal blades (7-9 times longer than wide vs 8-12 times longer than wide in the type species).

Sphaerodoropsis kitazatoi, a new species and the first record of Sphaerodoridae (Annelida: Phyllodocida) in SW Atlantic abyssal sediments around a whale carcass

NASA Astrophysics Data System (ADS)

Shimabukuro, Maurício; Rizzo, Alexandra E.; Alfaro-Lucas, Joan M.; Fujiwara, Yoshihiro; Sumida, Paulo Y. G.

2017-12-01

A new polychaete species, Sphaerodoropsis kitazatoi (Annelida: Phyllodocida: Sphaerodoridae), is described from the abyssal Southwest Atlantic Ocean at the base of São Paulo Ridge (4204 m depth). This species was found in sediments impacted by a whale carcass. The new species has four longitudinal rows of macrotubercles and one transversal row per chaetiger and shares several characters with S. anae Aguado and Rouse, 2006 that is also associated with chemosynthetic environments. They can be clearly distinguished from S. anae and other Sphaerodoropsis species by the arrangement and the number of prostomial, body and parapodial papillae.

Physiological responses to temperature and haeme synthesis modifiers in earthworm Lumbricus terrestris (Annelida: Oligochaeta).

PubMed

Khan, M A Q; Khan, Munawwar Ali; Hurlock, Peter; Ahmed, S A

2012-01-01

Earthworms (Lumbricus terrestris) acclimated at 2° and 6°C above their average habitat temperature (10°C) had respectively 15 and 40% higher rate of respiration than those at habitat temperature. At 14°C, the rate of respiration and blood hemoglobin (Hb) concentration both increased by ∼60 and 50%, respectively, of the values at habitat temperature. At higher temperatures the rate of respiration and Hb synthesis started decreasing. At 20-23°C, the respiration and Hb concentration decreased respectively by about 85% and 35% of that at 14°C. Decrease in blood Hb concentration at higher temperatures appeared to be due to the lowering of the activity of blood enzyme δ-aminolaevulinic acid dehydratase (ALAD). Exposure of 20-23°C-acclimated pale worms to ALAD inhibitor (lead), lowered the already compromised rate of respiration and blood Hb concentration; while exposure to hexachlorobenzene (HCB, inducer of haeme synthesis) and ferric chloride (enhancer of haeme synthesis) did not overcome the inhibitory effect of high temperature on Hb synthesis. At 20-23°C the affinity of Hb for oxygen also decreased as indicated by the lowering of oxy-Hb (HbO) concentration in blood. The lowering of concentration of blood Hb and its affinity for oxygen may lower the amount of oxygen delivered to cells, which may limit the level of aerobic metabolism (glycolysis, oxidative phosphorylation), as indicated by an increase in blood glucose concentration and a decrease in in vitro activities of mitochondrial electron transport system components (ETS) namely NADH-cytochrome c reductase, succinate dehydrogenase, cytochrome c oxidase, and ATPases. Although the oxygen concentration in air, at sea level, does not decrease significantly from 6° to 20-23°C (lack of hypoxia), lowering of both Hb and HbO concentrations by high temperature may cause significant hypoxemia. The latter may lead to inhibition of the activity of muscle mitochondrial respiratory enzymes (ETS). The resulting inhibition of ATP synthesis and hydrolysis may cause deficit of energy needed for peristalsis/fictive locomotion of body and heart muscles (as indicated by a decrease in heart rate) to facilitate diffusion and transport of gases. The upper critical temperature (20-23°C) also slows down the heart rate and causes hyperosmotic stress (hypovolemia). Thus, a rise in soil temperature above 18°C, which inhibits Hb synthesis, Hb oxygenation, and mitochondrial ETS activity, and slows down the heart rate and causes hyperosmotic stress, can make this and higher temperatures lethal to populations of these earthworms, especially in the presence of metabolic inhibitors and respiratory poisons. Copyright © 2010 Wiley Periodicals, Inc.

Combined toxicity of imidacloprid and three insecticides to the earthworm, Eisenia fetida (Annelida, Oligochaeta).

PubMed

Cang, Tao; Dai, Dejiang; Yang, Guiling; Yu, Yijun; Lv, Lu; Cai, Leiming; Wang, Qiang; Wang, Yanhua

2017-03-01

Although the earthworm Eisenia fetida has been used in many ecotoxicological studies in recent years, most of these studies have only focused on assessing the effects of individual insecticides. In the present study, we aimed to compare the individual and combined toxic effects of imidacloprid and three insecticides (phoxim, chlorpyrifos, and lambda-cyhalothrin) on E. fetida. We showed that imidacloprid had the highest intrinsic toxicity to the worms in filter paper contact test, followed by phoxim and lambda-cyhalothrin, while the least toxicity was found from chlorpyrifos. Moreover, 14-day soil toxicity test revealed that the highest toxicity was still detected for imidacloprid with an LC 50 value of 2.82 (2.61∼3.17) mg a.i. kg -1 dry weight (DW), followed by chlorpyrifos with an LC 50 value of 384.9 (353.5∼440.3) mg a.i. kg -1 DW. Meanwhile, a relatively less toxicity was found for lambda-cyhalothrin with an LC 50 value of 560.3 (475.9∼718.5) mg a.i. kg -1 DW, while the lowest toxicity to E. fetida was observed for phoxim with an LC 50 value of 901.5 (821.3∼1017) mg a.i. kg -1 DW. In addition, significant synergistic responses were found from the ternary mixture of imidacloprid-phoxim-lambda-cyhalothrin and quaternary mixture of imidacloprid-phoxim-chlorpyrifos-lambda-cyhalothrin in both bioassay systems. Therefore, our findings highlighted that the simultaneous presence of several insecticides in the soil environment might lead to increased toxicity, resulting in serious damage to the nontarget organisms compared with individual insecticides.

Elisesione, a new name for Wesenbergia Hartman, 1955, and the description of a new species (Annelida, Hesionidae)

PubMed Central

Salazar-Vallejo, Sergio I.

2016-01-01

Abstract Wesenbergia Hartman, 1955 (Annelida, Hesionidae) is both preoccupied and a junior homonym of Wesenbergia Kryger, 1943 (Hymenoptera, Pteromalidae), and must be renamed. Elisesione nom. n. is proposed as a replacement name, derived from the combination of the first name of the discoverer, Elise Wesenberg-Lund, and Hesione Savigny in Lamarck, 1818. Elisesione mezianei sp. n., is described from the Wallis and Futuna islands (southwest Pacific). A key to separate Elisesione mezianei sp. n. from its congener Elisesione problematica (Wesenberg-Lund, 1950) is included; further, the record of Elisesione problematica for Japan should be regarded as a distinct species because it has palps shorter than antennae (subequal in the type species), and shorter neurochaetal blades (7–9 times longer than wide vs 8–12 times longer than wide in the type species). PMID:27920600

A Fluorescent Marking and Re-count Technique Using the Invasive Earthworm, Pontoscolex corethrurus (Annelida: Oligochaeta)

Treesearch

Grizelle Gonzalez; Elianid Espinoza; Zhigang Liu; Xiaoming Zou

2006-01-01

We used a fluorescence technique to mark and re-count the invasive earthworm, Pontoscolex corethrurus from PVC tubes established in a forest and a recently abandoned pasture in Puerto Rico to test the effects of the labeling treatment on earthworm population survival over time. A fluorescent marker was injected into the earthworms in the middle third section of the...

The effect of cohabitation of Tubifex tubifex (Oligochaeta: Tubificidae) populations on infections to Myxobolus cerebralis (Myxozoa: Myxobolidae).

PubMed

Beauchamp, Katherine A; El-Matbouli, Mansour; Gay, Melanie; Georgiadis, Marios P; Nehring, R Barry; Hedrick, Ronald P

2006-01-01

The competitive interactions between susceptible and resistant Tubifex tubifex (Oligochaeta: Tubificidae) exposed to Myxobolus cerebralis (Myxozoa: Myxobolidae) infections were investigated in two laboratory trials. Competition was assessed by the total parasite production over the course of the trials in mixed and pure cultures of M. cerebralis exposed worms, and by the genetic analyses of worms from the control and experimental groups at the beginning and end of the experiments. Mixed cultures of resistant and susceptible worms showed a 70% reduction in production of parasites released when compared with pure cultures of susceptible worms. In studies with laboratory and field-collected oligochaetes the mixed cultures at the end of the cohabitation experiments were dominated by resistant Tubifex from lineage V (HB strain) this strain of Tubifex has a competitive advantage over worms from other lineages. The results of this study suggest that certain species of Tubifex may be dead-end hosts to M. cerebralis by absorbing or inactivating the parasite and may also show greater survival compared to susceptible oligochaetes in certain whirling disease enzootic habitats.

Unsegmented annelids? Possible origins of four lophotrochozoan worm taxa.

PubMed

Halanych, Kenneth M; Dahlgren, Thomas G; McHugh, Damhnait

2002-07-01

In traditional classification schemes, the Annelida consists of the Polychaeta and the Clitellata (the latter including the Oligochaeta and Hirudinida). However, recent analyses suggest that annelids are much more diverse than traditionally believed, and that polychaetes are paraphyletic. Specifically, some lesser-known taxa (previously regarded as separate phyla) appear to fall within the annelid radiation. Abundant molecular, developmental, and morphological data show that the Siboglinidae, which includes the formerly recognized Pogonophora and Vestimentifera, are derived annelids; recent data from the Elongation Factor-1α (EF-1α) gene also suggest that echiurids are of annelid ancestry. Further, the phylogenetic origins of two other lesser-known groups of marine worms, the Myzostomida and Sipuncula, have recently been called into question. Whereas some authors advocate annelid affinities, others argue that these taxa do not fall within the annelid radiation. With advances in our understanding of annelid phylogeny, our perceptions of body plan evolution within the Metazoa are changing. The evolution of segmentation probably is more plastic than traditionally believed. However, as our understanding of organismal evolution is being revised, we are also forced to reconsider the specific characters being examined. Should segmentation be considered a developmental process or an ontological endpoint?

Sabellaria jeramae, a new species (Annelida: Polychaeta: Sabellariidae) from the shallow waters of Malaysia, with a note on the ecological traits of reefs.

PubMed

Nishi, Eijiroh; Matsuo, Kanako; Capa, Maria; Tomioka, Shinri; Kajihara, Hiroshi; Kupriyanova, Elena K; Polgar, Gianluca

2015-12-07

A new species of the genus Sabellaria Lamarck, 1818 (Annelida: Polychaeta: Sabellariidae) is described from the intertidal zone of Jeram, Selangor, Malaysia. Sabellaria jeramae n. sp. is a gregarious species that constructs large reefs several hundreds of meters long and 50-200 m wide. The new species is distinguished from other congeners by the character combination of the presence of a single kind of middle paleae with conspicuous morphology, and outer paleae with long frayed teeth. Morphological features of the species are described and compared to those of all congeneric species. We also compare the reef structure and geographical distribution of the new species to those of the members of the family Sabellariidae around the world, demonstrating the ecological traits of the reefs.

Ecotoxicity of wastes in avoidance tests with Enchytraeus albidus, Enchytraeus crypticus and Eisenia fetida (Oligochaeta).

PubMed

Kobeticová, Klára; Hofman, Jakub; Holoubek, Ivan

2010-04-01

Contact bioassays are important for testing the ecotoxicity of solid materials. However, survival and reproduction tests are often not practical due to their duration which may last for several weeks. Avoidance tests with soil invertebrates may offer an alternative or extension to the classic test batteries due to their short duration (days rather than weeks) and due to a sensitive sub-acute endpoint (behavior). (a) to evaluate the effects of three solid industrial wastes (incineration ash, contaminated wood chips and contaminated soil) on three Oligochaeta species (enchytraeids Enchytraeusalbidus, Enchytraeus crypticus and earthworm Eisenia fetida) in avoidance tests; (b) to compare the sensitivity among the species and to compare results of avoidance test to reproduction tests; (c) to elucidate if measuring the weight in the earthworm avoidance test could be reasonable additional endpoint. Avoidance mostly increased with the increasing percent of waste in the mixture showing a dose-response curve. E. fetida was the most sensitive species and E. crypticus the least one. An additional endpoint, (changes in weight after two-day exposure) was not found to be more sensitive than avoidance reaction, but it confirmed that earthworms staying in the highest concentrations of the waste mixture were affected showing apparent weight reduction. Our results indicate that avoidance tests with earthworms and enchytraeids are feasible for waste testing. Copyright 2009 Elsevier Ltd. All rights reserved.

The developmental transcriptome atlas of the spoon worm Urechis unicinctus (Echiurida: Annelida).

PubMed

Park, Chungoo; Han, Yong-Hee; Lee, Sung-Gwon; Ry, Kyoung-Bin; Oh, Jooseong; Kern, Elizabeth M A; Park, Joong-Ki; Cho, Sung-Jin

2018-03-01

Echiurida is one of the most intriguing major subgroups of annelida because, unlike most other annelids, echiurids lack metameric body segmentation as adults. For this reason, transcriptome analyses from various developmental stages of echiurid species can be of substantial value for understanding precise expression levels and the complex regulatory networks during early and larval development. A total of 914 million raw RNA-Seq reads were produced from 14 developmental stages of Urechis unicinctus and were de novo assembled into contigs spanning 63,928,225 bp with an N50 length of 2700 bp. The resulting comprehensive transcriptome database of the early developmental stages of U. unicinctus consists of 20,305 representative functional protein-coding transcripts. Approximately 66% of unigenes were assigned to superphylum-level taxa, including Lophotrochozoa (40%). The completeness of the transcriptome assembly was assessed using benchmarking universal single-copy orthologs; 75.7% of the single-copy orthologs were presented in our transcriptome database. We observed 3 distinct patterns of global transcriptome profiles from 14 developmental stages and identified 12,705 genes that showed dynamic regulation patterns during the differentiation and maturation of U. unicinctus cells. We present the first large-scale developmental transcriptome dataset of U. unicinctus and provide a general overview of the dynamics of global gene expression changes during its early developmental stages. The analysis of time-course gene expression data is a first step toward understanding the complex developmental gene regulatory networks in U. unicinctus and will furnish a valuable resource for analyzing the functions of gene repertoires in various developmental phases.

Invasion of the tropical earthworm Pontoscolex corethrurus (Rhinodrilidae, Oligochaeta) in temperate grasslands

PubMed Central

Ortiz-Gamino, Diana; Pérez-Rodríguez, Paulino

2016-01-01

The tropical earthworm Pontoscolex corethrurus (Rhinodrilidae, Oligochaeta) presents a broad distribution (e.g., 56 countries from four continents). It is generally assumed that temperature appears to limit the success of tropical exotic species in temperate climates. However, the distribution range of this species could advance towards higher elevations (with lower temperatures) where no tropical species currently occur. The aim of this study was to evaluate the soil and climatic variables that could be closely associated with the distribution of P. corethrurus in four sites along an altitudinal gradient in central Veracruz, Mexico. We predicted that the distribution of P. corethrurus would be more related to climate variables than edaphic parameters. Five sampling points (in the grassland) were established at each of four sites along an altitudinal gradient: Laguna Verde (LV), La Concepción (LC), Naolinco (NA) and Acatlán (AC) at 11–55, 992–1,025, 1,550–1,619 y 1,772–1,800 masl, respectively. The climate ranged from tropical to temperate along the altitudinal gradient. Ten earthworm species (5 Neotropical, 4 Palearctic and 1 Nearctic) were found along the gradient, belonging to three families (Rhinodrilidae, Megascolecide and Lumbricidae). Soil properties showed a significant association (positive for Ngrass, pH, permanent wilting point, organic matter and P; and negative for Total N, K and water-holding capacity) with the abundance of the earthworm community. Also there seems to be a relationship between climate and earthworm distribution along the altitudinal gradient. P. corethrurus was recorded at tropical (LV and LC) and temperate sites (NA) along the altitudinal gradient. Our results reveal that soil fertility determines the abundance of earthworms and site (climate) can act as a barrier to their migration. Further research is needed to determine the genetic structure and lineages of P. corethrurus along altitudinal gradients. PMID:27761348

Sphaerodoridae (Annelida) of the deep Northwestern Atlantic, including remarkable new species of Euritmia and Sphaerephesia

PubMed Central

Capa, María; Osborn, Karen J.; Bakken, Torkild

2016-01-01

Abstract Sphaerodoridae (Annelida) is a seeming uncommon and minimally diverse group of polychaetes in the northwestern Atlantic, with only seven species reported from the United States, and none from the eastern coast of Canada, before the present study. Review of the large Smithsonian collection (National Museum of Natural History, Washington) revealed the presence of two morphologically extraordinary undescribed species and added a new record to the north-western Atlantic region. Euritmia carolensis sp. n. is characterised by bearing approximately 20 sessile spherical papillae arranged in three transverse rows per segment, ventrum with 4–6 larger papillae near the parapodial bases and parapodia without papillae; bearing 4–5 simple chaetae that are enlarged subdistally. Sphaerephesia amphorata sp. n. is distinguished from other congeners in the presence of four longitudinal rows of sessile, bottle-shaped macrotubercles with exceptionally long digitiform terminal papilla, and parapodia with four rounded and small papillae, bearing 4–7 compound chaetae, with blades 7–11 times as long as wide. Other encountered species are also herein re-described, including intraspecific variation and updated iconography. Comparison of material also allowed some systematic changes in the group, including the synonymisation of the genus Amacrodorum with Euritmia, and the transfer of Ephesiopsis shivae to Ephesiella. A key to the species reported from the Northwestern Atlantic is provided. PMID:27667938

Observation on Nematocystis kailashi sp. nov. (Apicomplexa: Eugregarinida) from an Indian earthworm Glyphidrilus tuberosus Stephenson (Annelida: Oligochaeta)

PubMed

Mallik, Partha; Bandyopadhyay, Prabir K

Surveys on aseptate gregarines in earthworm hosts in different districts of West Bengal state of India revealed the existence of one new species of aseptate gregarine of the genus Nematocystis Hesse, 1909 have been identified from the seminal vesicles of the earthworm, Glyphidrilus tuberosus Stephenson, 1916 in the district of Purba Midnapur, West Bengal of India. Gamonts of the organism are very much elongated, cylindrical, nematoid and without mucron. The terminal end adjacent to the nucleus rounded and the distal end pointed. The gamonts measure 846.45-1031.13 (931.86±70.48) μm in length and 18.40-20.45 (19.43±1.05) μm in width. Nucleus elongated or depressed elliptoid, measures 53.17-63.39 (60.33±3.28) μm in length and 13.29-16.36 (14.15±0.89) μm in width. The gametocysts are slightly ovoid, measuring 110.43-120.65 (114.31±3.44) μm in diameter. Oocysts navicular and measure 9.24-10.39 (9.78±0.40) μm×5.77-6.16 (6.04±0.18) μm. Based on critical analysis and comparison with earlier reported species, the species under discussion established as new one.

Observation on Monocystis kuidongae sp. nov. (Apicomplexa: Eugregarinida) from an Indian earthworm Perionyx excavatus Perrier (Annelida: Oligochaeta).

PubMed

Mallik, Partha; Bandyopadhyay, Probir K

2017-06-01

A survey to know the diversity of endoparasitic protozoan parasites of the earthworms of West Bengal, revealed a new species of the genus Monocystis Stein, 1848, that resides in the seminal vesicle of the earthworm Perionyx excavatus Perrier. Monocystis kuidongae sp. nov. is characterized by ovoidal gamonts (trophozoites) with inconspicuous mucron and measure 69.53-102.25 (86.29 ± 11.48) μm × 24.54-61.35 (35.17 ± 12.82) μm. Shape of the gametocysts are almost rounded and measure 81.80-110.43 (96.11 ± 8.85) μm in diameter. Oocysts are navicular with pointed ends and measure 11.55-12.32 (11.78 ± 0.36) µm × 5.00-5.77 (5.39 ± 0.25) µm.

New species and records of the earthworm genus Ramiellona (Annelida, Oligochaeta, Acanthodrilidae) from southern Mexico and Guatemala.

PubMed

Fragoso, Carlos; Rojas, Patricia

2014-01-10

Three new species from the Mexican states of Tabasco and Chiapas are added to the acanthodrilid earthworm genus Ramiellona, R. microscolecina sp. nov., R. tojolabala sp. nov. and R. teapaensis sp. nov. They belong to a group of species with penial setae and last pair of hearts in segment 12. All are holandric and the spermathecae have either a flat circular diverticle in a segment anterior to that of the ampulla (R. microscolecina sp. nov. and R. tojolabala sp. nov.) or two ovoidal and sessile diverticles on opposite sides in the same segment of the ampulla (R. teapaensis sp. nov.). Ramiellona americana (Gates) is re-described from a single specimen from central Guatemala, and the diagnosis of Ramiellona lasiura (Graff) from El Salvador is emended after reinvestigating a paratype specimen from the Senckenberg Naturmuseum Frankfurt. On the basis of several individuals from different populations of the Mexican states of Chiapas and Tabasco, the morphological variation of Ramiellona strigosa setosa Righi is described and its relationship with the Guatemalan Ramiellona strigosa strigosa Gates and Ramiellona eiseni (Michaelsen) is discussed. Finally, the position of Ramiellona within Acanthodrilidae and its relation to genera of the doubtful Octochaetidae is discussed.

On the diversity of the SE Indo-Pacific species of Terebellides (Annelida; Trichobranchidae), with the description of a new species

PubMed Central

Parapar, Julio; Moreira, Juan

2016-01-01

The study of material collected during routine monitoring surveys dealing with oil extraction and aquaculture in waters off Myanmar (North Andaman Sea) and in the Gulf of Thailand, respectively, allowed us to analyse the taxonomy and diversity of the polychaete genus Terebellides (Annelida). Three species were found, namely Terebellides cf. woolawa, Terebellides hutchingsae spec. nov. (a new species fully described and illustrated), and Terebellides sp. (likely a new species, but with only one available specimen). The new species is characterised by the combination of some branchial (number, fusion and relative length of lobes and papillation of lamellae), and thoracic (lateral lobes and relative length of notopodia) characters and is compared with all species described or reported in the SW Indo-Pacific area, as well as with those sharing similar morphological characteristics all around the world. The taxonomic relevance of the relative length of branchial lobes and different types of ciliature in branchial lamellae for species discrimination in the genus is discussed. A key to all Terebellides species described in SE Indo-Pacific waters is presented. PMID:27602280

On the diversity of the SE Indo-Pacific species of Terebellides (Annelida; Trichobranchidae), with the description of a new species.

PubMed

Parapar, Julio; Moreira, Juan; Martin, Daniel

2016-01-01

The study of material collected during routine monitoring surveys dealing with oil extraction and aquaculture in waters off Myanmar (North Andaman Sea) and in the Gulf of Thailand, respectively, allowed us to analyse the taxonomy and diversity of the polychaete genus Terebellides (Annelida). Three species were found, namely Terebellides cf. woolawa, Terebellides hutchingsae spec. nov. (a new species fully described and illustrated), and Terebellides sp. (likely a new species, but with only one available specimen). The new species is characterised by the combination of some branchial (number, fusion and relative length of lobes and papillation of lamellae), and thoracic (lateral lobes and relative length of notopodia) characters and is compared with all species described or reported in the SW Indo-Pacific area, as well as with those sharing similar morphological characteristics all around the world. The taxonomic relevance of the relative length of branchial lobes and different types of ciliature in branchial lamellae for species discrimination in the genus is discussed. A key to all Terebellides species described in SE Indo-Pacific waters is presented.

Adaptation and evolution of deep-sea scale worms (Annelida: Polynoidae): insights from transcriptome comparison with a shallow-water species

NASA Astrophysics Data System (ADS)

Zhang, Yanjie; Sun, Jin; Chen, Chong; Watanabe, Hiromi K.; Feng, Dong; Zhang, Yu; Chiu, Jill M. Y.; Qian, Pei-Yuan; Qiu, Jian-Wen

2017-04-01

Polynoid scale worms (Polynoidae, Annelida) invaded deep-sea chemosynthesis-based ecosystems approximately 60 million years ago, but little is known about their genetic adaptation to the extreme deep-sea environment. In this study, we reported the first two transcriptomes of deep-sea polynoids (Branchipolynoe pettiboneae, Lepidonotopodium sp.) and compared them with the transcriptome of a shallow-water polynoid (Harmothoe imbricata). We determined codon and amino acid usage, positive selected genes, highly expressed genes and putative duplicated genes. Transcriptome assembly produced 98,806 to 225,709 contigs in the three species. There were more positively charged amino acids (i.e., histidine and arginine) and less negatively charged amino acids (i.e., aspartic acid and glutamic acid) in the deep-sea species. There were 120 genes showing clear evidence of positive selection. Among the 10% most highly expressed genes, there were more hemoglobin genes with high expression levels in both deep-sea species. The duplicated genes related to DNA recombination and metabolism, and gene expression were only enriched in deep-sea species. Deep-sea scale worms adopted two strategies of adaptation to hypoxia in the chemosynthesis-based habitats (i.e., rapid evolution of tetra-domain hemoglobin in Branchipolynoe or high expression of single-domain hemoglobin in Lepidonotopodium sp.).

Adaptation and evolution of deep-sea scale worms (Annelida: Polynoidae): insights from transcriptome comparison with a shallow-water species

PubMed Central

Zhang, Yanjie; Sun, Jin; Chen, Chong; Watanabe, Hiromi K.; Feng, Dong; Zhang, Yu; Chiu, Jill M.Y.; Qian, Pei-Yuan; Qiu, Jian-Wen

2017-01-01

Polynoid scale worms (Polynoidae, Annelida) invaded deep-sea chemosynthesis-based ecosystems approximately 60 million years ago, but little is known about their genetic adaptation to the extreme deep-sea environment. In this study, we reported the first two transcriptomes of deep-sea polynoids (Branchipolynoe pettiboneae, Lepidonotopodium sp.) and compared them with the transcriptome of a shallow-water polynoid (Harmothoe imbricata). We determined codon and amino acid usage, positive selected genes, highly expressed genes and putative duplicated genes. Transcriptome assembly produced 98,806 to 225,709 contigs in the three species. There were more positively charged amino acids (i.e., histidine and arginine) and less negatively charged amino acids (i.e., aspartic acid and glutamic acid) in the deep-sea species. There were 120 genes showing clear evidence of positive selection. Among the 10% most highly expressed genes, there were more hemoglobin genes with high expression levels in both deep-sea species. The duplicated genes related to DNA recombination and metabolism, and gene expression were only enriched in deep-sea species. Deep-sea scale worms adopted two strategies of adaptation to hypoxia in the chemosynthesis-based habitats (i.e., rapid evolution of tetra-domain hemoglobin in Branchipolynoe or high expression of single-domain hemoglobin in Lepidonotopodium sp.). PMID:28397791

New species of Rhyacodrilus (Annelida: Clitellata: Rhyacodrilinae) of North America, with re-description of R. sodalis (Eisen, 1879)

USGS Publications Warehouse

Rodriguez, Pilar; Fend, Steven V.

2013-01-01

Six new Nearctic species of the aquatic oligochaete genus Rhyacodrilus (Annelida, Clitellata, Rhyacodrilinae), are de-scribed, five (R. saelonae sp. n., R. quileuticus sp. n., R. clio sp. n., R. alcyoneus sp. n. and R. longichaeta sp. n.) from western and one (R. propiporus sp. n.) from eastern North America. The taxonomy of the most common Rhyacodrilus species reported in the Nearctic region has been based largely on chaetal characters, which has generated certain confu-sion. The new species give a new perspective on the genus Rhyacodrilus in North America, suggesting a much higher diversity than previously expected. The description of R. longichaeta sp. n. questions the taxonomic status of R. montana (Brinkhurst), which is here regarded as species inquirenda. The taxonomic status of R. sodalis (Eisen) is discussed based on characters of the reproductive system, the existing Lake Tahoe neotype series is invalidated, and a neotype is described from Eisen's type locality. Based on the discussion of the characters of the genus Rhyacodrilus, the genus Stochidrilus Martínez-Ansemil et al. is proposed as a junior synonym of that genus. The presence of the widely reported species R. coccineus has not been confirmed in the study collections, although the species requires a sound revision. A key to the species bearing hair chaetae is provided, based mainly on features of the reproductive system.

Effects of 4-nonylphenol on benthic macroinvertebrates and insect emergence in littoral enclosures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmude, K.L.; Liber, K.; Corry, T.D.

1999-03-01

The effect of 4-nonylphenol (NP) on benthic, freshwater macroinvertebrates in littoral enclosures was evaluated over a 2-year period. Enclosures received 11 NP applications, 48 h apart, with nominal rates of 3, 30, 100, and 300 {micro}g/L. Mean measured peak concentrations in integrated water column samples over the 20-d application period were 5 {+-} 4, 23 {+-} 11, 76 {+-} 21, and 243 {+-} 41 {micro}g/L NP. Concentrations of NP in the water column decreased rapidly after the last application. Maximum NP concentrations measured in sediments, pore water, and macrophytes of a 300-{micro}g/L enclosure were 27.4 mg/kg, 29.9 {micro}g/L, and 89.6more » mg/kg, respectively. The most abundant macroinvertebrate groups, Chironomidae, Oligochaeta, and Mollusca, decreased in abundance after application. Effects on Mollusca were the most severe. Their numbers were significantly reduced at the highest treatment throughout most of the study. Oligochaetes and chironomids were also significantly reduced at the highest treatment, but populations recovered within 6 weeks. Snails and naidid oligochaetes were slightly affected at the second highest treatment (76 {+-} 21 {micro}g/L NP). Insect emergence was reduced during and immediately post-application, but the effects were likely caused or compounded by a surfactant sheen on the surface of the water that interfered with emergence and/or oviposition. The observed effects on the benthic community were most likely due to exposure from the water, although more persistent macrophyte-associated residues may have contributed to effects on Gastropoda, Naididae, and Tanytarsini. Macrophyte-associated NP residues may pose a small risk to benthic organisms, but it is probably minor compared to water exposures. The no-observed and lowest-observed-effect concentration for the benthic community was 23 {+-} 11 and 76 {+-} 21 {micro}g/L NP, respectively.« less

Reduced aggression and foraging efficiency of invasive signal crayfish (Pacifastacus leniusculus) infested with non-native branchiobdellidans (Annelida: Clitellata).

PubMed

James, J; Davidson, K E; Richardson, G; Grimstead, C; Cable, J

2015-11-17

Biological invasions are a principal threat to global biodiversity and identifying the determinants of non-native species' success is a conservation priority. Through their ability to regulate host populations, parasites are increasingly considered as important in determining the outcome of species' invasions. Here, we present novel evidence that the common crayfish ecto-symbiont, Xironogiton victoriensis (Annelida: Clitellata) can affect the behaviour of a widespread and ecologically important invader, the signal crayfish (Pacifastacus leniusculus). To assess the signal crayfish-X. victoriensis relationship naïve crayfish were infested with an intensity of worms typically observed under natural conditions. Over a 10-week period the growth rate and survivorship of these animals was monitored and compared to those of uninfested counterparts. Complementary dyadic competition and foraging experiments were run to assess the behaviour of infested compared to uninfested animals. These data were analysed using General Linear Models and Generalized Linear Mixed Models. Whilst X. victoriensis did not affect the growth rate or survivorship of signal crayfish under laboratory conditions, infested animals were significantly less aggressive and poorer foragers than uninfested individuals. Through reducing aggression and foraging efficiency, infestation with X. victoriensis may disrupt the social structure, and potentially growth rate and/or dispersal of afflicted crayfish populations, with potential effects on their invasion dynamics. This is important given the widespread invasive range of crayfish and their functional roles as ecosystem engineers and keystone species.

A new species of Enchytraeus (Enchytraeidae, Oligochaeta) from the profundal of Lake Van, the world's largest soda Lake (Turkey, East Anatolia).

PubMed

Arslan, Naİme; Timm, Tarmo; Rojo, VerÓnica; VizcaÍno, AntÓn; Schmelz, RÜdiger M

2018-02-21

Enchytraeus polatdemiri sp. nov. (Enchytaeidae, Oligochaeta) was discovered in the framework of a sampling campaign of the benthic invertebrate fauna of the hyperalkaline Lake Van in Eastern Anatolia, Turkey, the third-largest closed lake and the largest soda lake on Earth. It was the only oligochaete species found in all samples. DNA sequencing included a fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene, and a fragment of the nuclear histone 3 (H3) gene. For comparison, specimens from laboratory cultures of E. albidus Henle, 1837, a widespread and morphologically similar species, were sequenced as well. The new species differs from E. albidus in comparatively small body size, 2 or 3 chaetae per bundle, saddle-shaped clitellum, absence of a copulatory field between the male pores and vasa deferentia usually not extending beyond the clitellum. The individual gene trees of COI and H3, as well as the combined phylogenetic analysis of both trees, recovered Enchytraeus polatdemiri sp. nov. as a monophyletic group within the genus Enchytraeus, closely related to E. albidus, but with an average p-distance for COI of 14.5 %. E. polatdemiri sp. nov. may have evolved from a local population of Enchytraeus albidus, a species well-adapted to changing salinity conditions, or from a common ancestor into an extremophile species that dwells and reproduces in the profundal of a strongly alkaline soda lake.

Changes in the bottom fauna of western Lake Erie from 1930 to 1961

USGS Publications Warehouse

Carr, John F.; Hiltunen, Jarl K.

1965-01-01

Samples were collected at 40 stations in western Lake Erie in 1961 to determine the species composition, distribution, and abundance of macrobenthonic organisms and to document changes since 1930, when a similar survey was made. The fauna in 1961 was composed principally of Oligochaeta, Tendipedidae (7 genera), Sphaeriidae (15 species), and Gastropoda (at least 8 species). Stations with a high density of Oligochaeta were near the principal sources of pollution (Maumee, Raisin, and Detroit rivers). Stations with fewer Oligochaeta and a more diverse fauna were farthest from the river mouths. The population density of the burrowing mayfly, Hexagenia spp., was reduced from an average of 139/m2 in 1930 to less than 1/m2 in 1961. Organisms more abundant near the sources of pollution than in other areas were, in addition to Oligochaeta: the midge, Procladius; the fingernail clam, Sphaerium transversum; and the snail, Valvata sincera (sens. lat.). Organisms sensitive to pollution, such as amphipods, mayfly nymphs, caddisfly larvae, and naiad clams, were scarce and usually at the more lakeward stations. The most important changes in fauna during the 31-year period were: ninefold increase in Oligochaeta; fourfold increase in Tendipedidae; twofold increase in Sphaeriidae; sixfold increase in Gastropoda; and a reduction of Hexagenia to less than 1% of former abundance. The area of pollution (as judged from the abundance of Oligochaeta) increased from 263 km2 in 1930 to 1,020 km2 in 1961.

Pinpointing cryptic borders: Fine-scale phylogeography and genetic landscape analysis of the Hormogaster elisae complex (Oligochaeta, Hormogastridae).

PubMed

Marchán, Daniel F; Fernández, Rosa; de Sosa, Irene; Díaz Cosín, Darío J; Novo, Marta

2017-07-01

Spatial and temporal aspects of the evolution of cryptic species complexes have received less attention than species delimitation within them. The phylogeography of the cryptic complex Hormogaster elisae (Oligochaeta, Hormogastridae) lacks knowledge on several aspects, including the small-scale distribution of its lineages or the palaeogeographic context of their diversification. To shed light on these topics, a dense specimen collection was performed in the center of the Iberian Peninsula - resulting in 28 new H. elisae collecting points, some of them as close as 760m from each other- for a higher resolution of the distribution of the cryptic lineages and the relationships between the populations. Seven molecular regions were amplified: mitochondrial subunit 1 of cytochrome c oxidase (COI), 16S rRNA and tRNA Leu, Ala, and Ser (16S t-RNAs), one nuclear ribosomal gene (a fragment of 28S rRNA) and one nuclear protein-encoding gene (histone H3) in order to infer their phylogenetic relationships. Different representation methods of the pairwise divergence in the cytochrome oxidase I sequence (heatmap and genetic landscape graphs) were used to visualize the genetic structure of H. elisae. A nested approach sensu Mairal et al. (2015) (connecting the evolutionary rates of two datasets of different taxonomic coverage) was used to obtain one approximation to a time-calibrated phylogenetic tree based on external Clitellata fossils and a wide molecular dataset. Our results indicate that limited active dispersal ability and ecological or biotic barriers could explain the isolation of the different cryptic lineages, which never co-occur. Rare events of long distance dispersal through hydrochory appear as one of the possible causes of range expansion. Copyright © 2017 Elsevier Inc. All rights reserved.

Type material of Acanthocephala, Nematoda and other non-helminths phyla (Cnidaria, Annelida, and Arthropoda) housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016.

PubMed

Lopes, Daniela A; Gomes, Delir Corrêa; Knoff, Marcelo

2017-01-01

The third part of the catalogue of type material in the Helminthological Collection of the Oswaldo Cruz Institute/FIOCRUZ (CHIOC), comprising types deposited between 1979 and 2016, is presented to complement the first list of all types that was published in 1979. This part encompasses Acanthocephala, Nematoda and the other non-helminth phyla Cnidaria, Annelida, and Arthropoda. Platyhelminthes was covered in the first (Monogenoidea) and second (Rhabditophora Trematoda and Cestoda) parts of the catalogue published in September 2016 and March 2017, respectively. The present catalogue comprises type material for 116 species distributed across five phyla, nine classes, 50 families, and 80 genera. Specific names are listed systematically, followed by type host, infection site, type locality, and specimens with their collection numbers and references. Species classification and nomenclature are updated.

Type material of Acanthocephala, Nematoda and other non-helminths phyla (Cnidaria, Annelida, and Arthropoda) housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016

PubMed Central

Lopes, Daniela A.; Gomes, Delir Corrêa; Knoff, Marcelo

2017-01-01

Abstract The third part of the catalogue of type material in the Helminthological Collection of the Oswaldo Cruz Institute/FIOCRUZ (CHIOC), comprising types deposited between 1979 and 2016, is presented to complement the first list of all types that was published in 1979. This part encompasses Acanthocephala, Nematoda and the other non-helminth phyla Cnidaria, Annelida, and Arthropoda. Platyhelminthes was covered in the first (Monogenoidea) and second (Rhabditophora Trematoda and Cestoda) parts of the catalogue published in September 2016 and March 2017, respectively. The present catalogue comprises type material for 116 species distributed across five phyla, nine classes, 50 families, and 80 genera. Specific names are listed systematically, followed by type host, infection site, type locality, and specimens with their collection numbers and references. Species classification and nomenclature are updated. PMID:29134026

Benthic Community Response to Hypoxia: Baseline Data

DTIC Science & Technology

2009-01-01

were represented by six different phyla, namely Annelida, Sipuncula, Arthropoda, Cnidaria , Mollusca and Echinodermata (Table II). The phylum Annelida...was solely represented by polychaetes and the phylum Cnidaria was represented solely by hydroids. However, the phylum Mollusca was represented by

A new species of Monocystis stein, 1848 (Protista: Apicomplexa: Eugregarinida) from the Indian earthworm, Amynthas Hawayanus Rosa, 1891 (Annelida: Oligochaeta).

PubMed

Bandyopadhyay, Probir K; Göçmen, Bayram; Bhowmik, Biplab; Mitra, Amlan Kumar

2006-01-01

As a part of an ongoing biodiversity survey of aseptate gregarine fauna of oligochaete hosts of West Bengal, an expedition was carried out in the Darjeeling district of West Bengal and most of the earthworms collected were found to be infested with a species of Monocystis Stein, 1848. The monocystid species was collected from the seminal vesicles of the earthworm and was identified as a new species, Monocystis amynthae sp. nov. The gamont of the new species is characterized by having an elongated body with broad anterior end, separated from the narrow posterior end by a prominent constriction measuring 49.0-77.0 (66.0+/-1.3) microm x 32.0-41.0 (37.0+/-2.8) microm. The gametocysts are oval-shaped, measuring 40.0-65.0 (58.0+/-2.1) microm. The oocysts are navicular, measuring 8.0-12.0 (10.5+/-1.1) microm x 4.0-6.0 (5.5+/-1.1) microm.

Combined morphological and molecular data unveils relationships of Pseudobranchiomma (Sabellidae, Annelida) and reveals higher diversity of this intriguing group of fan worms in Australia, including potentially introduced species

PubMed Central

Capa, María; Murray, Anna

2016-01-01

Abstract Pseudobranchiomma (Sabellidae, Annelida) is a small and heterogeneous group of fan worms found in shallow marine environments and is generally associated with hard substrates. The delineation and composition of this genus is problematic since it has been defined only by plesiomorphic characters that are widely distributed among other sabellids. In this study we have combined morphological and molecular (mitochondrial and nuclear DNA sequences) data to evaluate species diversity in Australia and assess the phylogenetic relationships of these and other related sabellids. Unlike morphological data alone, molecular data and combined datasets suggest monophyly of Pseudobranchiomma. In this study, a new species of Pseudobranchiomma is described and three others are considered as potential unintentional introductions to Australian waters, one of them reported for the first time for the continent. Pseudobranchiomma pallida sp. n. bears 4–6 serrations along the radiolar flanges, lacks radiolar eyes and has uncini with three transverse rows of teeth over the main fang. In the new species the colour pattern as well is characteristic and species specific. PMID:27843378

A taxonomic guide to the fanworms (Sabellidae, Annelida) of Lizard Island, Great Barrier Reef, Australia, including new species and new records.

PubMed

Capa, María; Murray, Anna

2015-09-18

This comprehensive taxonomic work is the result of the study of fan worms (Sabellidae, Annelida) collected over the last 40 years from around the Lizard Island Archipelago, Great Barrier Reef, Australia. Some species described herein are commonly found in Lizard Island waters but had not previously been formally reported in the literature. Most species appear to be not particularly abundant, and few specimens have been collected despite the sampling effort in the area over this time period. After this study, the overall sabellid diversity of the archipelago has been greatly increased (by more than 650%). Before this revision, only four sabellid species had been recorded for Lizard Island, and in this paper we report 31 species, 13 of which belong to nominal species, six are formally described as new species (Euchone danieloi n. sp., Euchone glennoi n. sp., Jasmineira gustavoi n. sp., Megalomma jubata n. sp., Myxicola nana n. sp., and Paradialychone ambigua n. sp.), and the identity of 12 species is still unknown (those referred as cf. or sp.). Two species are newly recorded in Australia and two in Queensland. The invasive species Branchiomma bairdi is reported for the first time at Lizard Island. The genus Paradialychone is reported for Australia for the first time. Standardised descriptions, general photographs of live and/or preserved specimens and distribution data are provided for all species. New species descriptions are accompanied by detailed illustrations and exhaustive morphological information. A dichotomous key for sabellid identification is also included.

Effects of Ship-Induced Waves in an Ice Environment on the St. Marys River Ecosystem,

DTIC Science & Technology

1980-01-01

Oligochaeta (worms), and Gastropoda (snails) comprised about 67% of the total number of organisms collected. Pelecypoda (fingernail clams), Amphipoda...Identiflero/Open.Endad Terms St. Marys River, winter navigation, Chronomidae, Oligochaetes, Gastropoda , ice c. cosATI ieid/Group IS. Availaleity...Chronomidae (midge larvae), Oligochaeta (worms), and Gastropoda (snails); collectively they comprised about 67% of the total number of organisms

A comprehensive checklist of earthworm species and subspecies from Vietnam (Annelida: Clitellata: Oligochaeta: Almidae, Eudrilidae, Glossoscolecidae, Lumbricidae, Megascolecidae, Moniligastridae, Ocnerodrilidae, Octochaetidae).

PubMed

Nguyen, Tung T; Nguyen, Anh D; Tran, Binh T T; Blakemore, Robert J

2016-07-25

The comprehensive checklist of earthworms in Vietnam is presented here listing 24 genera and 212 species arranged in eight families. For each species, bibliographic citations are given, including the original descriptions as well as notable citations affecting taxonomic status or distributional reports of a species. Distributions of each species are also provided. The bibliography contains all relevant papers for Vietnamese earthworms. Of 212 species, 114 have been recorded only in Vietnam, and 25 are cosmopolitan. New combinations are made for Amynthas acalifornicus (Do & Huynh, 1991) comb. nov., A. binhgiaensis (Le, 1994) comb. nov., Metaphire catbaensis (Thai & Le, 1993) comb. nov., M. khoii (Do & Tran, 1994) comb. nov., M. phaluongana (Do & Huynh, 1992) comb. nov., and M. mangophila (Nguyen, 2011) comb. nov., M. tripidoporophoratus (Thai & Nguyen, 1993) comb. nov. Additionally, Pheretima paraalexandri Nguyen, 2011 is treated as a junior synonym of Amynthas polychaetiferus (Thai, 1984).

Mercury critical concentrations to Enchytraeus crypticus (Annelida: Oligochaeta) under normal and extreme conditions of moisture in tropical soils - Reproduction and survival.

PubMed

Buch, Andressa Cristhy; Schmelz, Rüdiger M; Niva, Cintia Carla; Correia, Maria Elizabeth Fernandes; Silva-Filho, Emmanoel Vieira

2017-05-01

Soil provides many ecosystem services that are essential to maintain its quality and healthy development of the flora, fauna and human well-being. Environmental mercury levels may harm the survival and diversity of the soil fauna. In this respect, efforts have been made to establish limit values of mercury (Hg) in soils to terrestrial fauna. Soil organisms such as earthworms and enchytraeids have intimate contact with trace metals in soil by their oral and dermal routes, reflecting the potentially adverse effects of this contaminant. The main goal of this study was to obtain Hg critical concentrations under normal and extreme conditions of moisture in tropical soils to Enchytraeus crypticus to order to assess if climate change may potentiate their acute and chronic toxicity effects. Tropical soils were sampled from of two Forest Conservation Units of the Rio de Janeiro State - Brazil, which has been contaminated by Hg atmospheric depositions. Worms were exposed to three moisture conditions, at 20%, 50% and 80% of water holding capacity, respectively, and in combination with different Hg (HgCl 2 ) concentrations spiked in three types of tropical soil (two natural soils and one artificial soil). The tested concentrations ranged from 0 to 512mg Hg kg -1 dry weight. Results indicate that the Hg toxicity is higher under increased conditions of moisture, significantly affecting survival and reproduction rate. Copyright © 2017 Elsevier Inc. All rights reserved.

Benthic Macro-Invertebrates of Bull Creek and Ramer Branch, Eglin AFB Reservation.

DTIC Science & Technology

1983-03-01

Oligochaeta, Coleoptera, Trichoptera, Plecoptera , Odonata, and Ephermeroptera. The faunas at the sites were similar with sites sharing from 69 to 82...Coleoptera (11.4 percent), Ephemeroptera (8.2 percent), Odonata (6.8 percent), Plecoptera (4.4 percent), and Oligochaeta (4.4 percent). In the light...Hexatoma sp. (Diptera); Stenelmis sp. (Coleoptera); Anisocentropus sp., Oecetis sp., and Agarodes sp. (Trichoptera); Allocapnia sp. ( Plecoptera ); Gomphus sp

Benthic and Sedimentologic Studies on the Charleston Harbor Ocean Disposal Area, Charleston Harbor Deepening Project.

DTIC Science & Technology

1979-08-01

Nolella stipate 1 Phylum S ipuncula Sipunculid (undet.) 14 Phylum Echiura Echiurid (undet.) 1 Phylum-. Annelida Hvdroides dianthus 27 Sabellaria...undet.) LEr-idomotus subievi.s Sab)ellaria \\’ulgaris HIvdroides dianthus 9 lu- Mloliusca * Polinices duplicatus0 Modiclus mocilolus squarnosus...tenuis Microporella ciliata Schizoporella cornuta Phvlum Annelida H-vdroides dianthus Sabelliaria x’ulgaris 41Ph’iu MToi 7lusca Creoidula olana Phylum

Subsurface earthworm casts can be important soil microsites specifically influencing the growth of grassland plants.

PubMed

Zaller, Johann G; Wechselberger, Katharina F; Gorfer, Markus; Hann, Patrick; Frank, Thomas; Wanek, Wolfgang; Drapela, Thomas

Earthworms (Annelida: Oligochaeta) deposit several tons per hectare of casts enriched in nutrients and/or arbuscular mycorrhizal fungi (AMF) and create a spatial and temporal soil heterogeneity that can play a role in structuring plant communities. However, while we begin to understand the role of surface casts, it is still unclear to what extent plants utilize subsurface casts. We conducted a greenhouse experiment using large mesocosms (volume 45 l) to test whether (1) soil microsites consisting of earthworm casts with or without AMF (four Glomus taxa) affect the biomass production of 11 grassland plant species comprising the three functional groups grasses, forbs, and legumes, (2) different ecological groups of earthworms (soil dwellers- Aporrectodea caliginosa vs. vertical burrowers- Lumbricus terrestris ) alter potential influences of soil microsites (i.e., four earthworms × two subsurface microsites × two AMF treatments). Soil microsites were artificially inserted in a 25-cm depth, and afterwards, plant species were sown in a regular pattern; the experiment ran for 6 months. Our results show that minute amounts of subsurface casts (0.89 g kg -1 soil) decreased the shoot and root production of forbs and legumes, but not that of grasses. The presence of earthworms reduced root biomass of grasses only. Our data also suggest that subsurface casts provide microsites from which root AMF colonization can start. Ecological groups of earthworms did not differ in their effects on plant production or AMF distribution. Taken together, these findings suggest that subsurface earthworm casts might play a role in structuring plant communities by specifically affecting the growth of certain functional groups of plants.

Temporal and spatial variations in the polychaete (Annelida) populations on the upper continental slope of the northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Qu, Fangyuan; Wang, Yuning; Rowe, Gilbert T.

2017-01-01

Polychaete worms (Annelida), the dominant macrofaunal taxon in most fine-grained marine sediments, were sampled in 1983-85 and then again in 2000-02 at nine locations at depths of 324-1454 m. on the upper continental slope of the northern Gulf of Mexico (GoM). The assemblages exhibited relative stability in abundance and diversity, but fell into six separate groups of species (>35% similarity) that were related to time-of-sampling, location, depth. This depth gradient experiences an increase in oxygen from 2.5 to 4.5 ml/L, a six degree decrease in temperature (10-12° down to 4 °C) and a decline of 30-37 mg C m-2 day-1 down to 7 mg C m-2 day-1 in estimates of the particulate organic carbon (POC) input to the sea floor, but these steep gradients had secondary effects on species turnover or depth-related zonation (Beta diversity). The species composition of four of the six groups was separated on the basis of sampling between 1983-85 and 2000-02 as opposed to depth or location. The species composition of the two groups on the eastern transect was different from the western sites and the two eastern groups differed in species composition from each other between 1983-85 and 2000-02. The two groups of species at the three deeper sites to the west (864-1410 m) were also separated on the basis of time-of-sampling but the group of species located at the three shallow locations (324-625 m) was not; it was a mixture of the two sampling periods. Significantly higher densities (p<0.05) in April 1984, on the eastern transect, suggest that seasonal recruitment may have occurred but the higher densities were attributed to only two species.

Megafauna of the UKSRL exploration contract area and eastern Clarion-Clipperton Zone in the Pacific Ocean: Annelida, Arthropoda, Bryozoa, Chordata, Ctenophora, Mollusca.

PubMed

Amon, Diva J; Ziegler, Amanda F; Drazen, Jeffrey C; Grischenko, Andrei V; Leitner, Astrid B; Lindsay, Dhugal J; Voight, Janet R; Wicksten, Mary K; Young, Craig M; Smith, Craig R

2017-01-01

There is growing interest in mining polymetallic nodules from the abyssal Clarion-Clipperton Zone (CCZ) in the tropical Pacific Ocean. Despite having been the focus of environmental studies for decades, the benthic megafauna of the CCZ remain poorly known. To predict and manage the environmental impacts of mining in the CCZ, baseline knowledge of the megafauna is essential. The ABYSSLINE Project has conducted benthic biological baseline surveys in the UK Seabed Resources Ltd polymetallic-nodule exploration contract area (UK-1). Prior to ABYSSLINE research cruises in 2013 and 2015, no biological studies had been done in this area of the eastern CCZ. Using a Remotely Operated Vehicle and Autonomous Underwater Vehicle (as well as several other pieces of equipment), the megafauna within the UK Seabed Resources Ltd exploration contract area (UK-1) and at a site ~250 km east of the UK-1 area were surveyed, allowing us to make the first estimates of megafaunal morphospecies richness from the imagery collected. Here, we present an atlas of the abyssal annelid, arthropod, bryozoan, chordate, ctenophore and molluscan megafauna observed and collected during the ABYSSLINE cruises to the UK-1 polymetallic-nodule exploration contract area in the CCZ. There appear to be at least 55 distinct morphospecies (8 Annelida, 12 Arthropoda, 4 Bryozoa, 22 Chordata, 5 Ctenophora, and 4 Mollusca) identified mostly by morphology but also using molecular barcoding for a limited number of animals that were collected. This atlas will aid the synthesis of megafaunal presence/absence data collected by contractors, scientists and other stakeholders undertaking work in the CCZ, ultimately helping to decipher the biogeography of the megafauna in this threatened habitat.

Megafauna of the UKSRL exploration contract area and eastern Clarion-Clipperton Zone in the Pacific Ocean: Annelida, Arthropoda, Bryozoa, Chordata, Ctenophora, Mollusca

PubMed Central

Ziegler, Amanda F; Drazen, Jeffrey C; Grischenko, Andrei V; Leitner, Astrid B; Lindsay, Dhugal J; Voight, Janet R; Wicksten, Mary K; Young, Craig M; Smith, Craig R

2017-01-01

Abstract Background There is growing interest in mining polymetallic nodules from the abyssal Clarion-Clipperton Zone (CCZ) in the tropical Pacific Ocean. Despite having been the focus of environmental studies for decades, the benthic megafauna of the CCZ remain poorly known. To predict and manage the environmental impacts of mining in the CCZ, baseline knowledge of the megafauna is essential. The ABYSSLINE Project has conducted benthic biological baseline surveys in the UK Seabed Resources Ltd polymetallic-nodule exploration contract area (UK-1). Prior to ABYSSLINE research cruises in 2013 and 2015, no biological studies had been done in this area of the eastern CCZ. New information Using a Remotely Operated Vehicle and Autonomous Underwater Vehicle (as well as several other pieces of equipment), the megafauna within the UK Seabed Resources Ltd exploration contract area (UK-1) and at a site ~250 km east of the UK-1 area were surveyed, allowing us to make the first estimates of megafaunal morphospecies richness from the imagery collected. Here, we present an atlas of the abyssal annelid, arthropod, bryozoan, chordate, ctenophore and molluscan megafauna observed and collected during the ABYSSLINE cruises to the UK-1 polymetallic-nodule exploration contract area in the CCZ. There appear to be at least 55 distinct morphospecies (8 Annelida, 12 Arthropoda, 4 Bryozoa, 22 Chordata, 5 Ctenophora, and 4 Mollusca) identified mostly by morphology but also using molecular barcoding for a limited number of animals that were collected. This atlas will aid the synthesis of megafaunal presence/absence data collected by contractors, scientists and other stakeholders undertaking work in the CCZ, ultimately helping to decipher the biogeography of the megafauna in this threatened habitat. PMID:28874906

Marine Ecological Index Survey of San Diego Bay

DTIC Science & Technology

2013-03-01

Ascidia zara Thermal DO Chordata Botrylloides violaceus Thermal DO Chordata Diplosoma listerianum Thermal DO Annelida Brania complex Thermal DO Annelida...x x Ascidia Zara x? x? x x Ascidia sp x? x x x x Styela canopus x x x x x Styela clava x x x x x Styela plicata x x x x x Polyandrocarpa zorritensis...Estuarine Marine Seasonally Hypersaline Thermal Native Pre ID Region(a) Aplidium californicum x x x Ascidia ceratodes x x Ascidia zara x Estuarine

Variability of invertebrate abundance in drinking water distribution systems in the Netherlands in relation to biostability and sediment volumes.

PubMed

van Lieverloo, J Hein M; Hoogenboezem, Wim; Veenendaal, Gerrit; van der Kooij, Dick

2012-10-15

A survey of invertebrates in drinking water from treatment works, internal taps and hydrants on mains was carried out by almost all water companies in the Netherlands from September 1993 to August 1995. Aquatic sow bugs (Asellidae, 1-12 mm) and oligochaeta worms (Oligochaeta, 1-100 mm), both known to have caused rare though embarrassing consumer complaints, were found to form 98% of the mean biomass in water flushed from mains. Their numbers in the mains water ranged up to 1500 (mean 37) Asellidae m(-3) and up to 9900 (mean 135) Oligochaeta m(-3). Smaller crustaceans (0.5-2 mm) dominated the numbers in water from mains. e.g. water fleas (Cladocera and Copepoda up to 14,000 m(-3)). Common invertebrates in treated water and in tap water were Rotifera (<1 mm) and nematode worms (Nematoda, <2 mm). No Asellidae, large Oligochaeta (>5 mm) or other large invertebrates were found in 1560 samples of 200 l treated water or tap water. Large variations in invertebrate abundance were found within and between distribution systems. Of the variability of mean biomass in mains per system, 55%, 60% and 63% could statistically be explained by differences in the Biofilm Formation Rate, non-particulate organic matter and the permanganate index of the treated water of the treatment works respectively. A similar correlation was found between mean invertebrate biomass and mean sediment volumes in the distribution systems (R(2) = 52%). Copyright © 2012 Elsevier Ltd. All rights reserved.

Barcoding Eophila crodabepis sp. nov. (Annelida, Oligochaeta, Lumbricidae), a Large Stripy Earthworm from Alpine Foothills of Northeastern Italy Similar to Eophila tellinii (Rosa, 1888)

PubMed Central

Paoletti, Maurizio G.; Blakemore, Robert J.; Csuzdi, Csaba; Dorigo, Luca; Dreon, Angelo Leandro; Gavinelli, Federico; Lazzarini, Francesca; Manno, Nicola; Moretto, Enzo; Porco, David; Ruzzier, Enrico; Toniello, Vladimiro; Squartini, Andrea; Concheri, Giuseppe; Zanardo, Marina; Alba-Tercedor, Javier

2016-01-01

A new Italian earthworm morphologically close to the similarly large and anecic Eophila tellinii (Rosa, 1888) is described. Distribution of Eophila crodabepis sp. nov. extends over 750 km2 from East to West on the Asiago Plateau and Vittorio Veneto Hills, from North to South on mounts Belluno Prealps (Praderadego and Cesen), Asiago, Grappa and onto the Montello foothills. This range abuts that of Eophila tellinii in northern Friuli Venezia Giulia region. Known localities of both E. tellinii and E.crodabepis sp. nov. are mapped. mtDNA barcoding definitively separates the new western species from classical Eophila tellinii (Rosa, 1888). PMID:27019284

Ecology and Disease Transmission Potential in the Colombian Amazon Basin.

DTIC Science & Technology

BRAZIL, *DISEASE VECTORS, *PARASITIC DISEASES, COLOMBIA, ECOLOGY, COLOMBIA, COLOMBIA, INFECTIOUS DISEASES, DIPTERA, HUMANS, EQUINES , BOVINES, REPTILES, TICKS, ANNELIDA, NEMATODA, PLATYHELMINTHES, FILARIAE.

A new species and new record of the commensal genus Alcyonosyllis Glasby & Watson, 2001 and a new species of Parahaplosyllis Hartmann-Schröder, 1990, (Annelida: Syllidae: Syllinae) from Philippines Islands.

PubMed

Alvarez-Campos, Patricia; Martín, Guillermo San; Aguado, M Teresa

2013-11-16

A new species of Alcyonosyllis (Annelida: Syllidae), A. aidae n.sp. is described from Luzón island, Philippines, associated with the alcyonacean Dendronephthya sp. (Nephthydae). This is the sixth known species of this genus living in the Indo-Pacific region. The new species differs from other Alcyonosyllis in having long and slender cirri with the first pair of dorsal cirri slightly thicker than remaining, bidentate chaetae with distal tooth larger than proximal one, and a distinct colour pattern, with a median longitudinal, slender reddish line, and two wider lateral bands, giving a tri-lineate appearance. A new report of the recently described species, A. hinterkircheri, previously known only from an area close to Bohol, in Philippines, is also included, being the first report of this species in Luzón Island. A new species of the genus Parahaplosyllis Hartmann-Schröder, 1990, is also described. Up to now, only the type species of the genus was known, from New South Wales, Australia; this is the second known species of this genus. It differs from P. brevicirra Hartmann-Schröder, 1990 by having unidentate dorsal simple chaetae (instead of bidentate ones as in P. brevicirra), ventral simple chaeta with shorter and less curved basal spur, more distinctly articulated dorsal cirri, with a long distal article, and a shorter proventricle. Finally, new different types of stolons are described for both genera.

Tolerance values of benthic macroinvertebrates for stream biomonitoring: assessment of assumptions underlying scoring systems worldwide.

PubMed

Chang, Feng-Hsun; Lawrence, Justin E; Rios-Touma, Blanca; Resh, Vincent H

2014-04-01

Tolerance values (TVs) based on benthic macroinvertebrates are one of the most widely used tools for monitoring the biological impacts of water pollution, particularly in streams and rivers. We compiled TVs of benthic macroinvertebrates from 29 regions around the world to test 11 basic assumptions about pollution tolerance, that: (1) Arthropoda are < tolerant than non-Arthropoda; (2) Insecta < non-Insecta; (3) non-Oligochaeta < Oligochaeta; (4) other macroinvertebrates < Oligochaeta + Chironomidae; (5) other macroinvertebrate taxa < Isopoda + Gastropoda + Hirudinea; (6) Ephemeroptera + Plecoptera + Trichoptera (EPT) < Odonata + Coleoptera + Heteroptera (OCH); (7) EPT < non-EPT insects; (8) Diptera < Insecta; (9) Bivalvia < Gastropoda; (10) Baetidae < other Ephemeroptera; and (11) Hydropsychidae < other Trichoptera. We found that the first eight of these 11 assumptions were supported despite regional variability. In addition, we examined the effect of Best Professional Judgment (BPJ) and non-independence of TVs among countries by performing all analyses using subsets of the original dataset. These subsets included a group based on those systems using TVs that were derived from techniques other than BPJ, and groups based on methods used for TV assignment. The results obtained from these subsets and the entire dataset are similar. We also made seven a priori hypotheses about the regional similarity of TVs based on geography. Only one of these was supported. Development of TVs and the reporting of how they are assigned need to be more rigorous and be better described.

Annelida, Euhirudinea (leeches)

EPA Science Inventory

Worldwide, there are over 600 species of leeches described which occur in freshwater, marine, estuarine, and moist-terrestrial ecosystems. Leeches are included in the Class Clitellata, Subclass Hirudinida, and Superorder Euhirudinea. Seven of the ten families of leeches occur in...

A Guide to the Principal Marine Fouling Organisms, with Particular Reference to Cockburn Sound, W.A.,

DTIC Science & Technology

1982-07-01

4. HYDROIDS (Phylum Cnidaria , Class Hydrozoa) 7 4.1 General 7 4.2 Common Species 7 4.3 Other Species 8 4.4 References 8 5. TUBEWORMS (Phylum Annelida...Classification of the Calcareous Sponges, British Museum (National History), London, England. 693 pp. 4. HYDROIDS (Phylum Cnidaria , Class Hydrozoa) 4.1

Biodiversity of the white coral bank off Cape Santa Maria di Leuca (Mediterranean Sea): An update

NASA Astrophysics Data System (ADS)

Mastrototaro, F.; D'Onghia, G.; Corriero, G.; Matarrese, A.; Maiorano, P.; Panetta, P.; Gherardi, M.; Longo, C.; Rosso, A.; Sciuto, F.; Sanfilippo, R.; Gravili, C.; Boero, F.; Taviani, M.; Tursi, A.

2010-03-01

The biodiversity of the Santa Maria di Leuca (SML) coral bank is summarized and its description is updated using data collected by means of underwater video systems, benthic samplers and fishing gears. A total of 222 living species have been recorded within the coral bank area in the depth range 280-1121 m. The most abundant benthic taxa recorded are Porifera (36 species) followed by Mollusca (35) and Cnidaria (31). The scleractinian corals Madrepora oculata and Lophelia pertusa are the main colonial species in the structure of the SML bank. Annelida, Crustacea and Bryozoa have been found with 24, 23 and 19 species, respectively. A total of 40 species of demersal fish have been recorded. Other faunal taxa were found with small numbers of species. One hundred and thirty-five species are new for the SML bank, 31 of which represent new records for the north-western Ionian Sea (2 Porifera, 17 Cnidaria, 1 Mollusca, 3 Annelida, 2 Crustacea, 4 Bryozoa and 4 Echinodermata). The finding of the annelid Harmothoë vesiculosa represents the first record for the Mediterranean Sea. The SML coral bank represents a biodiversity "hot-spot" on the bathyal bottoms of the Mediterranean Sea.

Sampling benthic macroinvertebrates in a large flood-plain river: Considerations of study design, sample size, and cost

USGS Publications Warehouse

Bartsch, L.A.; Richardson, W.B.; Naimo, T.J.

1998-01-01

Estimation of benthic macroinvertebrate populations over large spatial scales is difficult due to the high variability in abundance and the cost of sample processing and taxonomic analysis. To determine a cost-effective, statistically powerful sample design, we conducted an exploratory study of the spatial variation of benthic macroinvertebrates in a 37 km reach of the Upper Mississippi River. We sampled benthos at 36 sites within each of two strata, contiguous backwater and channel border. Three standard ponar (525 cm(2)) grab samples were obtained at each site ('Original Design'). Analysis of variance and sampling cost of strata-wide estimates for abundance of Oligochaeta, Chironomidae, and total invertebrates showed that only one ponar sample per site ('Reduced Design') yielded essentially the same abundance estimates as the Original Design, while reducing the overall cost by 63%. A posteriori statistical power analysis (alpha = 0.05, beta = 0.20) on the Reduced Design estimated that at least 18 sites per stratum were needed to detect differences in mean abundance between contiguous backwater and channel border areas for Oligochaeta, Chironomidae, and total invertebrates. Statistical power was nearly identical for the three taxonomic groups. The abundances of several taxa of concern (e.g., Hexagenia mayflies and Musculium fingernail clams) were too spatially variable to estimate power with our method. Resampling simulations indicated that to achieve adequate sampling precision for Oligochaeta, at least 36 sample sites per stratum would be required, whereas a sampling precision of 0.2 would not be attained with any sample size for Hexagenia in channel border areas, or Chironomidae and Musculium in both strata given the variance structure of the original samples. Community-wide diversity indices (Brillouin and 1-Simpsons) increased as sample area per site increased. The backwater area had higher diversity than the channel border area. The number of sampling sites

Clavadoce (Annelida: Phyllodocidae) from Australia.

PubMed

Wilson, Robin S; Greaves, Elizabeth

2016-01-04

The first records of the phyllodocid genus Clavadoce are provided from Australia, where the fifth species in the genus is now known: Clavadoce dorsolobata (Hartmann-Schröder, 1987) comb. nov. which is widely distributed in intertidal habitats in southeastern Australia. Clavadoce dorsolobata was described as Eumida (Sige) dorsolobata Hartmann-Schröder, 1987 and herein transferred to Clavadoce. Five species of Clavadoce are now known world wide, four of which are from different regions on the Pacific Ocean margin, while Clavadoce cristata is from the North Atlantic. The Australian species is the first record of Clavadoce for the southern hemisphere.

Destabilization of Cohesive Intertidal Sediments by Infauna

NASA Astrophysics Data System (ADS)

de Deckere, E. M. G. T.; Tolhurst, T. J.; de Brouwer, J. F. C.

2001-11-01

Bioturbation activity was reduced in four plots on an intertidal mudflat in the Humber estuary (UK) during 4 days, by spraying the sediment with an insecticide, namely vydate. Macrofaunal, especially Nereis diversicolor and oligochaeta, and meiofaunal densities decreased, while the diatom biomass did not change. This resulted in a 300% increase in sediment stability, caused by a reduction in bioturbation and grazing pressure and a decrease in the water content.

DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates.

PubMed

Folmer, O; Black, M; Hoeh, W; Lutz, R; Vrijenhoek, R

1994-10-01

We describe "universal" DNA primers for polymerase chain reaction (PCR) amplification of a 710-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) from 11 invertebrate phyla: Echinodermata, Mollusca, Annelida, Pogonophora, Arthropoda, Nemertinea, Echiura, Sipuncula, Platyhelminthes, Tardigrada, and Coelenterata, as well as the putative phylum Vestimentifera. Preliminary comparisons revealed that these COI primers generate informative sequences for phylogenetic analyses at the species and higher taxonomic levels.

An Overview of Hox Genes in Lophotrochozoa: Evolution and Functionality

PubMed Central

Barucca, Marco; Canapa, Adriana; Biscotti, Maria Assunta

2016-01-01

Hox genes are regulators of animal embryonic development. Changes in the number and sequence of Hox genes as well as in their expression patterns have been related to the evolution of the body plan. Lophotrochozoa is a clade of Protostomia characterized by several phyla which show a wide morphological diversity. Despite that the works summarized in this review emphasize the fragmentary nature of the data available regarding the presence and expression of Hox genes, they also offer interesting insight into the evolution of the Hox cluster and the role played by Hox genes in several phyla. However, the number of genes involved in the cluster of the lophotrochozoan ancestor is still a question of debate. The data presented here suggest that at least nine genes were present while two other genes, Lox4 and Post-2, may either have been present in the ancestor or may have arisen as a result of duplication in the Brachiopoda-Mollusca-Annelida lineage. Spatial and temporal collinearity is a feature of Hox gene expression which was probably present in the ancestor of deuterostomes and protostomes. However, in Lophotrochozoa, it has been detected in only a few species belonging to Annelida and Mollusca. PMID:29615580

Structural analysis of the α subunit of Na(+)/K(+) ATPase genes in invertebrates.

PubMed

Thabet, Rahma; Rouault, J-D; Ayadi, Habib; Leignel, Vincent

2016-01-01

The Na(+)/K(+) ATPase is a ubiquitous pump coordinating the transport of Na(+) and K(+) across the membrane of cells and its role is fundamental to cellular functions. It is heteromer in eukaryotes including two or three subunits (α, β and γ which is specific to the vertebrates). The catalytic functions of the enzyme have been attributed to the α subunit. Several complete α protein sequences are available, but only few gene structures were characterized. We identified the genomic sequences coding the α-subunit of the Na(+)/K(+) ATPase, from the whole-genome shotgun contigs (WGS), NCBI Genomes (chromosome), Genomic Survey Sequences (GSS) and High Throughput Genomic Sequences (HTGS) databases across distinct phyla. One copy of the α subunit gene was found in Annelida, Arthropoda, Cnidaria, Echinodermata, Hemichordata, Mollusca, Placozoa, Porifera, Platyhelminthes, Urochordata, but the nematodes seem to possess 2 to 4 copies. The number of introns varied from 0 (Platyhelminthes) to 26 (Porifera); and their localization and length are also highly variable. Molecular phylogenies (Maximum Likelihood and Maximum Parsimony methods) showed some clusters constituted by (Chordata/(Echinodermata/Hemichordata)) or (Plathelminthes/(Annelida/Mollusca)) and a basal position for Porifera. These structural analyses increase our knowledge about the evolutionary events of the α subunit genes in the invertebrates. Copyright © 2016 Elsevier Inc. All rights reserved.

Demonstration and Evaluation of Solid Phase Microextraction for the Assessment of Bioavailability and Contaminant Mobility

DTIC Science & Technology

2008-06-01

Toxicology and Chemistry, 8:499-512. Hansen, B.G., A.B. Paya-Perez, M. Rahman, and B.R. Larsen, QSARs for Kow and Koc of PCB Congeners: a Critical...Bioconcentration of Organic Chemicals in Earthworms (oligochaeta). Environmental Toxicology and Chemistry, 1998, 17, 2080-2090. Kraaij R, Mayer P. et al...Environmental Toxicology and Chemistry, 25, 11, 2869-2874 (2006). Lu, X.X., D.D Reible, J.W. Fleeger, ‘Adsorption/Desorption and Bioavailability

Complete mitochondrial genome of Bugula neritina (Bryozoa, Gymnolaemata, Cheilostomata): phylogenetic position of Bryozoa and phylogeny of lophophorates within the Lophotrochozoa

PubMed Central

Jang, Kuem Hee; Hwang, Ui Wook

2009-01-01

Background The phylogenetic position of Bryozoa is one of the most controversial issues in metazoan phylogeny. In an attempt to address this issue, the first bryozoan mitochondrial genome from Flustrellidra hispida (Gymnolaemata, Ctenostomata) was recently sequenced and characterized. Unfortunately, it has extensive gene translocation and extremely reduced size. In addition, the phylogenies obtained from the result were conflicting, so they failed to assign a reliable phylogenetic position to Bryozoa or to clarify lophophorate phylogeny. Thus, it is necessary to characterize further mitochondrial genomes from slowly-evolving bryozoans to obtain a more credible lophophorate phylogeny. Results The complete mitochondrial genome (15,433 bp) of Bugula neritina (Bryozoa, Gymnolaemata, Cheilostomata), one of the most widely distributed cheliostome bryozoans, is sequenced. This second bryozoan mitochondrial genome contains the set of 37 components generally observed in other metazoans, differing from that of F. hispida (Bryozoa, Gymnolaemata, Ctenostomata), which has only 36 components with loss of tRNAser(ucn) genes. The B. neritina mitochondrial genome possesses 27 multiple noncoding regions. The gene order is more similar to those of the two remaining lophophorate phyla (Brachiopoda and Phoronida) and a chiton Katharina tunicate than to that of F. hispida. Phylogenetic analyses based on the nucleotide sequences or amino acid residues of 12 protein-coding genes showed consistently that, within the Lophotrochozoa, the monophyly of the bryozoan class Gymnolaemata (B. neritina and F. hispida) was strongly supported and the bryozoan clade was grouped with brachiopods. Echiura appeared as a subtaxon of Annelida, and Entoprocta as a sister taxon of Phoronida. The clade of Bryozoa + Brachiopoda was clustered with either the clade of Annelida-Echiura or that of Phoronida + Entoprocta. Conclusion This study presents the complete mitochondrial genome of a cheliostome bryozoan, B

Effects of Reservoir Releases on Water Quality, Macroinvertebrates, and Fish in Tailwaters: Field Study Results.

DTIC Science & Technology

1983-02-01

abundant at station 1 included Simuliidae, Culicidae, and Trichoptera. Organisms more common to natural streams, such as Ephemeroptera, Plecoptera ...20 4 Culicidae 65 36 Ceratopogonidae 4 2 Trichoptera 56 25 Ephemeroptera 10 180 Plecoptera 1 10 Coleoptera 13 2 Lepidoptera 9 0 Hydracarima. 2 24... Plecoptera 0 0 25 Coleoptera 18 0 27 Odonata 86 43 156 Hydracarina 670 258 204 Oligochaeta 3,929 612 854 Hirudinea 97 2 22 Nema toda 208 74 44 Amphipoda

LEECHES (ANNELIDA: EUHIRUDINEA) OF NORTHERN ARKANSAS

EPA Science Inventory

Twenty-one lotic and lentic environments throughout central and northern Arkansas were surveyed for the presence of leeches during June 2004, and April, July - October, 2005. Fourteen species of leeches (Desserobdella cryptobranchii, Desserobdella phalera, Desserobdella picta, H...

Environmental Impact Research Program. Ecological Effects of Rubble-Mound Breakwater Construction and Channel Dredging at West Harbor, Ohio (Western Lake Erie).

DTIC Science & Technology

1985-09-01

Harbor, Ohio (August 1981-1983) Taxa* Percent Porifera (Spongil a) 0.01 Cnidaria (Hydra) 0.30 Rhabdocoela 0.35 Tricladida 0.16 Nemertinea 0.14 Nematoda...Breakwaters at West Harbor. Ohio (April 1982-September 1983) Taxa* Percent * Cnidaria (Hydra) 5.98 Rhabdocoela 0.14 Tricladida 0.37 Nemertinea 0.11 Nematoda...3 3.0 OL!GOCHAE1A 23 85 2t 2000 CHIRONOMIDAE 3 8 0 163 CNIDARIA 0 2 0 30 BRYOZDA + + + 4 4.0 OLIGOCHAETA 325 56 148 7836 CHIRONOMIDAE 26 13 21

Use of benthic invertebrate community structure and the sediment quality triad to evaluate metal-contaminated sediment in the upper Clark Fork River, Montana

USGS Publications Warehouse

Canfield, Timothy J.; Kemble, Nile E.; Brumbaugh, William G.; Dwyer, F. James; Ingersoll, Christopher G.; Fairchild, James F.

1994-01-01

The upper Clark Fork River, above Flathead River, is contaminated with large amounts of As, Cd, Cu, Pb, Mn, and Zn ores from past mining activities. The contaminated area extends from the Butte and Anaconda area to at least 230 km downstream to Milltown Reservoir. Both the upper Clark Fork River and Milltown Reservoir have been designated as U.S. Environmental Protection Agency Superfund sites because of metal-contaminated bottom sediments. We evaluated the impacts of past mining activities on the Clark Fork River ecosystem using benthic invertebrate community assessment, residue chemistry, and toxicity testing. Oligochaeta and Chironomidae generally accounted for over 90% of the benthic invertebrate community in the soft sediment depositional areas. Taxa of Oligochaeta and Chironomidae were predominantly pollution tolerant. Higher numbers of Chironomidae genera were present at stations with higher concentrations of metals in sediment identified as toxic by the amphipod Hyalella azteca in 28-d exposures. Frequency of mouthpart deformities in genera of Chironomidae was low and did not correspond to concentrations of metals in sediment. Total abundance of organisms/m2 did not correspond to concentrations of metals in the sediment samples. Chemical analyses, laboratory toxicity tests, and benthic community evaluations all provide evidence of metal-induced degradation to aquatic communities in both the reservoir and the river. Using a weight-of-evidence approach-the Sediment Quality Triad - provided good concurrence among measures of benthic community structure, sediment chemistry, and laboratory toxicity.

Effects of organic pollution and physical stress on benthic macroinvertebrate communities from two intermittently closed and open coastal lagoons (ICOLLs)

NASA Astrophysics Data System (ADS)

Coelho, Susana; Pérez-Ruzafa, Angel; Gamito, Sofia

2015-12-01

Benthic macroinvertebrate communities and environmental conditions were studied in two intermittently closed and open coastal lakes and lagoons (ICOLLs), located in southern Algarve (Foz do Almargem e Salgados), with the purpose of evaluating the effects of organic pollution, originated mainly from wastewater discharges, and the physical stress caused by the irregular opening of the lagoons. Most of the year, lagoons were isolated from the sea, receiving the freshwater inputs from small rivers and in Salgados, also from the effluents of a wastewater plant. According to environmental and biotic conditions, Foz do Almargem presented a greater marine influence and a lower trophic state (mesotrophic) than Salgados (hypereutrophic). Benthic macroinvertebrate communities in the lagoons were distinct, just as their relations with environmental parameters. Mollusca were the most abundant macroinvertebrates in Foz do Almargem, while Insecta, Oligochaeta and Crustacea were more relevant in Salgados. Corophium multisetosum occurred exclusively in Salgados stations and, just as Chironomus sp., other Insecta and Oligochaeta, densities were positively related to total phosphorus, clay content and chlorophyll a concentration in the sediment, chlorophyll a concentration in water and with total dissolved inorganic nitrogen. Abra segmentum, Cerastoderma glaucum, Peringia ulvae and Ecrobia ventrosa occurred only in Foz do Almargem, with lower values of the above mentioned parameters. Both lagoons were dominated by deposit feeders and taxa tolerant to environmental stress, although in Salgados there was a greater occurrence of opportunistic taxa associated to pronounced unbalanced situations, due to excess organic matter enrichment.

Invertebrate colonization rates in the tailwater of a Kentucky flood-control reservoir

USGS Publications Warehouse

Swink, W.D.; Novotny, J.F.

1985-01-01

Invertebrate colonization on newly introduced rock substrates was examined from July through October 1982 in the tailwater of Barren River Lake, Kentucky. Chironomidae, the dominant taxon of benthic insects, reached full colonization by day 14. Colonization by Oligochaeta, the other major invertebrate taxon, was not completed by the end of the 95-day period of observation. It may have been delayed because insufficient food (periphyton and detritus) had accumulated on the clean rocks. Rapid recolonization of dewatered substrates may be especially critical for maintaining adequate fish food in tailwaters of flood-control reservoir.

Taxonomy and distribution of Terebellides (Polychaeta: Trichobranchidae) in the northern South China Sea, with description of three new species.

PubMed

Zhang, Jinghuai; Hutchings, Pat

2018-02-02

Benthic ecology monitoring in the northern South China Sea revealed many individuals of the polychaete genus Terebellides (Annelida), which are common in soft sediments in shallow waters (4.5-41.0 m). Three new species of Terebellides are described, including T. guangdongensis n. sp., T. yangi n. sp. and T. ectopium n. sp. Terebellides guangdongensis n. sp. is mainly found in Guangdong waters. Terebellides yangi n. sp. and T. ectopium n. sp. are mainly found in Beibu Gulf. A key to all described species of Terebellides from the Northwestern Pacific is given.

Grays Harbor and Chehalis River Improvements to Navigation Environmental Studies. Benthic Invertebrate Studies in Grays Harbor, Washington,

DTIC Science & Technology

1982-04-01

protected from wave action by the jetty, ocean swells were a major environmental feature at the site. In addition, strong tidal currents sweep along thc...2 ) BIOMS j2 SURFACE OF ROCK 1 2Mean 1I Mean Crustacea 0 0 0 0 0 0 Corophium spinicorne 125,758 67,425 96,592 25.432 21.364 23,398 Annelida 0 0 0 0 0...variety of p 127 *I factors, both biotic (e.g., reproductive and distributive patterns of key species) and abiotic (e.g., salinity regimes). The most

Occurrence of two novel actinospore types (Cnidaria: Myxozoa) in fish farms in Mato Grosso do Sul state, Brazil.

PubMed

Milanin, Tiago; Atkinson, Stephen D; Silva, Márcia R M; Alves, Roberto G; Tavares, Luiz Eduardo R; Ribeiro, Amanda M; Maia, Antonio A M

2018-06-01

We investigated the involvement of oligochaetes in the life cycles of fresh water myxozoan parasites in Brazil. In a fish farm in the State of Mato Grosso do Sul, we examined 192 oligochaetes and found that two (1%) released Aurantiactinomyxon type actinospores. We identified infected oligochaetes by morphology: both were Pristina synclites, from family Naididae. This is the first report of the involvement of this species in the life cycle of myxozoans. Small-subunit ribosomal DNA sequences of Aurantiactinomyxon type 1 (1882 nt) and Aurantiactinomyxon type 2 (1900 nt) did not match any previously sequenced myxozoan in the NCBI database, with the highest BLAST search similarities of 83% with Myxobolus batalhensis MF361090 and 93% with Henneguya maculosus KF296344, respectively, and the two aurantiactinomyxons were only 75% similar to each other (over ~ 1900 bases). Phylogenetic analyses showed that Aurantiactinomyxon type 1 had closest affinities with myxozoans from fish hosts in Order Characiformes, and Aurantiactinomyxon type 2 had affinities with myxozoans from fish of Order Siluriformes.

Spiralian phylogeny informs the evolution of microscopic lineages.

PubMed

Laumer, Christopher E; Bekkouche, Nicolas; Kerbl, Alexandra; Goetz, Freya; Neves, Ricardo C; Sørensen, Martin V; Kristensen, Reinhardt M; Hejnol, Andreas; Dunn, Casey W; Giribet, Gonzalo; Worsaae, Katrine

2015-08-03

Despite rapid advances in the study of metazoan evolutionary history [1], phylogenomic analyses have so far neglected a number of microscopic lineages that possess a unique combination of characters and are thus informative for our understanding of morphological evolution. Chief among these lineages are the recently described animal groups Micrognathozoa and Loricifera, as well as the two interstitial "Problematica" Diurodrilus and Lobatocerebrum [2]. These genera show a certain resemblance to Annelida in their cuticle and gut [3, 4]; however, both lack primary annelid characters such as segmentation and chaetae [5]. Moreover, they show unique features such as an inverted body-wall musculature or a novel pharyngeal organ. This and their ciliated epidermis have led some to propose relationships with other microscopic spiralians, namely Platyhelminthes, Gastrotricha, and in the case of Diurodrilus, with Micrognathozoa [6, 7]-lineages that are grouped by some analyses into "Platyzoa," a clade whose status remains uncertain [1, 8-11]. Here, we assess the interrelationships among the meiofaunal and macrofaunal members of Spiralia using 402 orthologs mined from genome and transcriptome assemblies of 90 taxa. Lobatocerebrum and Diurodrilus are found to be deeply nested members of Annelida, and unequivocal support is found for Micrognathozoa as the sister group of Rotifera. Analyses using site-heterogeneous substitution models further recover a lophophorate clade and position Loricifera + Priapulida as sister group to the remaining Ecdysozoa. Finally, with several meiofaunal lineages branching off early in the diversification of Spiralia, the emerging concept of a microscopic, acoelomate, direct-developing ancestor of Spiralia is reviewed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Using aquatic macroinvertebrate species traits to build test batteries for sediment toxicity assessment: accounting for the diversity of potential biological responses to toxicants.

PubMed

Ducrot, Virginie; Usseglio-Polatera, Philippe; Péry, T Alexandre R R; Mouthon, Jacques; Lafont, Michel; Roger, Marie-Claude; Garric, Jeanne; Férard, Jean-François

2005-09-01

An original species-selection method for the building of test batteries is presented. This method is based on the statistical analysis of the biological and ecological trait patterns of species. It has been applied to build a macroinvertebrate test battery for the assessment of sediment toxicity, which efficiently describes the diversity of benthic macroinvertebrate biological responses to toxicants in a large European lowland river. First, 109 potential representatives of benthic communities of European lowland rivers were selected from a list of 479 taxa, considering 11 biological traits accounting for the main routes of exposure to a sediment-bound toxicant and eight ecological traits providing an adequate description of habitat characteristics used by the taxa. Second, their biological and ecological trait patterns were compared using coinertia analysis. This comparison allowed the clustering of taxa into groups of organisms that exhibited similar life-history characteristics, physiological and behavioral features, and similar habitat use. Groups exhibited various sizes (7-35 taxa), taxonomic compositions, and biological and ecological features. Main differences among group characteristics concerned morphology, substrate preferendum and habitat utilization, nutritional features, maximal size, and life-history strategy. Third, the best representatives of the mean biological and ecological characteristics of each group were included in the test battery. The final selection was composed of Chironomus riparius (Insecta: Diptera), Branchiura sowerbyi (Oligochaeta: Tubificidae), Lumbriculus variegatus (Oligochaeta: Lumbriculidae), Valvata piscinalis (Gastropoda: Valvatidae), and Sericostoma personatum (Trichoptera: Sericostomatidae). This approach permitted the biological and ecological variety of the battery to be maximized. Because biological and ecological traits of taxa determine species sensitivity, such maximization should permit the battery to better account

Spatial and seasonal distribution of macroinvertebrates in high altitude reservoir (Beyler Reservoir, Turkey)

NASA Astrophysics Data System (ADS)

Findik, Özlem

2013-09-01

A highland reservoir in the West Black Sea region of Turkey which belongs to the Mediterranean climatic zone was examined. Both littoral and profundal zones were sampled from October 2009 to September 2010, to determine taxonomic composition, biodiversity and abundance of benthic invertebrates as well as the seasonal variation of these measures. A total of 35 taxa were identified, of which 12 belong to Chironomidae and 10 to Oligochaeta groups. The highest diversity and abundance of benthic macroinvertebrates were found at the littoral stations. Macroinvertebrates showed significant positive correlations with water temperature and NO2 and NO3 concentrations, and negative correlation with dissolved oxygen.

The first hop: Use of Beaufort Sea deltas by hatch-year semipalmated sandpipers

USGS Publications Warehouse

Churchwell, Roy T.; Kendall, Steve J.; Brown, Stephen C.; Blanchard, Arny L.; Hollmen, Tuula E.; Powell, Abby

2018-01-01

River deltas along Alaska’s Beaufort Sea coast are used by hatch-year semipalmated sandpipers (Calidris pusilla) after leaving their terrestrial natal sites, but the drivers of their use of these stopover sites on the first “hop” of fall migration are unknown. We quantified sandpiper temporal distribution and abundance as related to food resources at three river deltas during the beginning of their fall migration (post-breeding period) to compare the habitat quality among these deltas. We conducted population counts, sampled invertebrates, and captured birds to collect blood samples from individuals for triglyceride and stable isotope analyses to determine fattening rates and diet. Patterns of sandpiper and invertebrate abundance were complex and varied among deltas and within seasons. River deltas were used by sandpipers from late July to late August, and peak sandpiper counts ranged from 1000 to 4000 individuals, of which 98% were hatch-year semipalmated sandpipers. Isotopic signatures from blood plasma samples indicated that birds switched from a diet of upland tundra to delta invertebrate taxa as the migration season progressed, suggesting a dependence on delta invertebrates. Despite differences in diet among deltas, we found no differences in fattening rates of juvenile sandpipers as indicated by triglyceride levels. The number of sandpipers was positively associated with abundance of Amphipoda and Oligochaeta at the Jago and Okpilak-Hulahula deltas; an isotopic mixing model indicated that sandpipers consumed Amphipoda and Oligochaeta at Jago, mostly Chironomidae at Okpilak-Hulahula and Spionidae at Canning. Regardless of the difference in sandpiper diets at the Beaufort Sea deltas, their similar fattening rates throughout the season indicate that all of these stopover sites provide a critical food resource for hatch-year sandpipers beginning their first migration.

Estuarine biodiversity as an indicator of groundwater discharge

NASA Astrophysics Data System (ADS)

Silva, A. C. F.; Tavares, P.; Shapouri, M.; Stigter, T. Y.; Monteiro, J. P.; Machado, M.; Cancela da Fonseca, L.; Ribeiro, L.

2012-01-01

Communities located in the interface between marine/brackish and freshwater habitats are likely to be early responders to climatic changes as they are exposed to both saline and freshwater conditions, and thus are expected to be sensitive to any change in their environmental conditions. Climatic effects are predicted to reduce the availability of groundwater, altering the hydrological balance on estuarine-aquifer interfaces. Here, we aimed to characterise the estuarine faunal community along a gradient dependent on groundwater input, under a predicted climatic scenario of reduction in groundwater discharge into the estuary. Sediment macrofauna was sampled along a salinity gradient following both the wet and dry seasons in 2009. Results indicated that species abundance varied significantly with the salinity gradient created by the groundwater discharge into the estuarine habitat and with sampling time. The isopode Cyathura carinata (Krøyer, 1847) and the polychaetes Heteromastus filiformis (Claparède, 1864) and Hediste diversicolor O.F. Muller, 1776 were associated with the more saline locations, while oligochaeta and Spionidae were more abundant in areas of lower salinity. The polychaete Alkmaria romijni Horst, 1919 was the dominant species and ubiquitous throughout sampling stations. This study provides evidence for estuarine fauna to be considered as a potentially valuable indicator of variation in the input of groundwater into marine-freshwater interface habitats, expected from climatic pressures on aquifer levels, condition and recharge rates. For instance, a reduction in the abundance of some polychaete species, found here to be more abundant in freshwater conditions, and increasing Oligochaeta found here on higher salinities, can potentially be early warnings of a reduction in the input of groundwater into estuaries. Estuarine benthic species are often the main prey for commercially important fish predators such as in our case study, making it important to

Extrapolation of toxic indices among test objects

PubMed Central

Tichý, Miloň; Rucki, Marián; Roth, Zdeněk; Hanzlíková, Iveta; Vlková, Alena; Tumová, Jana; Uzlová, Rút

2010-01-01

Oligochaeta Tubifex tubifex, fish fathead minnow (Pimephales promelas), hepatocytes isolated from rat liver and ciliated protozoan are absolutely different organisms and yet their acute toxicity indices correlate. Correlation equations for special effects were developed for a large heterogeneous series of compounds (QSAR, quantitative structure-activity relationships). Knowing those correlation equations and their statistic evaluation, one can extrapolate the toxic indices. The reason is that a common physicochemical property governs the biological effect, namely the partition coefficient between two unmissible phases, simulated generally by n-octanol and water. This may mean that the transport of chemicals towards a target is responsible for the magnitude of the effect, rather than reactivity, as one would assume suppose. PMID:21331180

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boore, Jeffrey L.; Staton, Joseph

We have determined the sequence of about half (7470 nts) of the mitochondrial genome of the sipunculid Phascolopsis gouldii, the first representative of this phylum to be so studied. All of the 19 identified genes are transcribed from the same DNA strand. The arrangement of these genes is remarkably similar to that of the oligochaete annelid Lumbricus terrestris. Comparison of both the inferred amino acid sequences and the gene arrangements of a variety of diverse metazoan taxa reveals that the phylum Sipuncula is more closely related to Annelida than to Mollusca. This requires reinterpretation of the homology of several embryologicalmore » features and of patterns of animal body plan evolution.« less

Ecophysiology of Nais elinguis (Oligochaeta) in a brackish-water lagoon

NASA Astrophysics Data System (ADS)

Little, Colin

1984-02-01

Population densities of Nais elinguis Müller were determined in Swanpool, a brackish-water lagoon at Falmouth, Cornwall, U.K., over a four-year period. High densities were found only from January to May, usually with a peak in March. Significant negative correlations were shown between population density and both salinity and temperature. In laboratory tests, feeding rates remained unchanged from freshwater to 20‰ salinity (S), but declined above this salinity. Nais elinguis was shown to be a good osmoregulator, remaining hyperosmotic below 7‰ S, and hypo-osmotic above this. Feeding rate showed a Q 10 of approximately 2 from 1 to 25°C, but above this the rate declined. Feeding rate was unaffected between pH 6 and 11. Increased salinity to (10‰ S) did not influence the effect of temperature on feeding rate. This high salinity did reduce feeding rate at a pH of 10 and above. It is concluded that the physical and chemical variables considered are unlikely to be direct causal factors limiting populations of N. elinguis in Swanpool. The influence of food supply, competition, predation and changes in reproductive mode are discussed as possible controlling factors. It is shown that the population decline of N. elinguis in early summer usually coincides with the rise of populations of chironomid larvae.

Molecular Barcoding of Aquatic Oligochaetes: Implications for Biomonitoring

PubMed Central

Vivien, Régis; Wyler, Sofia; Lafont, Michel; Pawlowski, Jan

2015-01-01

Aquatic oligochaetes are well recognized bioindicators of quality of sediments and water in watercourses and lakes. However, the difficult taxonomic determination based on morphological features compromises their more common use in eco-diagnostic analyses. To overcome this limitation, we investigated molecular barcodes as identification tool for broad range of taxa of aquatic oligochaetes. We report 185 COI and 52 ITS2 rDNA sequences for specimens collected in Switzerland and belonging to the families Naididae, Lumbriculidae, Enchytraeidae and Lumbricidae. Phylogenetic analyses allowed distinguishing 41 lineages separated by more than 10 % divergence in COI sequences. The lineage distinction was confirmed by Automatic Barcode Gap Discovery (ABGD) method and by ITS2 data. Our results showed that morphological identification underestimates the oligochaete diversity. Only 26 of the lineages could be assigned to morphospecies, of which seven were sequenced for the first time. Several cryptic species were detected within common morphospecies. Many juvenile specimens that could not be assigned morphologically have found their home after genetic analysis. Our study showed that COI barcodes performed very well as species identifiers in aquatic oligochaetes. Their easy amplification and good taxonomic resolution might help promoting aquatic oligochaetes as bioindicators for next generation environmental DNA biomonitoring of aquatic ecosystems. PMID:25856230

Disturbance caused by freshwater releases of different magnitude on the aquatic macroinvertebrate communities of two coastal lagoons

NASA Astrophysics Data System (ADS)

Cañedo-Argüelles, Miguel; Rieradevall, Maria

2010-06-01

The response of the aquatic macroinvertebrate communities to freshwater releases of different magnitude and persistence was investigated in two Mediterranean coastal lagoons (Ca l'Arana and Ricarda). The study was carried out during 14 months (June 2004-July 2005) in which different environmental variables and the macroinvertebrate communities associated with two different habitats, the Phragmites australis belt and the deep area of the lagoons, were sampled monthly. Additionally, potential colonizing sources were identified through the analysis of Chironomidae pupal exuviae. The initial response of the communities to the freshwater releases was similar, being characterized by a peak of opportunistic taxa (mainly Naididae), but the late response was different for each lagoon. In the Ca l'Arana, the magnitude of the freshwater release was higher (salinity dropped below five, which is the limit commonly established for most freshwater species) and its persistence was also higher, allowing the colonization of the lagoon by new insect taxa, which replaced the brackish water species. In the Ricarda, the salinity never dropped beyond five and pre-disturbance conditions were rapidly re-established. This, together with the acclimatizing mechanisms showed by the species Chironomus riparius and Hediste diversicolor, permitted the recovery of the pre-disturbance macroinvertebrate community.

The effect of phorate on wetland macroinvertebrates

USGS Publications Warehouse

Dieter, Charles D.; Flake, Lester D.; Duffy, Walter G.

1996-01-01

The effects of phorate, an organophosphorus insecticide, on aquatic macroinvertebrates was studied in littoral mesocosms in South Dakota wetlands. In 1991 and 1992, four mesocosms were constructed in each of three wetlands. In each wetland, one mesocosm was a reference and phorate concentrations of 1.2, 2.4, and 4.8 kg/ha were applied to treatment mesocosms. Phorate caused mortality to amphipods and chironomids throughout the study. Leeches and snails were resistant to phorate. Few living macroinvertebrates were present in mesocosms after phorate treatment and populations recovered only slightly after 1 month. Macroinvertebrate taxa that were sensitive to phorate included: Odonata, Hemiptera, Culicidae, Heliidae, Ephemeroptera, Acarina, Coleoptera, Stratio-myidae, and Hydracarina. Taxa that were tolerant to phorate included: Hirudinea, Gastropoda, Oligochaeta, and Ostracoda.

A Comparative Assessment of Zootherapeutic Remedies From Selected Areas in Albania, Italy, Spain and Nepal

PubMed Central

Quave, Cassandra Leah; Lohani, Usha; Verde, Alonso; Fajardo, José; Rivera, Diego; Obón, Concepción; Valdes, Arturo; Pieroni, Andrea

2011-01-01

Zootherapy is the treatment of human ailments with remedies derived from animals and their products. Despite its prevalence in traditional medical practices worldwide, research on this phenomenon has often been neglected in comparison to medicinal plant research. Interviews regarding zootherapeutic traditions were conducted with informants from Albania, Italy, Nepal and Spain. We identified 80 species used in zootherapeutic remedies, representing 4 phyla in the animal kingdom: Annelida, Arthropoda, Chordata, and Mollusca. Remedies were ranked by consensus indices. Our studies show that the selection of medicinal fauna is mediated by human subsistence patterns. Concepts of health and disease differ among our study sites in the Mediterranean and Asia, and these differences also play a substantive role in the selection and use of animal-based remedies. PMID:21625340

New aspects of the possible sites of ultrafiltration in annelids (oligochaeta).

PubMed

Hansen, U

1995-02-01

Electron microscopic investigations of blood vessels were conducted to show sites of filtration such as podocytes or fenestrated endothelia. The endothelia of the blood vessels of Aelosoma hemprichi, Nais elinguis, Dero obtusa and Enchytraeus buchholzi consist of myoendothelial cells, chloragocytes and podocytes. The podocytes form large archs over a considerable area of the vessels. On the lumen side of the vessel there are several columnar processes which split into numerous small pedicels. The gaps between the adjacent pedicles are bridged by slit membranes. The podocytes are restricted to the front part of the ventral vessel. They are presumed to form a filtration surface. Furthermore, some parts of the ventral vessel are formed by a fenestrated endothelium, mainly in Enchytraeus buchholzi. In the vascular system of E. buchholzi two separate filtration sites were found. Additionally to the filtration site between ventral vessel and coelomic cavity a second filtration site was found in the front part of the body between blood sinus and coelomic cavity. In such areas the basement membrane is the only continuous layer between the blood vessel and the coelomic cavity. Its thickness is in the range of 40 nm. Possible filtration sites in the form of podocytes and irregular fenestrations could be localized at the border between the blood compartment and the coelomic compartment. It can be presumed that the primary urine may be formed by ultrafiltration of blood.

Shifts in the diets of slimy sculpin (Cottus cognatus) and lake whitefish (Coregonus clupeaformis) in Lake Ontario following the collapse of the burrowing amphipod Diporeia

USGS Publications Warehouse

Owens, Randall W.; Dittman, Dawn E.

2003-01-01

In Lake Ontario, the diets of slimy sculpin Cottus cognatus and lake whitefish Coregonus clupeaformis shifted from a diet dominated by the burrowing amphipod, Diporeia, and to a lesser extent, Mysis, to a more diverse diet, after Diporeia collapsed, to one dominated by Mysis and prey that were formerly less important or uncommon such as Chironomidae, Oligochaeta, and Ostracoda. Additionally, lake whitefish still preyed on native mollusks like Sphaeriidae and Gastropoda, but also preyed on exotic mollusks, Dreissena spp., which are swallowed intact and subsequently crushed in its muscular stomach. Whether Diporeia was abundant (1992) or scarce (1999), selection indices for Diporeia by slimy sculpins was positive, suggesting that Diporeia was a preferred prey. Unlike lake whitefish, slimy sculpins avoided Dreissena; therefore, energy diverted to Dreissena production was a real loss for slimy sculpins. The shifts in the diet of these benthic fishes corresponded with drastic changes in the benthic community between 1992 and 1999. The collapse of Diporeia, formerly the most abundant macroinvertebrate in the benthic community, along with sharp declines in the abundance of Oligochaeta and Sphaeriidae, coincided with the establishment and rapid expansion of Dreissena bugensis, the quagga mussel, and to a lesser degree Dreissena polymorpha, the zebra mussel. It appears that the Diporeia population first collapsed at depths >70 m in southeastern Lake Ontario by autumn 1992, at shallower depths in the eastern Lake Ontario by 1995, and along the entire south shore line at depths <100 m, and perhaps in some areas >100 m by 1999. In response to the disappearance of Diporeia, populations of two native benthivores, slimy sculpin and lake whitefish, collapsed in eastern Lake Ontario, perhaps due in part to starvation, because Diporeia was their principal prey. Presently, alternative food resources do not appear sufficient to sustain these two benthivores at their former levels of

Historic developments in macrozoobenthos of the Rhine Meuse estuary: From a tidal inlet to a freshwater lake

NASA Astrophysics Data System (ADS)

Wijnhoven, S.; Sistermans, W.; Hummel, H.

2008-01-01

Water works during the 1960s and 1970s changed the northern part of the Rhine-Meuse estuary in the south-west of the Netherlands into a freshwater lake, from west to east divided into three basins called the Haringvliet, the Hollands Diep and the Biesbosch. Concurrently water quality parameters (e.g. nutrients and pollutants) changed drastically during the last 50 years. This study combines macrozoobenthic monitoring data from the region from 1960 to 2001 with trends in abiotic parameters to evaluate historic developments of the communities, including densities, species numbers and diversity, and assess future developments as a first step to a rehabilitation of the estuary as planned for January 01, 2008. During the 1960s, the macrozoobenthic densities of Oligochaeta and/or Polychaeta dominated communities increased with a gradual decrease of saltwater intrusion and salinity variability. The first years after the basins became stagnant, the species numbers per sample and the Shannon diversity were high due to the coexistence of salt and freshwater species. An increase in nutrient and pollutant loads led to a decrease in the macrozoobenthos densities. As water and sediment quality gradually improved, nowadays the former estuary contains high diversity and high density macrozoobenthic communities, whereas Oligochaeta and/or Polychaeta were dominant in the 1960s, and Bivalvia and Gastropoda were more abundant during the 1970s. Macrozoobenthic communities moved from the east to west with a time-lag, which may primarily be attributed to changing salinities, salinity variances and oxygen levels. Therefore, the current communities of the Haringvliet show similarities with the communities that occurred already during the 1960s in the Biesbosch. This study shows the value of macrozoobenthos monitoring data over longer periods. The possible impact of a new saltwater inlet in the west of the Haringvliet, allowing in the near future saltwater to enter 11.5 km eastward, yet

Activity and immunodetection of lysozyme in earthworm Dendrobaena veneta (Annelida).

PubMed

Fiołka, Marta J; Zagaja, Mirosław P; Hułas-Stasiak, Monika; Wielbo, Jerzy

2012-01-01

In the present study, lysozyme-like activity against Micrococcus luteus was detected in the coelomic fluid, the extract from coelomocytes, intestine and in the homogenates from cocoons of Dendrobaena veneta. Four hours after immunization with Escherichia coli, the lysozyme activity in the coelomic fluid increased about three times and in the extract of coelomocytes - four times, in comparison to the control. In three cases: of the coelomic fluid, the homogenates from cocoons and the extract from coelomocytes, the antibody against HEWL (hen egg white lysozyme) recognized only one protein with a molecular mass of about 14.4 kDa. In the coelomic fluid, apart from the protein with molecular mass of 14.4 kDa the antibody directed against human lysozyme recognized an additional protein of 22 kDa. Using the bioautography technique after electrophoretic resolution of native proteins in acidic polyacrylamide gels, two lytic zones of M. luteus were observed in the case of the coelomic fluid and three after the analysis of the extract of coelomocytes and the egg homogenates. The results indicated the existence of several forms of lysozyme with a different electric charge in the analyzed D. veneta samples. The highest lysozyme activity in the intestine of D. veneta was observed in the midgut. The antibody directed against human lysozyme indicated a strong positive signal in epidermal and midgut cells of earthworm. Copyright © 2011 Elsevier Inc. All rights reserved.

Comparative neuroanatomy suggests repeated reduction of neuroarchitectural complexity in Annelida

PubMed Central

2010-01-01

Background Paired mushroom bodies, an unpaired central complex, and bilaterally arranged clusters of olfactory glomeruli are among the most distinctive components of arthropod neuroarchitecture. Mushroom body neuropils, unpaired midline neuropils, and olfactory glomeruli also occur in the brains of some polychaete annelids, showing varying degrees of morphological similarity to their arthropod counterparts. Attempts to elucidate the evolutionary origin of these neuropils and to deduce an ancestral ground pattern of annelid cerebral complexity are impeded by the incomplete knowledge of annelid phylogeny and by a lack of comparative neuroanatomical data for this group. The present account aims to provide new morphological data for a broad range of annelid taxa in order to trace the occurrence and variability of higher brain centers in segmented worms. Results Immunohistochemically stained preparations provide comparative neuroanatomical data for representatives from 22 annelid species. The most prominent neuropil structures to be encountered in the annelid brain are the paired mushroom bodies that occur in a number of polychaete taxa. Mushroom bodies can in some cases be demonstrated to be closely associated with clusters of spheroid neuropils reminiscent of arthropod olfactory glomeruli. Less distinctive subcompartments of the annelid brain are unpaired midline neuropils that bear a remote resemblance to similar components in the arthropod brain. The occurrence of higher brain centers such as mushroom bodies, olfactory glomeruli, and unpaired midline neuropils seems to be restricted to errant polychaetes. Conclusions The implications of an assumed homology between annelid and arthropod mushroom bodies are discussed in light of the 'new animal phylogeny'. It is concluded that the apparent homology of mushroom bodies in distantly related groups has to be interpreted as a plesiomorphy, pointing towards a considerably complex neuroarchitecture inherited from the last common ancestor, Urbilateria. Within the annelid radiation, the lack of mushroom bodies in certain groups is explained by widespread secondary reductions owing to selective pressures unfavorable for the differentiation of elaborate brains. Evolutionary pathways of mushroom body neuropils in errant polychaetes remain enigmatic. PMID:20441583

Polychaete species (Annelida) described from the Philippine and China Seas.

PubMed

Salazar-Vallejo, Sergio I; Carrera-Parra, Luis F; Muir, Alexander I; De León-González, Jesús Angel; Piotrowski, Christina; Sato, Masanori

2014-07-30

The South China and Philippine Seas are among the most diverse regions in the Western Pacific. Although there are several local polychaete checklists available, there is none comprising the whole of this region. Presented herein is a comprehensive list of the original names of all polychaete species described from the region. The list contains 1037 species, 345 genera and 60 families; the type locality, type depository, and information regarding synonymy are presented for each species. 

Effects of sea lamprey (Petromyzon marinus) control in the Great Lakes on aquatic plants, invertebrates and amphibians

USGS Publications Warehouse

Gilderhus, P.A.; Johnson, B.G.H.

1980-01-01

The chemicals 3-trifluoromethyl-4-nitrophenol (TFM) or a combination of TFM and 2a??,5-dichloro-4a??-nitrosalicylanilide (Bayer 73) have been used to control the sea lamprey (Petromyzon marinus) in the Great Lakes for about 20 yr. These chemicals cause some mortalities of Oligochaeta and Hirudinea, immature forms of Ephemeroptera (Hexagenia sp.), and certain Trichoptera, Simuliidae, and Amphibia (Necturus sp.). The combination of TFM and Bayer 73 may affect some Pelecypoda and Gastropoda, but its overall effects on invertebrates are probably less than those of TFM alone. Granular Bayer 73 is likely to induce mortalities among oligochaetes, microcrustaceans, chironomids, and pelecypods. No evidence exists that the lampricides have caused the catastrophic decline or disappearance of any species. The overall impact of chemical control of sea lampreys on aquatic communities has been minor compared with the benefits derived.

Makrozoobentos as bioindicator water quality of Krukut River, Depok, West Java, Indonesia

NASA Astrophysics Data System (ADS)

Jayanti, A. D.; Fachrul, M. F.; Hendrawan, D.

2018-01-01

The purpose of this study was to determine the Diversity Index, Similarity Index, and Dominance Index. The research location in Krukut River along 12 km. The research was conducted in March - June 2017 in 7 sampling points. Macrozoobentos obtained as many as 23 species belonging to the 9 classes are 3 types of Bivalves, 7 types of Arthopoda, 2 types of Molusca, 4 types of insects, 4 types of Oligochaeta, 2 Malacostraca, 1 Crustacea, 1 Diptera, and 1 Nematodes. The highest abundance of macrozoobentos is 10550 Ind/m2, whereas the lowest macrozoobenthic abundance is 850 Ind/m2. The range of Diversity Index (H') 0.32 - 1.80, Similarity Index (E) 0.58-1.07 and Dominance Index (C) 0.40-0.63. Therefore the result shows that Krukut River is in category medium pollution.

NONATObase: a database for Polychaeta (Annelida) from the Southwestern Atlantic Ocean.

PubMed

Pagliosa, Paulo R; Doria, João G; Misturini, Dairana; Otegui, Mariana B P; Oortman, Mariana S; Weis, Wilson A; Faroni-Perez, Larisse; Alves, Alexandre P; Camargo, Maurício G; Amaral, A Cecília Z; Marques, Antonio C; Lana, Paulo C

2014-01-01

Networks can greatly advance data sharing attitudes by providing organized and useful data sets on marine biodiversity in a friendly and shared scientific environment. NONATObase, the interactive database on polychaetes presented herein, will provide new macroecological and taxonomic insights of the Southwestern Atlantic region. The database was developed by the NONATO network, a team of South American researchers, who integrated available information on polychaetes from between 5°N and 80°S in the Atlantic Ocean and near the Antarctic. The guiding principle of the database is to keep free and open access to data based on partnerships. Its architecture consists of a relational database integrated in the MySQL and PHP framework. Its web application allows access to the data from three different directions: species (qualitative data), abundance (quantitative data) and data set (reference data). The database has built-in functionality, such as the filter of data on user-defined taxonomic levels, characteristics of site, sample, sampler, and mesh size used. Considering that there are still many taxonomic issues related to poorly known regional fauna, a scientific committee was created to work out consistent solutions to current misidentifications and equivocal taxonomy status of some species. Expertise from this committee will be incorporated by NONATObase continually. The use of quantitative data was possible by standardization of a sample unit. All data, maps of distribution and references from a data set or a specified query can be visualized and exported to a commonly used data format in statistical analysis or reference manager software. The NONATO network has initialized with NONATObase, a valuable resource for marine ecologists and taxonomists. The database is expected to grow in functionality as it comes in useful, particularly regarding the challenges of dealing with molecular genetic data and tools to assess the effects of global environment change. Database URL: http://nonatobase.ufsc.br/.

Rhabditis pellio Schneider (nematoda) from the earthworm, Aporrectodea trapezoides Duges (Annelida).

PubMed

Poinar, G O; Thomas, G M

1975-10-01

Studies were conducted on the behavior of the nematode, Rhabditis pellio, in the earthworm, Aporrectodea trapezoides, from southern California. Juvenile and adult nematodes were found in the bladders and tubules of the metanephridia of the host. Similar nematodes that entered the coelom were encapsulated and incorporated into multiple capsules ("brown bodies"). It was demonstrated that this host response is an effective defense reaction since dead and dying nematodes, as well as living forms, were found in the capsules.

NONATObase: a database for Polychaeta (Annelida) from the Southwestern Atlantic Ocean

PubMed Central

Pagliosa, Paulo R.; Doria, João G.; Misturini, Dairana; Otegui, Mariana B. P.; Oortman, Mariana S.; Weis, Wilson A.; Faroni-Perez, Larisse; Alves, Alexandre P.; Camargo, Maurício G.; Amaral, A. Cecília Z.; Marques, Antonio C.; Lana, Paulo C.

2014-01-01

Networks can greatly advance data sharing attitudes by providing organized and useful data sets on marine biodiversity in a friendly and shared scientific environment. NONATObase, the interactive database on polychaetes presented herein, will provide new macroecological and taxonomic insights of the Southwestern Atlantic region. The database was developed by the NONATO network, a team of South American researchers, who integrated available information on polychaetes from between 5°N and 80°S in the Atlantic Ocean and near the Antarctic. The guiding principle of the database is to keep free and open access to data based on partnerships. Its architecture consists of a relational database integrated in the MySQL and PHP framework. Its web application allows access to the data from three different directions: species (qualitative data), abundance (quantitative data) and data set (reference data). The database has built-in functionality, such as the filter of data on user-defined taxonomic levels, characteristics of site, sample, sampler, and mesh size used. Considering that there are still many taxonomic issues related to poorly known regional fauna, a scientific committee was created to work out consistent solutions to current misidentifications and equivocal taxonomy status of some species. Expertise from this committee will be incorporated by NONATObase continually. The use of quantitative data was possible by standardization of a sample unit. All data, maps of distribution and references from a data set or a specified query can be visualized and exported to a commonly used data format in statistical analysis or reference manager software. The NONATO network has initialized with NONATObase, a valuable resource for marine ecologists and taxonomists. The database is expected to grow in functionality as it comes in useful, particularly regarding the challenges of dealing with molecular genetic data and tools to assess the effects of global environment change. Database URL: http://nonatobase.ufsc.br/ PMID:24573879

Two new genera of Lumbriculidae (Annelida, Clitellata) from North Carolina, USA

USGS Publications Warehouse

Fend, S.V.; Lenat, D.R.

2007-01-01

Recent benthic macroinvertebrate collections from North Carolina contained many undescribed oligochaete taxa, mostly belonging to the family Lumbriculidae. Three of the new species had arrangements of spermathecae and atria previously unreported for the family, and were assigned to new two genera. Pilaridrilus is distinguished by the location of spermathecal pores five segments behind the male pores. The single species, Pilaridrilus uliginosus, also has unusually complex penes and spermathecae. Martinidrilus is distinguished by spermathecae beginning more than two segments anterior to the atrial segment, and also by the the vasa deferentia, which join a common duct before joining the atria. The two Martinidrilus species also have unusual digitiform blood vessels in posterior segments. Martinidrilus carolinensis has lateral spermathecae in VI, and Martinidrilus arenosus has dorsolateral spermathecae in VII and VIII. Because arrangement and morphology of reproductive organs do not resemble those of described lumbriculids, the phylogenetic affinities of the new species are not clear. These new genera and species were generally collected from areas of high water quality, suggesting that lumbriculids can be useful in water quality monitoring and conservation evaluation. Copyright ?? 2007 Magnolia Press.

Great Lakes DNA barcode reference library: Mollusca, annelida, and minor phyla

EPA Science Inventory

In recent years, the research and development of DNA-based tools has improved both their sensitivity and costs. This technology has the potential to be useful in the early detection of aquatic invasive species, and can increase the scope of surveillance compared with traditional ...

Phylogenetic study of the arginine-vasotocin/arginine-vasopressin-like immunoreactive system in invertebrates.

PubMed

Mizuno, J; Takeda, N

1988-01-01

1. A phylogenetic study of arg-vasotocin (AVT)/arg-vasopressin (AVP)-like immunoreactive cells was performed by the PAP method in the central nervous system of invertebrates. 2. The immunoreactivity was detected in the nerve cells of Hydra magnipapillata of the Coelenterata; Neanthes japonica and Pheretima communissima of the Annelida; Pomacea canaliculata, Aplysia kurodai, Oncidium verrucosum, Bradybaena similaris, Achatina fulica, Limax marginatus and Meretrix lamarckii of the Mollusca; Gnorimosphaeroma rayi, Hemigrapsus sanguineus, Gryllus bimaculatus and Baratha brassicae of the Arthropoda; Asterina pectinifera of the Echinodermata; and Halocynthia roretzi of the Protochordata. 3. No immunoreactivity was detected in Bipalium sp. of the Platyhelminthes, or in Procambarus clarkii and Helice tridens of the Arthropoda. 4. From these results, it appears that AVT/AVP is a phylogenetically ancient peptide which is present in a wide variety of invertebrates. 5. The actions of AVT/AVP and its presence in invertebrates are discussed.

Phylogenetic study of the oxytocin-like immunoreactive system in invertebrates.

PubMed

Mizuno, J; Takeda, N

1988-01-01

1. A phylogenetic study of oxytocin (OXT)-like immunoreactive cells was performed by the PAP method in the central nervous system of invertebrates. 2. The immunoreactivity was detected in the nerve cells of Hydra magnipapillata of the Coelenterata; Neanthes japonica and Pheretima communissima of the Annelida; Oncidium verrucosum, Limax marginatus and Meretrix lamarckii of the Mollusca; and Baratha brassica of the Arthropoda. 3. No immunoreactive cells were found in Bipalium sp. of the Platyhelminthes; Pomacea canaliculata, Aplysia kurodai, Bradybaena similaris and Achatina fulica of the Mollusca; and Gnorimosphaeroma rayi, Procambarus clarkii, Hemigrapsus sanguineus, Helice tridens and Gryllus bimaculatus of the Arthropoda; Asterina pectinifera of the Echinodermata; and Halocynthia roretzi of the Protochordata. 4. These results demonstrate that an OXT-immunoreactive substance is widely present not only in vertebrates but also in invertebrates. 5. OXT seems to have been introduced into these invertebrates at an early stage of their phylogenetic history.

Interactions among two strains of Tubifex tubifex (Oligochaeta: Tubificidae) and Myxobolus cerebralis (Myxozoa)

USGS Publications Warehouse

Steinbach, Elwell L.C.; Kerans, B.L.; Rasmussen, C.; Winton, J.R.

2006-01-01

Host-parasite interactions influence host population growth, host evolution and parasite success. We examined the interactions among Myxobolus cerebralis, the parasite that causes salmonid whirling disease, and resistant and susceptible strains of the oligochaete host Tubifex tubifex. Strains of T. tubifex with diverse genotypes often coexist in nature and have variable susceptibilities to M. cerebralis infection. Further, parasite proliferation differs by several orders of magnitude among T. tubifex strains. We examined total biomass produced by individual T. tubifex, including progeny production and adult growth, parasite proliferation and prevalence of infection using 2 strains of T. tubifex at 2 myxospore doses in a response-surface experimental design. Total biomass production per individual oligochaete and progeny biomass produced by an individual adult oligochaete were density-dependent for both resistant and susceptible individuals and the effects did not change with the addition of myxospores. However, both resistant and susceptible adults had highest growth when exposed to M. cerebralis. The presence of resistant oligochaetes in mixed cultures did not reduce the infection prevalence or parasite proliferation in susceptible individuals. In natural aquatic communities, resistant strains of T. tubifex may not reduce the effects of M. cerebralis on the salmonid host, particularly if sufficient numbers of susceptible T. tubifex are present. ?? Inter-Research 2006.

Limnodrilus sulphurensis n. sp., from a sulfur cave in Colorado, USA, with notes on the morphologically similar L. profundicola (Clitellata, Naididae, Tubificinae).

PubMed

Fend, Steven V; Liu, Yingkui; Steinmann, David; Giere, Olav; Barton, Hazel A; Luiszer, Fred; Erséus, Christer

2016-01-18

A new species of the tubificine genus Limnodrilus is described and COI barcoded from Sulphur Cave and associated springs in Colorado, USA. The habitats are characterized by high sulfide concentrations. The new species, L. sulphurensis, is distinguished from all congeners by the elongate, nearly parallel teeth of chaetae in its anterior segments. It has a penis sheath resembling that of L. profundicola; consequently, museum specimens and new collections are examined here to resolve some of the taxonomic confusion surrounding that widespread, but uncommon species.

Assessment of macroinvertebrate communities in adjacent urban stream basins, Kansas City, Missouri, metropolitan area, 2007 through 2011

USGS Publications Warehouse

Christensen, Eric D.; Krempa, Heather M.

2013-01-01

Wastewater-treatment plant discharges during base flow, which elevated specific conductance and nutrient concentrations, combined sewer overflows, and nonpoint sources likely contributed to water-quality impairment and lower aquatic-life status at the Blue River Basin sites. Releases from upstream reservoirs to the Little Blue River likely decreased specific conductance, suspended-sediment, and dissolved constituent concentrations and may have benefitted water quality and aquatic life of main-stem sites. Chloride concentrations in base-flow samples, attributable to winter road salt application, had the highest correlation with the SUII (Spearman’s ρ equals 0.87), were negatively correlated with the SCI (Spearman’s ρ equals -0.53) and several pollution sensitive Ephemeroptera plus Plecoptera plus Trichoptera abundance and percent richness metrics, and were positively correlated with pollution tolerant Oligochaeta abundance and percent richness metrics. Study results show that the easily calculated SUII and the selected modeled multimetric indices are effective for comparing urban basins and for evaluation of water quality in the Kansas City metropolitan area.

Studies on regeneration of central nervous system and social ability of the earthworm Eudrilus eugeniae.

PubMed

Gopi Daisy, Nino; Subramanian, Elaiya Raja; Selvan Christyraj, Jackson Durairaj; Sudalai Mani, Dinesh Kumar; Selvan Christyraj, Johnson Retnaraj Samuel; Ramamoorthy, Kalidas; Arumugaswami, Vaithilingaraja; Sivasubramaniam, Sudhakar

2016-09-01

Earthworms are segmented invertebrates that belong to the phylum Annelida. The segments can be divided into the anterior, clitellar and posterior parts. If the anterior part of the earthworm, which includes the brain, is amputated, the worm would essentially survive even in the absence of the brain. In these brain amputee-derived worms, the nerve cord serves as the primary control center for neurological function. In this current work, we studied changes in the expression levels of anti-acetylated tubulin and serotonin as the indicators of neuro-regenerative processes. The data reveal that the blastemal tissues express the acetylated tubulin and serotonin from day four and that the worm amputated at the 7th segment takes 30 days to complete the regeneration of brain. The ability of self-assemblage is one of the specific functions of the earthworm's brain. The brain amputee restored the ability of self-assemblage on the eighth day.

Eukaryotic opportunists dominate the deep-subsurface biosphere in South Africa

PubMed Central

Borgonie, G.; Linage-Alvarez, B.; Ojo, A. O.; Mundle, S.O.C.; Freese, L B.; Van Rooyen, C.; Kuloyo, O.; Albertyn, J.; Pohl, C.; Cason, E. D.; Vermeulen, J.; Pienaar, C.; Litthauer, D.; Van Niekerk, H.; Van Eeden, J.; Lollar, B. Sherwood.; Onstott, T. C.; Van Heerden, E.

2015-01-01

Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines. Protozoa and Fungi have also been identified; however, they are present in low numbers. Characterization of the different species reveals that many are opportunistic organisms with an origin due to recharge from surface waters rather than soil leaching. This is the first known study to demonstrate the in situ distribution of biofilms on fissure rock faces using video documentation. Calculations suggest that food, not dissolved oxygen is the limiting factor for eukaryal population growth. The discovery of a group of Eukarya underground has important implications for the search for life on other planets in our solar system. PMID:26597082

Effects of the 2003 European heatwave on the benthic community of a severe transitional ecosystem (Comacchio Saltworks, Italy).

PubMed

Munari, Cristina

2011-12-01

The summer of 2003 was the warmest summer in Europe since the 16th century. Its consequences on the fauna of a transitional ecosystem were studied through biodiversity, functional and ecological indicators, from summer 2002 to winter 2005. The heatwave caused considerable changes in the benthic community structure and relative composition, persisting in 2005. Animal assemblages switched from mollusc- to annelida-dominated. Biodiversity and functional indicators captured changes in community structure and composition, proving to be powerful tools to detect responses related to global warming. Ecological indicators rendered a monotonic response oscillating between bad and poor ecological status across the study period. The resilience of mollusc biocoenosis resulted limited with respect to other taxa, posing concerns about their conservation if, as predicted, the frequency of summers as hot as that of 2003 will progressively increase to become the norm at the end of this century. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Phylogeny of protostome moulting animals (Ecdysozoa) inferred from 18 and 28S rRNA gene sequences].

PubMed

Petrov, N B; Vladychenskaia, N S

2005-01-01

Reliability of reconstruction of phylogenetic relationships within a group of protostome moulting animals was evaluated by means of comparison of 18 and 28S rRNA gene sequences sets both taken separately and combined. Reliability of reconstructions was evaluated by values of the bootstrap support of major phylogenetic tree nodes and by degree of congruence of phylogenetic trees inferred by various methods. By both criteria, phylogenetic trees reconstructed from the combined 18 and 28S rRNA gene sequences were better than those inferred from 18 and 28S sequences taken separately. Results obtained are consistent with phylogenetic hypothesis separating protostome animals into two major clades, moulting Ecdysozoa (Priapulida + Kinorhyncha, Nematoda + Nematomorpha, Onychophora + Tardigrada, Myriapoda + Chelicerata, Crustacea + Hexapoda) and unmoulting Lophotrochozoa (Plathelminthes, Nemertini, Annelida, Mollusca, Echiura, Sipuncula). Clade Cephalorhyncha does not include nematomorphs (Nematomorpha). Conclusion was taken that it is necessary to use combined 18 and 28S data in phylogenetic studies.

Invertebrate biomechanics.

PubMed

Patek, S N; Summers, A P

2017-05-22

Invertebrate biomechanics focuses on mechanical analyses of non-vertebrate animals, which at root is no different in aim and technique from vertebrate biomechanics, or for that matter the biomechanics of plants and fungi. But invertebrates are special - they are fabulously diverse in form, habitat, and ecology and manage this without the use of hard, internal skeletons. They are also numerous and, in many cases, tractable in an experimental and field setting. In this Primer, we will probe three axes of invertebrate diversity: worms (Phylum Annelida), spiders (Class Arachnida) and insects (Class Insecta); three habitats: subterranean, terrestrial and airborne; and three integrations with other fields: ecology, engineering and evolution. Our goal is to capture the field of invertebrate biomechanics, which has blossomed from having a primary focus on discoveries at the interface of physics and biology to being inextricably linked with integrative challenges that span biology, physics, mathematics and engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

Eukaryotic opportunists dominate the deep-subsurface biosphere in South Africa.

PubMed

Borgonie, G; Linage-Alvarez, B; Ojo, A O; Mundle, S O C; Freese, L B; Van Rooyen, C; Kuloyo, O; Albertyn, J; Pohl, C; Cason, E D; Vermeulen, J; Pienaar, C; Litthauer, D; Van Niekerk, H; Van Eeden, J; Sherwood Lollar, B; Onstott, T C; Van Heerden, E

2015-11-24

Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines. Protozoa and Fungi have also been identified; however, they are present in low numbers. Characterization of the different species reveals that many are opportunistic organisms with an origin due to recharge from surface waters rather than soil leaching. This is the first known study to demonstrate the in situ distribution of biofilms on fissure rock faces using video documentation. Calculations suggest that food, not dissolved oxygen is the limiting factor for eukaryal population growth. The discovery of a group of Eukarya underground has important implications for the search for life on other planets in our solar system.

Quantitative distribution and functional groups of intertidal macrofaunal assemblages in Fildes Peninsula, King George Island, South Shetland Islands, Southern Ocean.

PubMed

Liu, Xiaoshou; Wang, Lu; Li, Shuai; Huo, Yuanzi; He, Peimin; Zhang, Zhinan

2015-10-15

To evaluate spatial distribution pattern of intertidal macrofauna, quantitative investigation was performed in January to February, 2013 around Fildes Peninsula, King George Island, South Shetland Islands. A total of 34 species were identified, which were dominated by Mollusca, Annelida and Arthropoda. CLUSTER analysis showed that macrofaunal assemblages at sand-bottom sites belonged to one group, which was dominated by Lumbricillus sp. and Kidderia subquadrata. Macrofaunal assemblages at gravel-bottom sites were divided into three groups while Nacella concinna was the dominant species at most sites. The highest values of biomass and Shannon-Wiener diversity index were found in gravel sediment and the highest value of abundance was in sand sediment of eastern coast. In terms of functional group, detritivorous and planktophagous groups had the highest values of abundance and biomass, respectively. Correlation analysis showed that macrofaunal abundance and biomass had significant positive correlations with contents of sediment chlorophyll a, phaeophorbide and organic matter. Copyright © 2015 Elsevier Ltd. All rights reserved.

TreSpEx—Detection of Misleading Signal in Phylogenetic Reconstructions Based on Tree Information

PubMed Central

Struck, Torsten H

2014-01-01

Phylogenies of species or genes are commonplace nowadays in many areas of comparative biological studies. However, for phylogenetic reconstructions one must refer to artificial signals such as paralogy, long-branch attraction, saturation, or conflict between different datasets. These signals might eventually mislead the reconstruction even in phylogenomic studies employing hundreds of genes. Unfortunately, there has been no program allowing the detection of such effects in combination with an implementation into automatic process pipelines. TreSpEx (Tree Space Explorer) now combines different approaches (including statistical tests), which utilize tree-based information like nodal support or patristic distances (PDs) to identify misleading signals. The program enables the parallel analysis of hundreds of trees and/or predefined gene partitions, and being command-line driven, it can be integrated into automatic process pipelines. TreSpEx is implemented in Perl and supported on Linux, Mac OS X, and MS Windows. Source code, binaries, and additional material are freely available at http://www.annelida.de/research/bioinformatics/software.html. PMID:24701118

Six new deep-water sternaspid species (Annelida, Sternaspidae) from the Pacific Ocean.

PubMed

Salazar-Vallejo, Sergio I; Buzhinskaja, Galina

2013-01-01

Most sternaspid species have been described from shallow water, and Caulleryaspis Sendall & Salazar-Vallejo, 2013 includes one deep water species: C. gudmundssoni Sendall & Salazar-Vallejo, 2013 from Iceland. In Sternaspis Otto, 1821, the most speciose genus, most species were described from shallow water and only three thrive in deep water: S. maior Chamberlin, 1919 from the Gulf of California, S. princeps Selenka, 1885 from New Zealand, and S. riestchi Caullery, 1944 from Indonesia. The study of some deep sea sternaspids from the Pacific Ocean in the collections of six research institutions resulted in the discovery of six undescribed species, and for three of them there were abundant materials showing ventro-caudal shield development. Caulleryaspis fauchaldi sp. n. is described based on specimens from Oregon and California; it differs from the known species because it has a shield with rounded anterior margins and its peg chaetae form thin, small spines. Caulleryaspis nuda sp. n. was collected off Oregon; it is unique because its shield lacks a layer of sediment particles firmly attached, but has instead a thin layer of small particles loosely attached. Four other species are newly described in Sternaspis: S. annenkovae sp. n. was collected east off the northern Kurile Islands in about 4,000 m depth; it differs from other species by having a bicolored body, with the introvert darker than the abdomen, and its ventro-caudal shield plates are divergent resulting in a divided fan. The second species, S. maureri sp. n. was found off Peru in 1296-6489 m water depths and in the Southwestern Pacific in 795-3830 m; it resembles S. williamsae sp. n. but differs because its shield has better-developed ribs, the fan has a shallow or indistinct median notch and has lateral notches well-developed. The third species, S. uschakovi sp. n., was found in the Okhotsk Sea in 592-1366 m, off California in 1585 m, Gulf of California in 1200-1274 m, and Western Mexico in 2548 m; it resembles S. africana Augener, 1918 and S. andamanensis Sendall & Salazar-Vallejo, 2013 in having shields with a denticulate posterior margin; the latter two species live in shallow water and they differ from each other and from the new species by a combination of shield and papillae features. The fourth species, S. williamsae sp. n., was found off Oregon in 1000-2400 m, and off California in 878-1246 m; it resembles S. annenkovae because both species have shields with fans narrower than the anterior margin width, but differ in the relative development of shield features and in the relative size of prostomium and mouth; as stated above it also resembles S. maureri sp. n. but its shield has poorly-developed ribs, its median notch is distinct, and the lateral notches are poorly developed or indistinct. Keys to identify all species of Caulleryaspis and Sternaspis are also included.

Six new deep-water sternaspid species (Annelida, Sternaspidae) from the Pacific Ocean

PubMed Central

Salazar-Vallejo, Sergio I.; Buzhinskaja, Galina

2013-01-01

Abstract Most sternaspid species have been described from shallow water, and Caulleryaspis Sendall & Salazar-Vallejo, 2013 includes one deep water species: C. gudmundssoni Sendall & Salazar-Vallejo, 2013 from Iceland. In Sternaspis Otto, 1821, the most speciose genus, most species were described from shallow water and only three thrive in deep water: S. maior Chamberlin, 1919 from the Gulf of California, S. princeps Selenka, 1885 from New Zealand, and S. riestchi Caullery, 1944 from Indonesia. The study of some deep sea sternaspids from the Pacific Ocean in the collections of six research institutions resulted in the discovery of six undescribed species, and for three of them there were abundant materials showing ventro-caudal shield development. Caulleryaspis fauchaldi sp. n. is described based on specimens from Oregon and California; it differs from the known species because it has a shield with rounded anterior margins and its peg chaetae form thin, small spines. Caulleryaspis nuda sp. n. was collected off Oregon; it is unique because its shield lacks a layer of sediment particles firmly attached, but has instead a thin layer of small particles loosely attached. Four other species are newly described in Sternaspis: S. annenkovae sp. n. was collected east off the northern Kurile Islands in about 4,000 m depth; it differs from other species by having a bicolored body, with the introvert darker than the abdomen, and its ventro-caudal shield plates are divergent resulting in a divided fan. The second species, S. maureri sp. n. was found off Peru in 1296–6489 m water depths and in the Southwestern Pacific in 795–3830 m; it resembles S. williamsae sp. n. but differs because its shield has better-developed ribs, the fan has a shallow or indistinct median notch and has lateral notches well-developed. The third species, S. uschakovi sp. n., was found in the Okhotsk Sea in 592–1366 m, off California in 1585 m, Gulf of California in 1200–1274 m, and Western Mexico in 2548 m; it resembles S. africana Augener, 1918 and S. andamanensis Sendall & Salazar-Vallejo, 2013 in having shields with a denticulate posterior margin; the latter two species live in shallow water and they differ from each other and from the new species by a combination of shield and papillae features. The fourth species, S. williamsae sp. n., was found off Oregon in 1000–2400 m, and off California in 878–1246 m; it resembles S. annenkovae because both species have shields with fans narrower than the anterior margin width, but differ in the relative development of shield features and in the relative size of prostomium and mouth; as stated above it also resembles S. maureri sp. n. but its shield has poorly-developed ribs, its median notch is distinct, and the lateral notches are poorly developed or indistinct. Keys to identify all species of Caulleryaspis and Sternaspis are also included. PMID:24294071

Taxonomy of reproductive Nereididae (Annelida) in multispecies swarms at Ambon Island, Indonesia

PubMed Central

Pamungkas, Joko; Glasby, Christopher J.

2015-01-01

Abstract Multispecies, or mass, spawning of different invertebrate species is well known for coral reef systems; however, incidences involving polychaetes are poorly documented. In this study we report on mass swarming, prior to spawning, of Nereididae at Ambon Island, Maluku, on three occasions: in 1866, inferred from an historical sample deposited in Naturalis, Leiden, and in March, 2009 and 2014, based on newly collected samples. The 2009 and 2014 events co-occurred with spawning of other polychaetes, known locally as wawo and including the widespread Indo-Pacific eunicid, Palola viridis (Gray in Stair). Ten species of reproductive Nereididae are described, including Composetia marmorata (Horst) new combination, formerly Ceratonereis marmorata; epitokous modifications are described for both sexes of each species including taxonomically important features such as body colour and number of pre-natatory chaetigers. Three distinct types of natatory region morphologies are recognized, which appear to characterise groups of genera. The ten new records brings to 13 the total number of nereidid species known to undergo mass swarming at Ambon Island; a key to the 13 species is provided. Species composition varies slightly between the three time periods: four species were common between all three periods, five species were in common between 1866 and 2014, and four species were in common between 1995 and 2009/14. Two species of Neanthes and one of Nereis are identified as potentially new and will be described in subsequent papers. PMID:26448711

First records of Enchytraeidae (Annelida, Clitellata) from the Three Parallel Rivers region.

PubMed

Chen, Jing; Jiang, Wanxiang; Xie, Zhicai

2016-03-21

The Three Parallel Rivers region is not only an important World Natural Heritage area but also one of the hotspots of world biodiversity with many endemic organisms. However, little is known about the soil fauna of this region, and nothing about enchytraeids. Here we describe two species from the Laojun Mountain, one of the eight eminent mountain chains in this region, Chamaedrilus cf. ozensis Torii, 2015 and Mesenchytraeus laojunensis sp. nov. The latter belongs to a group of Mesenchytraeus species characterized by spermathecae with one ampullar diverticulum and a communication with the oesophagus, and is thus far the southernmost member of this genus in China. It has two exceptional traits within Mesenchytraeus: a large sperm funnel (more than 2000 µm in length) and a subterminal attachment of the vas deferens to the atrium. In addition, it is distinguished from the other congeners within this group by coelomocytes with distinct refractile vesicles, five pairs of preclitellar nephridia, and the presence of abundant and flame-shaped sperm bundles in sperm sacs, which extend backwards into XVII-XXII.

[Genetic aspects of species structure of the compost worm Eisenia foetida (Sav.) (Oligochaeta, Lumbricidae)].

PubMed

Bolotetskiĭ, N M; Kodolova, O P

2002-01-01

Distribution of frequencies alleles of polymorphous loci of peroxidase (Pox), leucineaminopeptidase (Lap), phosphoglucomutase (Pgm) and octanoldehydrogenase (Odh) were studied by electrophoresis in polyacrylamide gel in 22 local samples of Esenia foetida in Russia (European part), Ukraine, Kazakhstan and Kirghizia. The samples form two spatial groups--"northern" and "southern", distinguished by set of alleles in every studied locus. The "northern" groups is formed by local populations of European Russia from Murmansk region on the north to Smolensk region on the south, and also by cultivated population of selection line "red California hybrid". The "southern" group is formed by local populations on the territory of Russia from middle Volga to the North Caucasus, Ukraine, Kazakhstan, Kirghizia, cultivated populations from Kirghizia and Portugal. High degree of genetic difference between samples and independence of alleles frequencies distribution from geographical location and habitat allows to consider almost all studied groups as separate populations. Statistical processing of Nei genetic distances (Nei, 1972) revealed reliable differences between averages of within- and intergroup distances. Besides, discrete differences between intervals of significance of genetic distances were revealed. The results indicate that on the studied territory E. foetida has hierarchical two level structure. The first level is formed by local populations differed by frequency of the same alleles. The second level is formed by local populations, united into spatial groups, that are qualitatively distinguished by the set of alleles in the same loci.

A new species of Malmiana (Oligochaeta: Hirudinida: Piscicolidae) from tidepool fishes in northern California.

PubMed

Burreson, Eugene M; Kalman, Julianne E

2006-02-01

Malmiana buthi n. sp. is described from the body and fins of the fluffy sculpin, Oligocottus snyderi, the tidepool sculpin, Oligocottus maculosus, and the woolly sculpin, Clinocottus analis, collected from tidepools at Horseshoe Cove on the Bodega Marine Reserve in Sonoma County, California. Prevalence of the leech was 32.6% on live-caught O. snyderi; mean intensity on O. snyderi was 3.3 leeches per fish, with a range from 1 to 7. The leech is not known to exceed 8 mm total length. The body is smooth, lacking papillae, tubercles, or pulsatile vesicles. Two pairs of crescentiform eyes are present on the oral sucker, and 1 pair of punctiform eyes occurs on the second annulus of the trachelosome. The caudal sucker has 14 small punctiform ocelli spaced evenly around the margin. The last 9 segments of the urosome have pairs of large punctiform ocelli both dorsally and ventrally. Body and caudal sucker pigmentation is uniformly reddish brown dorsally and ventrally with segental, lateral, unpigmented areas on both the urosome and trachelosome; pigmentation on the oral sucker is in the form of a cross. There are 5 pairs of testisacs; accessory gland cells on the atrial cornua and vector tissue are absent.

Automated analysis of two-dimensional positions and body lengths of earthworms (Oligochaeta); MimizuTrack.

PubMed

Kodama, Naomi; Kimura, Toshifumi; Yonemura, Seiichiro; Kaneda, Satoshi; Ohashi, Mizue; Ikeno, Hidetoshi

2014-01-01

Earthworms are important soil macrofauna inhabiting almost all ecosystems. Their biomass is large and their burrowing and ingestion of soils alters soil physicochemical properties. Because of their large biomass, earthworms are regarded as an indicator of "soil heath". However, primarily because the difficulties in quantifying their behavior, the extent of their impact on soil material flow dynamics and soil health is poorly understood. Image data, with the aid of image processing tools, are a powerful tool in quantifying the movements of objects. Image data sets are often very large and time-consuming to analyze, especially when continuously recorded and manually processed. We aimed to develop a system to quantify earthworm movement from video recordings. Our newly developed program successfully tracked the two-dimensional positions of three separate parts of the earthworm and simultaneously output the change in its body length. From the output data, we calculated the velocity of the earthworm's movement. Our program processed the image data three times faster than the manual tracking system. To date, there are no existing systems to quantify earthworm activity from continuously recorded image data. The system developed in this study will reduce input time by a factor of three compared with manual data entry and will reduce errors involved in quantifying large data sets. Furthermore, it will provide more reliable measured values, although the program is still a prototype that needs further testing and improvement. Combined with other techniques, such as measuring metabolic gas emissions from earthworm bodies, this program could provide continuous observations of earthworm behavior in response to environmental variables under laboratory conditions. In the future, this standardized method will be applied to other animals, and the quantified earthworm movement will be incorporated into models of soil material flow dynamics or behavior in response to chemical substances present in the soil.

New species of Andiorrhinus Cognetti, 1908 (Oligochaeta: Rhinodrilidae) from Venezuela and Brazil.

PubMed

Feijoo, Alexander M; Brown, George G; James, Samuel W

2017-12-08

Findings pertinent to 11 earthworm species from Venezuela and Brazil are reported. Six of these species are described as new to science, one is re-described and relocated in the genus Andiorrhinus, and new sites of occurrence are reported for four other species. Eight species of oligochaetes were found in the Andes in the state of Mérida, Venezuela: Andiorrhinus (Turedrilus) duranti sp. nov., Andiorrhinus (Meridrilus) timotocuica sp. nov., Andiorrhinus (Meridrilus) torondoy sp. nov., Andiorrhinus (Meridrilus) sp. 1, Andiorrhinus (Quibario) tatuy sp. nov., Andiorrhinus (Meridrilus) kuika (Righi, 1993), Andiorrhinus (Meridrilus) mukuci (Righi, 1993), and Andiorrhinus (Meridrilus) rimeda (Righi & Araujo, 2000). Andiorrhinus (Meridrilus) sp. 1, represented by one specimen only, is possibly a new species. Three other species were collected in Brazil: Andiorrhinus (Amazonidrilus) karinae sp. nov. in the Cerrado bioregion of Mato Grosso state; Andiorrhinus (Amazonidrilus) rodriguezi sp. nov. in the Amazon region in compost, and Andiorrhinus (Amazonidrilus) duseni (Michaelsen, 1918) in the Atlantic Forest, in the states of São Paulo and Paraná, the last species characterized by broad geographical and land use occurrences. The new subgenus Quibario was distinguished by the presence of three pairs of hearts in segments 10, 11, and 12. Keys are also included to differentiate species of subgenera Amazonidrilus and Meridrilus. The implications of these results in the context of ecological interactions, and dispersion of Andiorrhinus species in South America are discussed.

First report of Amynthas carnosus (Goto & Hatai, 1899) (Oligochaeta: Megascolecidae) in the Western Hemisphere.

PubMed

Carrera-Martínez, Roberto; Snyder, Bruce A

2016-05-16

The earthworm fauna of North America is still greatly unknown, with undescribed native species and new records of invasive species continually being discovered. The most recent checklists are difficult to reconcile, since they vary in their geographic coverage and taxonomy. Reynolds & Wetzel (2012) state that North America (including all of Mexico, some of the Caribbean, and Hawaii) is home for 256 species of earthworms, from which 188 are considered native or endemic and 68 are peregrine, exotic, and invasive species. Blakemore (2008) listed North America north of Mexico as having 183 earthworm species, of which 59 species are exotic. One Megascolecidae genus, Amynthas, is mostly located in the warmer subtropical and tropical regions of the world, with a few species that are able to survive the winter in the temperate zones of North America (Edwards & Bohlen 1995; Görres et al. 2014). Here we report for the first time the occurrence of Amynthas carnosus (Goto & Hatai, 1899) in the United States. To our knowledge, this is not only the first report of A. carnosus in North America, but also its first report in the Western Hemisphere. The description below is intended to place our specimens in the correct taxon while avoiding future confusion with similar species, without making changes to the existing classification system.

OCCURRENCE OF TWO LEECH SPECIES (ANNELIDA: HIRUDINEA) ON FISHES IN THE KENTUCKY RIVER

EPA Science Inventory

Little is known specifically on the feeding relationships between parasitic leeches and fish in North America. During an electrofishing survey conducted on the main stem of the Kentucky River in the summer of 2000, the presence of leeches was documented on six species of fish. ...

Ultrastructure developments during spermiogenesis in Polydora ciliata (Annelida: Spionidae), a parasite of mollusca

NASA Astrophysics Data System (ADS)

Gao, Yan; Zhang, Tao; Zhang, Libin; Qiu, Tianlong; Xue, Dongxiu; Yang, Hongsheng

2014-12-01

Spionid worms of Polydora ciliata inhabit the shells of many commercially important bivalves and cause disease in molluscan aquaculture. Their sperm structure is closely related to their fertilization method. To give an insight into the sperm structure and spermatogenesis, ultrastructure details of the subcellular components of germ cells during spermiogenesis of Polydora ciliata are detected by transmission electron microscopy (TEM). In P. ciliata, during spermiogenesis, chromatin is regularly arranged as dense fibrils and becomes more condensed when the nucleus elongates. Microtubules do not surround the nucleus during its elongation. The Golgi phase is characterized by the formation of proacrosomal granules within the Golgi apparatus. The proacrosomal granules fuse to form a single, spherical acrosomal vesicle that migrates to the anterior pole of the cell. At the time of nuclear condensation, mitochondria become reduced in number but increased in size, causing deep indentation at the base of the nucleus. The mid-piece has a few mitochondria. The cap phase includes the spreading of the acrosomal granule over the surface of the nucleus of the differentiating spermatid. The acrosomal phase of spermiogenesis is typically associated with changes in the shape of the nucleus, acrosome and tail. The relationship of sperm ultrastructure to spermiogenesis in spionidae species was discussed.

Hydroides Gunnerus, 1768 (Annelida, Serpulidae) is feminine: a nomenclatural checklist of updated names

PubMed Central

Read, Geoffrey B.; ten Hove, Harry A.; Sun, Yanan; Kupriyanova, Elena K.

2017-01-01

Abstract As a service to taxonomists and ecologists using names in the well-known and species-rich ship-fouling serpulid genus Hydroides we present an update of all 107 non-synonymised scientific names, with additional information on Hydroides nomenclature, original names, etymologies, and type localities derived from original literature, and in accord with the World Register of Marine Species (WoRMS) database. An update is needed because the gender of genus Hydroides has from 1 January 2000 reverted to the original feminine, due to a change in the wording of International Code of Zoological Nomenclature which was overlooked at that time, and is contrary to the usage in practice of Hydroides as masculine which had started about 1992, although Code-required from the 1960s. We match 31 further original names of current WoRMS subjective junior synonyms to each non-synonymised name, and also report on the world distribution of the genus as illustrated by type localities of the valid names. We include notes on seven species inquirenda. The correct rendering is given of six names that have been altered for gender agreement for the first time herein. Hydroides gottfriedi nom. n. replaces junior homonym Hydroides rostrata Pillai, 1971. Currently there are 41 non-synonymised species-group names in Hydroides which should be gender invariant, and 23 names which would only change if moved to a neuter genus; the remaining 43 names are fully gender variable. Place-names (23), and personal names (16) make up more than a third (36%) of the species names, with most of the remainder (68) being descriptive of species character states, usually of operculum morphology (54). All species, except Hydroides norvegica (63°N), have type localities in shallow-water coastal locations in temperate to tropical waters below latitude 44°, with the highest number of new species (54) from the adjoining Western Pacific and Indian Ocean areas. The other concentration of new species (31) are those first found on the Pacific and Atlantic coasts of North America and in the Caribbean. PMID:28138297

A new species of Laonice (Spionidae, Polychaeta, Annelida) from Bellingshausen Sea (West Antarctica)

NASA Astrophysics Data System (ADS)

López, Eduardo

2011-06-01

During the Antarctic summers of 2002-2003 and of 2005-2006, the Spanish BENTART cruises were conducted to the Bellingshausen Sea (Western Antarctica), aiming to study its benthic communities, from depths ranging from 100 to 2,000 m. To achieve it, 30 stations were selected; each one was surveyed in such a way that the infaunal, epifaunal and suprabenthic components of the communities were sufficiently characterized. As a part of the study, some spionid individuals were identified as belonging to a new species of the genus Laonice Malmgren, 1867. The new species belongs to a group within the genus that is characterized by the presence of more than two rows of very numerous capillary chaetae in both noto- and neuropodial fascicles of anterior part of the body. However, it can be readily distinguished from the rest of species within the group by the posterior position in which neuropodial pouches appear (chaetiger 16 or 17) and by the caruncle reaching posteriorly chaetiger 19. In addition, other remarkable features of the new species are the short and triangular occipital tentacle, the rudimentary eyes, the hooded neuropodial hooks first appearing in chaetigers 34-37 and the sabre neurochaetae first occurring in chaetigers 20-27.

Occurrence of three leech species (Annelida: Hirudinida) on fishes in the Kentucky River

EPA Science Inventory

Leeches were collected from six fish species distributed among four of ten sites sampled. The leech species observed were Myzobdella reducta (Meyer, 1940) and Myzobdella lugubris Leidy, 1851 of the family Piscicolidae and Placobdella pediculata Hemingway, 1908 of the family Gloss...

Polychaeta (Annelida) associated with Thalassia testudinum in the northeastern coastal waters of Venezuela.

PubMed

Liñero Arana, Ildefonso; Díaz Díaz, Oscar

2006-09-01

Seasonal variations of polychaetes in a Thalassia testudinum bed were studied from June 2000 to April 2001 in Chacopata, northeastern Venezuela. Eight replicate samples were taken monthly with a 15 cm diameter core and the sediment was passed through a 0.5 mm mesh sieve. A total of 1,013 specimens, belonging to 35 species, was collected. The monthly density ranged from 387 ind/m2 (September) to 1,735 ind/m2 in May (x = 989+/-449 ind/m2). Species richness was lowest in August and September (8) and highest (25) in April (x = 18.00+/-5.29). The shoot density of Thalassia showed an average of 284+/-77.60 shoots/m2, with extreme values in February (164) and May (422). Species diversity ranged from 1.25 in August and 3.33 bits/ind in December (x = 2.47+/-0.64). Significant positive correlations were detected among the number of Thalassia shoots, polychaete abundance and species richness, as well as among species richness, polychaete abundance and species diversity. Species number and average density were found within the intervals of mean values reported in similar studies. The higher number of species and organisms obtained in March-April and June-July can be attributed to the recruitment correlated with the regional up-welling.

New species of Ampharetidae (Annelida: Polychaeta) from the Arctic Loki Castle vent field

NASA Astrophysics Data System (ADS)

Kongsrud, Jon A.; Eilertsen, Mari H.; Alvestad, Tom; Kongshavn, Katrine; Rapp, Hans Tore

2017-03-01

Ampharetid polychaetes adapted to live in chemosynthetic environments are well known from the deep Pacific and Atlantic Oceans, but to date no such species have been reported from the Arctic Ocean. Here, we describe two new species, Paramytha schanderi gen. et sp. nov. and Pavelius smileyi sp. nov., from the Arctic Loki's Castle vent field on the Knipovich Ridge north-east of the island of Jan Mayen. The new species are both tube-builders, and are found in a sedimentary area at the NE flank of the vent field, characterized by low-temperature venting and barite chimneys. The new genus, Paramytha, is characterized by a prostomium without lobes or glandular ridges, smooth buccal tentacles, four pairs of cirriform branchiae arranged as 2+1+1 without median gap dorsally on segments II-IV, absence of chaetae (paleae) on segment II, and absence of modified segments. P. smileyi sp. nov. is placed in the previously monotypic genus Pavelius, primarily based on the presence of a rounded prostomium without lobes and four pairs of branchiae arranged in a single transverse row without median gap dorsally on segment III. Pavelius smileyi sp. nov. differs from the type species, Pavelius uschakovi, in the number of thoracic and abdominal chaetigers, and the absence of chaetae (paleae) on segment II. The phylogenetic position of the two new species from Loki's Castle is further explored by use of molecular data. New sequences of mitochondrial (16S rDNA and cytochrome c oxidase subunit 1, COI) and nuclear (18S rDNA) markers have been produced for both species from Loki's Castle, as well as for specimens identified as Paramytha sp. from Setùbal Canyon off Portugal, and for the following species: Pavelius uschakovi, Grassleia cf. hydrothermalis, Sosane wireni, Amphicteis ninonae and Samythella neglecta. Results from phylogenetic analysis, including 22 species and 12 genera of Ampharetidae, recovered Paramytha gen. nov. as monophyletic with maximum support, and a close relationship between the genera Pavelius and Grassleia which together form a well supported monophyletic clade.

Behavioral effects of carbon monoxide on selected forest litter invertebrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kenyon, P.E.; Edgar, A.L.

1971-01-01

Man and higher vertebrates have been shown to be sensitive to CO in concentrations as low as 100 ppm. Various species of forest litter invertebrates were selected to investigate whether similar concentrations have deleterious effects on these animals. The animals were placed in various CO concentrations for a period of 7 weeks. Results indicated that all of the animals studied were found to spend long periods of time without moving. The animals studied were Oligochaeta, Gastropoda, Isopoda, Diplopoda, and Phalangida. Diplopod reactivity tests were performed and results for three individuals in air and three in 20% CO showed neither consistencymore » nor trend in reaction time. Eggs carried in brood pouches of several isopods hatched during the test period and the young emerged from the pouch. No difference in health and growth rate was observed between the control and any of the CO concentrations. Molting occurred frequently and normally in all chambers. Numerous activities were observed in the animals and no variation of behavior was detected which could be attributed to the presence of CO.« less

Decay of low-density polyethylene by bacteria extracted from earthworm's guts: A potential for soil restoration.

PubMed

Huerta Lwanga, Esperanza; Thapa, Binita; Yang, Xiaomei; Gertsen, Henny; Salánki, Tamás; Geissen, Violette; Garbeva, Paolina

2018-05-15

Low-density polyethylene (LDPE) is the most abundant source of microplastic pollution worldwide. A recent study found that LDPE decay was increased and the size of the plastic was decreased after passing through the gut of the earthworm Lumbricus terrestris (Oligochaeta). Here, we investigated the involvement of earthworm gut bacteria in the microplastic decay. The bacteria isolated from the earthworm's gut were Gram-positive, belonging to phylum Actinobacteria and Firmicutes. These bacteria were used in a short-term microcosm experiment performed with gamma-sterilized soil with or without LDPE microplastics (MP). We observed that the LDPE-MP particle size was significantly reduced in the presence of bacteria. In addition, the volatile profiles of the treatments were compared and clear differences were detected. Several volatile compounds such as octadecane, eicosane, docosane and tricosane were measured only in the treatments containing both bacteria and LDPE-MP, indicating that these long-chain alkanes are byproducts of bacterial LDPE-MP decay. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Role and convergent evolution of competing RNA secondary structures in mutually exclusive splicing

PubMed Central

Yue, Yuan; Hou, Shouqing; Wang, Xiu; Zhan, Leilei; Cao, Guozheng; Li, Guoli; Shi, Yang; Zhang, Peng; Hong, Weiling; Lin, Hao; Liu, Baoping; Shi, Feng; Yang, Yun; Jin, Yongfeng

2017-01-01

ABSTRACT Exon or cassette duplication is an important means of expanding protein and functional diversity through mutually exclusive splicing. However, the mechanistic basis of this process in non-arthropod species remains poorly understood. Here, we demonstrate that MRP1 genes underwent tandem exon duplication in Nematoda, Platyhelminthes, Annelida, Mollusca, Arthropoda, Echinodermata, and early-diverging Chordata but not in late-diverging vertebrates. Interestingly, these events were of independent origin in different phyla, suggesting convergent evolution of alternative splicing. Furthermore, we showed that multiple sets of clade-conserved RNA pairings evolved to guide species-specific mutually exclusive splicing in Arthropoda. Importantly, we also identified a similar structural code in MRP exon clusters of the annelid, Capitella teleta, and chordate, Branchiostoma belcheri, suggesting an evolutionarily conserved competing pairing-guided mechanism in bilaterians. Taken together, these data reveal the molecular determinants and RNA pairing-guided evolution of species-specific mutually exclusive splicing spanning more than 600 million years of bilaterian evolution. These findings have a significant impact on our understanding of the evolution of and mechanism underpinning isoform diversity and complex gene structure. PMID:28277933

Role and convergent evolution of competing RNA secondary structures in mutually exclusive splicing.

PubMed

Yue, Yuan; Hou, Shouqing; Wang, Xiu; Zhan, Leilei; Cao, Guozheng; Li, Guoli; Shi, Yang; Zhang, Peng; Hong, Weiling; Lin, Hao; Liu, Baoping; Shi, Feng; Yang, Yun; Jin, Yongfeng

2017-10-03

Exon or cassette duplication is an important means of expanding protein and functional diversity through mutually exclusive splicing. However, the mechanistic basis of this process in non-arthropod species remains poorly understood. Here, we demonstrate that MRP1 genes underwent tandem exon duplication in Nematoda, Platyhelminthes, Annelida, Mollusca, Arthropoda, Echinodermata, and early-diverging Chordata but not in late-diverging vertebrates. Interestingly, these events were of independent origin in different phyla, suggesting convergent evolution of alternative splicing. Furthermore, we showed that multiple sets of clade-conserved RNA pairings evolved to guide species-specific mutually exclusive splicing in Arthropoda. Importantly, we also identified a similar structural code in MRP exon clusters of the annelid, Capitella teleta, and chordate, Branchiostoma belcheri, suggesting an evolutionarily conserved competing pairing-guided mechanism in bilaterians. Taken together, these data reveal the molecular determinants and RNA pairing-guided evolution of species-specific mutually exclusive splicing spanning more than 600 million years of bilaterian evolution. These findings have a significant impact on our understanding of the evolution of and mechanism underpinning isoform diversity and complex gene structure.

Hyporheic invertebrate assemblages at reach scale in a Neotropical stream in Brazil.

PubMed

Mugnai, R; Messana, G; Di Lorenzo, T

2015-11-01

In the Neotropical Region, information concerning hyporheic communities is virtually non-existent. We carried out a sampling survey in the hyporheic zone of the Tijuca River, in the Tijuca National Park, located in the urban area of the city of Rio de Janeiro. Biological samples from the hyporheic zone were collected in three different stream reaches, in June 2012. The main objectives were: 1) to describe the structure of invertebrate assemblages in the hyporheic zone of a neotropical stream; 2) to apply a reach-scale approach in order to investigate spatial patterns of the hyporheic assemblages in relation to hydrology, depth and microhabitat typology. A total of 1460 individuals were collected and identified in 31 taxa belonging to Nematoda, Annelida, Crustacea, Hydrachnidia and Insecta. The class Insecta dominated the upper layer of the hyporheic zone. Copepods were the most abundant taxon among crustaceans and occurred mostly in the upwelling areas of the reaches. The results of this study represent one of the few contributions so far about hyporheic invertebrate assemblages of the Neotropical Region.

Fouling assemblage of benthic plastic debris collected from Mersin Bay, NE Levantine coast of Turkey.

PubMed

Gündoğdu, Sedat; Çevik, Cem; Karaca, Serkan

2017-11-15

The Mediterranean is an ecosystem that faces more and more microplastic pollution every day. This causes the whole of the Mediterranean to face the negative effects of plastic pollution. This study examines the state of plastic debris and fouling organisms found on it in one of the areas most affected by plastic pollution, Mersin Bay. As a result, a total of 3.88kg plastic (mean=0,97kg; n=120; 2670item/km 2 ; 86,3kg/km 2 ) was collected and based on the ATR-FTIR analysis, it was determined that this total contained 9 types of plastics. 17 different fouling species belonging to 6 phylum (Annelida, Arthropoda, Bryozoa, Chordata, Cnidaria, Mollusca) 7 class and 11 order were discovered on plastics. Spirobranchus triqueter, Hydroides sp. and Neopycnodonte cochlear were the most abundant species. In the end, the example of Mersin Bay shows that plastic debris as a substrate can contain a very high diversity of life just like natural substrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

High expression of new genes in trochophore enlightening the ontogeny and evolution of trochozoans.

PubMed

Xu, Fei; Domazet-Lošo, Tomislav; Fan, Dingding; Dunwell, Thomas L; Li, Li; Fang, Xiaodong; Zhang, Guofan

2016-10-04

Animals with trochophore larvae belong to Trochozoa, one of the main branches of Bilateria. In addition to exhibiting spiral cleavage and early cell fate determination, trochozoans typically undergo indirect development, which contributes to the most unique characteristics of their ontogeny. The indirect development of trochozoans has provoked discussion regarding the origin and evolution of marine larvae and is interesting from the perspective of phylogeny-ontogeny correspondence. While these phylo-onto correlations have an hourglass shape in Deuterostomia, Ecdysozoa, plants and even fungi, they have seldom been studied in Trochozoa, and even Lophotrochozoa. Here, we compared the ontogenetic transcriptomes of the Pacific oyster, Crassostrea gigas (Bivalvia, Mollusca), the Pacific abalone, Haliotis discus hannai (Gastropoda, Mollusca), and the sand worm Perinereis aibuhitensis (Polychaeta, Annelida) using several complementary phylotranscriptomic methods to examine their evolutionary trajectories. The results revealed the late trochophore stage as the phylotypic phase. However, this basic pattern is accompanied with increased use of new genes in the trochophore stages which marks specific adaptations of the larval body plans.

Cellular and Muscular Growth Patterns During Sipunculan Development

PubMed Central

KRISTOF, ALEN; WOLLESEN, TIM; MAIOROVA, ANASTASSYA S.; WANNINGER, ANDREAS

2015-01-01

Sipuncula is a lophotrochozoan taxon with annelid affinities, albeit lacking segmentation of the adult body. Here, we present data on cell proliferation and myogenesis during development of three sipunculan species, Phascolosoma agassizii, Thysanocardia nigra, and Themiste pyroides. The first anlagen of the circular body wall muscles appear simultaneously and not subsequently as in the annelids. At the same time, the rudiments of four longitudinal retractor muscles appear. This supports the notion that four introvert retractors were part of the ancestral sipunculan bodyplan. The longitudinal muscle fibers form a pattern of densely arranged fibers around the retractor muscles, indicating that the latter evolved from modified longitudinal body wall muscles. For a short time interval, the distribution of S-phase mitotic cells shows a metameric pattern in the developing ventral nerve cord during the pelagosphera stage. This pattern disappears close to metamorphic competence. Our findings are congruent with data on sipunculan neurogenesis, as well as with recent molecular analyses that place Sipuncula within Annelida, and thus strongly support a segmental ancestry of Sipuncula. PMID:21246707

Cellular and muscular growth patterns during sipunculan development.

PubMed

Kristof, Alen; Wollesen, Tim; Maiorova, Anastassya S; Wanninger, Andreas

2011-05-15

Sipuncula is a lophotrochozoan taxon with annelid affinities, albeit lacking segmentation of the adult body. Here, we present data on cell proliferation and myogenesis during development of three sipunculan species, Phascolosoma agassizii, Thysanocardia nigra, and Themiste pyroides. The first anlagen of the circular body wall muscles appear simultaneously and not subsequently as in the annelids. At the same time, the rudiments of four longitudinal retractor muscles appear. This supports the notion that four introvert retractors were part of the ancestral sipunculan bodyplan. The longitudinal muscle fibers form a pattern of densely arranged fibers around the retractor muscles, indicating that the latter evolved from modified longitudinal body wall muscles. For a short time interval, the distribution of S-phase mitotic cells shows a metameric pattern in the developing ventral nerve cord during the pelagosphera stage. This pattern disappears close to metamorphic competence. Our findings are congruent with data on sipunculan neurogenesis, as well as with recent molecular analyses that place Sipuncula within Annelida, and thus strongly support a segmental ancestry of Sipuncula. Copyright © 2011 Wiley-Liss, Inc., A Wiley Company.

Suitability of cholinesterase of polychaete Diopatra neapolitana as biomarker of exposure to pesticides: In vitro characterization.

PubMed

Mennillo, Elvira; Casu, Valentina; Tardelli, Federica; De Marchi, Lucia; Freitas, Rosa; Pretti, Carlo

2017-01-01

Cholinesterases of Diopatra neapolitana were characterized for their activity in whole body and different body segments (apical, intermediate, posterior), substrate affinity (acetyl-, butyryl-, propionylthiocholine), kinetic parameters (K m and V max ) and in vitro response to model inhibitors (eserine hemisulfate, isoOMPA, BW284C51) and carbamates (carbofuran, methomyl, aldicarb and carbaryl). Results showed that the rate of hydrolysis for acetyl- and propionylthiocholine was higher in the posterior segment than the apical/intermediate segments and whole body. Cholinesterases of D. neapolitana showed a substrate preference for acetylthiocholine followed by propionylthiocholine; butyrylthioline was poorly hydrolyzed indicating, together with the absence of inhibition by the specific inhibitor and the absence of reactive bands in native electrophoresis, a lack of an active butyrylcholinesterase, differently than that observed in other Annelida species. The degree of inhibition by selected carbamates of cholinesterase activity with propionylthiocholine as substrate was higher than that observed with ATChI-ChE activity; aldicarb showed the highest inhibitory effect. Copyright © 2016 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hancock, R.L.

Irradiation effects in the phylum Annelida are almost entirely unknown, nor is it know why the LD/sub 50/30// for amoebae is 100 kr, whereas mammals show LD/sub 50/ doses of approximates 0.5 kr. To shed more light on comparative radiosensitivity, Lumbricus terrestris was irradiated at a rate of 1 kr/min with 250-kr x rays to total doses of 10 to l00 kr. No lethal effect occurs at 45 kr or below in Lumbricus, whereas a definite mortality occurs with 75 kr. All worms died within 2 months after 100 kr. The LD/sub 50/35//and LD/sub 100/67// are approximates 100 kr. Thismore » is in contrast to the mollusk Radix which has a for lethal effects. The annelid Enchytraeus shows no apparent effect after 90 kr. It is suggested that some feature of biological organization, which has up to the present escaped discovery, may hold a clue to the fundamental nature of radiobiological action, and may explain the extremes of radiosensitivity present within a few selected invertebrate types. (BBB)« less

Stem cells in asexual reproduction of Enchytraeus japonensis (Oligochaeta, Annelid): proliferation and migration of neoblasts.

PubMed

Sugio, Mutsumi; Yoshida-Noro, Chikako; Ozawa, Kaname; Tochinai, Shin

2012-05-01

Enchytraeus japonensis is a small oligochaete that reproduces mainly asexually by fragmentation (autotomy) and regeneration. As sexual reproduction can also be induced, it is a good animal model for the study of both somatic and germline stem cells. To clarify the features of stem cells in regeneration, we investigated the proliferation and lineage of stem cells in E. japonensis. Neoblasts, which have the morphological characteristics of undifferentiated cells, were found to firmly adhere to the posterior surface of septa in each trunk segment. Also, smaller neoblast-like cells, which are designated as N-cells in this study, were located dorsal to the neoblasts on the septa. By conducting 5-bromo-2'-deoxyuridine (BrdU)-labeling-experiments, we have shown that neoblasts are slow-cycling (or quiescent) in intact growing worms, but proliferate rapidly in response to fragmentation. N-cells proliferate more actively than do neoblasts in intact worms. The results of pulse-chase experiments indicated that neoblast and N-cell lineage mesodermal cells that incorporated BrdU early in regeneration migrated toward the autotomized site to form the mesodermal region of the blastema, while the epidermal and intestinal cells also contributed to the blastema locally near the autotomized site. We have also shown that neoblasts have stem cell characteristics by expressing Ej-vlg2 and by the activity of telomerase during regeneration. Telomerase activity was high in the early stage of regeneration and correlated with the proliferation activity in the neoblast lineage of mesodermal stem cells. Taken together, our results indicate that neoblasts are mesodermal stem cells involved in the regeneration of E. japonensis. © 2012 The Authors. Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

Biochar alleviates the toxicity of imidacloprid and silver nanoparticles (AgNPs) to Enchytraeus albidus (Oligochaeta).

PubMed

Nyoka, Ngitheni Winnie-Kate; Kanyile, Sthandiwe Nomthandazo; Bredenhand, Emile; Prinsloo, Godfried Jacob; Voua Otomo, Patricks

2018-04-01

The present study investigated the use of biochar for the alleviation of the toxic effects of a nanosilver colloidal dispersion and a chloronicotinyl insecticide. The survival and reproduction of the potworm Enchytraeus albidus were assessed after exposure to imidacloprid and silver nanoparticles (AgNPs). E. albidus was exposed to 0, 25, 50, 100, 200, and 400 mg imidacloprid/kg and 0, 5, 25, 125, and 625 mg Ag/kg for 21 days in 10% biochar amended and non-biochar amended OECD artificial soil. In both exposure substrates, the effects of imidacloprid on survival were significant in the two highest treatments (p < 0.01). No biochar effect was observed as survival was statistically similar in both soils after exposure to imidacloprid. In the case of AgNPs, significant mortality was only observed in the highest AgNP treatments in both the amended and non-amended soils (p < 0.05). Nevertheless, statistically greater survival occurred in the biochar-amended treatment (p < 0.05). Reproduction results showed a more pronounced biochar effect with an EC 50  = 22.27 mg imidacloprid/kg in the non-amended soil and a higher EC 50  = 46.23 mg imidacloprid/kg in the biochar-amended soil. This indicated a 2-fold decrease in imidacloprid toxicity due to biochar amendment. A similar observation was made in the case of AgNPs where a reproduction EC 50  = 166.70 mg Ag/kg soil in the non-amended soil increased to an EC 50  > 625 mg Ag/kg soil (the highest AgNP treatment) in the amended soil. This indicated at least a 3.7-fold decrease in AgNPs toxicity due to biochar amendment. Although more studies may be needed to optimize the easing effects of biochar on the toxicity of these chemicals, the present results show that biochar could be useful for the alleviation of the toxic effects of imidacloprid and silver nanoparticles in the soil.

Distribution of Asellus aquaticus and microinvertebrates in a non-chlorinated drinking water supply system--effects of pipe material and sedimentation.

PubMed

Christensen, Sarah C B; Nissen, Erling; Arvin, Erik; Albrechtsen, Hans-Jørgen

2011-05-01

Danish drinking water supplies based on ground water without chlorination were investigated for the presence of the water louse, Asellus aquaticus, microinvertebrates (<2 mm) and annelida. In total, 52 water samples were collected from fire hydrants at 31 locations, and two elevated tanks (6000 and 36,000 m(3)) as well as one clean water tank at a waterworks (700 m(3)) were inspected. Several types of invertebrates from the phyla: arthropoda, annelida (worms), plathyhelminthes (flatworms) and mollusca (snails) were found. Invertebrates were found at 94% of the sampling sites in the piped system with A. aquaticus present at 55% of the sampling sites. Populations of A. aquaticus were present in the two investigated elevated tanks but not in the clean water tank at a waterworks. Both adult and juvenile A. aquaticus (length of 2-10 mm) were found in tanks as well as in pipes. A. aquaticus was found only in samples collected from two of seven investigated distribution zones (zone 1 and 2), each supplied directly by one of the two investigated elevated tanks containing A. aquaticus. Microinvertebrates were distributed throughout all zones. The distribution pattern of A. aquaticus had not changed considerably over 20 years when compared to data from samples collected in 1988-89. Centrifugal pumps have separated the distribution zones during the whole period and may have functioned as physical barriers in the distribution systems, preventing large invertebrates such as A. aquaticus to pass alive. Another factor characterising zone 1 and 2 was the presence of cast iron pipes. The frequency of A. aquaticus was significantly higher in cast iron pipes than in plastic pipes. A. aquaticus caught from plastic pipes were mainly single living specimens or dead specimens, which may have been transported passively trough by the water flow, while cast iron pipes provided an environment suitable for relatively large populations of A. aquaticus. Sediment volume for each sample was

STUDIES ON RARE AND POORLY KNOWN LEECHES (ANNELIDA: HIRUDINEA: GLOSSIPHONIIDAE) IN EASTERN NORTH AMERICA

EPA Science Inventory

Three taxa within the leech family Glossiphoniidae, Actinobdella inequiannulata, Placobdella hollensis, and Theromyzon spp., though widespread in eastern North America, remain poorly known with respect to their biology and systematics. All three taxa have been collected in New E...

Can Diopatra neapolitana (Annelida: Onuphidae) regenerate body damage caused by bait digging or predation?

NASA Astrophysics Data System (ADS)

Pires, A.; Freitas, R.; Quintino, V.; Rodrigues, A. M.

2012-09-01

The regenerative ability of Diopatra neapolitana was evaluated under laboratory conditions following nine experimental amputation levels: before the beginning of the branchiae (chaetiger 3 or 4), in the branchial region, at chaetigers 10, 15, 20, 25, 30, 35 and 40 and after the branchiae, at chaetigers 45-55. Specimens amputated at the 20th chaetiger were not able to regenerate and did not survive. The posterior portion of the specimens amputated up to chaetiger 15, regenerated the anterior part but the anterior ends were unable to survive. The anterior end of the specimens amputated at and beyond the 25th chaetiger regenerated the posterior part but the posterior ends were not able to regenerate an anterior part. Percent survival was directly related to the number of branchial segments left in the regenerating specimen and reached 100% only when the specimens were amputated beyond the branchial region. These results indicate that the species has regenerative ability and should survive the loss of a few anterior chaetigers, namely caused by predation. However, the results also indicate that bait digging could impair the survival of the posterior part remaining in the tube, as usually more than 20 chaetigers are harvested by bait collectors. Regarding field-collected specimens, D. neapolitana was found regenerating a mean of 9.0 ± 2.51 chaetigers, and Diopatra marocensis 7.5 ± 1.93 chaetigers, at the anterior end. The higher percentage of field-collected specimens showing regeneration of the anterior end belonged to D. marocensis. Only very few specimens, for both species, were found regenerating the posterior part of the body.

Bacteria associated with sabellids (Polychaeta: Annelida) as a novel source of surface active compounds.

PubMed

Rizzo, Carmen; Michaud, Luigi; Hörmann, Barbara; Gerçe, Berna; Syldatk, Christoph; Hausmann, Rudolf; De Domenico, Emilio; Lo Giudice, Angelina

2013-05-15

A total of 69 bacteria were isolated from crude oil enrichments of the polychaetes Megalomma claparedei, Sabella spallanzanii and Branchiomma luctuosum, and screened for biosurfactant (BS) production by conventional methods. Potential BS-producers (30 isolates) were primarily selected due to the production of both interesting spots on thin layer chromatography (TLC) plates and highly stable emulsions (E₂₄ ≥ 50%). Only few strains grew on cetyltrimethylammonium bromide and blood agar plates, indicating the probable production of anionic surfactants. The 16S rRNA gene sequencing revealed that selected isolates mainly belonged to the CFB group of Bacteroidetes, followed by Gammaproteobacteria and Alphaproteobacteria. A number of BS-producers belonged to genera (i.e., Cellulophaga, Cobetia, Cohaesibacter, Idiomarina, Pseudovibrio and Thalassospira) that have been never reported as able to produce BSs, even if they have been previously detected in hydrocarbon-enriched samples. Our results suggest that filter-feeding Polychaetes could represent a novel and yet unexplored source of biosurfactant-producing bacteria. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bone-eating Osedax worms (Annelida: Siboglinidae) regulate biodiversity of deep-sea whale-fall communities

NASA Astrophysics Data System (ADS)

Alfaro-Lucas, Joan M.; Shimabukuro, Maurício; Ferreira, Giulia D.; Kitazato, Hiroshi; Fujiwara, Yoshihiro; Sumida, Paulo Y. G.

2017-12-01

Although it is well recognized the capital role of "bone-eating" Osedax worms in the degradation of vertebrate skeletons in the deep sea, very little is known about their effects on bone faunal assemblages. Here we aim to shed light on the bone colonization process and determine 1) whether Osedax degradation induces different bone epi/infaunal assemblages and 2) how biodiversity is affected by Osedax colonization. We describe and compare the epi/infaunal assemblage structures of caudal vertebrae colonized and not colonized by Osedax of an abyssal juvenile whale carcass serendipitously found at 4204 m depth in the SW Atlantic Ocean by HOV Shinkai 6500. Our results show that whale skeletons are very heterogeneous habitats that harbor specific and very rich assemblages and that contrasting epi/infaunal community patterns are found depending on the presence of Osedax. Vertebrae not colonized by Osedax were both well preserved and in a highly sulfophilic stage with chemosynthetic bacterial mats and numerous epifaunal organisms that fed on them. On the contrary, vertebrae colonized by Osedax were heavily degraded and did not exhibit evidence of a sulfophilic stage, harboring a distinct epifaunal assemblage. In general, bone infaunal assemblages were dominated by nematodes, especially in vertebrae without Osedax (ca. 77%) where organisms were only found in bone outer layers, showing a colonization pattern similar to that described for bacteria. Infauna in Osedax-colonized bones were present throughout the inner-matrices and were on average three times more abundant (ca. 1800 ind. 100 cm-3) and twice as rich in number of species (16 species). Here, bones had a relatively higher proportion of the polychaete Capitella iatapiuna (ca. 39%) in comparison with nematodes (ca. 52%). Besides, a higher number of rare species were present in bones with Osedax. We suggest that Osedax degradation increases water diffusion through matrices probably modifying reduced-compound fluxes and truncating the sulfophilic stage. Furthermore, it is likely that larger and distinct infaunal biodiversity is a result of an increase in bone structural complexity caused by Osedax, which also facilitates the colonization of inner-bone matrices. We conclude that Osedax is an important ecosystem engineer that enhances biodiversity in deep-sea whale-fall communities.

A pyritized lepidocoleid machaeridian (Annelida) from the Lower Devonian Hunsrück Slate, Germany

PubMed Central

Högström, Anette E.S.; Briggs, Derek E.G.; Bartels, Christoph

2009-01-01

A machaeridian, Lepidocoleus hohensteini sp. nov., is described from the Hunsrück Slate (Lower Emsian) of Germany. The available material includes a unique example preserving evidence of the soft tissues, only the second machaeridian specimen to do so and the first lepidocoleid. This specimen shows that the plates are attached to alternate segments in the trunk. The morphology is consistent with an annelid affinity of the Lepidocoleidae and confirms the unity of the Machaeridia. This discovery adds an important group to the known diversity of this famous late Palaeozoic marine Konservat-Lagerstätte. PMID:19324782

Conservative Mechanisms of Extracellular Trap Formation by Annelida Eisenia andrei: Serine Protease Activity Requirement

PubMed Central

Ortmann, Weronika; Kolaczkowska, Elzbieta

2016-01-01

Formation of extracellular traps (ETs) capturing and immobilizing pathogens is now a well-established defense mechanism added to the repertoire of vertebrate phagocytes. These ETs are composed of extracellular DNA (extDNA), histones and antimicrobial proteins. Formation of mouse and human ETs depends on enzymes (i) facilitating decondensation of chromatin by citrullination of histones, and (ii) serine proteases degrading histones. In invertebrates, initial reports revealed existence of ETs composed of extDNA and histones, and here we document for the first time that also coelomocytes, immunocompetent cells of an earthworm Eisenia andrei, cast ETs which successfully trap bacteria in a reactive oxygen species (ROS)-dependent and -independent manner. Importantly, the formation of ETs was observed not only when coelomocytes were studied ex vivo, but also in vivo, directly in the earthworm coelom. These ETs were composed of extDNA, heat shock proteins (HSP27) and H3 histones. Furthermore, the formation of E. andrei ETs depended on activity of serine proteases, including elastase-like activity. Moreover, ETs interconnected and hold together aggregating coelomocytes, a processes proceeding encapsulation. In conclusion, the study confirms ET formation by earthworms, and unravels mechanisms leading to ET formation and encapsulation in invertebrates. PMID:27416067

Microphthalmus mahensis sp.n. (Annelida, Phyllodocida) together with an annotated key of the genus

NASA Astrophysics Data System (ADS)

Westheide, Wilfried

2013-09-01

An interstitial polychaete, Microphthalmus mahensis, new species (Phyllodocida), is described from sand sediments of a coral reef flat of the Seychelles island Mahé. A comprehensive discussion includes a complete list of all 38 valid Microphthalmus species, and a key together with critical remarks on problematic species and subspecies.

Meiofauna as descriptor of tourism-induced changes at sandy beaches.

PubMed

Gheskiere, Tom; Vincx, Magda; Weslawski, Jan Marcin; Scapini, Felicita; Degraer, Steven

2005-08-01

Tourism has long been considered as a 'clean industry' with almost no negative effects on the environment. This study demonstrated, in two different coastal systems (Mediterranean and Baltic), that tourism related activities are particularly affecting the sandy beach meio- and nematofauna in the upper beach zone, the specific ecotone in which many meiofauna species from both the marine and the terrestrial environment congregate. Tourist upper beaches are characterized by a lower % total organic matter (%TOM), lower densities, lower diversities (absence of Insecta, Harpacticoida, Oligochaeta, terrestrial nematodes and marine Ironidae nematodes) and higher community stress compared to nearby non-tourist locations. The %TOM was found to be the single most important factor for the observed differences in meiofauna assemblage structure at tourist versus non-tourist beaches in both the Mediterranean and the Baltic region. The free-living nematode assemblages from tourist upper zones depart significantly from expectations based on random selections from the regional nematode species pool. Furthermore upper zone assemblages are characterised by a low species diversity consisting of taxonomically closely related nematode species with r-strategist features. Generally, faunal differences between tourist and non-tourist beaches are decreasing towards the lower beach zones.

Benthic macrofaunal structure and secondary production in tropical estuaries on the Eastern Marine Ecoregion of Brazil.

PubMed

Bissoli, Lorena B; Bernardino, Angelo F

2018-01-01

Tropical estuaries are highly productive and support diverse benthic assemblages within mangroves and tidal flats habitats. Determining differences and similarities of benthic assemblages within estuarine habitats and between regional ecosystems may provide scientific support for management of those ecosystems. Here we studied three tropical estuaries in the Eastern Marine Ecoregion of Brazil to assess the spatial variability of benthic assemblages from vegetated (mangroves) and unvegetated (tidal flats) habitats. A nested sampling design was used to determine spatial scales of variability in benthic macrofaunal density, biomass and secondary production. Habitat differences in benthic assemblage composition were evident, with mangrove forests being dominated by annelids (Oligochaeta and Capitellidae) whereas peracarid crustaceans were also abundant on tidal flats. Macrofaunal biomass, density and secondary production also differed between habitats and among estuaries. Those differences were related both to the composition of benthic assemblages and to random spatial variability, underscoring the importance of hierarchical sampling in estuarine ecological studies. Given variable levels of human impacts and predicted climate change effects on tropical estuarine assemblages in Eastern Brazil, our data support the use of benthic secondary production to address long-term changes and improved management of estuaries in Eastern Brazil.

Meiobenthos assemblages in the mekong estuarine system with special focus on free-living marine nematodes

NASA Astrophysics Data System (ADS)

Quang, Ngo Xuan; Vanreusel, Ann; Smol, Nic; Chau, Nguyen Ngoc

2010-12-01

Meiobenthos assemblages in eight estuaries of the Mekong river system were investigated in August 2008 (from the Cua Tieu estuary to the Tran De estuary). In each estuary, one sampling station was established for meiobenthos sampling. Twelve major taxa of meiobenthos were recorded in this estuarine system, including Nematoda, Copepoda, Turbellaria, Polychaeta, Oligochaeta, Tardigrada, Bivalvia, Ostracoda, Amphipoda, Cumacea, Gastrotricha, Gastropoda, and Crustacean Nauplii larvae. The densities of the meiobenthos range from 581 to 3168 inds/10 cm2. Nematodes always occupy the highest numbers with a percentage ranging from 64-99%. There are 135 nematode genera recorded in this study with the following as dominant genera Desmodora, Leptolaimus, Halalaimus, Thalassomonhystera, Theristus, Daptonema, Rhynchonema, Parodontophora, and Oncholaimus. Although the biodiversity of the meiobenthos at higher taxa level is not high compared to other marine environments, the estimates of nematode biodiversity at the genus level indicates high values. The increase in number of genera with increasing sampling intensity illustrate that the diversity is underestimated and would have been higher if the authors had considered a larger number of individuals, more replicates per station, and more sampling stations.

Tundra ponds of the Yukon Delta, Alaska, and their macroinvertebrate communities.

USGS Publications Warehouse

Maciolek, J.A.

1989-01-01

The Yukon Delta, a low alluvial tundra in western Alaska, has more than 105 thaw-basin ponds within its 70000 km2 area. In 1984 and 1985, 68 ponds in three interior areas of the Delta were surveyed to determine limnological features, macroinvertebrate fauna, and trophic character. Ponds ranged up to 90 ha in area, 2 m in depth, and 17 m in elevation, and occurred in various temporal stages of growth and senescence. Among the 18 major invertebrate taxa collected, in order of decreasing frequency of occurrence, Trichoptera, Hemiptera, Diptera, Pelecypoda, Isopoda, Coleoptera, Gastropoda, and Oligochaeta were found in over 50% of the ponds. Trichoptera, the only taxon occurring in all ponds, was represented by 22 species of 6 families. The average Delta pond had 6.6 of the nine more common taxa. This measure of faunal richness was similar among study areas but was higher in low-tundra (sea level) ponds and in older ponds on raised tundra. In comparison, lentic invertebrate communities in five other areas of Alaskan and Canadian tundra had fewer taxa and also lower average richness based on occurrence of the same nine taxa.

Oil spill effects on macrofaunal communities and bioturbation of pristine marine sediments (Caleta Valdés, Patagonia, Argentina): experimental evidence of low resistance capacities of benthic systems without history of pollution.

PubMed

Ferrando, Agustina; Gonzalez, Emilia; Franco, Marcos; Commendatore, Marta; Nievas, Marina; Militon, Cécile; Stora, Georges; Gilbert, Franck; Esteves, José Luis; Cuny, Philippe

2015-10-01

The Patagonian coast is characterized by the existence of pristine ecosystems which may be particularly sensitive to oil contamination. In this study, a simulated oil spill at acute and chronic input levels was carried out to assess the effects of contamination on the macrobenthic community structure and the bioturbation activity of sediments sampled in Caleta Valdés creek. Superficial sediments were either noncontaminated or contaminated by Escalante crude oil and incubated in the laboratory for 30 days. Oil contamination induced adverse effects on macrobenthic community at both concentrations with, for the highest concentration, a marked decrease of approximately 40 and 55 % of density and specific richness, respectively. Besides the disappearance of sensitive species, some other species like Oligochaeta sp. 1, Paranebalia sp., and Ostracoda sp. 2 species have a higher resistance to oil contamination. Sediment reworking activity was also affected by oil addition. At the highest level of contamination, nearly no activity was observed due to the high mortality of macroorganisms. The results strongly suggest that an oil spill in this protected marine area with no previous history of contamination would have a deep impact on the non-adapted macrobenthic community.

Taxonomic diversity and structure of benthic macroinvertebrates in Aby Lagoon (Ivory Coast, West Africa).

PubMed

Kouadio, K N; Diomandé, D; Ouattara, A; Koné, Y J M; Gourène, G

2008-09-15

The benthic macroinvertebrates of Aby lagoon (West Africa: Ivory coast) was studied during four seasons (high dry season, high rainy season, low dry season and low rainy season, respectively) from June 2006 to March 2007. The distribution of the benthic macroinvertebrates species was recorded at 13 stations on the whole of the lagoon. A total of 62 taxa of benthic macroinvertebrates belonging to 28 families and 10 orders were listed. The molluscs and crustaceans dominate qualitatively by adding up 51 and 24%, respectively of the total number of organisms. Five taxa (Corbula trigona (20%), Pachymelania aurita (12%), Clibernhardius cooki (7%), Oligochaeta (7%) and Crassostrea gasar (6%) accounted for 52% of total abundance. Classification analysis used to perform the characterisation of the lagoon on the basis of benthic macroinvertebrates showed the existence of four main clusters in which the seasonal pattern in benthic macroinvertebrates were very similar in the four seasons. In contrast the species richness and diversity indices were significantly different. Furthermore these indices where higher in the stations closer to the sea and surrounded by mangrove trees (southern area) compared to the inland ones.

Photoautotrophic microorganisms as a carbon source for temperate soil invertebrates.

PubMed

Schmidt, Olaf; Dyckmans, Jens; Schrader, Stefan

2016-01-01

We tested experimentally if photoautotrophic microorganisms are a carbon source for invertebrates in temperate soils. We exposed forest or arable soils to a (13)CO2-enriched atmosphere and quantified (13)C assimilation by three common animal groups: earthworms (Oligochaeta), springtails (Hexapoda) and slugs (Gastropoda). Endogeic earthworms (Allolobophora chlorotica) and hemiedaphic springtails (Ceratophysella denticulata) were highly (13)C enriched when incubated under light, deriving up to 3.0 and 17.0%, respectively, of their body carbon from the microbial source in 7 days. Earthworms assimilated more (13)C in undisturbed soil than when the microbial material was mixed into the soil, presumably reflecting selective surface grazing. By contrast, neither adult nor newly hatched terrestrial slugs (Deroceras reticulatum) grazed on algal mats. Non-photosynthetic (13)CO2 fixation in the dark was negligible. We conclude from these preliminary laboratory experiments that, in addition to litter and root-derived carbon from vascular plants, photoautotrophic soil surface microorganisms (cyanobacteria, algae) may be an ecologically important carbon input route for temperate soil animals that are traditionally assigned to the decomposer channel in soil food web models and carbon cycling studies. © 2016 The Author(s).

Benthic macrofaunal structure and secondary production in tropical estuaries on the Eastern Marine Ecoregion of Brazil

PubMed Central

Bissoli, Lorena B.

2018-01-01

Tropical estuaries are highly productive and support diverse benthic assemblages within mangroves and tidal flats habitats. Determining differences and similarities of benthic assemblages within estuarine habitats and between regional ecosystems may provide scientific support for management of those ecosystems. Here we studied three tropical estuaries in the Eastern Marine Ecoregion of Brazil to assess the spatial variability of benthic assemblages from vegetated (mangroves) and unvegetated (tidal flats) habitats. A nested sampling design was used to determine spatial scales of variability in benthic macrofaunal density, biomass and secondary production. Habitat differences in benthic assemblage composition were evident, with mangrove forests being dominated by annelids (Oligochaeta and Capitellidae) whereas peracarid crustaceans were also abundant on tidal flats. Macrofaunal biomass, density and secondary production also differed between habitats and among estuaries. Those differences were related both to the composition of benthic assemblages and to random spatial variability, underscoring the importance of hierarchical sampling in estuarine ecological studies. Given variable levels of human impacts and predicted climate change effects on tropical estuarine assemblages in Eastern Brazil, our data support the use of benthic secondary production to address long-term changes and improved management of estuaries in Eastern Brazil. PMID:29507833

Size evolution in Goodwin’s small-eared shrew, Cryptotis goodwini

USGS Publications Warehouse

Woodman, N.; Merritt, J.F.; Churchfield, S.; Hutterer, R.; Sheftel, B.A.

2005-01-01

Fossils of Cryptotis goodwini from Honduras indicate that body sizes of modern individuals average at least 18% larger than among members of the late Pleistocene population of this species. Palynological and other paleoenvironmental studies provide evidence that the Neotropical montane environments that these shrews inhabit were cooler and drier in the late Pleistocene than at present and supported communities of plants without modern analog. Therefore, the most likely cause of this change in size ultimately was related to climatic change at the end of the Pleistocene?but to what specific factors did the species respond? I examined the possibilities that this species changed in size: to accommodate a change in temperature regime; to escape from predators; as a response to a change in intensity of interspecific competition; to take advantage of a newly abundant food resource. Based on evidence from studies of modern communities of shrews and niche partitioning, I hypothesized that size evolution in C. goodwini was directly related to changes in the community of soil and soil-surface invertebrates upon which the species depends, specifically an increase in the availability of earthworms (Annelida).

Redescription of Terebellides kerguelensis stat. nov. (Polychaeta: Trichobranchidae) from Antarctic and subantarctic waters

NASA Astrophysics Data System (ADS)

Parapar, Julio; Moreira, Juan

2008-06-01

During the Spanish Antarctic expeditions “Bentart” 1994, 1995 and 2003, a number of trichobranchid (Annelida: Polychaeta) specimens were collected and identified initially as Terebellides stroemii kerguelensis McIntosh, 1885, the only known species of the genus widely recognised as valid in Antarctic waters. In the framework of a worldwide revision of the genus Terebellides, a reconsideration of the taxonomic status of this subspecies of the boreal Terebellides stroemii Sars, 1835 is done through the examination of the syntypes of T. s. kerguelensis compared with recent descriptions of the nominal species from Norwegian waters and material from Icelandic waters. Thus, T. s. kerguelensis is regarded as a valid species, T. kerguelensis stat. nov., and redescribed designating a lectotype and paralectotypes. The species is mainly characterised by the presence of an anterior branchial extension (fifth lobe), lateral lappets in five anterior thoracic chaetigers, segmental organs in chaetigers 1, 4 and 5, and first thoracic acicular neurochaetae sharply bent with pointed tips. The biological role of the segmental organs, the presence and disposition of cilia in branchial lamellae and the finding of new structures located in dorsal part of thoracic notopodia are discussed.

The inland water macro-invertebrate occurrences in Flanders, Belgium.

PubMed

Vannevel, Rudy; Brosens, Dimitri; Cooman, Ward De; Gabriels, Wim; Frank Lavens; Mertens, Joost; Vervaeke, Bart

2018-01-01

The Flanders Environment Agency (VMM) has been performing biological water quality assessments on inland waters in Flanders (Belgium) since 1989 and sediment quality assessments since 2000. The water quality monitoring network is a combined physico-chemical and biological network, the biological component focusing on macro-invertebrates. The sediment monitoring programme produces biological data to assess the sediment quality. Both monitoring programmes aim to provide index values, applying a similar conceptual methodology based on the presence of macro-invertebrates. The biological data obtained from both monitoring networks are consolidated in the VMM macro-invertebrates database and include identifications at family and genus level of the freshwater phyla Coelenterata, Platyhelminthes, Annelida, Mollusca, and Arthropoda. This paper discusses the content of this database, and the dataset published thereof: 282,309 records of 210 observed taxa from 4,140 monitoring sites located on 657 different water bodies, collected during 22,663 events. This paper provides some background information on the methodology, temporal and spatial coverage, and taxonomy, and describes the content of the dataset. The data are distributed as open data under the Creative Commons CC-BY license.

The making of a branching annelid: an analysis of complete mitochondrial genome and ribosomal data of Ramisyllis multicaudata.

PubMed

Aguado, M Teresa; Glasby, Christopher J; Schroeder, Paul C; Weigert, Anne; Bleidorn, Christoph

2015-07-17

Ramisyllis multicaudata is a member of Syllidae (Annelida, Errantia, Phyllodocida) with a remarkable branching body plan. Using a next-generation sequencing approach, the complete mitochondrial genomes of R. multicaudata and Trypanobia sp. are sequenced and analysed, representing the first ones from Syllidae. The gene order in these two syllids does not follow the order proposed as the putative ground pattern in Errantia. The phylogenetic relationships of R. multicaudata are discerned using a phylogenetic approach with the nuclear 18S and the mitochondrial 16S and cox1 genes. Ramisyllis multicaudata is the sister group of a clade containing Trypanobia species. Both genera, Ramisyllis and Trypanobia, together with Parahaplosyllis, Trypanosyllis, Eurysyllis, and Xenosyllis are located in a long branched clade. The long branches are explained by an accelerated mutational rate in the 18S rRNA gene. Using a phylogenetic backbone, we propose a scenario in which the postembryonic addition of segments that occurs in most syllids, their huge diversity of reproductive modes, and their ability to regenerate lost parts, in combination, have provided an evolutionary basis to develop a new branching body pattern as realised in Ramisyllis.

Survival and reproduction of enchytraeid worms, Oligochaeta, in different soil types amended with energetic cyclic nitramines.

PubMed

Dodard, Sabine G; Sunahara, Geoffrey I; Kuperman, Roman G; Sarrazin, Manon; Gong, Ping; Ampleman, Guy; Thiboutot, Sonia; Hawari, Jalal

2005-10-01

Hexanitrohexaazaisowurtzitane (CL-20), a new polycyclic polynitramine, has the same functional nitramine groups (N-NO2) as the widely used energetic chemicals hexahydro-1,3,5-trinitro-1,3,5-triazacyclohexane (royal demolition explosive [RDX]) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (high-melting explosive [HMX]). Potential impacts of CL-20 as an emerging contaminant must be assessed before its use. The effects of CL-20, RDX, or HMX on adult survival and juvenile production by potworms Enchytraeus albidus and Enchytraeus crypticus were studied in three soil types, including Sassafras sandy loam (1.2% organic matter [OM], 11% clay, pH 5.5), an agricultural soil (42% OM, 1% clay, pH 8.2), and a composite agricultural-forest soil (23% OM, 2% clay, pH 7.9) by using ISO method 16387 (International Standard Organization, Geneva, Switzerland). Results showed that CL-20 was toxic to E. crypticus with median lethal concentration values for adult survival ranging from 0.1 to 0.7 mg/kg dry mass (DM) when using the three tested soils. In addition, CL-20 adversely affected juvenile production by both species in all soils tested, with median effective concentration (EC50) values ranging from 0.08 to 0.62 mg/kg DM. Enchytraeus crypticus and E. albidus were similarly sensitive to CL-20 exposure in the composite agricultural-forest soil, which supported reproduction by both species and enabled comparisons. Correlation analysis showed weak or no relationship overall among the soil properties and reproduction toxicity endpoints. Neither RDX nor HMX affected (p > 0.05) adult survival of either species below 658 and 918 mg/kg DM, respectively, indicating that CL-20 is more toxic to enchytraeids than RDX or HMX. Examination of data shows that CL-20 should be considered as a potential reproductive toxicant to soil invertebrates, and that safeguards should be considered to minimize the potential for release of CL-20 into the environment.

Assessing the toxicity of herbicide isoproturon on Aporrectodea caliginosa (Oligochaeta) and its fate in soil ecosystem.

PubMed

Mosleh, Yahia Youssef Ismail

2009-08-01

This study was conducted to determine the residues of isoproturon and its metabolites, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl) urea, and 4-isopropylanilin in soil and mature earthworms under laboratory conditions. Mature earthworms (Aporrectodea caliginosa) were exposed for various durations (7, 15, 30, and 60 days) to soils contaminated with isoproturon concentrations (2, 4, 6, 8, and 10 mg kg(-1) soil). The decrease in isoproturon concentration in the soil was inversely correlated to it's initial concentration. The highest concentration detected for isoproturon in earthworms was observed during the first 15 days and decreased thereafter. Acute toxicity of isoproturon was investigated; total soluble protein content and glycogen of the worms were evaluated. Levels of these parameters were related to isoproturon concentration in soil and earthworms. No lethal effect of isoproturon was observed even at the concentration of 1200 mg kg(-1) soil after 60 days of exposure. A reduction of total soluble protein was observed in all treated worms (maximum 59.54%). This study suggests the use of the total soluble protein content and glycogen of earthworms as biomarkers of exposure to isoproturon. 2008 Wiley Periodicals, Inc.

Effects of structural marsh management and salinity on invertebrate prey of waterbirds in marsh ponds during winter on the Gulf Coast Chenier Plain

USGS Publications Warehouse

Bolduc, F.; Afton, A.D.

2003-01-01

. Furthermore, as predicted, an a priori MANOVA contrast indicated that biomass of a single invertebrate class adapted to low salinity (Oligochaeta, 200 to 999 ??m) was greater in ponds of IF marshes than in those of IO and IM marshes. A canonical correspondence analysis indicated that variation in salinity and O2 penetration best explained differences among sites that maximized biomass of the common invertebrate classes. Salinity was positively correlated with the silt-clay fraction, O2, and O2 penetration, and negatively correlated with water depth, sediment hardness, carbon, and C:N. Nematoda, Foraminifera, and Copepoda generally were associated with UM marsh ponds and high salinity, whereas other invertebrate classes were distributed among impounded marsh ponds and associated with lower salinity. Our results suggest that SMM and salinity have relatively small effects on invertebrate prey of wintering waterbirds in marsh ponds because they affect biomass of Nematoda and Oligochaeta, and few waterbirds consume these invertebrates. ?? 2003, The Society of Wetland Scientists.

Revision of Brada Stimpson, 1853, and Bradabyssa Hartman, 1967 (Annelida, Flabelligeridae).

PubMed

Salazar-Vallejo, Sergio I

2017-11-03

Among flabelligerid genera Brada Stimpson, 1853 includes several species whose bodies are fusiform or club-shaped, often with a reduced number of chaetigers, and their members are found in temperate and polar waters. In contrast, Bradabyssa Hartman, 1967 is regarded as a monotypic genus with a single Antarctic species with a cylindrical body and a variable number of chaetigers. After examination of all type and non-type material available of both genera, two distinct body patterns were distinguished: one includes the type species for Brada, B. granosa Stimpson, 1853, has only 8 branchial filaments and the neurochaetae are thick, blunt, often falcate, whereas the other includes the type species of Bradabyssa, B. papillata Hartman, 1967, usually has many branchial filaments and neurochaetae are straighter and mucronate. Consequently, Brada is herein restricted to include only 5 species, one of which is new, Brada kudenovi n. sp. Bradabyssa is herein emended to include many species formerly regarded as belonging in Brada, as new combinations, and species can be separated into four groups according to the development of the tunic and its sediment load. Thirteen new species of Bradabyssa are also described: B. indica n. sp., B. mexicana n. sp., B. alaskensis n. sp., B. elinae n. sp., B. grangieri n. sp., B. levensteinae n. sp., B. harrisae n. sp., B. hartmanae n. sp., B. jirkovi n. sp., B. kirkegaardi n. sp., B. monnioti n. sp., B. mezianei n. sp. and B. willeyi n. sp. The species belonging to Brada are B. granosa, B. granulosa Hansen, 1880, B. incrustata Støp-Bowitz, 1948, B. inhabilis (Rathke, 1843), and B. kudenovi n. sp. The species belonging to Bradabyssa are separated into four groups according to the development of their tunic and its sediment load. Group crustosa includes B. indica n. sp., B. mexicana n. sp., B. minuta (Amoureux, 1986) n. comb., and B. sachalina (Annenkova-Chlopina, 1922) n. comb. Group nuda includes B. alaskensis n. sp., B. antarctica (Hartman, 1978) n. comb., B. bransfieldia (Hartman, 1966) n. comb., B. nuda (Annenkova-Chlopina, 1922) n. comb., B. rugosa (Hansen, 1880) n. comb., and B. strelzovi (Jirkov & Filippova in Jirkov, 2001) n. comb. Group verrucosa contains B. abyssalis (Fauchald, 1972) n. comb., B. annenkovae (Buzhinskaja, 2001) n. comb., B. elinae n. sp., B. grangieri n. sp., B. irenaia (Chamberlin, 1919) n. comb., B. levensteinae n. sp., B. mammillata (Grube, 1877) n. comb., B. ochotensis (Annenkova-Chlopina, 1922) n. comb., B. papillata Hartman, 1967, B. tenebricosa (Berkeley, 1966) n. comb., n. status, and B. verrucosa (Chamberlin, 1919) n. comb. Group villosa contains B. capensis (Day, 1961) n. comb., n. status, B. harrisae n. sp., B. hartmanae n. sp., B. ilyvestis (Hartman, 1960) n. comb., B. intoshi (Caullery, 1944) n. comb., B. jirkovi n. sp., B. kirkegaardi n. sp., B. monnioti n. sp., B. parthenopeia (Lo Bianco, 1893) n. comb., B. pilosa (Moore, 1906) n. comb., B. pluribranchiata (Moore, 1923) n. comb., B. setosa (Verrill, 1873) n. comb., B. mezianei n. sp., B. tzetlini (Jirkov & Filippova in Jirkov, 2001) n. comb, B. villosa (Rathke, 1843) n. comb., B. whiteavesi (McIntosh, 1885) n. comb and  B. willeyi n. sp. Keys to aid identification of all genera in Flabelligeridae, to species in Brada, and for the species belonging in the four species groups of Bradabyssa are included.

Redescription and biology of Diopatra neapolitana (Annelida: Onuphidae), a protandric hermaphrodite with external spermaducal papillae

NASA Astrophysics Data System (ADS)

Arias, Andrés; Paxton, Hannelore; Budaeva, Nataliya

2016-06-01

A one-year study of the reproductive biology of a population of Diopatra neapolitana at Villaviciosa estuary, northern Spain, was undertaken. Field observations together with a histological study of monthly collected individuals revealed that the population was iteroparous, had a discontinuous reproductive season with a resting period during August and September and a spawning season from March to July. The study showed that D. neapolitana was not dioecious as previously suggested but consisted of protandric sequential hermaphrodites, pure males and pure females with a male biased sex ratio of 3:1. During the peak reproductive period from May to August we observed simultaneous hermaphrodites with two dorsal papillae per segment in the branchial region. Histological studies demonstrated that the papillae were acting as seminal vesicles, storing own sperm, and also as sperm ducts, providing an exit route; hence we termed them 'spermaducal papillae'. The papillae are not the only sperm repositories as the coelom of males and simultaneous hermaphrodites in smaller size classes is also filled with sperm. The worms are broadcast spawners with a brief pelagic larval stage as previously reported but the finer points of this unusual fertilisation system need still to be elaborated. Diopatra cryptornata was recently described as a new species, supposedly differing from D. neapolitana in chaetal detail and the possession of the papillae. We have shown conclusively with morphological and genetical studies that the former species is a junior synonym of the latter. In the absence of type material we are here designating a neotype from recently collected material from Naples.

Syllidae (Annelida: Phyllodocida) from the deep Mediterranean Sea, with the description of three new species.

PubMed

Langeneck, Joachim; Musco, Luigi; Busoni, Giulio; Conese, Ilaria; Aliani, Stefano; Castelli, Alberto

2018-01-03

Despite almost two centuries of research, the diversity of Mediterranean deep-sea environments remain still largely unexplored. This is particularly true for the polychaete family Syllidae. We report herein 14 species; among them, we describe Erinaceusyllis barbarae n. sp., Exogone sophiae n. sp. and Prosphaerosyllis danovaroi n. sp. and report Parexogone wolfi San Martín, 1991, Exogone lopezi San Martín, Ceberio Aguirrezabalaga, 1996 and Anguillosyllis Day, 1963 for the first time from the Western Mediterranean, the latter based on a single individual likely belonging to an undescribed species. Moreover, we re-establish Syllis profunda Cognetti, 1955 based on type and new material. Present data, along with a critical analysis of available literature, show that Syllidae are highly diverse in deep Mediterranean environments, even though they are rarely reported, probably due to the scarce number of studies devoted to the size-fraction of benthos including deep-sea syllids. Most deep-sea Syllidae have wide distributions, which do not include shallow-waters. 100 m depth apparently represents the boundary between the assemblages dominated by generalist shallow water syllids like Exogone naidina Ørsted, 1843 and Syllis parapari San Martín López, 2000, and those deep-water assemblages characterised by strictly deep-water species like Parexogone campoyi San Martín, Ceberio Aguirrezabalaga, 1996, Parexogone wolfi San Martín, 1991 and Syllis sp. 1 (= Langerhansia caeca Katzmann, 1973).

Bitentaculate Cirratulidae (Annelida: Polychaeta) from the northwestern Pacific Islands with description of nine new species.

PubMed

Magalhães, Wagner F; Bailey-Brock, Julie H

2013-01-01

Thirteen cirratulid species from the Hawaiian, Mariana and Marshall Islands are described. Nine species are new to science: Aphelochaeta arizonae sp. nov., Aphelochaeta honouliuli sp. nov., Caulleriella cordiformia sp. nov., Chaetozone michellae sp. nov., Chaetozone ronaldi sp. nov., Monticellina anterobranchiata sp. nov., Monticellina hanaumaensis sp. nov., and Tharyx tumulosa sp. nov., from Oahu, Hawaii and Aphelochaeta saipanensis sp. nov., from Saipan in the Mariana Islands. Dodecaceria fewkesi and Monticellina nr. cryptica are newly recorded from the Hawaiian Islands. Dodecaceria laddi is widely distributed in the western Pacific and material collected from the Hawaiian, Mariana and Marshall islands is described. We provide SEM photographs for all species in addition to line drawings and methyl green staining pattern photographs for the new species.

Spermatogenesis and spermatozoa ultrastructure of two Dipolydora species (Annelida: Spionidae) from the Sea of Japan.

PubMed

Radashevsky, Vasily I; Yurchenko, Olga V; Tyurin, Sergey A; Alexandrova, Yana N

2015-02-01

Spermatogenesis and the structure of the spermatozoa of two spionid polychaetes Dipolydora bidentata and Dipolydora carunculata are described by light and transmission electron microscopy. Both species are gonochoristic borers in shells of various molluscs. Proliferation of spermatogonia occurs in paired testes regularly arranged in fertile segments, and the rest of spermatogenesis occurs in the coelomic cavity. Early spermatogenesis occurs quite similarly in the two species but results in formation of tetrads of interconnected spermatids in D. bidentata and octads of spermatids in D. carunculata. Three consecutive stages of spermiogenesis are recognized according to the condensation of chromatin in nucleus: (1) early spermatids with heterogeneous, partly clumped chromatin, (2) middle spermatids with homogeneous, coarsely granular chromatin, and (3) late spermatids with homogeneous fibrillar chromatin. Moreover, late stage of spermatids is further classified into two stages, I and II, according to the position of the acrosome and shape of the nucleus. In late spermatids I, the acrosome is situated in the anterior invagination of the funnel-shaped to oval nucleus, whereas in late spermatids II the acrosome is situated on top of the elongated nucleus. Ultrastructural composition of cells at each stage of spermatogenesis is described and illustrated. The possible process of morphogenesis of organelles during spermato- and spermiogenesis is reconstructed for both species. The proacrosomal vesicle first appears in early spermatids near the Golgi complex and then migrates anteriorly; in the middle spermatids, the acrosome comes to lie in a deep anterior nuclear fossa. In late spermatids I, this fossa evaginates and a posterior fossa develops in the nucleus housing basal body and the anterior part of the axoneme. In late spermatids II, the mitochondria elongate and probably reduce in number due to fusion of some of them. The mature spermatozoa in both species are introsperm with the conical acrosome, subacrosomal plate, long nucleus with short posterior fossa, long midpiece with elongated mitochondria, and long flagellum with 9×2+2 organization of microtubules. Numerous flat rounded platelets with putative glycogen are present throughout most part of the nucleus and the midpiece. The process of spermatogenesis in D. bidentata and D. carunculata is similar to that in other Dipolydora, Polydora and Pseudopolydora species. Spermatozoa in these polydorin spionids have similar composition and differ mainly in size of the nucleus and the midpiece. Elongated spermatozoa are adapted for transfer in spermatophores and an internal fertilization which is characteristic for brooding species. Diversely modified spermatozoa among spionids may be signs of the diversity of fertilization biology within the Spionidae. The exact places where fertilization occurs in brooding spionids however remains unknown. Copyright © 2014 Elsevier Ltd. All rights reserved.

Alike but different: the evolution of the Tubifex tubifex species complex (Annelida, Clitellata) through polyploidization.

PubMed

Marotta, Roberto; Crottini, Angelica; Raimondi, Elena; Fondello, Cristina; Ferraguti, Marco

2014-04-02

Tubifex tubifex is a widespread annelid characterized by considerable variability in its taxonomic characteristics and by a mixed reproductive strategy, with both parthenogenesis and biparental reproduction. In a molecular phylogenetic analysis, we detected substantial genetic variability among sympatric Tubifex spp. from the Lambro River (Milano, Italy), which we suggested comprise several cryptic species. To gain insights into the evolutionary events that generated this differentiation, we performed a cytogenetic analysis in parallel with a molecular assay. Approximately 80 cocoons of T. tubifex and T. blanchardi were collected and dissected. For each cocoon, we sequenced a fragment of the 16S rRNA from half of the sibling embryos and karyotyped the other half. To generate a robust phylogeny enabling the reconstruction of the evolutionary processes shaping the diversity of these sympatric lineages, we complemented our original 16S rRNA gene sequences with additional COI sequences. The chromosome number distribution was consistent with the presence of at least six sympatric euploid chromosome complements (one diploid, one triploid, three tetraploids and one hexaploid), as confirmed by a FISH assay performed with an homologous 18S rDNA probe. All the worms with 2n = 50 chromosomes belonged to an already identified sibling species of T. tubifex, T. blanchardi. The six euploid sets were coherently arranged in the phylogeny, with each lineage grouping specimens with the same chromosome complement. These results are compatible with the hypothesis that multiple polyploidization events, possibly enhanced by parthenogenesis, may have driven the evolution of the T. tubifex species complex.

Comparison of neuromuscular development in two dinophilid species (Annelida) suggests progenetic origin of Dinophilus gyrociliatus.

PubMed

Kerbl, Alexandra; Fofanova, Elizaveta G; Mayorova, Tatiana D; Voronezhskaya, Elena E; Worsaae, Katrine

2016-01-01

Several independent meiofaunal lineages are suggested to have originated through progenesis, however, morphological support for this heterochronous process is still lacking. Progenesis is defined as an arrest of somatic development (synchronously in various organ systems) due to early maturation, resulting in adults resembling larvae or juveniles of the ancestors. Accordingly, we established a detailed neuromuscular developmental atlas of two closely related Dinophilidae using immunohistochemistry and CLSM. This allows us to test for progenesis, questioning whether i) the adult smaller, dimorphic Dinophilus gyrociliatus resembles a younger developmental stage of the larger, monomorphic D. taeniatus and whether ii) dwarf males of D. gyrociliatus resemble an early developmental stage of D. gyrociliatus females. Both species form longitudinal muscle bundles first, followed by circular muscles, creating a grid of body wall musculature, which is the densest in adult D. taeniatus , while the architecture in adult female D. gyrociliatus resembles that of prehatching D. taeniatus . Both species display a subepidermal ganglionated nervous system with an anterior dorsal brain and five longitudinal ventral nerve bundles with six sets of segmental commissures (associated with paired ganglia). Neural differentiation of D. taeniatus and female D. gyrociliatus commissures occurs before hatching: both species start out forming one transverse neurite bundle per segment, which are thereafter joined by additional thin bundles. Whereas D. gyrociliatus arrests its development at this stage, adult D. taeniatus condenses the thin commissures again into one thick commissural bundle per segment. Generally, D. taeniatus adults demonstrate a seemingly more organized (= segmental) pattern of serotonin-like and FMRFamide-like immunoreactive elements. The dwarf male of D. gyrociliatus displays a highly aberrant neuromuscular system, showing no close resemblance to any early developmental stage of female Dinophilus , although the onset of muscular development mirrors the early myogenesis in females. The apparent synchronous arrest of nervous and muscular development in adult female D. gyrociliatus, resembling the prehatching stage of D. taeniatus, suggests that D. gyrociliatus have originated through progenesis. The synchrony in arrest of three organ systems, which show opposing reduction and addition of elements, presents one of the morphologically best-argued cases of progenesis within Spiralia.

Yamaguchia toyensis n. sp., n. gen. (Annelida, Clitellata, Lumbriculidae) from profundal lake habitat in Japan

USGS Publications Warehouse

Fend, S.V.; Ohtaka, A.

2004-01-01

Yamaguchia toyensis n. sp., n. gen. is described from an oligotrophic caldera lake, Lake Toya, Hokkaido, Japan. Although the taxonomic affinities are unknown, the genus differs from all other Lumbriculidae in having the combination of testes and atria in X, a single, prosoporous male funnel per atrium, and spermathecae in XI. Unlike other Japanese lakes that have thus far been surveyed, Lake Toya supports abundant populations of lumbriculids in the profundal benthos.

Do syntopic host species harbour similar symbiotic communities? The case of Chaetopterus spp. (Annelida: Chaetopteridae).

PubMed

Britayev, Temir A; Mekhova, Elena; Deart, Yury; Martin, Daniel

2017-01-01

To assess whether closely related host species harbour similar symbiotic communities, we studied two polychaetes, Chaetopterus sp. ( n  = 11) and Chaetopterus cf. appendiculatus ( n  = 83) living in soft sediments of Nhatrang Bay (South China Sea, Vietnam). The former harboured the porcellanid crabs Polyonyx cf. heok and Polyonyx sp., the pinnotherid crab Tetrias sp. and the tergipedid nudibranch Phestilla sp. The latter harboured the polynoid polychaete Ophthalmonoe pettiboneae , the carapid fish Onuxodon fowleri and the porcellanid crab Eulenaios cometes , all of which, except O. fowleri , seemed to be specialized symbionts. The species richness and mean intensity of the symbionts were higher in Chaetopterus sp. than in C. cf. appendiculatus (1.8 and 1.02 species and 3.0 and 1.05 individuals per host respectively). We suggest that the lower density of Chaetopterus sp. may explain the higher number of associated symbionts observed, as well as the 100% prevalence (69.5% in C. cf. appenciculatus ). Most Chaetopterus sp. harboured two symbiotic species, which was extremely rare in C. cf. appendiculatus , suggesting lower interspecific interactions in the former. The crab and nudibranch symbionts of Chaetopterus sp. often shared a host and lived in pairs, thus partitioning resources. This led to the species coexisting in the tubes of Chaetopterus sp., establishing a tightly packed community, indicating high species richness and mean intensity, together with a low species dominance. In contrast, the aggressive, strictly territorial species associated with C. cf. appendiculatus established a symbiotic community strongly dominated by single species and, thus, low species richness and mean intensity. Therefore, we suggest that interspecific interactions are determining species richness, intensity and dominance, while intraspecific interactions are influencing only intensity and abundance. It is possible that species composition may have influenced the differences in community structure observed. We hypothesize that both host species could originally be allopatric. The evolutionary specialization of the symbiotic communities would occur in separated geographical areas, while the posterior disappearance of the existing geographical barriers would lead to the overlapped distribution.

Do syntopic host species harbour similar symbiotic communities? The case of Chaetopterus spp. (Annelida: Chaetopteridae)

PubMed Central

Britayev, Temir A.; Mekhova, Elena; Deart, Yury

2017-01-01

To assess whether closely related host species harbour similar symbiotic communities, we studied two polychaetes, Chaetopterus sp. (n = 11) and Chaetopterus cf. appendiculatus (n = 83) living in soft sediments of Nhatrang Bay (South China Sea, Vietnam). The former harboured the porcellanid crabs Polyonyx cf. heok and Polyonyx sp., the pinnotherid crab Tetrias sp. and the tergipedid nudibranch Phestilla sp. The latter harboured the polynoid polychaete Ophthalmonoe pettiboneae, the carapid fish Onuxodon fowleri and the porcellanid crab Eulenaios cometes, all of which, except O. fowleri, seemed to be specialized symbionts. The species richness and mean intensity of the symbionts were higher in Chaetopterus sp. than in C. cf. appendiculatus (1.8 and 1.02 species and 3.0 and 1.05 individuals per host respectively). We suggest that the lower density of Chaetopterus sp. may explain the higher number of associated symbionts observed, as well as the 100% prevalence (69.5% in C. cf. appenciculatus). Most Chaetopterus sp. harboured two symbiotic species, which was extremely rare in C. cf. appendiculatus, suggesting lower interspecific interactions in the former. The crab and nudibranch symbionts of Chaetopterus sp. often shared a host and lived in pairs, thus partitioning resources. This led to the species coexisting in the tubes of Chaetopterus sp., establishing a tightly packed community, indicating high species richness and mean intensity, together with a low species dominance. In contrast, the aggressive, strictly territorial species associated with C. cf. appendiculatus established a symbiotic community strongly dominated by single species and, thus, low species richness and mean intensity. Therefore, we suggest that interspecific interactions are determining species richness, intensity and dominance, while intraspecific interactions are influencing only intensity and abundance. It is possible that species composition may have influenced the differences in community structure observed. We hypothesize that both host species could originally be allopatric. The evolutionary specialization of the symbiotic communities would occur in separated geographical areas, while the posterior disappearance of the existing geographical barriers would lead to the overlapped distribution. PMID:28168108

New species of semi-aquatic freshwater earthworm genus Glyphidrilus Horst, 1889 from Thailand and Laos (Oligochaeta, Almidae)

PubMed Central

Chanabun, Ratmanee; Inkavilay, Khamla; Panha, Somsak

2017-01-01

Abstract Seven new species of semi-aquatic freshwater earthworms belonging to the genus Glyphidrilus Horst, 1889 are described from Thailand and Laos, Glyphidrilus nanensis Chanabun & Panha sp. n., G. satunensis Chanabun & Panha sp. n., G. chiangraiensis Chanabun & Panha sp. n., G. namphao Chanabun & Panha sp. n., G. sekongensis Chanabun & Panha sp. n., G. namdonensis Chanabun & Panha sp. n., and G. champasakensis Chanabun & Panha sp. n. The species are characterized by their external and internal morphological characteristics, as well as body sizes. Other morphological character differences between these seven species were also compared, and an identification key is provided. The relationships of the new species to congeners are discussed. PMID:28769665

cDNA identification, comparison and phylogenetic aspects of lombricine kinase from two oligochaete species.

PubMed

Doumen, Chris

2010-06-01

Creatine kinase and arginine kinase are the typical representatives of an eight-member phosphagen kinase family, which play important roles in the cellular energy metabolism of animals. The phylum Annelida underwent a series of evolutionary processes that resulted in rapid divergence and radiation of these enzymes, producing the greatest diversity of the phosphagen kinases within this phylum. Lombricine kinase (EC 2.7.3.5) is one of such enzymes and sequence information is rather limited compared to other phosphagen kinases. This study presents data on the cDNA sequences of lombricine kinase from two oligochaete species, the California blackworm (Lumbriculus variegatus) and the sludge worm (Tubifex tubifex). The deduced amino acid sequences are analyzed and compared with other selected phosphagen kinases, including two additional lombricine kinase sequences extracted from DNA databases and provide further insights in the evolution and position of these enzymes within the phosphagen kinase family. The data confirms the presence of a deleted region within the flexible loop (the GS region) of all six examined lombricine kinases. A phylogenetic analysis of these six lombricine kinases clearly positions the enzymes together in a small subcluster within the larger creatine kinase (EC 2.7.3.2) clade. 2010. Published by Elsevier Inc.

Composition and abundance of epibenthic-sledge catches in the South Polar Front of the Atlantic

NASA Astrophysics Data System (ADS)

Brandt, A.; Havermans, C.; Janussen, D.; Jörger, K. M.; Meyer-Löbbecke, A.; Schnurr, S.; Schüller, M.; Schwabe, E.; Brandão, S. N.; Würzberg, L.

2014-10-01

An epibenthic sledge (EBS) was deployed at seven different deep-sea stations along the South Polar Front of the Atlantic in order to explore the composition and abundance of macrofaunal organisms and to identify the most abundant taxa in this transition zone to the Southern Ocean. In total 3,130 specimens were sampled by means of the EBS on board of RV Polarstern during the expedition ANT-XXVIII/3 in the austral summer of 2012. Benthic and suprabenthic Crustacea occurred to be most frequent in the samples. Among those, copepods were by far most numerous, with 1,585 specimens followed by the peracarid taxa Isopoda (236 ind.), Amphipoda (103 ind.), Tanaidacea (78 ind.) and Cumacea (50 ind.). Annelida were represented by a high number of specimens belonging to different polychaete taxa (404 ind.). The molluscan fauna was clearly dominated by Bivalvia (255 ind.), followed in numbers of specimens by Gastropoda (47 ind.). The deep-sea benthos sampled along the Southern Polar Front occurred in surprisingly low abundances, contrasting the largely high surface productivity of the area. Numbers of specimens across different macrofaunal taxa and especially of peracarid crustaceans underscored by far those from South Ocean sites at higher latitudes in the Weddell Sea.

A checklist of helminth parasites of Elasmobranchii in Mexico

PubMed Central

Merlo-Serna, Aldo Iván; García-Prieto, Luis

2016-01-01

Abstract A comprehensive and updated summary of the literature and unpublished records contained in scientific collections on the helminth parasites of the elasmobranchs from Mexico is herein presented for the first time. At present, the helminth fauna associated with Elasmobranchii recorded in Mexico is composed of 132 (110 named species and 22 not assigned to species), which belong to 70 genera included in 27 families (plus 4 incertae sedis families of cestodes). These data represent 7.2% of the worldwide species richness. Platyhelminthes is the most widely represented, with 128 taxa: 94 of cestodes, 22 of monogeneans and 12 of trematodes; Nematoda and Annelida: Hirudinea are represented by only 2 taxa each. These records come from 54 localities, pertaining to 15 states; Baja California Sur (17 sampled localities) and Baja California (10), are the states with the highest species richness: 72 and 54 species, respectively. Up to now, 48 elasmobranch species have been recorded as hosts of helminths in Mexico; so, approximately 82% of sharks and 67% of rays distributed in Mexican waters lack helminthological studies. The present list provides the host, distribution (with geographical coordinates), site of infection, accession number in scientific collections, and references for the parasites. A host-parasite list is also provided. PMID:27047240

A checklist of helminth parasites of Elasmobranchii in Mexico.

PubMed

Merlo-Serna, Aldo Iván; García-Prieto, Luis

2016-01-01

A comprehensive and updated summary of the literature and unpublished records contained in scientific collections on the helminth parasites of the elasmobranchs from Mexico is herein presented for the first time. At present, the helminth fauna associated with Elasmobranchii recorded in Mexico is composed of 132 (110 named species and 22 not assigned to species), which belong to 70 genera included in 27 families (plus 4 incertae sedis families of cestodes). These data represent 7.2% of the worldwide species richness. Platyhelminthes is the most widely represented, with 128 taxa: 94 of cestodes, 22 of monogeneans and 12 of trematodes; Nematoda and Annelida: Hirudinea are represented by only 2 taxa each. These records come from 54 localities, pertaining to 15 states; Baja California Sur (17 sampled localities) and Baja California (10), are the states with the highest species richness: 72 and 54 species, respectively. Up to now, 48 elasmobranch species have been recorded as hosts of helminths in Mexico; so, approximately 82% of sharks and 67% of rays distributed in Mexican waters lack helminthological studies. The present list provides the host, distribution (with geographical coordinates), site of infection, accession number in scientific collections, and references for the parasites. A host-parasite list is also provided.

Proximate Content of “Klekap” (Microphytobenthos and Their Associated Meiofauna) from Milk-Fish Pond

NASA Astrophysics Data System (ADS)

Widianingsih; Zainuri, Muhammad; Anggoro, Sutrisno; Pancasakti Kusumaningrum, Hermin

2017-02-01

Microphytobentos and their associated mieofauna (‘klekap”) have important role in milkfish pond ecosystem expecially traditional fish pond. Microphytobenthos and their associated meiofauna not only consists of unicellular microalgae from class Bacillariophyceae, Cyanophyceae, Chlorophyceae but also a lot of meiofauna such as Nematoda, Annelida, Mollusc, Arthropoda, etc. Microphytobenthos and their associated meiofauna inhabit in the upper most surface sediment layer. They also have important role in the primary and secondary productivity. This research has purpose to investigate the composition of proximate in the microphytobenthos and their associated meiofauna. Microphytobenthos and their associated meiofauna were taken from three milkfish ponds in Pati area, Central of Jawa, Indonesia. Samples were taken directly by hand core from 3 stations with 3 replications. The research result showed that the value of protein content had range 6.9±0.33 - 7.73±0.37 %-dw, the value of carbohydrate content had range 10.44±1.2 - 12.59±0.15 %-dw, the value of lipid content had range 0.86±0.07 - 0.96±0.07 %-dw. It concluded that the third station has higher value of protein, lipid and carbohydrate compared than the first and the second station.

Pheromonal communication in nereids and the likely intervention by petroleum derived pollutants.

PubMed

Müller, Carsten T; Priesnitz, Frank M; Beckmann, Manfred

2005-01-01

Nereis succinea and Platynereis dumerilii (Annelida, Polychaeta) are broadcast spawners and reproduce semelparously. The final events in reproduction, swarming and spawning are co-ordinated by sex pheromones.A water-soluble fraction of crude oil, the volatile fraction (C9-C16) of EKO FISK crude oil was found to induce release of gametes in male nereids at levels <0.3 ppm.Using vacuum distillation, column chromatography, preparative GC and GC-MS analysis we showed that C(5)-alkylated benzenes were most potent in inducing sperm release, of those n-butyl-4-methylbenzene and 1,4-diethyl-2-methylbenzene were found to induce release of gametes at concentrations ≥4 nM. This threshold is lower than those reported for natural pheromones (nereithione: 60 nM, uric acid: 600 nM) but higher than background levels of aromatic compounds of 0.05 nM and below.Other oil fractions showed additional effects, blocking pheromone reception or narcotising and intoxicating animals. Part of these effects could be assigned to naphthalenes at levels down to approx. 320 nM. In the original mixtures, their action was modified or compensated by the presence of gamete release inducing alkylated benzenes. Other highly paralysing substances remained elusive.

Quality of laboratory studies assessing effects of Bt-proteins on non-target organisms: minimal criteria for acceptability.

PubMed

De Schrijver, Adinda; Devos, Yann; De Clercq, Patrick; Gathmann, Achim; Romeis, Jörg

2016-08-01

The potential risks that genetically modified plants may pose to non-target organisms and the ecosystem services they contribute to are assessed as part of pre-market risk assessments. This paper reviews the early tier studies testing the hypothesis whether exposure to plant-produced Cry34/35Ab1 proteins as a result of cultivation of maize 59122 is harmful to valued non-target organisms, in particular Arthropoda and Annelida. The available studies were assessed for their scientific quality by considering a set of criteria determining their relevance and reliability. As a case-study, this exercise revealed that when not all quality criteria are met, weighing the robustness of the study and its relevance for risk assessment is not obvious. Applying a worst-case expected environmental concentration of bioactive toxins equivalent to that present in the transgenic crop, confirming exposure of the test species to the test substance, and the use of a negative control were identified as minimum criteria to be met to guarantee sufficiently reliable data. This exercise stresses the importance of conducting studies meeting certain quality standards as this minimises the probability of erroneous or inconclusive results and increases confidence in the results and adds certainty to the conclusions drawn.

The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

PubMed Central

2014-01-01

Over 95% of all metazoan (animal) species comprise the “invertebrates,” but very few genomes from these organisms have been sequenced. We have, therefore, formed a “Global Invertebrate Genomics Alliance” (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site (http://giga.nova.edu) has been launched to facilitate this collaborative venture. PMID:24336862

The Global Invertebrate Genomics Alliance (GIGA): developing community resources to study diverse invertebrate genomes.

PubMed

Bracken-Grissom, Heather; Collins, Allen G; Collins, Timothy; Crandall, Keith; Distel, Daniel; Dunn, Casey; Giribet, Gonzalo; Haddock, Steven; Knowlton, Nancy; Martindale, Mark; Medina, Mónica; Messing, Charles; O'Brien, Stephen J; Paulay, Gustav; Putnam, Nicolas; Ravasi, Timothy; Rouse, Greg W; Ryan, Joseph F; Schulze, Anja; Wörheide, Gert; Adamska, Maja; Bailly, Xavier; Breinholt, Jesse; Browne, William E; Diaz, M Christina; Evans, Nathaniel; Flot, Jean-François; Fogarty, Nicole; Johnston, Matthew; Kamel, Bishoy; Kawahara, Akito Y; Laberge, Tammy; Lavrov, Dennis; Michonneau, François; Moroz, Leonid L; Oakley, Todd; Osborne, Karen; Pomponi, Shirley A; Rhodes, Adelaide; Santos, Scott R; Satoh, Nori; Thacker, Robert W; Van de Peer, Yves; Voolstra, Christian R; Welch, David Mark; Winston, Judith; Zhou, Xin

2014-01-01

Over 95% of all metazoan (animal) species comprise the "invertebrates," but very few genomes from these organisms have been sequenced. We have, therefore, formed a "Global Invertebrate Genomics Alliance" (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site (http://giga.nova.edu) has been launched to facilitate this collaborative venture.

Designation of a neotype and redescription of Hesione reticulata von Marenzeller, 1879 from Japan (Annelida, Hesionidae).

PubMed

Jimi, Naoto; Salazar-Vallejo, Sergio I; Kajihara, Hiroshi

2017-01-01

The hesionid polychaete Hesione reticulata von Marenzeller, 1879 was described from Enoshima Island, Japan and has been recorded also from the Red Sea. Depending on researchers, it has been regarded as either a distinct species or synonymous with older established ones. The type specimen has been lost. In order to clarify its taxonomic status, Hesione reticulata is herein redescribed, illustrated, and a neotype is proposed based on recent material collected near the type locality. The diagnostic features include the presence of several dorsal, discontinuous longitudinal bands, interrupted by pale segmental spots; prostomium with tiny antennae; a tuberculated dorsal integument; acicular lobes double; and neurochaetal blades with guards approaching the distal tooth. The dorsal color pattern in life enables a clear distinction from similar species such as Hesione intertexta Grube, 1878 amongst others. Mitochondrial COI barcoding sequences are deposited in the DNA Data Bank of Japan. A key to Hesione species from Japan is also included.

Interplay between abiotic factors and species assemblages mediated by the ecosystem engineer Sabellaria alveolata (Annelida: Polychaeta)

NASA Astrophysics Data System (ADS)

Jones, Auriane G.; Dubois, Stanislas F.; Desroy, Nicolas; Fournier, Jérôme

2018-01-01

Sabellaria alveolata is a gregarious polychaete that uses sand particles to build three-dimensional structures known as reefs, fixed atop rocks or built on soft sediments. These structures are known to modify the local grain-size distribution and to host a highly diversified macrofauna, altered when the reef undergoes disturbances. The goal of this study was to investigate the different sedimentary and biological changes associated with the presence of a S. alveolata reef over two contrasting seasons (late winter and late summer), and how these changes were linked. Three different sediments were considered: the engineered sediment (the actual reef), the associated sediment (the soft sediment surrounding the reef structures) and a control soft sediment (i.e. no reef structures in close proximity). Univariate and multivariate comparisons of grain-size distribution, soft sediment characteristics (organic matter content, chlorophyll a, pheopigments and carbohydrate concentrations) and macrofauna were conducted between the different sediment types at both seasons and between the two seasons for each sediment type. A distance-based redundancy analyses (dbRDA) was used to investigate the link between the different environmental parameters and the macrofauna assemblages. Finally, we focused on a disturbance continuum of the engineered sediments proxied by an increase in the mud present in these sediments. The effects of a continuous and increasing disturbance on the associated fauna were investigated using pairwise beta diversity indices (Sørensen and Bray-Curtis dissimilarities and their decomposition into turnover and nestedness). Results showed a significant effect of the reef on the local sediment distribution (coarser sediments compared to the control) and on the benthic primary production (higher in the associated sediments). At both seasons, S. alveolata biomass and sediment principal mode were the environmental parameters which best differentiated the engineered, associated and control sediment assemblages. These two parameters are under the ecosystem engineer's influence stressing its importance in structuring benthic macrofauna. Furthermore, in late summer but not in late winter, presence/absence and abundance-based beta diversity were positively correlated to our disturbance proxy (mud content) a tendency driven by a species replacement and a rise in the associated fauna density. Our first set of results highlight the importance of S. alveolata reefs as benthic primary production enhancers via their physical structure and their biological activity. The results obtained using beta diversity indices emphasize the importance of recruitment in structuring the reef's macrofauna and - paradoxically - the ecological value of S. alveolata degraded forms as biodiversity and recruitment promoters.

Actinobdella inequinnulata (Annelida: Hirudinida:Rhynchobdellida:Glossiphoniidae) from White Crappie, Pomoxis annularis (Perciformes: Centrarchidae), in Arkansas, USA

EPA Science Inventory

One of 4 (25%) white crappie, Pomoxis annularis from the Ouachita River, Dallas County, Arkansas, was found to be infested with 8 glossiphoniid leeches, Actinobdella inequiannulata Moore, 1901. Leeches were removed from within the oeprculum on gills and gill arches. This leech i...

A new Capitella polychaete worm (Annelida: Capitellidae) living inside whale bones in the abyssal South Atlantic

NASA Astrophysics Data System (ADS)

Silva, Camila F.; Shimabukuro, Maurício; Alfaro-Lucas, Joan M.; Fujiwara, Yoshihiro; Sumida, Paulo Y. G.; Amaral, Antonia C. Z.

2016-02-01

A new species of the genus Capitella, Capitella iatapiuna sp. nov., has been found in deep sea whale-fall samples, São Paulo Ridge-Southwest Atlantic. The new species is mainly characterized by a bluntly rounded prostomium and a very distinct peristomium forming a complete ring. Ribosomal 16S sequences were obtained and used for inter-specific comparisons. This species is herein described and compared to others species of the genus. Its ecological role in the whale-fall community is also discussed.

Bone-boring worms: characterizing the morphology, rate, and method of bioerosion by Osedax mucofloris (Annelida, Siboglinidae).

PubMed

Higgs, Nicholas D; Glover, Adrian G; Dahlgren, Thomas G; Little, Crispin T S

2011-12-01

Osedax worms possess unique "root" tissues that they use to bore into bones on the seafloor, but details of the boring pattern and processes are poorly understood. Here we use X-ray micro-computed tomography to investigate the borings of Osedax mucofloris in bones of the minke whale (Balaenoptera acutorostrata), quantitatively detailing their morphological characteristics for the first time. Comparative thin-sections of the borings reveal how the bone is eroded at the sub-millimeter level. On the basis of these results we hypothesize a model of boring that is dependent on the density and microstructure of the bone. We also present evidence of acidic mucopolysaccharides in the mucus of the root tissue, and hypothesize that this plays an important role in the boring mechanism. We discuss the utility of these new data in evaluating Osedax trace fossils and their relevance for O. mucofloris ecology. Measured rates of bone erosion (6% per year) and evidence of enhanced sulfide release from the borings indicate that Osedax worms are important habitat modifiers in whale-fall communities.

Branchiosyllis, Haplosyllis, Opisthosyllis and Trypanosyllis (Annelida: Syllidae) from Brazil, with the Description of Two New Species

PubMed Central

Paresque, Karla; Fukuda, Marcelo Veronesi; Nogueira, João Miguel de Matos

2016-01-01

Brazilian specimens of Branchiosyllis cf. exilis, B. tamandarensis sp. n., Haplosyllis lattigae sp. n., H. loboi, Opisthosyllis brunnea and O. viridis are described and illustrated herein, from recently collected material; also, the distributions of Haplosyllis amphimedonicola and H. rosenalessoae are expanded to other localities in the states of Paraíba and Pernambuco. Branchiosyllis tamandarensis sp. n. was found associated with sponges and is characterized by having a flattened, ribbon-like body, with longitudinal line of mid-dorsal papillae, peristomium dorsally inconspicuous, branchiae with up to six lobes, branchiae and ungulae on all parapodia, and falcigers absent. Haplosyllis lattigae sp. n. is characterized by having two kinds of chaetae with different sizes and shapes per parapodium, papillate dorsum from midbody, and midbody dorsal cirri alternating in length. Additionally, we provide keys to the Brazilian species of Branchiosyllis, Haplosyllis and Opisthosyllis, comparative tables of the new species described herein and selected similar congeners, and the first record for Trypanosyllis zebra in the states of Espírito Santo and Paraíba. PMID:27144528

Availability of polycyclic aromatic hydrocarbons to earthworms (Eisenia andrei, Oligochaeta) in field-polluted soils and soil-sediment mixtures.

PubMed

Jager, Tjalling; Baerselman, Rob; Dijkman, Ellen; de Groot, Arthur C; Hogendoorn, Elbert A; de Jong, Ad; Kruitbosch, Jantien A W; Peijnenburg, Willie J G M

2003-04-01

The bioavailability of polycyclic aromatic hydrocarbons (PAHs) for earthworms (Eisenia andrei) was experimentally determined in seven field-polluted soils and 15 soil-sediment mixtures. The pore-water concentration of most PAHs was higher than predicted. However, most of the compound was associated with dissolved organic carbon (DOC) and not directly available for uptake by earthworms. The apparent sorption could be reasonably predicted on the basis of interactions with DOC; however, the biota-soil accumulation factors (BSAFs) for earthworms were up to two orders of magnitude lower than predicted by equilibrium partitioning. The large variability between sites was not fully explained by differences in sorption. Experimental results indicate that the pool of freely dissolved PAHs in the pore water became partially depleted because of uptake by the earthworms and that bioaccumulation is thus also influenced by the kinetics of PAH desorption and mass transport. A pilot study with Lumbricus rubellus showed that steady-state body residues were well correlated to E. andrei. Current results show that depositing dredge spoil on land may lead to increased bioavailability of the lower-molecular-weight PAHs. However, risk assessment can conservatively rely on equilibrium partitioning, but accurate prediction requires quantification of the kinetics of bioavailability.

Managing Earthworm Castings (Oligochaeta: Lumbricidae) in Turfgrass using a Natural By-Product of Tea Oil (Camellia sp.) Manufacture

USDA-ARS?s Scientific Manuscript database

Earthworm casts are a problem on golf courses and sport fields when they disrupt the playability, aesthetics, and maintenance of playing surfaces. Abundant earthworms alongside airport runways can increase bird strike risk. Currently no pesticides are labeled for earthworms in the United States. W...

Composition of macrobenthos in the Bakkhali channel system, Cox's Bazar with notes on soil parameter.

PubMed

Abu Hena, M K; Kohinoor, S M S; Siddique, M A M; Ismail, J; Idris, M H; Amin, S M N

2012-07-01

Macrobenthos in coastal environment that play a significant role in the food web. It could also use as a good indicator of aquatic ecosystem health. The abundance and composition of macrobenthos in Bakkhali channel system, Cox's Bazar were conducted in relation to the soil parameters. Samples were collected using Ekman Berge bottom grab from five different stations of Bakkhali channel. Macrobenthos were comprised of five major groups namely Polychaeta (9.96-30.31%), Oligochaeta (3.68-59.707%), Crustacea (0.02-58.40%), Bivalvia (1.40-82.09%) and Gastropoda (0.08-4.25%). Total number of macrobenthos was higher at station I (9000 individuals m(-2)) and station II (8517 individuals m(-2)) compared to other stations. Shannon diversity index among the stations ranged from 0.65-1.04. Soil pH and soil moisture ranged from 6.1-6.4 and 23.44-31.29%, respectively. The highest organic carbon concentration was observed at station I (2.11%) and lowest at station III (1.40%). Maximum fraction of sand by weight was found at stations II (81.88%) and III (87.88) while the highest fraction of clay (21.52%) and silt (8.0%) were recorded in station I. It was observed that benthic bivalves were positively correlated (r = 0.891, p > 0.05) with silt fraction of the sediments.

Occurrence of polycyclic aromatic hydrocarbons below coal-tar-sealed parking lots and effects on stream benthic macroinvertebrate communities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scoggins, M.; McClintock, N.L.; Gosselink, L.

2007-12-15

Parking-lot pavement sealants recently have been recognized as a major source of polycyclic aromatic hydrocarbons (PAHs) in urban stream sediments in Austin, Texas. Laboratory and field studies have shown that PAHs in sediments can be toxic to aquatic organisms and can degrade aquatic communities. After identifying increases in concentrations of PAHs in sediments below seal-coated parking lots, we investigated whether the increases had significant effects on stream biota in 5 Austin streams. We sampled sediment chemistry and biological communities above and below the point at which stormwater runoff from the parking lots discharged into the streams, thus providing 5 upstreammore » reference sites and 5 downstream treatment sites. Differences between upstream and downstream concentrations of total PAH ranged from 3.9 to 32 mg/kg. Analysis of the species occurrence data from pool and riffle habitats indicated a significant decrease in community health at the downstream sites, including decreases in richness, intolerant taxa, Diptera taxa, and density. In pool sediments, Chironomidae density was negatively correlated with PAH concentrations, whereas Oligochaeta density responded positively to PAH concentrations. In general, pool taxa responded more strongly than riffle taxa to PAHs, but riffle taxa responded more broadly than pool taxa. Increases in PAH sediment-toxicity units between upstream and downstream sites explained decreases in taxon richness and density in pools between upstream and downstream sites.« less

Assessing contamination in Great Lakes sediments using benthic invertebrate communities and the sediment quality triad approach

USGS Publications Warehouse

Canfield, Timothy J.; Dwyer, F. James; Fairchild, James F.; Haverland, Pamela S.; Ingersoll, Christopher G.; Kemble, Nile E.; Mount, David R.; La Point, Thomas W.; Burton, G. Allen; Swift, M. C.

1996-01-01

Sediments in many Great Lakes harbors and tributary rivers are contaminated. As part of the USEPA's Assessment and Remediation of Contaminated Sediment (ARCS) program, a number of studies were conducted to determine the nature and extent of sediment contamination in Great Lakes Areas of Concern (AOC). This paper describes the composition of benthic invertebrate communities in contaminated sediments and is one in a series of papers describing studies conducted to evaluate sediment toxicity from three AOC's (Buffalo River, NY; Indiana Harbor, IN; Saginaw River, MI), as part of the ARCS Program. Oligochaeta (worms) and Chironomidae (midge) comprised over 90% of the benthic invertebrate numbers in samples collected from depositional areas. Worms and midge consisted of taxa identified as primarily contaminant tolerant organisms. Structural deformities of mouthparts in midge larvae were pronounced in many of the samples. Good concurrence was evident between measures of laboratory toxicity, sediment contaminant concentration, and benthic invertebrate community composition in extremely contaminated samples. However, in moderately contaminated samples, less concordance was observed between the benthos community composition and either laboratory toxicity test results or sediment contaminant concentration. Laboratory sediment toxicity tests may better identify chemical contamination in sediments than many commonly used measures of benthic invertebrate community composition. Benthic measures may also reflect other factors such as habitat alteration. Evaluation of non-contaminant factors are needed to better interpret the response of benthic invertebrates to sediment contamination.

Ecological effects of rubble-mound breakwater construction and channel dredging at West Harbor, Ohio (western Lake Erie)

USGS Publications Warehouse

Manny, Bruce A.; Schloesser, Donald W.; Brown, Charles L.; French, John R. P.

1985-01-01

The investigation reported herein indicated that breakwater construction and associated channel dredging activities by the US Army Corps of Engineers in western Lake Erie at the entrance to West Harbor (Ohio) had no detectable adverse impacts on the distributions or abundances of macrozoobenthos and fishes. Rather, increases were noted in the number of fish eggs and larvae and in the density and biomass of periphyton and macrozoobenthos on and near the breakwaters. The area also served as a nursery ground for 20 species of fishes both during and after construction and dredging activities. Colonization of the breakwaters by periphyton, primarily a green alga (Cladophora glomerata), diatoms (Gomphonema parvulum), and a bluegreen alga (Oscillatoria tenuis), and by macrozoobenthos, primarily worms (Oligochaeta), amphipods (Gammarus spp.), and midge larvae (Chironomidae), was rapid and extensive, indicating that the breakwaters provided new, favorable habitat for primary and secondary producer organisms. Marked adverse changes in water quality, especially reduced dissolved oxygen concentrations (25 mg/l), occurred around the entrance to West Harbor in 1983 following cessation of construction and dredging activities. These water quality changes, however, could not be ascribed with certainty to construction and dredging activities at West Harbor. Construction of additional breakwaters in the study area at that time by the State of Ohio served to confound determination of the responsible causal factors.

Assessment of benthic macroinvertebrates at Nile tilapia production using artificial substrate samplers.

PubMed

Moura E Silva, M S G; Graciano, T S; Losekann, M E; Luiz, A J B

2016-05-17

Biomonitoring is a cheap and effective tool for evaluation of water quality, and infer on the balance of aquatic ecosystems. The benthic macroinvertebrates are bioindicators sensitive to environmental changes, and can assist in detecting and preventing impacts such as organic enrichment and imbalance in the food chain. We compared the structure of benthic communities on artificial substrate samplers located in places near and far from net cages for production of Nile tilapia (Oreochromis niloticus). Samplers were manufactured with nylon net, using substrates such as crushed stone, gravel, loofah and cattail leaves. Samples were collected after 30 days of colonization, rinsed and then the specimens were identified and quantified. The following metrics were calculated: richness of Operational Taxonomic Units, Margalef richness, abundance of individuals, Shannon index and evenness index. The macrobenthic community structure was strongly modified according to the proximity of the net cages. Metrics showed significant differences (p < 0.05) between near and distant sites, for both periods (dry and rainy seasons). The position of the samplers significantly affected the structure of macroinvertebrate community, as near sites showed higher values for the community metrics, such as richness and diversity. Near sites presented a larger number of individuals, observed both in the dry and rainy seasons, with a predominance of Chironomidae (Diptera) in the dry season and Tubificidae (Oligochaeta) in the rainy season.

Does biodiversity of macroinvertebrates and genome response of Chironomidae larvae (Diptera) reflect heavy metal pollution in a small pond?

PubMed

Michailova, Paraskeva; Warchałowska-Śliwa, Elzbieta; Szarek-Gwiazda, Ewa; Kownacki, Andrzej

2012-01-01

The investigation was carried out on a small pond situated on a recent mine spoil at Bolesław in the Olkusz region with Zn-Pb ore deposits. Water of the pond had pH 7.2-8.5 and low concentrations of heavy metals. Concentrations of Pb (487 μg g( - 1)) and Zn (1,991 μg g( - 1)) in the sediment were very high and potentially could lead to toxicological effects. In the pond, 48 taxa of macroinvertebrates belonging to Oligochaeta and water stages of Ephemeroptera, Odonata, Megaloptera, Trichoptera, Heteroptera, Coleoptera and Diptera (mainly Chironomidae family) were found. The influence of heavy metals on macroinvertebrates diversity was not found. Effect of heavy metal pollution was observed on the appearance of chromosome aberrations in the polytene chromosomes of Chironomidae larvae. It was manifested by two ways: (1) in Kiefferulus tendipediformis and Chironomus sp. chromosome rearrangements in fixed state (tandem fusion and homozygous inversions), indicated intensive process of speciation; (2) in Chironomus sp., K. tendipediformis, Glyptotendipes gripekoveni (Chironomidae) somatic chromosome rearrangements (inversions, deficiencies, specific puffs, polyploidy) affected few cells of every individual. The somatic functional and structural alterations in Chironomidae species are particular suitable as biomarkers-they can be easily identified and used for detecting toxic agents in the environment.

[Structure and function of Fenshuijiang Reservoir ecosystem based on the analysis with Ecopath model].

PubMed

Wu, Zhen; Jia, Pei-Qiao; Hu, Zhong-Jun; Chen, Li-Qiao; Gu, Zhi-Min; Liu, Qi-Gen

2012-03-01

Based on the 2008-2009 survey data of fishery resources and eco-environment of Fenshuijiang Reservoir, a mass balance model for the Reservoir ecosystem was constructed by Ecopath with Ecosim software. The model was composed of 14 functional groups, including silver carp, bighead carp, Hemibarbus maculates, Cutler alburnus, Microlepis and other fishes, Oligochaeta, aquatic insect, zooplankton, phytoplankton, and organic detritus, etc. , being able to better simulate Fenshuijiang Reservoir ecosystem. In this ecosystem, there were five trophic levels (TLs), and the nutrient flow mainly occurred in the first three TLs. Grazing and detritus food chains were the main energy flows in the ecosystem, but the food web was simpler and susceptible to be disturbed by outer environment. The transfer efficiency at lower TLs was relatively low, indicating that the ecosystem had a lower capability in energy utilization, and the excessive stock of nutrients in the ecosystem could lead to eutrophication. The lower connectance index, system omnivory index, Finn' s cycled index, and Finn's mean path length demonstrated that the ecosystem was unstable, while the high ecosystem property indices such as Pp/R and Pp/B showed that the ecosystem was immature and highly productive. It was suggested that Fenshuijiang Reservoir was still a developing new reservoir ecosystem, with a very short history and comparatively high primary productivity.

The impact of fossil data on annelid phylogeny inferred from discrete morphological characters.

PubMed

Parry, Luke A; Edgecombe, Gregory D; Eibye-Jacobsen, Danny; Vinther, Jakob

2016-08-31

As a result of their plastic body plan, the relationships of the annelid worms and even the taxonomic makeup of the phylum have long been contentious. Morphological cladistic analyses have typically recovered a monophyletic Polychaeta, with the simple-bodied forms assigned to an early-diverging clade or grade. This is in stark contrast to molecular trees, in which polychaetes are paraphyletic and include clitellates, echiurans and sipunculans. Cambrian stem group annelid body fossils are complex-bodied polychaetes that possess well-developed parapodia and paired head appendages (palps), suggesting that the root of annelids is misplaced in morphological trees. We present a reinvestigation of the morphology of key fossil taxa and include them in a comprehensive phylogenetic analysis of annelids. Analyses using probabilistic methods and both equal- and implied-weights parsimony recover paraphyletic polychaetes and support the conclusion that echiurans and clitellates are derived polychaetes. Morphological trees including fossils depict two main clades of crown-group annelids that are similar, but not identical, to Errantia and Sedentaria, the fundamental groupings in transcriptomic analyses. Removing fossils yields trees that are often less resolved and/or root the tree in greater conflict with molecular topologies. While there are many topological similarities between the analyses herein and recent phylogenomic hypotheses, differences include the exclusion of Sipuncula from Annelida and the taxa forming the deepest crown-group divergences. © 2016 The Authors.

Unusually Long Palindromes Are Abundant in Mitochondrial Control Regions of Insects and Nematodes

PubMed Central

Arunkumar, K. P.; Nagaraju, Javaregowda

2006-01-01

Background Palindromes are known to be involved in a variety of biological processes. In the present investigation we carried out a comprehensive analysis of palindromes in the mitochondrial control regions (CRs) of several animal groups to study their frequency, distribution and architecture to gain insights into the origin of replication of mtDNA. Methodology/Principal Findings Many species of Arthropoda, Nematoda, Mollusca and Annelida harbor palindromes and inverted repeats (IRs) in their CRs. Lower animals like cnidarians and higher animal groups like chordates are almost devoid of palindromes and IRs. The study revealed that palindrome occurrence is positively correlated with the AT content of CRs, and that IRs are likely to give rise to longer palindromes. Conclusions/Significance The present study attempts to explain possible reasons and gives in silico evidence for absence of palindromes and IRs from CR of vertebrate mtDNA and acquisition and retention of the same in insects. Study of CRs of different animal phyla uncovered unique architecture of this locus, be it high abundance of long palindromes and IRs in CRs of Insecta and Nematoda, or short IRs of 10–20 nucleotides with a spacer region of 12–14 bases in subphylum Chelicerata, or nearly complete of absence of any long palindromes and IRs in Vertebrata, Cnidaria and Echinodermata. PMID:17205114

Testing the new animal phylogeny: a phylum level molecular analysis of the animal kingdom.

PubMed

Bourlat, Sarah J; Nielsen, Claus; Economou, Andrew D; Telford, Maximilian J

2008-10-01

The new animal phylogeny inferred from ribosomal genes some years ago has prompted a number of radical rearrangements of the traditional, morphology based metazoan tree. The two main bilaterian clades, Deuterostomia and Protostomia, find strong support, but the protostomes consist of two sister groups, Ecdysozoa and Lophotrochozoa, not seen in morphology based trees. Although widely accepted, not all recent molecular phylogenetic analyses have supported the tripartite structure of the new animal phylogeny. Furthermore, even if the small ribosomal subunit (SSU) based phylogeny is correct, there is a frustrating lack of resolution of relationships between the phyla that make up the three clades of this tree. To address this issue, we have assembled a dataset including a large number of aligned sequence positions as well as a broad sampling of metazoan phyla. Our dataset consists of sequence data from ribosomal and mitochondrial genes combined with new data from protein coding genes (5139 amino acid and 3524 nucleotide positions in total) from 37 representative taxa sampled across the Metazoa. Our data show strong support for the basic structure of the new animal phylogeny as well as for the Mandibulata including Myriapoda. We also provide some resolution within the Lophotrochozoa, where we confirm support for a monophyletic clade of Echiura, Sipuncula and Annelida and surprising evidence of a close relationship between Brachiopoda and Nemertea.

[Phylogenetic analysis of tyrosinase gene family in the Pacific oyster (Crassostrea gigas Thunberg)].

PubMed

Yu, Xue; Yu, Hong; Kong, Lingfeng; Li, Qi

2014-02-01

The deduced amino acid sequence characteristics, classification and phylogeny of tyrosinase gene family in the Pacific oyster (Crassostrea gigas Thunberg) were analyzed using bioinformatics methods. The results showed that gene duplication was the major cause of tyrosinase gene expansion in the Pacific oyster. The tyrosinase gene family in the Pacific oyster can be further classified into three types: secreted form (Type A), cytosolic form (Type B) and membrane-bound form (Type C). Based on the topology of the phylogenetic tree of the Pacific oyster tyrosinases, among Type A isoforms, tyr18 seemed divergent from other Type A tyrosinases early, while tyr2 and tyr9 appeared divergent early in Type B. In Type C tyrosinses, tyr8 was divergent early. The cluster of the Pacific oyster tyrosinasesis determined by their classifications and positions in the scaffolds. Further analysis suggested that Type A tyrosinases of C. gigas clustered with those from cephalopods and then with nematodes and cnidarians. Type B tyrosinases were generally clustered with the same type of tyrosinases from molluscas and nematodes, and then with those from platyhelminths, cnidarians and chordates. Type A tyrosinases in the Pacific oyster and the Pearl oyster expanded independently and were divergent from membrane-bound form of tyrosinases in chordata, platyhelminthes and annelida. These observations suggested that Type C tyrosinases in the bivalve had a distinct evolution direction.

Environmental DNA metabarcoding reveals primary chemical contaminants in freshwater sediments from different land-use types.

PubMed

Xie, Yuwei; Wang, Jizhong; Yang, Jianghua; Giesy, John P; Yu, Hongxia; Zhang, Xiaowei

2017-04-01

Land-use intensification threatens freshwater biodiversity. Freshwater eukaryotic communities are affected by multiple chemical contaminants with a land-use specific manner. However, biodiversities of eukaryotes and their associations with multiple chemical contaminants are largely unknown. This study characterized in situ eukaryotic communities in sediments exposed to mixtures of chemical contaminants and assessed relationships between various environmental variables and eukaryotic communities in sediments from the Nanfei River. Eukaryotic communities in the sediment samples were dominated by Annelida, Arthropoda, Rotifera, Ochrophyta, Chlorophyta and Ciliophora. Alpha-diversities (Shannon entropy) and structures of eukaryotic communities were significantly different between land-use types. According to the results of multiple statistical tests (PCoA, distLM, Mantel and network analysis), dissimilarity of eukaryotic community structures revealed the key effects of pyrethroid insecticides, manganese, zinc, lead, chromium and polycyclic aromatic hydrocarbons (PAHs) on eukaryotic communities in the sediment samples from the Nanfei River. Furthermore, taxa associated with land-use types were identified and several sensitive eukaryotic taxa to some of the primary contaminants were identified as potential indicators to monitor effects of the primary chemical contaminants. Overall, environmental DNA metabarcoding on in situ eukaryotic communities provided a powerful tool for biomonitoring and identifying primary contaminants and their complex effects on benthic eukaryotic communities in freshwater sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genetic diversity of Timarete punctata (Annelida: Cirratulidae): Detection of pseudo-cryptic species and a potential biological invader

NASA Astrophysics Data System (ADS)

Seixas, Victor Corrêa; Zanol, Joana; Magalhães, Wagner F.; Paiva, Paulo Cesar

2017-10-01

Among the processes that drive biological invasions, the presence of asexual reproduction, as observed in many polychaetes, is an important feature because it allows a rapid spread and colonization in the invaded site. Despite its ecological importance for benthic communities, studies on the biological invasive context are rare for this abundant taxon. Here, the phylogeographic pattern of a common asexual reproducer polychaete, Timarete punctata, was analyzed at five sites along the Atlantic and Pacific Oceans to investigate if its wide distribution is associated to human-mediated transport. Sequences of COI and 16S revealed the presence of two cryptic species. One of them exhibits a wide distribution range (∼14,000 km), very low level of genetic diversity and a high frequency of shared haplotypes along sampled sites. The genetic pattern indicates that this species has probably been introduced in all sampled sites, and its wide distribution is associated to human-mediated transport. In addition, the great capability of T. punctata to reproduce by fragmentation makes the colonization process easier. Thus, the number of alien polychaete species is probably underestimated and future studies are necessary to reach a more realistic perspective.

Biodiversity and distribution of polynoid and spionid polychaetes (Annelida) in the Vema Fracture Zone, tropical North Atlantic

NASA Astrophysics Data System (ADS)

Guggolz, Theresa; Lins, Lidia; Meißner, Karin; Brandt, Angelika

2018-02-01

During the Vema-TRANSIT (Bathymetry of the Vema-Fracture Zone and Puerto Rico TRench and Abyssal AtlaNtic BiodiverSITy Study) expedition from December, 2014 to January, 2015, a transect along the Vema Fracture Zone in the equatorial Atlantic was surveyed and sampled at about 10°N. The Vema Fracture Zone is one of the largest fracture zones of the Mid-Atlantic Ridge and it is characterized by a large left-lateral offset. Benthic communities of the transect and the abyssal basins on both sides were investigated to examine whether the Mid-Atlantic Ridge serves as a physical barrier for these organisms, or if there is a potential connection from east to west via the Vema Fracture Zone. Samples comprised 4149 polychaetes, belonging to 42 families. Exemplary, Polynoidae and Spionidae, both typical deep-sea families with high abundances in all investigated regions, were identified up to species level. The present results show significant differences in polychaete faunistic composition between both sides of the Mid-Atlantic Ridge. Moreover, the eastern and western Vema Fracture Zone characterizes divergent habitats, since the two basins differ in sedimentology and environmental variables (e.g. temperature, salinity), hence characterizing divergent habitats. Most species found were restricted to either eastern or western VFZ, but there was a trans-Mid-Atlantic Ridge distribution of certain abundant species observed, indicating that the Mid-Atlantic Ridge might rather act limiting to dispersal between ocean basins than as an absolute barrier. Given the abyssal valley formed by the Vema Fracture Zone and its role in oceanic currents, this seafloor feature may well represent exchange routes between eastern and western faunas.

BIOLOGY AND OCCURRENCE OF THE LEECH, ACTINOBDELLA INEQUIANNULATA (ANNELIDA: HIRUDINEA: GLOSSIPHONIIDAE) PARASITIC ON TWO SPECIES OF SUCKERS

EPA Science Inventory

Actinobdella inequiannulata was found on the white sucker, Catostomus commersoni, and less frequently on the longnose sucker, Catostomus catostomus, in Algonquin Provincial Park, Ontario, Canada. This study established the presence of only one species of leech, Actinobdela inequ...

Demystifying the Capitella capitata complex (Annelida, Capitellidae) diversity by morphological and molecular data along the Brazilian coast

PubMed Central

Di Domenico, Maikon; Amaral, Antonia C. Z.; Paiva, Paulo C.

2017-01-01

The sibling species of Capitella capitata are globally known for their tolerance to disturbed habitats and the C. capitata complex is often used as an ecological indicator. A recent re-description proposed that C. capitata, originally described in Greenland is restricted to the Artic and Subarctic regions. Given their ecological relevance, we conducted a morphological and molecular analyses based on mtDNA sequences to investigate the diversity and distribution of the C. capitata complex along the Brazilian coast. Our morphological and molecular data were congruent and revealed the existence of four new species distinct from C. capitata, collected from the type locality. This study is the first characterization of the biodiversity and distribution of Capitella species made along the Brazilian coast and yielded a set of morphological characters corroborated by the mtDNA sequences for species identification. Our results increase the biodiversity of the genus along the Brazilian coast by describing four new species (Capitella aracaensis sp. n., Capitella biota sp. n., Capitella neoaciculata sp. n. and Capitella nonatoi sp. n.). One species was collected from only one sampling site, while the others are distributed along the coast. PMID:28562616

Review of the Capitellidae (Annelida, Polychaeta) from the Eastern Tropical Pacific region, with notes on selected species

PubMed Central

García-Garza, María Elena; León-González, Jesús Angel De

2011-01-01

Abstract The main objective of this work is to contribute to the taxonomic knowledge of the species of Capitellidae reported for the Eastern Tropical Pacific. This catalogue includes the original name of each species, new names, synonymies, type localities, the museum or institution where the type material is deposited, revision of the material reported for the region by different authors, new examined material, previous reports from other regions of the world, and comments on systematics and distributions. The catalogue lists 43 species in 19 genera. Of these, 6 species were erroneously recorded for the region (Decamastus gracilis Hartman, 1963; Decamastus nudus Thomassin, 1970; Mastobranchus variabilis Edwing, 1984; Notomastus aberans Day, 1957; Notomastus americanus Day, 1973; Notomastus latericeus Sars, 1851) and 5 species are found here to be questionable records for the Eastern Tropical Pacific (Capitella capitata (Fabricius, 1780); Dasybranchus glabrus Moore, 1909; Decamastus lumbricoides Grube, 1878; Notomastus lineatus Claparède, 1870 and Notomastus tenuis Moore, 1909). PMID:22368451

A new species of Pectinaria (Annelida, Pectinariidae), with a key to pectinariids from the South China Sea.

PubMed

Zhang, Jinghuai; Qiu, Jian-Wen

2017-01-01

Pectinariidae is a family of polychaetes building unique ice-cream cone shaped sandy tubes. Pectinaria torquata sp. n. (Pectinariidae) is described from the coastal waters of the northern South China Sea. This new species can be distinguished from all other 25 recognized species in the genus by a combination of characters: 16 chaetigers; 26-32 cirri in the cephalic veil; 11-12 pairs of cephalic spines; uncini with major teeth arranged in two rows, each with 7-8 major teeth; presence of a dorsal posterior lobe on segments 2 and 20; 4-5 pairs of curved scaphal hooks; and an anal flap with a crenulated margin. A key to all recognized pectinariids in the South China Sea is provided.

Diversity of Sternaspidae (Annelida: Terebellida) in the South China Sea, with descriptions of four new species.

PubMed

Wu, Xuwen; Xu, Kuidong

2017-03-20

Sternaspidae is one of the most common groups of polychaetes in the South China Sea, where however, the knowledge of its diversity and distribution is insufficiently understood and reports of the European species Sternaspis scutata are misidentifications. Based on the examination of material deposited in the Marine Biological Museum of the Chinese Academy of Sciences, we made a comprehensive investigation on the sternaspid polychaetes in the northern South China Sea. Five species belonging to two genera are described: Petersenaspis salazari sp. nov., Sternaspis radiata sp. nov., S. spinosa Sluiter, 1882, S. sunae sp. nov. and S. wui sp. nov. A taxonomic key to ten species of Sternaspidae found in the South China Sea is provided.

A new species of Pectinaria (Annelida, Pectinariidae), with a key to pectinariids from the South China Sea

PubMed Central

Zhang, Jinghuai; Qiu, Jian-Wen

2017-01-01

Abstract Pectinariidae is a family of polychaetes building unique ice-cream cone shaped sandy tubes. Pectinaria torquata sp. n. (Pectinariidae) is described from the coastal waters of the northern South China Sea. This new species can be distinguished from all other 25 recognized species in the genus by a combination of characters: 16 chaetigers; 26–32 cirri in the cephalic veil; 11–12 pairs of cephalic spines; uncini with major teeth arranged in two rows, each with 7–8 major teeth; presence of a dorsal posterior lobe on segments 2 and 20; 4–5 pairs of curved scaphal hooks; and an anal flap with a crenulated margin. A key to all recognized pectinariids in the South China Sea is provided. PMID:28769730

Sternaspidae (Annelida, Sedentaria) from Vietnam with description of three new species and clarification of some morphological features.

PubMed

Zhadan, Anna E; Tzetlin, Alexander B; Salazar-Vallejo, Sergio I

2017-01-25

Five sternaspid species were found near Vietnam shores: Sternaspis britayevi sp. nov., S. costata von Marenzeller, 1879, S. nana sp. nov., S. papillosa sp. nov., and S. spinosa Sluiter 1882. Sternaspis britayevi is described from the shallow water in Vietnam inhabiting soft bottoms; it resembles S. spinosa described from Java and S. thorsoni Sendall & Salazar-Vallejo, 2013 described from the Persian Gulf, but differs in having a medially projected and markedly ribbed fan of the ventro-caudal shield and nearly parallel, distally widened and rounded branchial plates. Sternaspis nana sp. nov. is described from Nha Trang Bay; it differs from the other known species by the combination of the following characters: small size, evenly distributed micropapillae and regular rows of long cirriform papillae; posterior chaetal fascicles consisting of single thick chaeta; a ventral shield with smooth integument, without ribs and usually without concentric lines. Sternaspis papillosa sp. nov. is also described from Nha Trang Bay; it resembles S. africana Augener, 1918 and S. andamanensis Sendall & Salazar-Vallejo, 2013 by having similar ventro-caudal shields but differs by body papillation and details of the ventro-caudal shield. Based upon observations of different species some morphological features are clarified: 1) notochaetae are present in introvert chaetigers as delicate capillaries; 2) peg-chaetae are really a dense group of more than 100 thin individual chaetae, embedded in a fibrous matrix, and covered by a common sheath; 3) the pharynx is an eversible, lobed, axial non-muscular proboscis with a ciliated surface; 4) the body cavity is divided by three septa in the anterior body region, and there are no other septa; and 5) an eversible anal peduncle is confirmed, as has been shown by early taxonomists.

A new Notomastus (Annelida, Capitellidae) species from Korean waters, with genetic comparison based on three gene markers.

PubMed

Jeong, Man-Ki; Soh, Ho Young; Wi, Jin Hee; Suh, Hae-Lip

2018-01-01

Notomastus koreanus sp. n. , collected from the sublittoral muddy bottom of Korean waters, is described as a new species. The Korean new species closely resembles N. torquatus Hutchings & Rainer, 1979 in the chaetal arrangement and the details of abdominal segments, but differs in the position of genital pores and the absence of eyes. DNA sequences (mtCOI, 16S rRNA, and histone H3) of the new species were compared with all the available sequences of Notomastus species in the GenBank database. Three genes showed significant genetic differences between the new species and its congeners (COI: 51.2%, 16S: 38.1-47.3%, H3: 3.7-9.3%). This study also includes a comprehensive comparison of the new Korean Notomastus species with its most closely similar species, based on the morphological and genetic results.

Rhynchelmis subgenus Sutroa Eisen new rank, with two new species from western North America (Annelida, Clitellata, Lumbriculidae)

USGS Publications Warehouse

Fend, Steven V.; Carter, James L.

2014-01-01

The lumbriculid Rhynchelmis subgenus Sutroa Eisen, 1888 new rank is defined for a group of Nearctic species having multiple diverticula originating at the spermathecal ducts and eversible penial bulbs. Characters are confirmed in specimens of the type species, Rhynchelmis (Sutroa) rostrata (Eisen, 1888), collected from the type locality. Rhynchelmis (Sutroa) klamathensis Fend n. sp. is described from open water benthic habitats in Upper Klamath Lake, Oregon, USA. It resembles other R. (Sutroa) species in the paired spermathecal diverticula, the spermathecal and penial bulbs, the histological structure of the atria, the nonfunctional anterior male funnels, and the arrangement of blood vessels. Rhynchelmis klamathensis differs from all Nearctic Rhynchelmis in lacking a filiform proboscis. The combination of large body size, the elongate spermathecal ducts with paired and usually unbranched diverticula, the highly contorted atria, and the complex male pores with conical penes also distinguish typical R. klamathensis from other Rhynchelmis species. Smaller specimens with otherwise similar morphology, from the Sacramento River Delta, California, are also assigned to this species. Rhynchelmis (Sutroa) diespluviae Fend n. sp. is described from several stream sites, mostly in northern Idaho, USA. Rhynchelmis diespluviae differs from closely related species in morphology of the conical penes, and in the structure and anterolateral position of the paired spermathecae.

Use of Amynthas gracilis (Oligochaeta, Megascolecidae) and Bougainvillea litter for rehabilitation of overexploited soils, in Campeche, Yucatan Peninsula, Mexico.

NASA Astrophysics Data System (ADS)

Huerta, Esperanza; Alonso Gongora, Erick

2014-05-01

Yucatan peninsula is one of the recent emerged lands in Mexico; where more of the soils have low organic matter content, and/or the organic horizon is thin (2-5cm). The industry of material extraction for construction purposes is well developed in Yucatan Peninsula, due to the fact of the calcareous material that can be obtained by the maternal rock. Therefore, the material extraction promotes the desertification of the areas, and soil erosion. Bougainvillea sp is a tropical and subtropical woody, evergreen, shrubby vine (Kobayashi et al. 2007), it has a wide range of distribution and it roots are superficial, what allows the plant to inhabit soils with a thin layer of soil organic matter. Earthworms as ecosystem engineers (Jones et al. 1994) can modify their environment, forming borrows and incorporation organic matter into the soil. The aim of this study was to rehabilitate soils without organic matter horizon by the use of earthworms and Bougainvillea litter. The study was developed at mesocosmos level in the laboratory of soils at El Colegio de la Frontera Sur, Unidad Campeche, Mexico. Individual of anecic earthworms were collected and reproduced previously, anecic worms can better incorporate organic matter in to the soil than epigeics or endogeics worms, in Mexican tropical terrestrial ecosystems, anecic worms are almost absent or scarce. In this study we used the exotic earthworm Amynthas gracilis (native in Taiwan),that used to inhabit banana plantations with low technology in southeast Mexico, as exotic has a wide range of tolerance to different amounts of soil organic matter and pH. Four treatments with 4 replicas were established: a) calcareous soil without organic matter horizon+earthworms+litter, b) calcareous soil with organic matter horizon+ earthworms+litter, c) calcareous soil without organic matter horizon+litter, d) calcareous soil with organic matter horizon+litter. After 60 days of study, we observed how earthworms developed successfully in treatments with and without organic matter horizon. Higher amount of litter was incorporated into the soil in those treatments with earthworms. Soil invertebrates populated those treatments with organic matter and earthworms. This study shows that Bougainvillea sp and A. gracilis can be a good combination for rehabilitation of soils without organic matter layer in tropics. Further studies are required in order to observe same results at the field level.

Effects of the herbicide isoproturon on metallothioneins, growth, and antioxidative defenses in the aquatic worm Tubifex tubifex (Oligochaeta, Tubificidae).

PubMed

Mosleh, Yahia Y; Paris-Palacios, Séverine; Couderchet, Michel; Biagianti-Risbourg, Sylvie; Vernet, Guy

2005-07-01

Metallothioneins (MTs) are low molecular weight proteins, mainly implicated in metal ion detoxification. Increase in MT contents is considered to be a specific biomarker of metal exposure. Recently it has been demonstrated that MTs participate in several cellular functions such as regulation of growth, and antioxidative defenses. Therefore, the induction of MTs as biomarkers of exposure to the pesticide isoproturon has been investigated in the aquatic worms Tubifex tubifex. MT levels in exposed worms increased significantly (p < 0.05) after 2, 4, and 7 days of exposure to different concentrations of isoproturon (maximum increase compared to unexposed controls: +148.56% for 10 mg l(-1) after 4 days of exposure). In response to isoproturon, the activity of glutathione-S-transferase (max. +52%), glutathione-reductase (max. +100%), and catalase (max. +117%) increased, demonstrating the occurrence of an oxidative stress response to the herbicide. Thus, the increase in MT contents caused by isoproturon was interpreted as a defense response towards increased oxidative stress generated by the herbicide. Residues of isoproturon and its metabolites, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl) urea, and 4-isopropylanilin were detected in the worm growth medium. Half-life of the herbicide was shorter at a low (0.1 mg l(-1)) initial concentration. The herbicide accumulated in T. tubifex but no metabolite could be detected.

Sabellaria spinulosa (Polychaeta, Annelida) reefs in the Mediterranean Sea: Habitat mapping, dynamics and associated fauna for conservation management

NASA Astrophysics Data System (ADS)

Gravina, Maria Flavia; Cardone, Frine; Bonifazi, Andrea; Bertrandino, Marta Simona; Chimienti, Giovanni; Longo, Caterina; Marzano, Carlotta Nonnis; Moretti, Massimo; Lisco, Stefania; Moretti, Vincenzo; Corriero, Giuseppe; Giangrande, Adriana

2018-01-01

Bio-constructions by Sabellaria worms play a key functional role in the coastal ecosystems being an engineer organism and for this reason are the object of protection. The most widespread reef building species along Atlantic and Mediterranean coasts is S. alveolata (L.), while the aggregations of S. spinulosa are typically limited to the North Sea coasts. This paper constitutes the first detailed description of unusual large S. spinulosa reefs in the Mediterranean Sea. Defining current health status and evaluating the most important threats and impacts is essential to address conservation needs and design management plans for these large biogenic structures. Present knowledge on Mediterranean reefs of S. alveolata is fragmentary compared to Northeast Atlantic reefs, and concerning S. spinulosa, this paper represents a focal point in the knowledge on Mediterranean reefs of this species. A one-year study on temporal changes in reef structure and associated fauna is reported. The annual cycle of S. spinulosa reef shows a spawning event in winter-early spring, a period of growth and tubes aggregation from spring-early summer to autumn and a degeneration phase in winter. The variations exhibited in density of the worm aggregation and the changes in the reef elevation highlight a decline and regeneration of the structure over a year. The many ecological roles of the S. spinulosa reef were mainly in providing a diversity of microhabitats hosting hard and sandy bottom species, sheltering rare species, and producing biogenic structures able to provide coastal protection. The Mediterranean S. spinulosa reef does not shelter a distinctive associated fauna; however the richness in species composition underscores the importance of the reef as a biodiversity hot-spot. Finally, the roles of the biogenic formations and their important biotic and physical dynamics support the adoption of strategies for conservation of Mediterranean S.spinulosa reefs, according to the aims of the Habitat Directive.

The Potent Respiratory System of Osedax mucofloris (Siboglinidae, Annelida) - A Prerequisite for the Origin of Bone-Eating Osedax?

PubMed Central

Huusgaard, Randi S.; Vismann, Bent; Kühl, Michael; Macnaugton, Martin; Colmander, Veronica; Rouse, Greg W.; Glover, Adrian G.; Dahlgren, Thomas; Worsaae, Katrine

2012-01-01

Members of the conspicuous bone-eating genus, Osedax, are widely distributed on whale falls in the Pacific and Atlantic Oceans. These gutless annelids contain endosymbiotic heterotrophic bacteria in a branching root system embedded in the bones of vertebrates, whereas a trunk and anterior palps extend into the surrounding water. The unique life style within a bone environment is challenged by the high bacterial activity on, and within, the bone matrix possibly causing O2 depletion, and build-up of potentially toxic sulphide. We measured the O2 distribution around embedded Osedax and showed that the bone microenvironment is anoxic. Morphological studies showed that ventilation mechanisms in Osedax are restricted to the anterior palps, which are optimized for high O2 uptake by possessing a large surface area, large surface to volume ratio, and short diffusion distances. The blood vascular system comprises large vessels in the trunk, which facilitate an ample supply of oxygenated blood from the anterior crown to a highly vascularised root structure. Respirometry studies of O. mucofloris showed a high O2 consumption that exceeded the average O2 consumption of a broad line of resting annelids without endosymbionts. We regard this combination of features of the respiratory system of O. mucofloris as an adaptation to their unique nutrition strategy with roots embedded in anoxic bones and elevated O2 demand due to aerobic heterotrophic endosymbionts. PMID:22558289

A new species and the shallowest record of Flabegraviera Salazar-Vallejo, 2012 (Annelida: Flabelligeridae) from Antarctica.

PubMed

Jimi, Naoto; Tsujimoto, Megumu; Watanabe, Kentaro; Kakui, Keiichi; Kajihara, Hiroshi

2017-01-19

A new species of polychaete, Flabegraviera fujiae sp. nov., is described and the first report of F. mundata (Gravier, 1906) from the shallow water around Syowa Station, Antarctica, is presented. Flabegraviera fujiae sp. nov. resembles F. profunda Salazar-Vallejo, 2012 but is discriminated from the latter by having eyes and an exposed cephalic cage. The specimen of F. mundata was collected from a depth of 8 m, providing the shallowest record of this species to date.

Are Fireworms Venomous? Evidence for the Convergent Evolution of Toxin Homologs in Three Species of Fireworms (Annelida, Amphinomidae)

PubMed Central

Simpson, Danny

2018-01-01

Abstract Amphinomids, more commonly known as fireworms, are a basal lineage of marine annelids characterized by the presence of defensive dorsal calcareous chaetae, which break off upon contact. It has long been hypothesized that amphinomids are venomous and use the chaetae to inject a toxic substance. However, studies investigating fireworm venom from a morphological or molecular perspective are scarce and no venom gland has been identified to date, nor any toxin characterized at the molecular level. To investigate this question, we analyzed the transcriptomes of three species of fireworms—Eurythoe complanata, Hermodice carunculata, and Paramphinome jeffreysii—following a venomics approach to identify putative venom compounds. Our venomics pipeline involved de novo transcriptome assembly, open reading frame, and signal sequence prediction, followed by three different homology search strategies: BLAST, HMMER sequence, and HMMER domain. Following this pipeline, we identified 34 clusters of orthologous genes, representing 13 known toxin classes that have been repeatedly recruited into animal venoms. Specifically, the three species share a similar toxin profile with C-type lectins, peptidases, metalloproteinases, spider toxins, and CAP proteins found among the most highly expressed toxin homologs. Despite their great diversity, the putative toxins identified are predominantly involved in three major biological processes: hemostasis, inflammatory response, and allergic reactions, all of which are commonly disrupted after fireworm stings. Although the putative fireworm toxins identified here need to be further validated, our results strongly suggest that fireworms are venomous animals that use a complex mixture of toxins for defense against predators. PMID:29293976

Taxonomy, distribution and ecology of the order Phyllodocida (Annelida, Polychaeta) in deep-sea habitats around the Iberian margin

NASA Astrophysics Data System (ADS)

Ravara, Ascensão; Ramos, Diana; Teixeira, Marcos A. L.; Costa, Filipe O.; Cunha, Marina R.

2017-03-01

The polychaetes of the order Phyllodocida (excluding Nereidiformia and Phyllodociformia incertae sedis) collected from deep-sea habitats of the Iberian margin (Bay of Biscay, Horseshoe continental rise, Gulf of Cadiz and Alboran Sea), and Atlantic seamounts (Gorringe Bank, Atlantis and Nameless) are reported herein. Thirty-six species belonging to seven families - Acoetidae, Pholoidae, Polynoidae, Sigalionidae, Glyceridae, Goniadidae and Phyllodocidae, were identified. Amended descriptions and/or new illustrations are given for the species Allmaniella setubalensis, Anotochaetonoe michelbhaudi, Lepidasthenia brunnea and Polynoe sp. Relevant taxonomical notes are provided for other seventeen species. Allmaniella setubalensis, Anotochaetonoe michelbhaudi, Harmothoe evei, Eumida longicirrata and Glycera noelae, previously known only from their type localities were found in different deep-water places of the studied areas and constitute new records for the Iberian margin. The geographic distributions and the bathymetric range of thirteen and fifteen species, respectively, are extended. The morphology-based biodiversity inventory was complemented with DNA sequences of the mitochondrial barcode region (COI barcodes) providing a molecular tag for future reference. Twenty new sequences were obtained for nine species in the families Acoetidae, Glyceridae and Polynoidae and for three lineages within the Phylodoce madeirensis complex (Phyllodocidae). A brief analysis of the newly obtained sequences and publicly available COI barcode data for the genera herein reported, highlighted several cases of unclear taxonomic assignments, which need further study.

Adaptive response of trivial activated sludge towards toxic effect of oNP, PCP and combination oNP/PCP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Topalova, Y.; Dimkov, R.; Kozuharov, D.

1999-01-01

The reaction of the real aerobic activated sludge taken from the Sofia Waste Water Treatment Plant (SWWTP) and treated with the xenobiotics pentachlorphenol (PCP) (0.16 mMol), ortho-nitrophenol (oNP) (0.58 mMol) and with a combination of PCP (0.08 mMol), oNP (0.29 mMol) has been investigated in a model detoxification process. The adaptive changes are studied in the microbial structure level and at the level of changes in the qualitative and quantitative parameters of the macro-organisms in the activated sludge (consuments of 1 and 2 level). The presence of several different taxonomic groups has been shown by other researchers to be essentialmore » in the detoxification process. The quantitative changes in these taxonomic and physiological groups of micro-organisms are studied. The number of micro-organisms from Pseudomonas, Acinetobacter and the bacteria from the xenobiotic-catabolizing complex considerably increased with the individual and the combined effect of the xenobiotics oNP, PCP and oNP PCP. At the same time the toxic shock leads to a remarkable reduction of NH[sub 3] releasing, nitrifying bacteria and those from family Enterobacteriaceae. It is ascertained that the number of Ciliata, Flagellata apochromata, Oligochaeta and Rotatoria is strongly decreased in the series of samples treated with xenobiotics. The leading role of micro-organisms in the real detoxification of hazardous pollutants was experimentally confirmed by research.« less

Development and validation of a macroinvertebrate index of biotic integrity (IBI) for assessing urban impacts to Northern California freshwater wetlands.

PubMed

Lunde, Kevin B; Resh, Vincent H

2012-06-01

Despite California policies requiring assessment of ambient wetland condition and compensatory wetland mitigations, no intensive monitoring tools have been developed to evaluate freshwater wetlands within the state. Therefore, we developed standardized, wadeable field methods to sample macroinvertebrate communities and evaluated 40 wetlands across Northern California to develop a macroinvertebrate index of biotic integrity (IBI). A priori reference sites were selected with minimal urban impacts, representing a best-attainable condition. We screened 56 macroinvertebrate metrics for inclusion in the IBI based on responsiveness to percent urbanization. Eight final metrics were selected for inclusion in the IBI: percent three dominant taxa; scraper richness; percent Ephemeroptera, Odonata, and Trichoptera (EOT); EOT richness; percent Tanypodinae/Chironomidae; Oligochaeta richness; percent Coleoptera; and predator richness. The IBI (potential range 0-100) demonstrated significant discriminatory power between the reference (mean = 69) and impacted wetlands (mean = 28). It also declined with increasing percent urbanization (R (2) = 0.53, p < 0.005) among wetlands in an independent validation dataset (n = 14). The IBI was robust in showing no significant bias with environmental gradients. This IBI is a functional tool to determine the ecological condition at urban (stormwater and flood control ponds), as well as rural freshwater wetlands (stockponds, seasonal wetlands, and natural ponds). Biological differences between perennial and non-perennial wetlands suggest that developing separate indicators for these wetland types may improve applicability, although the existing data set was not sufficient for exploring this option.

[Effects of large-area planting water hyacinth on macro-benthos community structure and biomass].

PubMed

Liu, Guo-Feng; Liu, Hai-Qin; Zhang, Zhi-Yong; Zhang, Ying-Ying; Yan, Shao-Hua; Zhong, Ji-Cheng; Fan, Cheng-Xin

2010-12-01

The effects on macro-benthos and benthos environment of planting 200 hm2 water hyacinth (E. crassipens) in Zhushan Bay, Lake Taihu, were studied during 8-10 months consecutive surveys. Results indicated that average densities of mollusca (the main species were Bellamya aeruginosa) in far-planting, near-planting and planting area were 276.67, 371.11 and 440.00 ind/m2, respectively, and biomass were 373.15, 486.57 and 672.54 g/m2, respectively, showed that average density and biomass of planting area's were higher than those of others. However, the average density and biomass of Oligochaeta (the main species was Limodrilus hoffmeisteri) and Chironomidae in planting area were lower than that of outside planting area. The density and biomass of three dominant species of benthic animal increased quickly during 8-9 months, decreased quickly in October inside and outside water hyacinth planting area. The reason of this phenomenon could be possible that lots of cyanobacteria cells died and consumed dissolve oxygen in proceed decomposing. Algae cells released lots of phosphorus and nitrogen simultaneously, so macro-benthos died in this environment. The indexes of Shannon-Weaver and Simpson indicated that water environment was in moderate polluted state. On the basis of the survey results, the large-area and high-density planting water hyacinth haven't demonstrated a great impact on macrobenthos and benthos environment in short planting time (about 6 months planting time).

Effects of land use on the water quality and biota of three streams in the Piedmont province of North Carolina

USGS Publications Warehouse

Crawford, J.K.; Lenat, D.R.

1989-01-01

Three small streams in North Carolina 's northern Piedmont were studied to compare the effects of land use in their watersheds on water quality characteristics and aquatic biota. Devil 's Cradle Creek (agricultural watershed) had more than two times the sediment yield of Smith Creek (forested watershed) (0.34 tons/acre compared to 0.13 tons/acre), and Marsh Creek (urban watershed) had more than four times the yield of Smith Creek (0.59 tons/acre). Concentrations of nutrients were consistently highest in Devil 's Craddle Creek. Concentrations of total copper, iron, and lead in samples from each of the three streams at times exceeded State water quality standards as did concentrations of total zinc in samples from both Smith and Marsh Creeks. Successively lower aquatic invertebrate taxa richness was found in the forested, the agricultural, and the urban watershed streams. Invertebrate biota in Smith Creek was dominated by insects, such as Ephemeroptera, that are intolerant to stress from pollution, whereas Devil 's Cradle Creek was dominated by the more tolerant Diptera, and Marsh Creek was dominated by the most pollution-tolerant group, the Oligochaeta. Fish communities in the forested and agricultural watershed streams were characterized by more species and more individuals of each species, relative to a limited community in urban Marsh Creek. Three independent variables closely linked to land use--suspended-sediment yield, suspended-sediment load, and total lead concentrations in stream water--are inversely associated with the biological communities of the streams.

Effects of 4-nonylphenol on the biota in a littoral pond ecosystem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liber, K.; Schmude, K.; O`Halloran, S.

1994-12-31

National water quality criteria for 4-nonylphenol, a surfactant precursor and metabolite, are currently being developed by the US EPA. Preliminary data from laboratory tests indicate that the criterion maximum concentration may be as low as 3--10 {mu}g/L; field data on biological effects are rare. The study presented here was designed to assess the effects of 4-nonylphenol on a natural aquatic community using a set of 18 littoral enclosures (average volume 33 m{sup 3}). The common occurrence of 4-nonylphenol in municipal and industrial discharges dictated the use of a ``chronic`` exposure scenario for this study. Test concentrations ranged from 3 tomore » 300 {mu}g/L, with applications every 48 hours for a 20 day period. This ensured a 21-day ``chronic`` exposure period and allowed sediment concentration of 4-nonylphenol to steadily increase. Survival of juvenile bluegill sunfish was reduced at 300 {mu}g/L, but not at 100, {mu}g/L; no effects on growth were noted over the 68-day assessment period. Abundance of Cladocera and Copepoda were also reduced at 300 {mu}g/L, with recovery observed within 2--4 weeks after the last nonylphenol application. Benthic macroinvertebrates, including Chironomidae, Oligochaeta, and Mollusca, were affected at 100--300 {mu}g/L, with impacts persisting for several months. The slow recovery of benthic macroinvertebrates was partially attributed to their prolonged exposure to sediment associated nonylphenol residues.« less

Spatial heterogeneity of stream environmental conditions and macroinvertebrates community in an agriculture dominated watershed and management implications for a large river (the Liao River, China) basin.

PubMed

Gao, Xin; Niu, Cuijuan; Chen, Yushun; Yin, Xuwang

2014-04-01

Understanding the effects of watershed land uses (e.g., agriculture, urban industry) on stream ecological conditions is important for the management of large river basins. A total of 41 and 56 stream sites (from first to fourth order) that were under a gradient of watershed land uses were monitored in 2009 and 2010, respectively, in the Liao River Basin, Northeast China. The monitoring results showed that a total of 192 taxa belonging to four phyla, seven classes, 21 orders and 91 families were identified. The composition of macroinvertebrate community in the Liao River Basin was dominated by aquatic insect taxa (Ephemeroptera and Diptera), Oligochaeta and Molluscs. The functional feeding group GC (Gatherer/Collector) was dominant in the whole basin. Statistical results showed that sites with less watershed impacts (lower order sites) were characterized by higher current velocity and habitat score, more sensitive taxa (e.g., Ephemeroptera), and the substrate was dominated by high percentage of cobble and pebble. The sites with more impacts from agriculture and urban industry (higher order sites) were characterized by higher biochemical (BOD5) and chemical oxygen demand (COD), more tolerant taxa (e.g., Chironominae), and the substrate was dominated by silt and sand. Agriculture and urban-industry activities have reduced habitat condition, increased organic pollutants, reduced macroinvertebrate abundance, diversity, and sensitive taxa in streams of the lower Liao River Basin. Restoration of degraded habitat condition and control of watershed organic pollutants could be potential management priorities for the Basin.

The mode of bioturbation triggers pesticide remobilization from aquatic sediments.

PubMed

Bundschuh, Mirco; Schletz, Marco; Goedkoop, Willem

2016-08-01

After their release into the aquatic environment, contaminants may - depending on the physicochemical properties - adsorb to sediments. From there these contaminants can either be buried or remobilised by abiotic factors (e.g., resuspension) as well as by the bioturbating activity of sediment dwelling invertebrates. Little is, however, know about the effects of bioturbation on the fate of pesticides. Therefore, the present study quantified the impact of the bioturbation mode of benthic invertebrate species (bio-diffusor vs. bio-irrigation), the invertebrate density (i.e. 0-8 individuals per replicate), and the substance-inherent properties (i.e. hydrophobicity, water solubility) on the remobilization of sediment-associated pesticides in a laboratory-based set-up over 13 days. We found that both the bioturbation mode (i.e., species identity) and species density, as well as pesticide properties (i.e., hydrophobicity) affected the direction and magnitude of remobilisation of sediment-bound pesticides. The oligochaeta Lumbriculus variegatus showed a density-dependent effect on the remobilization of lindane to the water phase, whereas those with the amphipod Monoporeia affinis and larvae of the midge Chironomus riparius did not. Although these findings show that sediments not per definition are a sink for pesticides, the rates of pesticide remobilization are limited. This observation, thus, suggests that the risk for aquatic communities posed by the remobilization of pesticides from the sediment due to bioturbation is low. Copyright © 2016. Published by Elsevier Inc.

EvolMarkers: a database for mining exon and intron markers for evolution, ecology and conservation studies.

PubMed

Li, Chenhong; Riethoven, Jean-Jack M; Naylor, Gavin J P

2012-09-01

Recent innovations in next-generation sequencing have lowered the cost of genome projects. Nevertheless, sequencing entire genomes for all representatives in a study remains expensive and unnecessary for most studies in ecology, evolution and conservation. It is still more cost-effective and efficient to target and sequence single-copy nuclear gene markers for such studies. Many tools have been developed for identifying nuclear markers, but most of these have focused on particular taxonomic groups. We have built a searchable database, EvolMarkers, for developing single-copy coding sequence (CDS) and exon-primed-intron-crossing (EPIC) markers that is designed to work across a broad range of phylogenetic divergences. The database is made up of single-copy CDS derived from BLAST searches of a variety of metazoan genomes. Users can search the database for different types of markers (CDS or EPIC) that are common to different sets of input species with different divergence characteristics. EvolMarkers can be applied to any taxonomic group for which genome data are available for two or more species. We included 82 genomes in the first version of EvolMarkers and have found the methods to be effective across Placozoa, Cnidaria, Arthropod, Nematoda, Annelida, Mollusca, Echinodermata, Hemichordata, Chordata and plants. We demonstrate the effectiveness of searching for CDS markers within annelids and show how to find potentially useful intronic markers within the lizard Anolis. © 2012 Blackwell Publishing Ltd.

Response of seafloor ecosystems to abrupt global climate change

PubMed Central

Moffitt, Sarah E.; Hill, Tessa M.; Roopnarine, Peter D.; Kennett, James P.

2015-01-01

Anthropogenic climate change is predicted to decrease oceanic oxygen (O2) concentrations, with potentially significant effects on marine ecosystems. Geologically recent episodes of abrupt climatic warming provide opportunities to assess the effects of changing oxygenation on marine communities. Thus far, this knowledge has been largely restricted to investigations using Foraminifera, with little being known about ecosystem-scale responses to abrupt, climate-forced deoxygenation. We here present high-resolution records based on the first comprehensive quantitative analysis, to our knowledge, of changes in marine metazoans (Mollusca, Echinodermata, Arthropoda, and Annelida; >5,400 fossils and trace fossils) in response to the global warming associated with the last glacial to interglacial episode. The molluscan archive is dominated by extremophile taxa, including those containing endosymbiotic sulfur-oxidizing bacteria (Lucinoma aequizonatum) and those that graze on filamentous sulfur-oxidizing benthic bacterial mats (Alia permodesta). This record, from 16,100 to 3,400 y ago, demonstrates that seafloor invertebrate communities are subject to major turnover in response to relatively minor inferred changes in oxygenation (>1.5 to <0.5 mL⋅L−1 [O2]) associated with abrupt (<100 y) warming of the eastern Pacific. The biotic turnover and recovery events within the record expand known rates of marine biological recovery by an order of magnitude, from <100 to >1,000 y, and illustrate the crucial role of climate and oceanographic change in driving long-term successional changes in ocean ecosystems. PMID:25825727

Repurposed transcriptomic data facilitate discovery of innate immunity toll-like receptor (TLR) Genes across Lophotrochozoa.

PubMed

Halanych, Kenneth M; Kocot, Kevin M

2014-10-01

The growing volume of genomic data from across life represents opportunities for deriving valuable biological information from data that were initially collected for another purpose. Here, we use transcriptomes collected for phylogenomic studies to search for toll-like receptor (TLR) genes in poorly sampled lophotrochozoan clades (Annelida, Mollusca, Brachiopoda, Phoronida, and Entoprocta) and one ecdysozoan clade (Priapulida). TLR genes are involved in innate immunity across animals by recognizing potential microbial infection. They have an extracellular leucine-rich repeat (LRR) domain connected to a transmembrane domain and an intracellular toll/interleukin-1 receptor (TIR) domain. Consequently, these genes are important in initiating a signaling pathway to trigger defense. We found at least one TLR ortholog in all but two taxa examined, suggesting that a broad array of lophotrochozoans may have innate immune systems similar to those observed in vertebrates and arthropods. Comparison to the SMART database confirmed the presence of both the LRR and the TIR protein motifs characteristic of TLR genes. Because we looked at only one transcriptome per species, discovery of TLR genes was limited for most taxa. However, several TRL-like genes that vary in the number and placement of LRR domains were found in phoronids. Additionally, several contigs contained LRR domains but lacked TIR domains, suggesting they were not TLRs. Many of these LRR-containing contigs had other domains (e.g., immunoglobin) and are likely involved in innate immunity. © 2014 Marine Biological Laboratory.

Phylogeny and mitochondrial gene order variation in Lophotrochozoa in the light of new mitogenomic data from Nemertea

PubMed Central

Podsiadlowski, Lars; Braband, Anke; Struck, Torsten H; von Döhren, Jörn; Bartolomaeus, Thomas

2009-01-01

Background The new animal phylogeny established several taxa which were not identified by morphological analyses, most prominently the Ecdysozoa (arthropods, roundworms, priapulids and others) and Lophotrochozoa (molluscs, annelids, brachiopods and others). Lophotrochozoan interrelationships are under discussion, e.g. regarding the position of Nemertea (ribbon worms), which were discussed to be sister group to e.g. Mollusca, Brachiozoa or Platyhelminthes. Mitochondrial genomes contributed well with sequence data and gene order characters to the deep metazoan phylogeny debate. Results In this study we present the first complete mitochondrial genome record for a member of the Nemertea, Lineus viridis. Except two trnP and trnT, all genes are located on the same strand. While gene order is most similar to that of the brachiopod Terebratulina retusa, sequence based analyses of mitochondrial genes place nemerteans close to molluscs, phoronids and entoprocts without clear preference for one of these taxa as sister group. Conclusion Almost all recent analyses with large datasets show good support for a taxon comprising Annelida, Mollusca, Brachiopoda, Phoronida and Nemertea. But the relationships among these taxa vary between different studies. The analysis of gene order differences gives evidence for a multiple independent occurrence of a large inversion in the mitochondrial genome of Lophotrochozoa and a re-inversion of the same part in gastropods. We hypothesize that some regions of the genome have a higher chance for intramolecular recombination than others and gene order data have to be analysed carefully to detect convergent rearrangement events. PMID:19660126

Bone-eating Osedax females and their 'harems' of dwarf males are recruited from a common larval pool.

PubMed

Vrijenhoek, R C; Johnson, S B; Rouse, G W

2008-10-01

Extreme male dwarfism occurs in Osedax (Annelida: Siboglinidae), marine worms with sessile females that bore into submerged bones. Osedax are hypothesized to use environmental sex determination, in which undifferentiated larvae that settle on bones develop as females, and subsequent larvae that settle on females transform into dwarf males. This study addresses several hypotheses regarding possible recruitment sources for the males: (i) common larval pool--males and females are sampled from a common pool of larvae; (ii) neighbourhood--males are supplied by a limited number of neighbouring females; and (iii) arrhenotoky--males are primarily the sons of host females. Osedax rubiplumus were sampled from submerged whalebones located at 1820-m and 2893-m depths in Monterey Bay, California. Immature females typically did not host males, but mature females maintained male 'harems' that grew exponentially in the number of males as female size increased. Allozyme analysis of the females revealed binomial proportions of nuclear genotypes, an indication of random sexual mating. Analysis of mitochondrial DNA sequences from the male harems and their host females allowed us to reject the arrhenotoky and neighbourhood hypotheses for male recruitment. No significant partitioning of mitochondrial diversity existed between the male and female sexes, or between subsamples of worms collected at different depths or during different years (2002-2007). Mitochondrial sequence diversity was very high in these worms, suggesting that as many as 10(6) females contributed to a common larval pool from which the two sexes were randomly drawn.

A dwarf male reversal in bone-eating worms.

PubMed

Rouse, Greg W; Wilson, Nerida G; Worsaae, Katrine; Vrijenhoek, Robert C

2015-01-19

Darwin hypothesized that sexes in a species should be similar unless sexual selection, fecundity selection, or resource partitioning has driven them apart. Male dwarfism has evolved multiple times in a range of animals, raising questions about factors that drive such extreme size dimorphism. Ghiselin noted that dwarf males are more common among smaller marine animals, and especially among sedentary and sessile species living at low densities, where mates are difficult to find, or in deep-sea environments with limited energy sources. These benefits of male dwarfism apply well to Osedax (Annelida: Siboglinidae), bone-eating marine worms. Osedax males, notable for extreme sexual size dimorphism (SSD), are developmentally arrested larvae that produce sperm from yolk reserves. Harems of dwarf males reside in the lumen of the tube surrounding a female. Herein, we describe Osedax priapus n. sp., a species that deviates remarkably by producing males that anchor into, and feed on, bone via symbiont-containing "roots," just like female Osedax. Phylogenetic analyses revealed O. priapus n. sp. as a derived species, and the absence of dwarf males represents a character reversal for this genus. Some dwarf male features are retained due to functional and morphological constraints. Since O. priapus n. sp. males are anchored in bone, they possess an extensible trunk that allows them to roam across the bone to contact and inseminate females. Evolutionary and ecological implications of a loss of male dwarfism are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

The eyes of Tullimonstrum reveal a vertebrate affinity.

PubMed

Clements, Thomas; Dolocan, Andrei; Martin, Peter; Purnell, Mark A; Vinther, Jakob; Gabbott, Sarah E

2016-04-28

Tullimonstrum gregarium is an iconic soft-bodied fossil from the Carboniferous Mazon Creek Lagerstätte (Illinois, USA). Despite a large number of specimens and distinct anatomy, various analyses over the past five decades have failed to determine the phylogenetic affinities of the 'Tully monster', and although it has been allied to such disparate phyla as the Mollusca, Annelida or Chordata, it remains enigmatic. The nature and phylogenetic affinities of Tullimonstrum have defied confident systematic placement because none of its preserved anatomy provides unequivocal evidence of homology, without which comparative analysis fails. Here we show that the eyes of Tullimonstrum possess ultrastructural details indicating homology with vertebrate eyes. Anatomical analysis using scanning electron microscopy reveals that the eyes of Tullimonstrum preserve a retina defined by a thick sheet comprising distinct layers of spheroidal and cylindrical melanosomes. Time-of-flight secondary ion mass spectrometry and multivariate statistics provide further evidence that these microbodies are melanosomes. A range of animals have melanin in their eyes, but the possession of melanosomes of two distinct morphologies arranged in layers, forming retinal pigment epithelium, is a synapomorphy of vertebrates. Our analysis indicates that in addition to evidence of colour patterning, ecology and thermoregulation, fossil melanosomes can also carry a phylogenetic signal. Identification in Tullimonstrum of spheroidal and cylindrical melanosomes forming the remains of retinal pigment epithelium indicates that it is a vertebrate; considering its body parts in this new light suggests it was an anatomically unusual member of total group Vertebrata.

Response of seafloor ecosystems to abrupt global climate change

NASA Astrophysics Data System (ADS)

Moffitt, Sarah E.; Hill, Tessa M.; Roopnarine, Peter D.; Kennett, James P.

2015-04-01

Anthropogenic climate change is predicted to decrease oceanic oxygen (O2) concentrations, with potentially significant effects on marine ecosystems. Geologically recent episodes of abrupt climatic warming provide opportunities to assess the effects of changing oxygenation on marine communities. Thus far, this knowledge has been largely restricted to investigations using Foraminifera, with little being known about ecosystem-scale responses to abrupt, climate-forced deoxygenation. We here present high-resolution records based on the first comprehensive quantitative analysis, to our knowledge, of changes in marine metazoans (Mollusca, Echinodermata, Arthropoda, and Annelida; >5,400 fossils and trace fossils) in response to the global warming associated with the last glacial to interglacial episode. The molluscan archive is dominated by extremophile taxa, including those containing endosymbiotic sulfur-oxidizing bacteria (Lucinoma aequizonatum) and those that graze on filamentous sulfur-oxidizing benthic bacterial mats (Alia permodesta). This record, from 16,100 to 3,400 y ago, demonstrates that seafloor invertebrate communities are subject to major turnover in response to relatively minor inferred changes in oxygenation (>1.5 to <0.5 mLṡL-1 [O2]) associated with abrupt (<100 y) warming of the eastern Pacific. The biotic turnover and recovery events within the record expand known rates of marine biological recovery by an order of magnitude, from <100 to >1,000 y, and illustrate the crucial role of climate and oceanographic change in driving long-term successional changes in ocean ecosystems.

Pharmacological Potential of Phylogenetically Diverse Actinobacteria Isolated from Deep-Sea Coral Ecosystems of the Submarine Avilés Canyon in the Cantabrian Sea.

PubMed

Sarmiento-Vizcaíno, Aida; González, Verónica; Braña, Alfredo F; Palacios, Juan J; Otero, Luis; Fernández, Jonathan; Molina, Axayacatl; Kulik, Andreas; Vázquez, Fernando; Acuña, José L; García, Luis A; Blanco, Gloria

2017-02-01

Marine Actinobacteria are emerging as an unexplored source for natural product discovery. Eighty-seven deep-sea coral reef invertebrates were collected during an oceanographic expedition at the submarine Avilés Canyon (Asturias, Spain) in a range of 1500 to 4700 m depth. From these, 18 cultivable bioactive Actinobacteria were isolated, mainly from corals, phylum Cnidaria, and some specimens of phyla Echinodermata, Porifera, Annelida, Arthropoda, Mollusca and Sipuncula. As determined by 16S rRNA sequencing and phylogenetic analyses, all isolates belong to the phylum Actinobacteria, mainly to the Streptomyces genus and also to Micromonospora, Pseudonocardia and Myceligenerans. Production of bioactive compounds of pharmacological interest was investigated by high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) techniques and subsequent database comparison. Results reveal that deep-sea isolated Actinobacteria display a wide repertoire of secondary metabolite production with a high chemical diversity. Most identified products (both diffusible and volatiles) are known by their contrasted antibiotic or antitumor activities. Bioassays with ethyl acetate extracts from isolates displayed strong antibiotic activities against a panel of important resistant clinical pathogens, including Gram-positive and Gram-negative bacteria, as well as fungi, all of them isolated at two main hospitals (HUCA and Cabueñes) from the same geographical region. The identity of the active extracts components of these producing Actinobacteria is currently being investigated, given its potential for the discovery of pharmaceuticals and other products of biotechnological interest.

Earthworms as Invasive Species in Latin America — the 2nd Latin American Meeting on Oligochaeta (Earthworm) Ecology and Taxonomy

Treesearch

Grizelle Gonzalez

2006-01-01

This special issue is based on scientific contributions presented at the 2nd Latin American Symposium of Earthworm Ecology and Taxonomy (ELAETAO, for its Spanish acronym) held in San Juan, Puerto Rico November 14-18, 2005. The first of these symposia was organized by George G. Brown and Klaus D. Sautter and held at Londrina, Brazil from December 1-3, 2003.The objective...

Macrofaunal involvement in the sublittoral decay of kelp debris: the polychaete Platynereis dumerilii (Audouin and Milne-Edwards) (Annelida: Polychaeta)

NASA Astrophysics Data System (ADS)

Bedford, A. P.; Moore, P. G.

1985-02-01

Platynereis dumerilii is found in large numbers in parchment-like tubes attached to sublittoral accumulations of detached maroalgae (principally Laminaria saccharina) in Kames Bay, Isle of Cumbrae and Lochranza, Isle of Arran. Its rôle in weed decomposition has been examined by comparing its responses (behavioural choice, growth rates, absorption efficiencies of both carbon and protein, gut retention times and rate of faecal output) to fresh and rotting weed. Worms grew significantly on either diet, with older individuals gaining more weight than small individuals. Animals of a standard size (derived from measurements of maximum bite size) feeding on fresh weed, however, grew significantly faster than those feeding on rotting weed. The former had a significantly higher protein absorption efficiency which was linearly related to protein content of ingested weed. This was not so on rotting weed. Organic carbon absorption efficiencies did not differ significantly between the two groups, neither did gut retention times nor rates of faecal output. Given a choice, Platynereis chooses to build its tube, and to feed, on fresh kelp—a strategem which ensures both maximum scope for occupancy before fronds decay and a superabundance of preferred food. Platynereis feeds around its tube entrance, recropping small areas for 2-3 days, prior to switching to another area nearby. Ciliate population densities on Platynereis faeces are much lower than on either homogenized or intact weed, associated with their lower, nutritional value (at first). Platynereis bubes act to bind kelp fronds together stabilizing the faecal input to infaunal detritivores. Platynereis is an example of a detritivore which exploits the detrital substratum directly.

Proceraea exoryxae sp. nov. (Annelida, Syllidae, Autolytinae), the first known polychaete miner tunneling into the tunic of an ascidian

PubMed Central

Nygren, Arne

2017-01-01

While studying organisms living in association with the solitary tunicate Phallusia nigra (Ascidiacea, Ascidiidae) from a shallow fringing reef at Zeytouna Beach (Egyptian Red Sea), one of the collected ascidians showed peculiar perforations on its tunic. Once dissected, the perforations revealed to be the openings of a network of galleries excavated in the inner tunic (atrium) by at least six individuals of a polychaetous annelid. The worms belonged to the Autolytinae (Syllidae), a subfamily that is well known to include specialized predators and/or symbionts, mostly associated with cnidarians. The Red Sea worms are here described as Proceraea exoryxae sp. nov., which are anatomically distinguished by the combination of simple chaetae only in anterior chaetigers, and a unique trepan with 33 teeth in one outer ring where one large tooth alternates with one medium-sized tricuspid tooth, and one inner ring with small teeth located just behind the large teeth. Male and female epitokes were found together with atokous individuals within galleries. Proceraea exoryxae sp. nov. constitutes the first known miner in the Autolytinae and the second species in this taxon known to live symbiotically with ascidians. The implications of finding this specialized parasite are discussed considering that Phallusia nigra has been introduced worldwide, in tropical and sub-tropical ecosystems, where it has the potential of becoming invasive. PMID:28584710

Habitat selection and adult-recruit interactions in Pectinaria koreni (Malmgren) (Annelida: Polychaeta) post-larval populations: Results of flume experiments

NASA Astrophysics Data System (ADS)

Olivier, Frédéric; Desroy, Nicolas; Retière, Christian

1996-12-01

The fate of recently settled populations of soft-bottom invertebrates depends not only on dispersal of pelagic larvae by tidal currents but also on other physical ( e. g. resuspension) and biological mechanisms ( e.g. habitat selection and adult-recruit interactions) acting at the water-substratum interface. To assess the relative importance of such processes under megatidal conditions in the Abra alba community of the eastern Baie de Seine (English Channel), flume experiments were conducted on post-larvae of the dominant polychaete species, Pectinaria koreni. Habitat selection by post-larvae of P. koreni was determined in a first set of experiments, where individuals were sowed either on a suitable or on an unsuitable substratum. Once resuspended, post-larvae were given a choice between two highly contrasting treatments with a natural organic-rich muddy sand and a bare flat PVC surface. P. koreni post-larvae were able to leave an unfavourable substratum into which they had initially burrowed and reach a more suitable substrate by drifting (induced by the secretion of mucus) before final settlement. The influence of adults on habitat selection and survival of P. koreni post-larvae was analysed in a second set of experiments, where individuals were sowed onto a suitable sediment with adults (test treatment) or without (control treatment). The presence of conspecific adults induced a high resuspension rate of the post-larvae. Drifting occurred mainly just after the introduction of the current and affected the whole experimental population, regardless of size. Such a response seems to be related to the intense bioturbation caused by the sub-surface deposit-feeding habit of the adults, which alters the boundary-layer flow. In contrast, the presence of adults of Owenia fusiformis, another dominant polychaete of the Abra alba community, led to an enhanced recruitment by a reduction in post-larvae resuspension. In fact, at low shear velocities, dense aggregates of tubes stabilize the sediment and so act as particle traps. Thus, in the megatidal environment of the Baie de Seine, physical conditions and behavioural responses interact and contribute to structuring the benthic community.

The semi-aquatic freshwater earthworms of the genus Glyphidrilus Horst, 1889 from Thailand (Oligochaeta, Almidae) with re-descriptions of several species

PubMed Central

Chanabun, Ratmanee; Sutcharit, Chirasak; Tongkerd, Piyoros; Panha, Somsak

2013-01-01

Abstract The semi-aquatic freshwater earthworm genus Glyphidrilus Horst, 1889 from Thailand was investigated based on extensive recent collecting. The species in this genus were characterized by their external and internal morphological characters of the location of wings, genital openings, genital organ structures and their locations, as well as the dimensions of body length and number of segments. Several type specimens were compared with both previous and newly collected materials. Ten new species are described from several river systems in Thailand; as Glyphidrilus borealis sp. n., Glyphidrilus chaophraya sp. n., Glyphidrilus chiensis sp. n., Glyphidrilus huailuangensis sp. n., Glyphidrilus kratuensis sp. n., Glyphidrilus quadratus sp. n., Glyphidrilus trangensis sp. n., Glyphidrilus wararamensis sp. n., Glyphidrilus vangthongensis sp. n. and Glyphidrilus vesper sp. n. Each species is endemic to a single river system. All 26 previously described species are re-described, and eight lectotypes have been designated. An identification key and a morphological comparison summary are provided. PMID:23653518

Microbiological and faunal soil attributes of coffee cultivation under different management systems in Brazil.

PubMed

Lammel, D R; Azevedo, L C B; Paula, A M; Armas, R D; Baretta, D; Cardoso, E J B N

2015-11-01

Brazil is the biggest coffee producer in the world and different plantation management systems have been applied to improve sustainability and soil quality. Little is known about the environmental effects of these different management systems, therefore, the goal of this study was to use soil biological parameters as indicators of changes. Soils from plantations in Southeastern Brazil with conventional (CC), organic (OC) and integrated management systems containing intercropping of Brachiaria decumbens (IB) or Arachis pintoi (IA) were sampled. Total organic carbon (TOC), microbial biomass carbon (MBC) and nitrogen (MBN), microbial activity (C-CO2), metabolic quotient (qCO2), the enzymes dehydrogenase, urease, acid phosphatase and arylsulphatase, arbuscular mycorrhizal fungi (AMF) colonization and number of spores and soil fauna were evaluated. The greatest difference between the management systems was seen in soil organic matter content. The largest quantity of TOC was found in the OC, and the smallest was found in IA. TOC content influenced soil biological parameters. The use of all combined attributes was necessary to distinguish the four systems. Each management presented distinct faunal structure, and the data obtained with the trap method was more reliable than the TSBF (Tropical Soils) method. A canonic correlation analysis showed that Isopoda was correlated with TOC and the most abundant order with OC. Isoptera was the most abundant faunal order in IA and correlated with MBC. Overall, OC had higher values for most of the biological measurements and higher populations of Oligochaeta and Isopoda, corroborating with the concept that the OC is a more sustainable system.

[Effects of cascading hydropower dams operation on the structure and distribution pattern of benthic macroinvertebrate assemblages in Manwan Reservoir, Southwest China].

PubMed

Li, Jin Peng; Dong, Shi Kui; Peng, Ming Chun; Wu, Xuan; Zhou, Fang; Yu, Yin

2017-12-01

Benthic macroinvertebrate assemblages are one of the biological groups in aquatic ecosystem most sensitive to the habitat change and degradation, and can be a biological indicator for the aquatic ecosystem change and succession in cascading hydropower dam reservoir. The middle and lower reaches of the Lancang River are key spot for international biodiversity conservation and ecological studies on the effects of cascading hydropower dam exploitation. In this study, the reservoir of Manwan hydropower dam, the first dam in Lancang-Mekong river main stream, was selected as the study site. The benthic macroinvertebrate assemblages were sampled in 2011 and 2016 respectively. Meanwhile, the survey data before impounding (natural river, 1996) and early stage of single dam (1997) were collected to conduct the overall analysis for structure, distribution pattern and evolution of benthic macroinvertebrate assemblages. The results showed that the dominant biological group was gradually changed from the Oligochaeta and Insecta to the Mollusca. Along the longitudinal gradient, the density and biomass of the benthic macroinvertebrate assemblages were remarkably increased in reservoir, especially in the lacustrine zone. As for the functional feeding group, the predator and gatherer-collector changed into filter-collector predominantly in lacustrine zone. With the cascading dams operation, the biotic index indicated that the water quality of reservoir in 2016 was better than in 2011. The evolution of benthic macroinvertebrate assemblages in the Manwan Reservoir was related to the operation of Xiaowan dam in the upper reach, the hydrological regime and siltation in the reservoir, and would continue with dynamic changes with the operation of the cascading hydropower dam.

Sine systemate chaos? A versatile tool for earthworm taxonomy: non-destructive imaging of freshly fixed and museum specimens using micro-computed tomography.

PubMed

Fernández, Rosa; Kvist, Sebastian; Lenihan, Jennifer; Giribet, Gonzalo; Ziegler, Alexander

2014-01-01

In spite of the high relevance of lumbricid earthworms ('Oligochaeta': Lumbricidae) for soil structure and functioning, the taxonomy of this group of terrestrial invertebrates remains in a quasi-chaotic state. Earthworm taxonomy traditionally relies on the interpretation of external and internal morphological characters, but the acquisition of these data is often hampered by tedious dissections or restricted access to valuable and rare museum specimens. The present state of affairs, in conjunction with the difficulty of establishing primary homologies for multiple morphological features, has led to an almost unrivaled instability in the taxonomy and systematics of certain earthworm groups, including Lumbricidae. As a potential remedy, we apply for the first time a non-destructive imaging technique to lumbricids and explore the future application of this approach to earthworm taxonomy. High-resolution micro-computed tomography (μCT) scanning of freshly fixed and museum specimens was carried out using two cosmopolitan species, Aporrectodea caliginosa and A. trapezoides. By combining two-dimensional and three-dimensional dataset visualization techniques, we demonstrate that the morphological features commonly used in earthworm taxonomy can now be analyzed without the need for dissection, whether freshly fixed or museum specimens collected more than 60 years ago are studied. Our analyses show that μCT in combination with soft tissue staining can be successfully applied to lumbricid earthworms. An extension of the approach to other families is poised to strengthen earthworm taxonomy by providing a versatile tool to resolve the taxonomic chaos currently present in this ecologically important, but taxonomically neglected group of terrestrial invertebrates.

Aquatic macroinvertebrates associated with Eichhornia azurea (Swartz) Kunth and relationships with abiotic factors in marginal lentic ecosystems (São Paulo, Brazil).

PubMed

Silva, C V; Henry, R

2013-02-01

Marginal lakes are characterised by their having high biological diversity due to the presence of aquatic macrophytes in their coastal zones, providing habitats for refuge and food for animal community members. Among the fauna components associated with macrophytes, aquatic macroinvertebrates are important because they are an energy source for predators and fish. In six lakes and two different seasons (March and August 2009), the ecological attributes of aquatic macroinvertebrate community associated with Eichhornia azurea were compared and the controlling environmental factors were identified. Since the attributes of macroinvertebrate community are strictly associated with abiotic variables of each distinct habitat, our hypothesis was that each site associated with the same floating aquatic macrophyte (E. azurea) should have a typical composition and density of organisms. We identified 50 taxa of macroinvertebrates, with greater taxa richness for aquatic insects (37 taxa) divided into eight orders; the order Diptera being the most abundant in the two study periods. On the other hand, higher values of total taxa richness were recorded in August. Dissolved oxygen and pH presented the greatest number of significant positive correlations with the different taxa. The animals most frequently collected in the six lakes in March and August 2009 were Hirudinea, Oligochaeta, Hydrachnidae, Conchostraca, Ostracoda, Noteridae, Ceratopogonidae, Chironomidae, Culicidae, Caenidae, Pleidae, Aeshnidae, Libellulidae, Coenagrionidae and Nematoda. Only densities of Trichoptera, Ostracoda and Conchostraca presented the highest significant differences between lakes in both study periods and considering the composition of macroinvertebrates no significant differences were registered for macroinvertebrate composition.

Impact of extreme oxygen consumption by pollutants on macroinvertebrate assemblages in plain rivers of the Ziya River Basin, north China.

PubMed

Ding, Yuekui; Rong, Nan; Shan, Baoqing

2016-07-01

The aim of the study was to estimate the impact of oxygen depletion on macroinvertebrate community structure in benthic space. Macroinvertebrate assemblages and potential of dissolved oxygen (DO) consumption were investigated simultaneously in the plain rivers of the Ziya River Basin. The degree of DO depletion was represented by sediment oxygen demand (SOD) and DO, chemical oxygen demand (CODCr), and ammonia nitrogen (NH4 (+)-N) in the overlying water. The results showed an all-around hypoxia environment formed, and the values of DO, SOD, CODCr, and NH4 (+)-N were separately 0.11-4.03 mg L(-1), 0.41-2.60 g m(-2) day(-1), 27.50-410.00 mg L(-1), and 1.79-101.41 mg L(-1). There was an abnormal macroinvertebrate assemblage, and only 3 classes, Insecta, Gastropoda, and Oligochaeta, were found, which included 9 orders, 30 families, and 54 genera. The biodiversity was at a low level, and Shannon-Wiener index was 0.00-1.72. SOD, and NH4 (+)-N had major impact on the macroinvertebrate community, and the former had negative effect on most taxa, for instance, Nais, Branchiura, Paraleptophlebia, etc., which were sensitive or had a moderate-high tolerance to pollution. NH4 (+)-N had both positive and negative impacts on benthic animals, for instance, Dicrotendipes, Gomphus, Cricotopus, etc., for the former, and Procladius, Limnodrilus, Hippeutis, etc., for the latter. They all had a moderate-high tolerance to pollution. It is significant to improve DO condition and macroinvertebrate diversity in river harnessing and management.

Glowing Worms: Biological, Chemical, and Functional Diversity of Bioluminescent Annelids.

PubMed

Verdes, Aida; Gruber, David F

2017-07-01

Bioluminescence, the ability to produce light by living organisms, has evolved independently in numerous lineages across the tree of life. Luminous forms are found in a wide range of taxonomic groups from bacteria to vertebrates, although the great majority of bioluminescent organisms are marine taxa. Within the phylum Annelida, bioluminescence is widespread, present in at least 98 terrestrial and marine species that represent 45 genera distributed in thirteen lineages of clitellates and polychaetes. The ecological diversity of luminous annelids is unparalleled, with species occupying a great variety of habitats including both terrestrial and marine ecosystems, from coastal waters to the deep-sea, in benthic and pelagic habitats from polar to tropical regions. This great taxonomic and ecological diversity is matched by the wide array of bioluminescent colors-including yellow light, which is very rare among marine taxa-different emission wavelengths even between species of the same genus, and varying patterns, chemical reactions and kinetics. This diversity of bioluminescence colors and patterns suggests that light production in annelids might be involved in a variety of different functions, including defensive mechanisms like sacrificial lures or aposematic signals, and intraspecific communication systems. In this review, we explore the world of luminous annelids, particularly focusing on the current knowledge regarding their taxonomic and ecological diversity and discussing the putative functions and chemistries of their bioluminescent systems. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology 2017. This work is written by US Government employees and is in the public domain in the US.

Highly sensitive avoidance plays a key role in sensory adaptation to deep-sea hydrothermal vent environments.

PubMed

Ogino, Tetsuya; Maegawa, Shingo; Shigeno, Shuichi; Fujikura, Katsunori; Toyohara, Haruhiko

2018-01-01

The environments around deep-sea hydrothermal vents are very harsh conditions for organisms due to the possibility of exposure to highly toxic compounds and extremely hot venting there. Despite such extreme environments, some indigenous species have thrived there. Alvinellid worms (Annelida) are among the organisms best adapted to high-temperature and oxidatively stressful venting regions. Although intensive studies of the adaptation of these worms to the environments of hydrothermal vents have been made, little is known about the worms' sensory adaptation to the severe chemical conditions there. To examine the sensitivity of the vent-endemic worm Paralvinella hessleri to low pH and oxidative stress, we determined the concentration of acetic acid and hydrogen peroxide that induced avoidance behavior of this worm, and compared these concentrations to those obtained for related species inhabiting intertidal zones, Thelepus sp. The concentrations of the chemicals that induced avoidance behavior of P. hessleri were 10-100 times lower than those for Thelepus sp. To identify the receptors for these chemicals, chemical avoidance tests were performed with the addition of ruthenium red, a blocker of transient receptor potential (TRP) channels. This treatment suppressed the chemical avoidance behavior of P. hessleri, which suggests that TRP channels are involved in the chemical avoidance behavior of this species. Our results revealed for the first time hypersensitive detection systems for acid and for oxidative stress in the vent-endemic worm P. hessleri, possibly mediated by TRP channels, suggesting that such sensory systems may have facilitated the adaptation of this organism to harsh vent environments.

Quantifying invertebrate resistance to floods: a global-scale meta-analysis.

PubMed

McMullen, Laura E; Lytle, David A

2012-12-01

Floods are a key component of the ecology and management of riverine ecosystems around the globe, but it is not clear whether floods have predictable effects on organisms that can allow us to generalize across regions and continents. To address this, we conducted a global-scale meta-analysis to investigate effects of natural and managed floods on invertebrate resistance, the ability of invertebrates to survive flood events. We considered 994 studies for inclusion in the analysis, and after evaluation based on a priori criteria, narrowed our analysis to 41 studies spanning six of the seven continents. We used the natural-log-ratio of invertebrate abundance before and within 10 days after flood events because this measure of effect size can be directly converted to estimates of percent survival. We conducted categorical and continuous analyses that examined the contribution of environmental and study design variables to effect size heterogeneity, and examined differences in effect size among taxonomic groups. We found that invertebrate abundance was lowered by at least one-half after flood events. While natural vs. managed floods were similar in their effect, effect size differed among habitat and substrate types, with pools, sand, and boulders experiencing the strongest effect. Although sample sizes were not sufficient to examine all taxonomic groups, floods had a significant, negative effect on densities of Coleoptera, Eumalacostraca, Annelida, Ephemeroptera, Diptera, Plecoptera, and Trichoptera. Results from this study provide guidance for river flow regime prescriptions that will be applicable across continents and climate types, as well as baseline expectations for future empirical studies of freshwater disturbance.

Using Voice Coils to Actuate Modular Soft Robots: Wormbot, an Example

PubMed Central

Nemitz, Markus P.; Mihaylov, Pavel; Barraclough, Thomas W.; Ross, Dylan

2016-01-01

Abstract In this study, we present a modular worm-like robot, which utilizes voice coils as a new paradigm in soft robot actuation. Drive electronics are incorporated into the actuators, providing a significant improvement in self-sufficiency when compared with existing soft robot actuation modes such as pneumatics or hydraulics. The body plan of this robot is inspired by the phylum Annelida and consists of three-dimensional printed voice coil actuators, which are connected by flexible silicone membranes. Each electromagnetic actuator engages with its neighbor to compress or extend the membrane of each segment, and the sequence in which they are actuated results in an earthworm-inspired peristaltic motion. We find that a minimum of three segments is required for locomotion, but due to our modular design, robots of any length can be quickly and easily assembled. In addition to actuation, voice coils provide audio input and output capabilities. We demonstrate transmission of data between segments by high-frequency carrier waves and, using a similar mechanism, we note that the passing of power between coupled coils in neighboring modules—or from an external power source—is also possible. Voice coils are a convenient multifunctional alternative to existing soft robot actuators. Their self-contained nature and ability to communicate with each other are ideal for modular robotics, and the additional functionality of sound input/output and power transfer will become increasingly useful as soft robots begin the transition from early proof-of-concept systems toward fully functional and highly integrated robotic systems. PMID:28078195

Broad Phylogenetic Occurrence of the Oxygen-Binding Hemerythrins in Bilaterians

PubMed Central

Schrago, Carlos G.; Halanych, Kenneth M.

2017-01-01

Abstract Animal tissues need to be properly oxygenated for carrying out catabolic respiration and, as such, natural selection has presumably favored special molecules that can reversibly bind and transport oxygen. Hemoglobins, hemocyanins, and hemerythrins (Hrs) fulfill this role, with Hrs being the least studied. Knowledge of oxygen-binding proteins is crucial for understanding animal physiology. Hr genes are present in the three domains of life, Archaea, Bacteria, and Eukaryota; however, within Animalia, Hrs has been reported only in marine species in six phyla (Annelida, Brachiopoda, Priapulida, Bryozoa, Cnidaria, and Arthropoda). Given this observed Hr distribution, whether all metazoan Hrs share a common origin is circumspect. We investigated Hr diversity and evolution in metazoans, by employing in silico approaches to survey for Hrs from of 120 metazoan transcriptomes and genomes. We found 58 candidate Hr genes actively transcribed in 36 species distributed in 11 animal phyla, with new records in Echinodermata, Hemichordata, Mollusca, Nemertea, Phoronida, and Platyhelminthes. Moreover, we found that “Hrs” reported from Cnidaria and Arthropoda were not consistent with that of other metazoan Hrs. Contrary to previous suggestions that Hr genes were absent in deuterostomes, we find Hr genes present in deuterostomes and were likely present in early bilaterians, but not in nonbilaterian animal lineages. As expected, the Hr gene tree did not mirror metazoan phylogeny, suggesting that Hrs evolutionary history was complex and besides the oxygen carrying capacity, the drivers of Hr evolution may also consist of secondary functional specializations of the proteins, like immunological functions. PMID:29016798

Musculature in sipunculan worms: ontogeny and ancestral states.

PubMed

Schulze, Anja; Rice, Mary E

2009-01-01

Molecular phylogenetics suggests that the Sipuncula fall into the Annelida, although they are morphologically very distinct and lack segmentation. To understand the evolutionary transformations from the annelid to the sipunculan body plan, it is important to reconstruct the ancestral states within the respective clades at all life history stages. Here we reconstruct the ancestral states for the head/introvert retractor muscles and the body wall musculature in the Sipuncula using Bayesian statistics. In addition, we describe the ontogenetic transformations of the two muscle systems in four sipunculan species with different developmental modes, using F-actin staining with fluorescent-labeled phalloidin in conjunction with confocal laser scanning microscopy. All four species, which have smooth body wall musculature and less than the full set of four introvert retractor muscles as adults, go through developmental stages with four retractor muscles that are eventually reduced to a lower number in the adult. The circular and sometimes the longitudinal body wall musculature are split into bands that later transform into a smooth sheath. Our ancestral state reconstructions suggest with nearly 100% probability that the ancestral sipunculan had four introvert retractor muscles, longitudinal body wall musculature in bands and circular body wall musculature arranged as a smooth sheath. Species with crawling larvae have more strongly developed body wall musculature than those with swimming larvae. To interpret our findings in the context of annelid evolution, a more solid phylogenetic framework is needed for the entire group and more data on ontogenetic transformations of annelid musculature are desirable.

Cloning, analysis and functional annotation of expressed sequence tags from the Earthworm Eisenia fetida

PubMed Central

Pirooznia, Mehdi; Gong, Ping; Guan, Xin; Inouye, Laura S; Yang, Kuan; Perkins, Edward J; Deng, Youping

2007-01-01

Background Eisenia fetida, commonly known as red wiggler or compost worm, belongs to the Lumbricidae family of the Annelida phylum. Little is known about its genome sequence although it has been extensively used as a test organism in terrestrial ecotoxicology. In order to understand its gene expression response to environmental contaminants, we cloned 4032 cDNAs or expressed sequence tags (ESTs) from two E. fetida libraries enriched with genes responsive to ten ordnance related compounds using suppressive subtractive hybridization-PCR. Results A total of 3144 good quality ESTs (GenBank dbEST accession number EH669363–EH672369 and EL515444–EL515580) were obtained from the raw clone sequences after cleaning. Clustering analysis yielded 2231 unique sequences including 448 contigs (from 1361 ESTs) and 1783 singletons. Comparative genomic analysis showed that 743 or 33% of the unique sequences shared high similarity with existing genes in the GenBank nr database. Provisional function annotation assigned 830 Gene Ontology terms to 517 unique sequences based on their homology with the annotated genomes of four model organisms Drosophila melanogaster, Mus musculus, Saccharomyces cerevisiae, and Caenorhabditis elegans. Seven percent of the unique sequences were further mapped to 99 Kyoto Encyclopedia of Genes and Genomes pathways based on their matching Enzyme Commission numbers. All the information is stored and retrievable at a highly performed, web-based and user-friendly relational database called EST model database or ESTMD version 2. Conclusion The ESTMD containing the sequence and annotation information of 4032 E. fetida ESTs is publicly accessible at . PMID:18047730

Triploblastic relationships with emphasis on the acoelomates and the position of Gnathostomulida, Cycliophora, Plathelminthes, and Chaetognatha: a combined approach of 18S rDNA sequences and morphology.

PubMed

Giribet, G; Distel, D L; Polz, M; Sterrer, W; Wheeler, W C

2000-09-01

Triploblastic relationships were examined in the light of molecular and morphological evidence. Representatives for all triploblastic "phyla" (except Loricifera) were represented by both sources of phylogenetic data. The 18S ribosomal (rDNA) sequence data for 145 terminal taxa and 276 morphological characters coded for 36 supraspecific taxa were combined in a total evidence regime to determine the most consistent picture of triploblastic relationships for these data. Only triploblastic taxa are used to avoid rooting with distant outgroups, which seems to happen because of the extreme distance that separates diploblastic from triploblastic taxa according to the 18S rDNA data. Multiple phylogenetic analyses performed with variable analysis parameters yield largely inconsistent results for certain groups such as Chaetognatha, Acoela, and Nemertodermatida. A normalized incongruence length metric is used to assay the relative merit of the multiple analyses. The combined analysis having the least character incongruence yields the following scheme of relationships of four main clades: (1) Deuterostomia [((Echinodermata + Enteropneusta) (Cephalochordata (Urochordata + Vertebrata)))]; (2) Ecdysozoa [(((Priapulida + Kinorhyncha) (Nematoda + Nematomorpha)) ((Onychophora + Tardigrada) Arthropoda))]; (3) Trochozoa [((Phoronida + Brachiopoda) (Entoprocta (Nemertea (Sipuncula (Mollusca (Pogonophora (Echiura + Annelida)))))))]; and (4) Platyzoa [((Gnathostomulida (Cycliophora + Syndermata)) (Gastrotricha + Plathelminthes))]. Chaetognatha, Nemertodermatida, and Bryozoa cannot be assigned to any one of these four groups. For the first time, a data analysis recognizes a clade of acoelomates, the Platyzoa (sensu Cavalier-Smith, Biol. Rev. 73:203-266, 1998). Other relationships that corroborate some morphological analyses are the existence of a clade that groups Gnathostomulida + Syndermata (= Gnathifera), which is expanded to include the enigmatic phylum Cycliophora, as sister group

Strong pathways for incorporation of terrestrially derived organic matter into benthic communities

NASA Astrophysics Data System (ADS)

McLeod, Rebecca J.; Wing, Stephen R.

2009-05-01

In Fiordland, New Zealand, large volumes of organic matter are deposited into the marine environment from pristine forested catchments. Analyses of δ15N, δ13C and δ34S were employed to determine whether these inputs were contributing to marine food webs via assimilation by common macroinvertebrates inhabiting the inner reaches of the fjords. Terrestrially derived organic matter (TOM) had values of δ15N, δ13C and δ34S that were distinct from other carbon source pools, providing sufficient power to quantify the contribution of TOM to the benthic food web. Isotopic values among macroinvertebrates varied significantly, with consistently low values of δ15N, δ13C and δ34S for the abundant deposit feeders Echinocardium cordatum (Echinodermata) and Pectinaria australis (Annelida), indicating assimilation of TOM. High concentrations of bacterial fatty acid biomarkers in E. cordatum, and values of δ13C of these biomarkers similar to TOM (-27 to -30‰) confirmed that TOM is indirectly assimilated by these sea urchins via heterotrophic bacteria. TOM was also found to enter the infaunal food web via chemoautotrophic bacteria that live symbiotically within Solemya parkinsonii (Bivalvia). Echinocardium cordatum, Pectinaria australis and S. parkinsonii comprised up to 33.5% of the biomass of the macroinfaunal community, and thus represent strong pathways for movement of organic matter from the forested catchments into the benthic food web. This demonstration of connectivity among adjacent marine and terrestrial habitats has important implications for coastal land management, and highlights the importance of intact coastal forests to marine ecosystem function.

Using Voice Coils to Actuate Modular Soft Robots: Wormbot, an Example.

PubMed

Nemitz, Markus P; Mihaylov, Pavel; Barraclough, Thomas W; Ross, Dylan; Stokes, Adam A

2016-12-01

In this study, we present a modular worm-like robot, which utilizes voice coils as a new paradigm in soft robot actuation. Drive electronics are incorporated into the actuators, providing a significant improvement in self-sufficiency when compared with existing soft robot actuation modes such as pneumatics or hydraulics. The body plan of this robot is inspired by the phylum Annelida and consists of three-dimensional printed voice coil actuators, which are connected by flexible silicone membranes. Each electromagnetic actuator engages with its neighbor to compress or extend the membrane of each segment, and the sequence in which they are actuated results in an earthworm-inspired peristaltic motion. We find that a minimum of three segments is required for locomotion, but due to our modular design, robots of any length can be quickly and easily assembled. In addition to actuation, voice coils provide audio input and output capabilities. We demonstrate transmission of data between segments by high-frequency carrier waves and, using a similar mechanism, we note that the passing of power between coupled coils in neighboring modules-or from an external power source-is also possible. Voice coils are a convenient multifunctional alternative to existing soft robot actuators. Their self-contained nature and ability to communicate with each other are ideal for modular robotics, and the additional functionality of sound input/output and power transfer will become increasingly useful as soft robots begin the transition from early proof-of-concept systems toward fully functional and highly integrated robotic systems.

MARINE LEECH ANTICOAGULANT DIVERSITY AND EVOLUTION.

PubMed

Tessler, Michael; Marancik, David; Champagne, Donald; Dove, Alistair; Camus, Alvin; Siddall, Mark E; Kvist, Sebastian

2018-03-16

Leeches (Annelida: Hirudinea) possess powerful salivary anticoagulants and, accordingly, are frequently employed in modern, authoritative medicine. Members of the almost exclusively marine family Piscicolidae account for 20% of leech species diversity, and feed on host groups (e.g., sharks) not encountered by their freshwater and terrestrial counterparts. Moreover, some species of Ozobranchidae feed on endangered marine turtles and have been implicated as potential vectors for the tumor-associated turtle herpesvirus. In spite of their ecological importance and unique host associations, there is a distinct paucity of data regarding the salivary transcriptomes of either of these families. Using next generation sequencing, we profiled transcribed, putative anticoagulants and other salivary bioactive compounds that have previously been linked to bloodfeeding from 7 piscicolid species (3 elasmobranch-feeders; 4 non-cartilaginous fish-feeders) and 1 ozobranchid species (2 samples). In total, 149 putative anticoagulants and bioactive loci were discovered in varying constellations throughout the different samples. The putative anticoagulants showed a broad spectrum of described antagonistic pathways, such as inhibition of factor Xa and platelet aggregation, that likely have similar bioactive roles in marine fish and turtles. A transcript with homology to ohanin, originally isolated from king cobras, was found in Cystobranchus vividus but is otherwise unknown from leeches. Estimation of selection pressures for the putative anticoagulants recovered evidence for both positive and purifying selection along several isolated branches in the gene trees and positive selection was also estimated for a few select codons in a variety of marine species. Similarly, phylogenetic analyses of the amino acid sequences for several anticoagulants indicated divergent evolution.

The description of a new species Polymastigos javaensis n.sp. (Annelida: Capitellidae) from the Segara Anakan mangroves, Central Java, Indonesia.

PubMed

Pamungkas, Joko

2015-06-29

A new species, Polymastigos javaensis n. sp., is described from sandy clay sediment (0-30 cm depth) of the Segara Anakan mangroves. The species is described based on the distribution of capillaries and hooks, and the form of the prostomium, thorax, abdomen, lateral organs, genital pores, branchiae and pygidium. Methyl green staining pattern was applied to examine the similarity between the material of this study and Green's material. Polymastigos javaensis n. sp. is the second species belonging to the genus Polymastigos, after P. reishi Green, 2002. It differs from P. reishi in the form of abdominal segments and hooks, and the methyl green staining pattern. A key to distinguish the two species is provided in this paper.

A new eyeless species of Neanthes (Annelida: Nereididae) associated with a whale-fall community from the deep Southwest Atlantic Ocean

NASA Astrophysics Data System (ADS)

Shimabukuro, Maurício; Santos, Cinthya S. G.; Alfaro-Lucas, Joan M.; Fujiwara, Yoshihiro; Sumida, Paulo Y. G.

2017-12-01

A new whale-fall community was discovered in the abyssal SW Atlantic Ocean (4204 m depth) during the Iatá-piúna expedition. Several specimens of a new nereidid were found living in sediments around and immediately below whalebones. This new species, Neanthes shinkai, is described here. The most interesting feature of the new species is the absence of eyes on the prostomium. Although three other deep-sea Neanthes species are also eyeless, the arrangement of paragnaths on the pharynx, the shape of parapodia and the type of neuropodial falcigers chaetae can distinguish N. shinkai n. sp. from these other species. In addition, interspecific comparisons using COI fragment shown a high genetic divergence (23.6-24.9% K2P) from other Neanthes species. Some nereidids have been already known to live in association with deep-sea organic falls and other reducing environments, however this is the first record and description of a Neanthes species in a deep-sea whale-fall community. Observed behavioral and carbon and nitrogen isotopes suggest that N. shinkai n. sp. is an omnivore relying mainly on whale carcass with slightly contribution of chemosynthetic bacterial mats, suggesting that it is an inhabitant of whale-falls from SW Atlantic.

A new species of Paraonis and an annotated checklist of polychaetes from mangroves of the Brazilian Amazon Coast (Annelida, Paraonidae)

PubMed Central

Ribeiro, Rannyele Passos; Alves, Paulo Ricardo; de Almeida, Zafira da Silva; Ruta, Christine

2018-01-01

Abstract The polychaete fauna from the mangroves of the Amazon Coast in Maranhão state, Brazil, is reported in this study. Fourteen species are listed, namely Alitta succinea (Leuckart, 1847); Arabella (Arabella) iricolor Montagu, 1804; Capitella capitata (Fabricius, 1780) complex; Exogone (Exogone) breviantennata Hartmann-Schröder, 1959; Heteromastus filiformis (Claparède, 1864); Isolda pulchella Müller, 1858; Mediomastus californiensis Hartman, 1944; Namalycastis fauveli Nageswara Rao, 1981; Namalycastis geayi (Gravier, 1901); Namalycastis senegalensis (Saint-Joseph, 1901); Nephtys simoni Perkins, 1980; Paraonis amazonica sp. n.; Sigambra bassi (Hartman, 1945); and Sigambra grubii Müller, 1858. Among them, Namalycastis fauveli and Namalycastis geayi are recorded for the first time in Brazil. Paraonis amazonica sp. n. is a new species for science, characterized by a rounded prostomium, 4–8 pairs of foliaceous branchiae, absent eyes, and two types of modified neurochaetae, acicular and hook-shaped. PMID:29674886

Clarifying the taxonomic status of the alien species Branchiomma bairdi and Branchiomma boholense (Annelida: Sabellidae) using molecular and morphological evidence

PubMed Central

Schulze, Anja; Tovar-Hernández, María Ana; Keppel, Erica; Lezzi, Marco; Gambi, Maria Cristina; Giangrande, Adriana

2018-01-01

This study was performed to analyse the genetic and morphological diversity of the sabellid annelid genus Branchiomma, with special emphasis on a taxon so far identified as Branchiomma bairdi. This species, originally described from Bermuda, has frequently been reported as an invader in the Mediterranean, the Atlantic and the Eastern Pacific, but recent observations have raised some taxonomic questions. Samples of this taxon were collected from five sites in the Mediterranean Sea, two sites in the original distribution area of B. bairdi in the Gulf of Mexico and four localities in the east Pacific and Atlantic Oceans where B. bairdi has been reported as invasive. The molecular results revealed a conspicuous genetic divergence (18.5% K2P) between the sampled Mediterranean populations and all the other ones that led to a re-evaluation of their morphological characters. The latter showed that the Mediterranean and extra-Mediterranean populations also differ in some discrete morphological and reproductive features. Consequently, the Mediterranean samples were re-designated as B. boholense, another non-indigenous species originally described from Philippines. Branchiomma bairdi and B. boholense differ in body size, development and shape of micro and macrostylodes, size of radiolar eyes and body pigmentation. Genetic diversity was high in B. boholense from the Mediterranean as well as in B. bairdi from the Gulf of Mexico, but low in B. bairdi populations outside their native range. The phylogenetic analysis revealed the presence of connections between the Mediterranean localities as well as between native and introduced B. bairdi populations that focus the attention on the Panama Canal as important passage for the introduction of the species from the Gulf of Mexico to the north-east Pacific Ocean. PMID:29746553

Taxonomic description and 3D modelling of a new species of myzostomid (Annelida, Myzostomida) associated with black corals from Madagascar.

PubMed

Terrana, Lucas; Eeckhaut, Igor

2017-03-19

Eenymeenymyzostoma nigrocorallium n. sp. is the first species of myzostomid worm associated with black corals to be described. Endoparasitic specimens of E. nigrocorallium were found associated with three species of antipatharians on the Great Reef of Toliara. Individuals inhabit the gastrovascular ducts of their hosts and evidence of infestation is, most of the time, not visible externally. Phylogenetic analyses based on 18S rDNA, 16S rDNA and COI data indicate a close relation to Eenymeenymyzostoma cirripedium, the only other species of the genus. The morphology of E. nigrocorallium is very unusual compared to that of the more conventional E. cirripedium. The new species has five pairs of extremely reduced parapodia located on the body margin and no introvert, cirri or lateral organs. Individuals are hermaphroditic, with the male and female gonads both being located dorsally in the trunk. It also has a highly developed parenchymo-muscular layer on the ventral side, and the digestive system lies in the middle part of the trunk. A three-dimensional digital model of this worm's body plan has been constructed whereby the external morphology and in toto views of the observed organ systems (nervous, digestive and reproductive) can be viewed on-screen: http://doi.org/10.13140/RG.2.2.17911.21923.

Symbiotic association between Solanderia secunda (Cnidaria, Hydrozoa, Solanderiidae) and Medioantenna variopinta sp. nov. (Annelida, Polychaeta, Polynoidae) from North Sulawesi (Indonesia)

NASA Astrophysics Data System (ADS)

di Camillo, Cristina Gioia; Martin, Daniel; Britayev, Temir A.

2011-12-01

A mimic scale-worm was found associated with the athecate hydroid Solanderia secunda, commonly found on reefs of the NW coast of North Sulawesi, Indonesia. The species resembled Medioantenna clavata Imajima 1997, which was originally described without any reference to a symbiotic mode of life and later reported to be living on a solanderiid hydroid both in Japanese waters. A detailed morphological analysis led us to consider the Indonesian specimens as a new species, namely Medioantenna variopinta sp. nov., which is congeneric with the Japanese species. The new species differs from the type material of M. clavata as it has elytra with one prominent finger-like papilla and all neurochaetae with unidentate tip, instead of an elytral lump and both unidentate and bidentate neurochaetae on segment two. In turn, the Japanese worms associated with Solanderia are here referred to our new species. Two morphological features in M. variopinta sp. nov. are rather unusual among scale-worms. One of them is its extremely high level of bilateral asymmetry and antero-posterior variability in elytral distribution and the other one is its elongated, upwardly directed nephridial papillae. The morphology and geographical distribution of the host together with the known characteristics of the symbiotic association have also been highlighted.

[Freshwater macroinvertebrates from Cocos Island, Costa Rica: species and comparison with other islands of the Eastern Tropical Pacific].

PubMed

Gutiérrez-Fonseca, Pablo E; Ramírez, Alonso; Umaña, Gerardo; Springer, Monika

2013-06-01

Freshwater macroinvertebrates from Cocos Island, Costa Rica: species and comparison with other islands of the Eastern Tropical Pacific. Cocos Island is an oceanic island in the Eastern Pacific, at 496km from Cabo Blanco, Costa Rica. This 24 km2 island is surrounded by a protected marine area of 9640 km2. it was declared National Park in 1978 and a World Heritage by UNESCO in 1997. Freshwater macroinvertebrate fauna was collected in 20 sites covering three rivers (Genio, Chatam and Sucio) and two creeks (Minuto and an unnamed creek behind the park rangers' house). Tank bromeliads or phytotelmata were also examined for aquatic macroinvertebrates. Physicochemical parameters were determined in 13 study sites. Additionally, a comparison with other islands in the Eastern Tropical Pacific was conducted to determine the most important factors controlling the diversity in Tropical Pacific islands. A total of 455 individuals were collected belonging to 20 taxa (mostly identified to genus level) from 15 families of aquatic insects. Other macroinvertebrates such as Palaemonid shrimps, Hidrachnida and Oligochaeta were also collected. The family Staphylinidae (Coleoptera) was the most abundant, followed by Chironomidae (Diptera). Diptera was the order of insects with the highest taxonomic richness. A relationship between distance and the number of families was observed supporting the premises of the Theory of island Biogeography. This relationship was improved by correcting area by island elevation, indicating that mountainous islands had the richest faunas, potentially due to high cloud interception that feeds freshwater environments favoring the establishment of aquatic fauna. Physicochemical variables were similar in all sites, possibly due to the geology and the absence of significant sources of pollution on the island.

Ecotoxicological assessment of biosolids by microcosms.

PubMed

Groth, Vitor Avelar; Carvalho-Pereira, Ticiana; da Silva, Eduardo Mendes; Niemeyer, Júlia Carina

2016-10-01

Biosolids have been applied as soil amendments to improve and maintain the soil fertility and faster plant growth. In spite of its beneficial use, the potential risks of land disposal should be analyzed, considering potential ecological receptors in soil and water. This work describes the use of an early warning laboratory microcosm system to evaluate the integrated ecotoxicological potential of two biosolids: BIO-1 and BIO-2 (18 and 28 months after landfarming, respectively), from an effluent treatment station in a petrochemical and industrial district. The endpoints related to habitat function were: a) germination, growth and biomass of Phaseolus vulgaris; b) survival, biomass and number of cocoons of Eisenia andrei (Oligochaeta) and; c) reproduction of Folsomia candida (Collembola). The retention function was evaluated by testing the leachates using the tropical cladoceran Latonopsis australis (Cladocera) in a 48-h acute toxicity test, and growth of the aquatic plant Lemna minor in a 7-d chronic test. Tropical artificial soil (TAS) and a natural soil (NS) from the region were used as control soils. Results showed no chronic toxicity of BIO-1 and BIO-2 to the soil organisms tested, but acute toxicity of BIO-1 in the leachate for 50% of L. australis, and chronic toxicity of both biosolid leachates to L. minor (inhibition of growth rate), indicating potential risks to aquatic ecosystems. The results confirmed the ability of this microcosm system as a rapid tool to assess biosolid toxicity over time and its potential for hazardous waste characterization in environmental risk assessment, in a screening phase. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of repeated TFM applications on riffle macroinvertebrate communities in four Great Lakes tributaries

USGS Publications Warehouse

Weisser, John W.; Adams, Jean V.; Schuldt, Richard J.; Baldwin, Gregg A.; Lavis, Dennis S.; Slade, Jeffrey W.; Heinrich, John W.

2003-01-01

As part of the sea lamprey control program in the Great Lakes, a suite of about 150 sea lamprey producing streams have been regularly treated with the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) every 3 to 5 years since 1958. State, provincial, and tribal agencies in the basin supported the use of TFM and urged that the risk to nontarget organisms be minimized. To determine the response of riffle macroinvertebrate communities to repeated TFM treatments over several years, paired samples were taken at control and treatment sites during 1986 to 1995 on four Great Lakes tributaries: the Bois Brule, West Branch Whitefish, Boardman, and Sturgeon (tributary to Cheboygan River system) rivers. Macroinvertebrates were collected in spring and fall by a standard traveling kick method. The communities were described with several metrics, and general linear models were used to test for different patterns of response in the paired control and treatment sites. Relative abundance of the class Oligochaeta, relative abundance of the genus Ephemerella, the Bray-Curtis similarity index (at the taxonomic level of order), EPT genus richness (the number of genera in the orders Ephemeroptera, Plecoptera, and Trichoptera), and total genus richness all increased more at the treatment sites than at the control sites after TFM application. The greater increase in abundance, similarity, and richness at the treatment sites was an indication of recovery in the treatment sites, where a short-term response to TFM was followed by a several-year rebound. TFM treatments in this study during the 1980s and 1990s had no long-lasting effects on riffle macroinvertebrate communities.

Trends in Benthic macroinvertebrate community Biomass and Energy Budgets in Lake Sevan, 1928-2004

USGS Publications Warehouse

Stapanian, Martin A.; Jenderedjian, K.; Hakobyan, S.

2012-01-01

Water levels of Lake Sevan (Armenia) were artificially lowered by nearly 20 m between 1949 and 1997. Lowered water levels, combined with increased eutrophication, were associated with seasonally anoxic conditions (lasting 1–4 months) near the bottom of the profundal zone each year during 1976–2004. In addition, the extents of the macrophyte zone and of certain substrate types were severely reduced following drawdown. Maximal depth of occurrence decreased by 2–44 m for at least for 50 species of benthic macroinvertebrates between 1982 and 2004 compared to 1937–1961. Species richness of benthic macroinvertebrates declined from 25 to three species at depths where seasonal anoxia occurred. Total biomass increased by a factor of 10 from the period 1928–1948 to 1976–1979 then declined by a factor of 3 to 4 between 1987 and 2004. Energy flow through detritivores was more than tripled during 1976–2004 compared to 1928–1971, a result of increased plankton primary production. In contrast, energy flow through herbivorous benthic macroinvertebrates decreased by a factor of nearly 5, due to reduced areal coverage of macrophytes. Energy flow through filter feeders did not change over the time period examined, but energy flow through the entire zoobenthos community was nearly tripled. The biomasses of Oligochaeta, Chironomidae, and total zoobenthos showed a delayed response to changes in primary production of 7–9, 2, and 2–4 years, respectively. These patterns may provide a basis to predict results of restoration efforts based on the abundance of the zoobenthos in future years as the level of the lake is restored and water quality improves.

The mineralogical responses of marine calcifiers to CO2-induced ocean acidification

NASA Astrophysics Data System (ADS)

Ries, J. B.; Cohen, A. L.; McCorkle, D. C.

2008-12-01

We have conducted 6-month laboratory experiments to investigate the effect of pCO2-induced reductions in seawater CaCO3 saturation state on biocalcification by 18 aragonitic and calcitic (low-high Mg) taxa representing eight of the major marine calcifying groups: Chlorophyta; Rhodophyta; Crustacea; Bivalvia; Gastropoda; Annelida; Cnidaria; and Echinodermata. The CaCO3 saturation states of the experimental seawaters, constrained by intercalibrated determinations of pH, alkalinity, and DIC, were attained with bubbled air-CO2 mixtures of 400 (ambient), 600, 900, and 2850 ppm pCO2, yielding Ωarag of 2.5 (ambient), 2.0, 1.5, 0.7, respectively. We previously showed that while rates of net calcification obtained from buoyant weighing declined with increasing pCO2 for nearly half of the species investigated, a nearly equal number exhibited constant or, in some cases, increased calcification under moderately (600 ppm) or extremely (900 or 2850 ppm) elevated pCO2. The organisms' investigated in this study secrete various forms of CaCO3, which differ in crystallographic structure and therefore solubility: aragonite and high-Mg are generally more soluble than low-Mg calcite. We have employed powder x-ray diffraction, Raman spectroscopy, inductively-coupled-plasma mass-spectrometry, and scanning electron microscopy to quantify changes in the organisms' skeletal mineralogy (aragonite:calcite ratio) and Mg-content (MgCO3:CaCO3 ratio) that occurred in response to the prescribed reductions in seawater CaCO3 saturation state. We will compare calcification and mineralogical response patterns amongst the organisms to elucidate the role of mineral lability in driving species-specific responses to CO2-induced ocean acidification.

Benthic community structure and composition in sediment from the northern Gulf of Mexico shoreline, Texas to Florida

USGS Publications Warehouse

Demopoulos, Amanda W.J.; Strom, Douglas G.

2012-01-01

From April 20 through July 15, 2010, approximately 4.93 million barrels of crude oil spilled into the Gulf of Mexico from the British Petroleum Macondo-1 well, representing the largest spill in U.S. waters. Baseline benthic community conditions were assessed from shoreline sediment samples collected from 56 stations within the swash zone (for example, sample depth ranged from 0 to 1.5 feet) along the northern Gulf of Mexico coastline. These sites were selected because they had a high probability of being impacted by the oil. Cores collected at 24 stations contained no sediment infauna. Benthic community metrics varied greatly among the remaining stations. Mississippi stations had the highest mean abundances (38.9 ± 23.9 individuals per 32 square centimeters (cm2); range: 0 to 186), while Texas had the lowest abundances, 4.9 ± 3 individuals per 32 cm2 (range: 0 to 25). Dominant phyla included Annelida, Arthropoda, and Mollusca, but proportional contributions of each group varied by State. Diversity indices Margalef's richness (d) and Shannon-Wiener diversity (H') were highest at Louisiana and Mississippi stations (0.4 and 0.4, for both, respectively) and lowest at Texas (values for both indices were 0.1 ± 0.1). Evenness (J') was low for all the States, ranging from 0.2 to 0.3, indicating a high degree of patchiness at these sites. Across stations within a State, average similarity ranged from 11.1 percent (Mississippi) to 41.1 percent (Louisiana). Low within-state similarity may be a consequence of differing habitat and physical environment conditions. Results provide necessary baseline information that will facilitate future comparisons with post-spill community metrics.

Broad Phylogenetic Occurrence of the Oxygen-Binding Hemerythrins in Bilaterians.

PubMed

Costa-Paiva, Elisa M; Schrago, Carlos G; Halanych, Kenneth M

2017-10-01

Animal tissues need to be properly oxygenated for carrying out catabolic respiration and, as such, natural selection has presumably favored special molecules that can reversibly bind and transport oxygen. Hemoglobins, hemocyanins, and hemerythrins (Hrs) fulfill this role, with Hrs being the least studied. Knowledge of oxygen-binding proteins is crucial for understanding animal physiology. Hr genes are present in the three domains of life, Archaea, Bacteria, and Eukaryota; however, within Animalia, Hrs has been reported only in marine species in six phyla (Annelida, Brachiopoda, Priapulida, Bryozoa, Cnidaria, and Arthropoda). Given this observed Hr distribution, whether all metazoan Hrs share a common origin is circumspect. We investigated Hr diversity and evolution in metazoans, by employing in silico approaches to survey for Hrs from of 120 metazoan transcriptomes and genomes. We found 58 candidate Hr genes actively transcribed in 36 species distributed in 11 animal phyla, with new records in Echinodermata, Hemichordata, Mollusca, Nemertea, Phoronida, and Platyhelminthes. Moreover, we found that "Hrs" reported from Cnidaria and Arthropoda were not consistent with that of other metazoan Hrs. Contrary to previous suggestions that Hr genes were absent in deuterostomes, we find Hr genes present in deuterostomes and were likely present in early bilaterians, but not in nonbilaterian animal lineages. As expected, the Hr gene tree did not mirror metazoan phylogeny, suggesting that Hrs evolutionary history was complex and besides the oxygen carrying capacity, the drivers of Hr evolution may also consist of secondary functional specializations of the proteins, like immunological functions. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

The Unique Morgue Ubiquitination Protein Is Conserved in a Diverse but Restricted Set of Invertebrates

PubMed Central

Zhou, Ying; Carpenter, Zachary W.; Brennan, Gregory

2009-01-01

Drosophila Morgue is a unique ubiquitination protein that facilitates programmed cell death and associates with DIAP1, a critical cell death inhibitor with E3 ubiquitin ligase activity. Morgue possesses a unique combination of functional domains typically associated with distinct types of ubiquitination enzymes. This includes an F box characteristic of the substrate-binding subunit in Skp, Cullin, and F box (SCF)-type ubiquitin E3 ligase complexes and a variant ubiquitin E2 conjugase domain where the active site cysteine is replaced by a glycine. Morgue also contains a single C4-type zinc finger motif. This architecture suggests potentially novel ubiquitination activities for Morgue. In this study, we address the evolutionary origins of this distinctive protein utilizing a combination of bioinformatics and molecular biology approaches. We find that Morgue exhibits widespread but restricted phylogenetic distribution among metazoans. Morgue proteins were identified in a wide range of Protostome phyla, including Arthropoda, Annelida, Mollusca, Nematoda, and Platyhelminthes. However, with one potential exception, Morgue was not detected in Deuterostomes, including Chordates, Hemichordates, or Echinoderms. Morgue was also not found in Ctenophora, Cnidaria, Placozoa, or Porifera. Characterization of Morgue sequences within specific animal lineages suggests that gene deletion or acquisition has occurred during divergence of nematodes and that at least one arachnid expresses an atypical form of Morgue consisting only of the variant E2 conjugase domain. Analysis of the organization of several morgue genes suggests that exon-shuffling events have contributed to the evolution of the Morgue protein. These results suggest that Morgue mediates conserved and distinctive ubiquitination functions in specific cell death pathways. PMID:19602541

Orthonectids Are Highly Degenerate Annelid Worms.

PubMed

Schiffer, Philipp H; Robertson, Helen E; Telford, Maximilian J

2018-05-24

The animal groups of Orthonectida and Dicyemida are tiny, extremely simple, vermiform endoparasites of various marine animals and have been linked in the Mesozoa (Figure 1). The Orthonectida (Figures 1A and 1B) have a few hundred cells, including a nervous system of just ten cells [2], and the Dicyemida (Figure 1C) are even simpler, with ∼40 cells [3]. They are classic "Problematica" [4]-the name Mesozoa suggests an evolutionary position intermediate between Protozoa and Metazoa (animals) [5] and implies that their simplicity is a primitive state, but molecular data have shown they are members of Lophotrochozoa within Bilateria [6-9], which means that they derive from a more complex ancestor. Their precise affinities remain uncertain, however, and it is disputed whether they even constitute a clade. Ascertaining their affinities is complicated by the very fast evolution observed in their genes, potentially leading to the common systematic error of long-branch attraction (LBA) [10]. Here, we use mitochondrial and nuclear gene sequence data and show that both dicyemids and orthonectids are members of the Lophotrochozoa. Carefully addressing the effects of unequal rates of evolution, we show that the Mesozoa is polyphyletic. While the precise position of dicyemids remains unresolved within Lophotrochozoa, we identify orthonectids as members of the phylum Annelida. This result reveals one of the most extreme cases of body-plan simplification in the animal kingdom; our finding makes sense of an annelid-like cuticle in orthonectids [2] and suggests that the circular muscle cells repeated along their body [11] may be segmental in origin. Copyright © 2018 Elsevier Ltd. All rights reserved.

Canyon effect and seasonal variability of deep-sea organisms in the NW Mediterranean: Synchronous, year-long captures of ;swimmers; from near-bottom sediment traps in a submarine canyon and its adjacent open slope

NASA Astrophysics Data System (ADS)

Romano, C.; Flexas, M. M.; Segura, M.; Román, S.; Bahamon, N.; Gili, J. M.; Sanchez-Vidal, A.; Martin, D.

2017-11-01

Numerous organisms, including both passive sinkers and active migrators, are captured in sediment traps together with sediments. By capturing these "swimmers", the traps become an extraordinarily tool to obtain relevant information on the biodiversity and dynamics of deep-sea organisms. Here we analyze near-bottom swimmers larger than 500 μm and their fluxes collected from eight near-bottom sediment traps installed on instrumented moorings deployed nearby Blanes Canyon (BC). Our data, obtained from November 2008 to October 2009 with a sampling rate of 15 days, constitutes the first year-long, continuous time series of the whole swimmers' community collected at different traps and bottom depths (from 300 m to 1800 m) inside a submarine canyon and on its adjacent open slope (OS). The traps captured 2155 specimens belonging to 70 taxa, with Crustacea (mainly Copepoda) and Annelida Polychaeta accounting for more than 90% of the total abundance. Almost half of the identified taxa (33) were only present in BC traps, where mean annual swimmer fluxes per trap were almost one order of magnitude higher than in the OS ones. Temporal variability in swimmer fluxes was more evident in BC than in OS. Fluxes dropped in winter (in coincidence with the stormy period in the region) and remained low until the following spring. In spring, there was a switch in taxa composition, including an increase of planktonic organisms. Additionally, we report drastic effects of extreme events, such as major storms, on deep-sea fauna. The impact of such extreme events along submarine canyon systems calls to rethink the influence of climate-driven phenomena on deep-sea ecosystems and, consequently, on their living resources.

Rediscovery and redescription of Leodice laurillardi (Quatrefages, 1866) comb. nov. (Annelida: Eunicidae)-a rare European polychaete or just an overlooked species?

PubMed

Arias, Andrés; Fernández-Álvarez, Fernando Á; Martins, Roberto; Anadón, Nuria

2015-06-04

The eunicid polychaete, Eunice laurillardi Quatrefages, 1866, originally described from the central Mediterranean, has been discovered on the northern Iberian Peninsula, constituting the first report of the species since its original description. The new specimens are compared with the type collection and the species is redescribed. Furthermore, the species is assigned to the genus Leodice Savigny in Lamarck, 1818, based on information provided by re-examination of type material and the newly collected specimens. A summary of the complex taxonomic history of the species and a discussion of its current status are also provided.

Nereididae (Annelida: Phyllodocida) of the Persian Gulf and Gulf of Oman, including description of two new species and 11 new records.

PubMed

Bonyadi-Naeini, Alieh; Rastegar-Pouyani, Nasrullah; Rastegar-Pouyani, Eskandar; Glasby, Christopher J; Rahimian, Hassan

2017-03-17

Currently, only 31 nereidid species are known from the Persian Gulf and Gulf of Oman. The present study was carried out in order to investigate the poorly known diversity of nereidid polychaetes from seas of the southern coasts of Iran. Specimens were collected from 23 locations along the intertidal zones of the two water bodies. Among the 26 species found: two are new, and are described here, including Simplisetia qeshmensis sp. nov. and Neanthes biparagnatha sp. nov.; 11 are new geographical records. Neanthes biparagnatha sp. nov. is most similar to N. deplanata (Mohammed, 1971), which is also found in the Persian Gulf, but can be most easily distinguished from it by the presence of bars in addition to cones in Area IV of the pharynx. Simplisetia qeshmensis sp. nov. may be distinguished from its closest congener, S. erythraeensis (Fauvel, 1918), also reported from the Persian Gulf, by having a greater number of paragnaths in Area I of the pharynx, an additional type of chaeta (homogomph spinigers) in the ventral neuropodial fascicle and having a reduced notopodial lobe in posterior chaetigers. The list of new records includes: one species from both areas, Neanthes glandicincta (Southern, 1921); eight species from the Persian Gulf, Leonnates decipiens Fauvel, 1929, Neanthes acuminata (Ehlers, 1868), Neanthes sp., Neanthes sp. cf. N. acuminata, Nereis sp. cf. N. pelagica Linnaeus, 1758, Perinereis cultrifera (Grube, 1840) species complex., Pseudonereis trimaculata (Horst, 1924), Pseudonereis sp. cf. P. variegata (Grube, 1857) and two from the Gulf of Oman, Leonnates persicus Wesenberg-Lund, 1949 and Perinereis kuwaitensis Mohammed, 1970. The present study brings to 40 the number of nereidid species currently known from the Persian Gulf and Gulf of Oman. A taxonomic key to nereidid species from the intertidal zones of the Persian Gulf and Gulf of Oman is presented to facilitate future investigations.

Do ampharetids take sedimented steps between vents and seeps? Phylogeny and habitat-use of Ampharetidae (Annelida, Terebelliformia) in chemosynthesis-based ecosystems.

PubMed

Eilertsen, Mari H; Kongsrud, Jon A; Alvestad, Tom; Stiller, Josefin; Rouse, Greg W; Rapp, Hans T

2017-10-31

A range of higher animal taxa are shared across various chemosynthesis-based ecosystems (CBEs), which demonstrates the evolutionary link between these habitats, but on a global scale the number of species inhabiting multiple CBEs is low. The factors shaping the distributions and habitat specificity of animals within CBEs are poorly understood, but geographic proximity of habitats, depth and substratum have been suggested as important. Biogeographic studies have indicated that intermediate habitats such as sedimented vents play an important part in the diversification of taxa within CBEs, but this has not been assessed in a phylogenetic framework. Ampharetid annelids are one of the most commonly encountered animal groups in CBEs, making them a good model taxon to study the evolution of habitat use in heterotrophic animals. Here we present a review of the habitat use of ampharetid species in CBEs, and a multi-gene phylogeny of Ampharetidae, with increased taxon sampling compared to previous studies. The review of microhabitats showed that many ampharetid species have a wide niche in terms of temperature and substratum. Depth may be limiting some species to a certain habitat, and trophic ecology and/or competition are identified as other potentially relevant factors. The phylogeny revealed that ampharetids have adapted into CBEs at least four times independently, with subsequent diversification, and shifts between ecosystems have happened in each of these clades. Evolutionary transitions are found to occur both from seep to vent and vent to seep, and the results indicate a role of sedimented vents in the transition between bare-rock vents and seeps. The high number of ampharetid species recently described from CBEs, and the putative new species included in the present phylogeny, indicates that there is considerable diversity still to be discovered. This study provides a molecular framework for future studies to build upon and identifies some ecological and evolutionary hypotheses to be tested as new data is produced.

A new earthworm species within a controversial genus: Eiseniona gerardoi sp. n. (Annelida, Lumbricidae) - description based on morphological and molecular data

PubMed Central

Díaz Cosín, Darío J.; Novo, Marta; Fernández, Rosa; Fernández Marchán, Daniel; Gutiérrez, Mónica

2014-01-01

Abstract The morphological and anatomical simplicity of soil dwelling animals, such as earthworms, has limited the establishment of a robust taxonomy making it sometimes subjective to authors’ criteria. Within this context, integrative approaches including molecular information are becoming more popular to solve the phylogenetic positioning of conflictive taxa. Here we present the description of a new lumbricid species from the region of Extremadura (Spain), Eiseniona gerardoi sp. n. The assignment to this genus is based on both a morphological and a phylogenetic study. The validity of the genus Eiseniona, one of the most controversial within Lumbricidae, is discussed. A synopsis of the differences between the type species and the west-European members of the genus is provided. PMID:24843253

The genus Syllis Savigny in Lamarck, 1818 (Annelida, Syllidae) from Australia. Molecular analysis and re-description of some poorly-known species.

PubMed

Álvarez-Campos, Patricia; Riesgo, Ana; Hutchings, Pat; San Martín, Guillermo

2015-12-03

The taxonomy and phylogenetic relationships within Syllis Savigny in Lamarck, 1818, the type genus of the family Syllidae, are still a matter of debate because the group does not show clear synapomorphies and because of the lack of molecular data for many of the species. In order to help understand some of the phylogenetic relationships within the genus Syllis, we have performed a morphological revision of part of the material collected during decades by the Australian Museum staff, and provide molecular data for species not sequenced before. In particular, seven poorly known Australian species of the genus Syllis Savigny in Lamarck, 1818 have been re-described in detail and sequenced to analyze their phylogenetic position: Syllis broomensis n. comb., S. crassicirrata (Treadwell, 1925) n. comb., Syllis cruzi Núñez & San Martín, 1991, S. edensis (Hartmann-Schröder, 1989), Syllis gracilis Grube, 1840, Syllis picta (Kinberg, 1866) n. comb., and S. setoensis (Imajima, 1966). The results obtained indicate the paraphyly of Typosyllis and a possible new organization of Syllis, which contains at least four well-supported clades.

Adding complexity to the complex: new insights into the phylogeny, diversification and origin of parthenogenesis in the Aporrectodea caliginosa species complex (Oligochaeta, Lumbricidae).

PubMed

Fernández, Rosa; Almodóvar, Ana; Novo, Marta; Simancas, Bárbara; Díaz Cosín, Darío J

2012-08-01

The importance of the Aporrectodea caliginosa species complex lies in the great abundance and wide distribution of the species which exist within it. For more than a century, chaos has surrounded this complex; morphological criteria has failed to solve the taxonomic status of these species. This present body of work aims to study the phylogeny of this complex by increasing the number of samples used in previous molecular works and by including morphologically-similar species that were never studied using molecular tools (A. giardi, Nicodrilus monticola, N. carochensis and N. tetramammalis). Two basal clades were obtained: one formed by A. caliginosa and A. tuberculata and the other by the rest of the species. This second clade was divided into two more: one with Eurosiberian and another with Mediterranean forms. A. caliginosa and A. longa were divided into two paraphyletic groups. Both A. giardi and A. nocturna showed characteristics consistent with monophyletic groups. Each of the two recovered lineages of A. trapezoides were phylogenetically related to different sexual species. While lineage I of A. trapezoides was monophyletic, lineage II resulted to be paraphyletic, as well as the three Nicodrilus 'species'. The diversification of the complex occurred during the Late Miocene-Early Pliocene (6.92-11.09 Mya). The parthenogenetic forms within the Mediterranean clade would have diversified before the ones in the Eurosiberian clade (3.13-4.64 Mya and 1.05-3.48 Mya, respectively), thus implying the existence not only of at least two different moments in which parthenogenesis arose within this complex of species, but also of two different and independent evolutionary lines. Neither the 4× rule nor the GMYC method for species delimitation were successful for distinguishing taxonomically-distinct species. Copyright © 2012 Elsevier Inc. All rights reserved.

Lavellodrilus notosetosus sp. nov. (Annelida, Crassiclitellata, Acanthodrilidae): a new Mexican earthworm with uncommon characters, revealed by a preliminary revision of subfamily Acanthodrilinae.

PubMed

Fragoso, Carlos; Rojas, Patricia

2016-08-19

A new acanthodriline earthworm species, Lavellodrilus notosetosus sp. nov., is described from tropical rain forests of southern Mexico. The new species is placed within the genus Lavellodrilus by the presence of mesial spermathecal pores. It is separated from other species of the genus by the dorsal location of setae cd in most of the body, last hearts in segment 13, first intestinal segment in 20 and genital setae in segment 12. A preliminary morphological revision of all genera and species of Acanthodrilinae was undertaken in order to: i) evaluate if the mesial spermathecal pores justify the status of Lavellodrilus, ii) determine how common (expressed as percentages of species having the character) the diagnostic characters of the new species are in the subfamily, iii) clarify if these characters exhibit a geographical pattern, and iv) contribute towards a comprehensive analysis of the Acanthodrilinae. In this revision, species were separated in nine geographical regions: USA, northern Mexico, southern Mexico, Caribbean Islands (northern hemisphere), and South America, South Africa, Madagascar, Australia, New Zealand, New Caledonia and Antarctic Islands (southern hemisphere). As a result of the revision it was found that among the 511 recognized species of Acanthodrilinae only 11 species have a mesial location of the spermathecal pores, in two cases probably representing monophyletic groups (Lavellodrilus and a group of South African Parachilota species). It was also found that the distinguishing characters in L. notosetosus sp. nov., notably the location of last hearts, genital setae and the first intestinal segment, are uncommon characters in the acanthodriline earthworm fauna of southern Mexico and Central America, but more frequent in North America, the Caribbean, and the southern hemisphere. We conclude that the acanthodrilines from the northern hemisphere are morphologically more similar to those from Australia, New Zealand, and New Caledonia than to those of South Africa and South America.

Effects of Lumbriculus variegatus (Annelida, Oligochaete) bioturbation on zinc sediment chemistry and toxicity to the epi-benthic invertebrate Chironomus tepperi (Diptera: Chironomidae).

PubMed

Colombo, Valentina; Pettigrove, Vincent J; Hoffmann, Ary A; Golding, Lisa A

2016-09-01

Classical laboratory-based single-species sediment bioassays do not account for modifications to toxicity from bioturbation by benthic organisms which may impact predictions of contaminated sediment risk to biota in the field. This study aims to determine the effects of bioturbation on the toxicity of zinc measured in a standard laboratory bioassay conducted with chironomid larvae (Chironomus tepperi). The epi-benthic chironomid larvae were exposed to two different levels of sediment contamination (1600 and 1980 mg/kg of dry weight zinc) in the presence or absence of annelid worms (Lumbriculus variegatus) which are known to be tolerant to metal and to have a large impact on sediment properties through bioturbation. Chironomids had 5-6x higher survival in the presence of L. variegatus which shows that bioturbation had a beneficial effect on the chironomid larvae. Chemical analyses showed that bioturbation induced a flux of zinc from the pore water into the water column, thereby reducing the bioavailability of zinc in pore water to the chironomid larvae. This also suggested that pore water was the major exposure path for the chironomids to metals in sediment. During the study, annelid worms (Oligochaetes) produced a thin layer of faecal pellets at the sediment surface, a process known to: (i) create additional adsorption sites for zinc, thus reducing its availability, (ii) increase the microbial abundance that in turn could represent an additional food source for opportunistic C. tepperi larvae, and (iii) modify the microbial community's structure and alter the biogeochemical processes it governs thus indirectly impact zinc toxicity. This study represents a contribution in recognising bioturbating organisms as "ecological engineers" as they directly and indirectly influence metal bioavailability and impact other sediment-inhabiting species. This is significant and should be considered in risk assessment of zinc levels (and other metals) in contaminated sediment when extrapolating from laboratory studies to the field. Copyright © 2016 Elsevier Ltd. All rights reserved.

An evaluation of the relative quality of dike pools for benthic macroinvertebrates in the Lower Missouri River, USA

USGS Publications Warehouse

Poulton, B.C.; Allert, A.L.

2012-01-01

A habitat-based aquatic macroinvertebrate study was initiated in the Lower Missouri River to evaluate relative quality and biological condition of dike pool habitats. Water-quality and sediment-quality parameters and macroinvertebrate assemblage structure were measured from depositional substrates at 18 sites. Sediment porewater was analysed for ammonia, sulphide, pH and oxidation-reduction potential. Whole sediments were analysed for particle-size distribution, organic carbon and contaminants. Field water-quality parameters were measured at subsurface and at the sediment-water interface. Pool area adjacent and downstream from each dike was estimated from aerial photography. Macroinvertebrate biotic condition scores were determined by integrating the following indicator response metrics: % of Ephemeroptera (mayflies), % of Oligochaeta worms, Shannon Diversity Index and total taxa richness. Regression models were developed for predicting macroinvertebrate scores based on individual water-quality and sediment-quality variables and a water/sediment-quality score that integrated all variables. Macroinvertebrate scores generated significant determination coefficients with dike pool area (R2=0.56), oxidation–reduction potential (R2=0.81) and water/sediment-quality score (R2=0.71). Dissolved oxygen saturation, oxidation-reduction potential and total ammonia in sediment porewater were most important in explaining variation in macroinvertebrate scores. The best two-variable regression models included dike pool size + the water/sediment-quality score (R2=0.84) and dike pool size + oxidation-reduction potential (R2=0.93). Results indicate that dike pool size and chemistry of sediments and overlying water can be used to evaluate dike pool quality and identify environmental conditions necessary for optimizing diversity and productivity of important aquatic macroinvertebrates. A combination of these variables could be utilized for measuring the success of habitat enhancement

Distribution and Prevalence of Myxobolus cerebralis in Postfire Areas of Plumas National Forest: Utility of Environmental DNA Sampling.

PubMed

Richey, Christine A; Kenelty, Kirsten V; Van Stone Hopkins, Kristina; Stevens, Brittany N; Martínez-López, Beatriz; Barnum, Samantha M; Hallett, Sascha L; Atkinson, Stephen D; Bartholomew, Jerri L; Soto, Esteban

2018-04-30

Myxobolus cerebralis is a myxozoan parasite and the etiological agent of whirling disease in salmonids. The parasite's life cycle involves waterborne spores and requires both a salmonid fish and the benthic freshwater oligochaete worm Tubifex tubifex (Oligochaeta: Tubificidae). Wildfires can lead to the erosion of fine sediments into stream channels and have been implicated as promoting environmental conditions that are suitable for the survival and success of T. tubifex, whose presence in turn can affect the prevalence of M. cerebralis. Analysis of environmental DNA (eDNA) has the potential to be a powerful tool for evaluating the presence of microorganisms, for which direct observation is impossible. We investigated the presence of M. cerebraliseDNA in river water and river sediment samples collected from areas affected by recent fire activity in Plumas National Forest, California. We compared eDNA loads in the environment to M. cerebralis infection in T. tubifex and sentinel-exposed Rainbow Trout Oncorhynchus mykiss and the presence of T. tubifex lineages in the same environment. For the latter, we developed a multiplex quantitative PCR assay for detection of T. tubifex lineages I, III, and V. Lineage IIIT. tubifex and M. cerebralis (eDNA as well as DNA extracted from fish and worm tissues) were detected only in samples obtained from areas affected by the Moonlight wildfire. The association between M. cerebralis infection in sentinel-exposed fish and eDNA detection in environmental samples only approached significance at a P-value of 0.056. However, given the difference in relative effort between the two sampling methods (host versus nonhost environment), our data suggest that eDNA sampling of water and substrate is a promising approach for surveillance of myxozoan fish parasites. © 2018 American Fisheries Society.

Foraging Ecology of Fall-Migrating Shorebirds in the Illinois River Valley

PubMed Central

Smith, Randolph V.; Stafford, Joshua D.; Yetter, Aaron P.; Horath, Michelle M.; Hine, Christopher S.; Hoover, Jeffery P.

2012-01-01

Populations of many shorebird species appear to be declining in North America, and food resources at stopover habitats may limit migratory bird populations. We investigated body condition of, and foraging habitat and diet selection by 4 species of shorebirds in the central Illinois River valley during fall migrations 2007 and 2008 (Killdeer [Charadrius vociferus], Least Sandpiper [Calidris minutilla], Pectoral Sandpiper [Calidris melanotos], and Lesser Yellowlegs [Tringa flavipes]). All species except Killdeer were in good to excellent condition, based on size-corrected body mass and fat scores. Shorebird diets were dominated by invertebrate taxa from Orders Diptera and Coleoptera. Additionally, Isopoda, Hemiptera, Hirudinea, Nematoda, and Cyprinodontiformes contribution to diets varied by shorebird species and year. We evaluated diet and foraging habitat selection by comparing aggregate percent dry mass of food items in shorebird diets and core samples from foraging substrates. Invertebrate abundances at shorebird collection sites and random sites were generally similar, indicating that birds did not select foraging patches within wetlands based on invertebrate abundance. Conversely, we found considerable evidence for selection of some diet items within particular foraging sites, and consistent avoidance of Oligochaeta. We suspect the diet selectivity we observed was a function of overall invertebrate biomass (51.2±4.4 [SE] kg/ha; dry mass) at our study sites, which was greater than estimates reported in most other food selection studies. Diet selectivity in shorebirds may follow tenants of optimal foraging theory; that is, at low food abundances shorebirds forage opportunistically, with the likelihood of selectivity increasing as food availability increases. Nonetheless, relationships between the abundance, availability, and consumption of Oligochaetes for and by waterbirds should be the focus of future research, because estimates of foraging carrying capacity

Evidence of Niche Partitioning under Ontogenetic Influences among Three Morphologically Similar Siluriformes in Small Subtropical Streams

PubMed Central

Bonato, Karine Orlandi; Fialho, Clarice Bernhardt

2014-01-01

Ontogenetic influences in patterns of niche breadth and feeding overlap were investigated in three species of Siluriformes (Heptapterus sp., Rhamdia quelen and Trichomycterus poikilos) aiming at understanding the species coexistence. Samplings were conducted bimonthly by electrofishing technique from June/2012 to June/2013 in ten streams of the northwestern state of Rio Grande do Sul, Brazil. The stomach contents of 1,948 individuals were analyzed by volumetric method, with 59 food items identified. In general Heptapterus sp. consumed a high proportion of Aegla sp., terrestrial plant remains and Megaloptera; R. quelen consumed fish, and Oligochaeta, followed by Aegla sp.; while the diet of T. poikilos was based on Simuliidae, Ephemeroptera and Trichoptera. Specie segregation was observed in the NMDS. Through PERMANOVA analysis feeding differences among species, and between a combination of species plus size classes were observed. IndVal showed which items were indicators of these differences. Niche breadth values were high for all species. The niche breadth values were low only for the larger size of R. quelen and Heptapterus sp. while T. poikilos values were more similar. Overall the species were a low feeding overlap values. The higher frequency of high feeding overlap was observed for interaction between Heptapterus sp. and T. poikilos. The null model confirmed the niche partitioning between the species. The higher frequency of high and intermediate feeding overlap values were reported to smaller size classes. The null model showed resource sharing between the species/size class. Therefore, overall species showed a resource partitioning because of the use of occasional items. However, these species share resources mainly in the early ontogenetic stages until the emphasized change of morphological characteristics leading to trophic niche expansion and the apparent segregation observed. PMID:25340614

Temporal and spatial distribution of the meiobenthic community in Daya Bay, South China Sea

NASA Astrophysics Data System (ADS)

Tang, L.; Li, H. X.; Yan, Y.

2012-04-01

Spatial and temporal biodiversity patterns of the meiobenthos were studied for the first time in Daya Bay, which is a tropical semi-enclosed basin located in the South China Sea. The abundance, biomass, and composition of the meiobenthos and the basic environmental factors in the bay were investigated. The following 19 taxonomic groups were represented in the meiofauna: Nematoda, Copepoda, Polychaeta, Oligochaeta, Kinorhyncha, Gastrotricha, Ostracoda, Bivalvia, Turbellaria, Nemertinea, Sipuncula, Hydroida, Amphipoda, Cumacea, Halacaroidea, Priapulida, Echinodermata, Tanaidacea, and Rotifera. Total abundance and biomass of the meiobenthos showed great spatial and temporal variation, with mean values of 993.57 ± 455.36 ind cm-2 and 690.51 ± 210.64 μg 10 cm-2, respectively. Nematodes constituted 95.60 % of the total abundance and thus had the greatest effect on meiofauna quantity and distribution, followed by copepods (1.55 %) and polychaetes (1.39 %). Meiobenthos abundance was significantly negatively correlated with water depth at stations (r=-0.747, P<0.05) and significantly negatively correlated with silt-clay content (r=-0.516, P<0.01) and medium diameter (r=-0.499, P<0.01) of the sediment. Similar results were found for correlations of biomass and abundance of nematodes with environmental parameters. Polychaete abundance was positively correlated with the bottom water temperature (r=0.456, P<0.01). Meiobenthos abundance differed significantly among seasons (P<0.05), although no significant difference among stations and the interaction of station × season was detected by two-way ANOVA. In terms of vertical distribution, most of the meiobenthos was found in the surface layer of sediment. This pattern was apparent for nematodes and copepods, but a vertical distribution pattern for polychaetes was not as obvious. Based on the biotic indices and analyses of their correlations and variance, the diversity of this community was likely to be influenced by

Metals in the Scheldt estuary: From environmental concentrations to bioaccumulation.

PubMed

Van Ael, Evy; Blust, Ronny; Bervoets, Lieven

2017-09-01

To investigate the relationship between metal concentrations in abiotic compartments and in aquatic species, sediment, suspended matter and several aquatic species (Polychaeta, Oligochaeta, four crustacean species, three mollusc species and eight fish species) were collected during three seasons at six locations along the Scheldt estuary (the Netherlands-Belgium) and analysed on their metal content (Ag, Cd, Co, Cr, Cu, Ni, Pb, Zn and the metalloid As). Sediment and biota tissue concentrations were significantly influenced by sampling location, but not by season. Measurements of Acid Volatile Sulphides (AVS) concentrations in relation to Simultaneously Extracted Metals (SEM) in the sediment suggested that not all metals in the sediment will be bound to sulphides and some metals might be bioavailable. For all metals but zinc, highest concentrations were measured in invertebrate species; Ag and Ni in periwinkle, Cr, Co and Pb in Oligochaete worms and As, Cd and Cu in crabs and shrimp. Highest concentrations of Zn were measured in the kidney of European smelt. In fish, for most of the metals, the concentrations were highest in liver or kidney and lowest in muscle. For Zn however, highest concentrations were measured in the kidney of European smelt. For less than half of the metals significant correlations between sediment metal concentrations and bioaccumulated concentrations were found (liver/hepatopancreas or whole organism). To calculate the possible human health risk by consumption, average and maximum metal concentrations in the muscle tissues were compared to the minimum risk levels (MRLs). Concentrations of As led to the highest risk potential for all consumable species. Cadmium and Cu posed only a risk when consuming the highest contaminated shrimp and shore crabs. Consuming blue mussel could result in a risk for the metals As, Cd and Cr. Copyright © 2017 Elsevier Ltd. All rights reserved.

Natural disturbance shapes benthic intertidal macroinvertebrate communities of high latitude river deltas

USGS Publications Warehouse

Churchwell, Roy T.; Kendall, Steve J.; Blanchard, Amy L.; Dunton, Kenneth H.; Powell, Abby N.

2016-01-01

Unlike lower latitude coastlines, the estuarine nearshore zones of the Alaskan Beaufort Sea are icebound and frozen up to 9 months annually. This annual freezing event represents a dramatic physical disturbance to fauna living within intertidal sediments. The main objectives of this study were to describe the benthic communities of Beaufort Sea deltas, including temporal changes and trophic structure. Understanding benthic invertebrate communities provided a baseline for concurrent research on shorebird foraging ecology at these sites. We found that despite continuous year-to-year episodes of annual freezing, these estuarine deltas are populated by a range of invertebrates that represent both marine and freshwater assemblages. Freshwater organisms like Diptera and Oligochaeta not only survive this extreme event, but a marine invasion of infaunal organisms such as Amphipoda and Polychaeta rapidly recolonizes the delta mudflats following ice ablation. These delta sediments of sand, silt, and clay are fine in structure compared to sediments of other Beaufort Sea coastal intertidal habitats. The relatively depauperate invertebrate community that ultimately develops is composed of marine and freshwater benthic invertebrates. The composition of the infauna also reflects two strategies that make life on Beaufort Sea deltas possible: a migration of marine organisms from deeper lagoons to the intertidal and freshwater biota that survive the 9-month ice-covered period in frozen sediments. Stable isotopic analyses reveal that both infaunal assemblages assimilate marine and terrestrial sources of organic carbon. These results provide some of the first quantitative information on the infaunal food resources of shallow arctic estuarine systems and the long-term persistence of these invertebrate assemblages. Our data help explain the presence of large numbers of shorebirds in these habitats during the brief summer open-water period and their trophic importance to migrating

Diet and trophic level of the longnose spurdog Squalus blainville (Risso, 1826) in the deep waters of the Aegean Sea

NASA Astrophysics Data System (ADS)

Kousteni, Vasiliki; Karachle, Paraskevi K.; Megalofonou, Persefoni

2017-06-01

Knowledge of the diet and trophic level of marine predators is essential to develop an understanding of their ecological role in ecosystems. Research conducted on the trophic ecology of the deep-sea sharks is rather limited. The purpose of this study was to examine the diet of the longnose spurdog Squalus blainville, a deep-sea shark categorized as "data deficient" within its distribution range, with respect to sex, maturity, age, season and sampling location. The stomach contents of 211 specimens, captured in the Aegean (off Skyros and the Cyclades Islands) and Cretan Seas, using commercial bottom-trawlers from 2005 to 2012, were analysed. The cumulative prey curve showed that the sample size was adequate to describe the species' diet. The identified prey items belonged to five major groups: Teleostei, Crustacea, Cephalopoda, Annelida and Phanerogams. Higher diet diversity was observed in females compared to males, in immature individuals compared to mature ones, regardless of sex, and in spring and winter compared to other seasons. Age and sampling location seemed to influence both the diet diversity and trophic spectrum of the species. Feeding intensity based on the vacuity index was not significantly influenced by any of the factors examined, while the stomach filling degree was significantly influenced by all factors, except sex, showing significantly higher values in mature females compared to immature ones, in older individuals, in autumn compared to winter, and a significantly lower value in the Cyclades Islands compared to other locations. Females showed a significant larger mouth length compared to males of the same length, while no between-sex differences were found in gut morphometrics. The estimated fractional trophic level (TROPH=4.41) classified the species as carnivore with a preference for Teleostei and Cephalopoda, confirming its high trophic position.

Conservation and diversification of Msx protein in metazoan evolution.

PubMed

Takahashi, Hirokazu; Kamiya, Akiko; Ishiguro, Akira; Suzuki, Atsushi C; Saitou, Naruya; Toyoda, Atsushi; Aruga, Jun

2008-01-01

Msx (/msh) family genes encode homeodomain (HD) proteins that control ontogeny in many animal species. We compared the structures of Msx genes from a wide range of Metazoa (Porifera, Cnidaria, Nematoda, Arthropoda, Tardigrada, Platyhelminthes, Mollusca, Brachiopoda, Annelida, Echiura, Echinodermata, Hemichordata, and Chordata) to gain an understanding of the role of these genes in phylogeny. Exon-intron boundary analysis suggested that the position of the intron located N-terminally to the HDs was widely conserved in all the genes examined, including those of cnidarians. Amino acid (aa) sequence comparison revealed 3 new evolutionarily conserved domains, as well as very strong conservation of the HDs. Two of the three domains were associated with Groucho-like protein binding in both a vertebrate and a cnidarian Msx homolog, suggesting that the interaction between Groucho-like proteins and Msx proteins was established in eumetazoan ancestors. Pairwise comparison among the collected HDs and their C-flanking aa sequences revealed that the degree of sequence conservation varied depending on the animal taxa from which the sequences were derived. Highly conserved Msx genes were identified in the Vertebrata, Cephalochordata, Hemichordata, Echinodermata, Mollusca, Brachiopoda, and Anthozoa. The wide distribution of the conserved sequences in the animal phylogenetic tree suggested that metazoan ancestors had already acquired a set of conserved domains of the current Msx family genes. Interestingly, although strongly conserved sequences were recovered from the Vertebrata, Cephalochordata, and Anthozoa, the sequences from the Urochordata and Hydrozoa showed weak conservation. Because the Vertebrata-Cephalochordata-Urochordata and Anthozoa-Hydrozoa represent sister groups in the Chordata and Cnidaria, respectively, Msx sequence diversification may have occurred differentially in the course of evolution. We speculate that selective loss of the conserved domains in Msx family

[Articulata and Ecdysozoa].

PubMed

Ivanova-Kazas, O M

2015-01-01

Science has accumulated to date such amounts of valuable and diverse information that no scientists can be encyclopedists (like those of the 17th and 18th centuries). Now every scientist is usually well informed only in one particular area and often needs consultations of other specialists. The current situation in biology is similar. In addition to evolutionary morphology, which represents fundamentals of zoology, there is a new, clearly cutting-edge and progressive area of studies, molecular genetics, which has already revealed many important general biological patterns. But the conclusions that follow from examining natural phenomena from this new point of view using new methods sometimes prove to be at odds with conventional notions. Considerable controversies have emerged on the phylogenetic position of the type Arthropoda. The peculiar features of the general body plan and the type of development of these animals seem to give evidence that they evolved from Annelida, with which they are often combined under the name Articulata. But attempts have been made to replace this concept by the idea that the clade Ecdysozoa, which includes Arthropods as well as such animals with low levels of organization as Nematoda and Priapulida, emerged early in the evolution of Bilateria. The main reason for combining the said animals in this clade is the fact that they have molts regulated with ecdysone; this point of view is supported by molecular genetic arguments. Although in this review this controversial problem is considered from the morphological point of view, the main purpose of the review is to emphasize the need to establish mutual understanding.between morphologists and molecular biologists and carefully find out the causes of the existing disagreements. Rather than ideological opponents, the two areas of science should be allies helping each other to solve complicated problems.

Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada.

PubMed

Rincón, Beatriz; Kenchington, Ellen L

2016-01-01

We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km-all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna.

Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada

PubMed Central

2016-01-01

We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km–all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna. PMID:27649419

Patterns of Diversity in Soft-Bodied Meiofauna: Dispersal Ability and Body Size Matter

PubMed Central

Curini-Galletti, Marco; Artois, Tom; Delogu, Valentina; De Smet, Willem H.; Fontaneto, Diego; Jondelius, Ulf; Leasi, Francesca; Martínez, Alejandro; Meyer-Wachsmuth, Inga; Nilsson, Karin Sara; Tongiorgi, Paolo; Worsaae, Katrine; Todaro, M. Antonio

2012-01-01

Background Biogeographical and macroecological principles are derived from patterns of distribution in large organisms, whereas microscopic ones have often been considered uninteresting, because of their supposed wide distribution. Here, after reporting the results of an intensive faunistic survey of marine microscopic animals (meiofauna) in Northern Sardinia, we test for the effect of body size, dispersal ability, and habitat features on the patterns of distribution of several groups. Methodology/Principal Findings As a dataset we use the results of a workshop held at La Maddalena (Sardinia, Italy) in September 2010, aimed at studying selected taxa of soft-bodied meiofauna (Acoela, Annelida, Gastrotricha, Nemertodermatida, Platyhelminthes and Rotifera), in conjunction with data on the same taxa obtained during a previous workshop hosted at Tjärnö (Western Sweden) in September 2007. Using linear mixed effects models and model averaging while accounting for sampling bias and potential pseudoreplication, we found evidence that: (1) meiofaunal groups with more restricted distribution are the ones with low dispersal potential; (2) meiofaunal groups with higher probability of finding new species for science are the ones with low dispersal potential; (3) the proportion of the global species pool of each meiofaunal group present in each area at the regional scale is negatively related to body size, and positively related to their occurrence in the endobenthic habitat. Conclusion/Significance Our macroecological analysis of meiofauna, in the framework of the ubiquity hypothesis for microscopic organisms, indicates that not only body size but mostly dispersal ability and also occurrence in the endobenthic habitat are important correlates of diversity for these understudied animals, with different importance at different spatial scales. Furthermore, since the Western Mediterranean is one of the best-studied areas in the world, the large number of undescribed species (37

Patterns of diversity in soft-bodied meiofauna: dispersal ability and body size matter.

PubMed

Curini-Galletti, Marco; Artois, Tom; Delogu, Valentina; De Smet, Willem H; Fontaneto, Diego; Jondelius, Ulf; Leasi, Francesca; Martínez, Alejandro; Meyer-Wachsmuth, Inga; Nilsson, Karin Sara; Tongiorgi, Paolo; Worsaae, Katrine; Todaro, M Antonio

2012-01-01

Biogeographical and macroecological principles are derived from patterns of distribution in large organisms, whereas microscopic ones have often been considered uninteresting, because of their supposed wide distribution. Here, after reporting the results of an intensive faunistic survey of marine microscopic animals (meiofauna) in Northern Sardinia, we test for the effect of body size, dispersal ability, and habitat features on the patterns of distribution of several groups. As a dataset we use the results of a workshop held at La Maddalena (Sardinia, Italy) in September 2010, aimed at studying selected taxa of soft-bodied meiofauna (Acoela, Annelida, Gastrotricha, Nemertodermatida, Platyhelminthes and Rotifera), in conjunction with data on the same taxa obtained during a previous workshop hosted at Tjärnö (Western Sweden) in September 2007. Using linear mixed effects models and model averaging while accounting for sampling bias and potential pseudoreplication, we found evidence that: (1) meiofaunal groups with more restricted distribution are the ones with low dispersal potential; (2) meiofaunal groups with higher probability of finding new species for science are the ones with low dispersal potential; (3) the proportion of the global species pool of each meiofaunal group present in each area at the regional scale is negatively related to body size, and positively related to their occurrence in the endobenthic habitat. Our macroecological analysis of meiofauna, in the framework of the ubiquity hypothesis for microscopic organisms, indicates that not only body size but mostly dispersal ability and also occurrence in the endobenthic habitat are important correlates of diversity for these understudied animals, with different importance at different spatial scales. Furthermore, since the Western Mediterranean is one of the best-studied areas in the world, the large number of undescribed species (37%) highlights that the census of marine meiofauna is still very far

High prevalence of buccal ulcerations in largemouth bass, Micropterus salmoides (Centrarchidae) from Michigan inland lakes associated with Myzobdella lugubris Leidy 1851 (Annelida: Hirudinea)

PubMed Central

Faisal, M.; Schulz, C.; Eissa, A.; Whelan, G.

2011-01-01

Widespread mouth ulcerations were observed in largemouth bass collected from eight inland lakes in the Lower Peninsula of Michigan during the summer months of 2002 and 2003. These ulcerations were associated with, and most likely caused by, leech parasitism. Through the use of morphological dichotomous keys, it was determined that all leeches collected are of one species: Myzobdella lugubris. Among the eight lakes examined, Lake Orion and Devils Lake had the highest prevalence of leech parasitism (34% and 29%, respectively) and mouth ulcerations (53% and 68%, respectively). Statistical analyses demonstrated that leech and ulcer prevalence varied significantly from one lake to the other. Additionally, it was determined that the relationship between the prevalence of ulcers and the prevalence of leech attachment is significant, indicating that leech parasitism is most likely the cause of ulceration. The ulcers exhibited deep hemorrhagic centers and raised irregular edges. Affected areas lost their epithelial lining and submucosa, with masses of bacteria colonizing the damaged tissues. Since largemouth bass is a popular global sportfish and critical to the food web of inland lakes, there are concerns that the presence of leeches, damaged buccal mucosa, and general unsightliness may negatively affect this important sportfishery. PMID:21395209

Onuphis and Mooreonuphis (Annelida: Onuphidae) from West Africa with the description of three new species and the reinstatement of O. landanaensis Augener, 1918.

PubMed

Arias, Andrés

2016-09-16

The taxonomy of eastern Atlantic species of the genus Onuphis has been confused due to the somewhat cursory and misleading descriptions of species and the disregard of the true identity of the type species of the genus, O. eremita, which has been commonly reported from West Africa, along with O. geophiliformis and O. rullieriana. However, all three species are now considered as unlikely to occur in western Africa. This work recognises three species of Onuphis from this region. Two of them, Onuphis augeneri sp. nov. and O. hanneloreae sp. nov., are newly described from Nyanga estuary (Gabon) and Sal Island (Cape Verde) respectively. Furthermore, Onuphis landanaensis, a species described from the Gulf of Guinea and subsequently synonymised with O. eremita, is formally reinstated and redescribed based upon the re-examination of the original types. Detailed descriptions and illustrations of all species are presented as well as the ontogenetic changes of the brooder O. hanneloreae sp. nov. Furthermore, the genus Mooreonuphis is recorded for the first time in Africa with the description of M. nunezi sp. nov. from Cape Verde archipelago. Additionally, a dichotomous key to all species of the genera Onuphis and Mooreonuphis from the eastern Atlantic is included.

First record of Streptosyllis nunezi Faulwetter et al., 2008 (Annelida, Syllidae) from the United Kingdom, and amendment to the genus Streptosyllis Webster & Benedict, 1884.

PubMed

Musk, Will; Faulwetter, Sarah; McIlwaine, Paul

2016-01-01

During a benthic survey of a Marine Conservation Zone located on the Skerries Bank in the English Channel off the south-west coast of England, three specimens of Streptosyllis nunezi Faulwetter et al., 2008 were found. This is the second ever record of the species after its original description, and the first record from waters around the U.K. and a significant northerly range extension for a species previously only recorded from the Canary Islands and the Mediterranean Sea. A single simple ventral chaeta in each of the two posterior-most segments was discovered in this and two other species of Streptosyllis Webster & Benedict, 1884. The generic definition of Streptosyllis is emended to include this feature previously unknown for the genus, and an updated key to the Streptosyllis found in UK waters is provided.

Glacial influence and stream macroinvertebrate biodiversity under climate change: Lessons from the Southern Alps.

PubMed

Lencioni, Valeria

2018-05-01

The aim of this work was to highlight the main ecological predictors driving invertebrate distribution in eight glacier-fed streams in the Southern Alps. Thirty-five sites belonging to four stream types were sampled monthly during the ablation season of one, two or three years between 1996 and 2014. Taxa from glacial (kryal and glacio-rhithral) and non-glacial (kreno-rhithral and lake outlet) sites were separated by canonical correspondence analysis (CCA) along a glacial influence gradient and a hydrological-altitudinal gradient. High glacial influence was associated mainly with low maximum water temperature (Tmax), high Glacial Index (calculated as a function of glacier area and distance from the glacier), and the abundance of Diamesa species (D. steinboecki, D. goetghebueri, D. zernyi, and D. latitarsis). Change-point analysis and Threshold Indicator Taxa Analysis confirmed the CCA results in identifying these Diamesa species as the taxa with the strongest preference for high percent glacier cover in the catchment (change point~30%) and low Tmax (change point~6°C). Temporal changes in community structure were highlighted in seven sites fed by glaciers under different retreat rates. Where the rate was faster and the remaining glacier smaller (≪1km 2 ), the most cold-stenothermal kryal inhabitant, D. steinboecki, almost disappeared or survived only as brachypterous populations, whereas other Diamesinae (Pseudokiefferiella parva), Orthocladiinae (e.g. Eukiefferiella, Orthocladius), Limoniidae, Baetidae, Nemouridae, and non-insect taxa (e.g. Oligochaeta, Hydracarina) became more abundant. Upstream migration was observed in Diamesa spp. which conquered new stream reaches left free by the retreating glacier, and euriecious taxa which colonized reaches with ameliorated environmental conditions, no longer the exclusive habitat of Diamesa spp. Co-occurrence of stochastic and deterministic assembly processes seem to drive spatio-temporal changes in these invertebrate

[Effect of environmental factors on macroinvertebrate community structure in the Huntai River basin in the Huntai River basin].

PubMed

Li, Yan-li; Li, Yan-fen; Xu, Zong-xue

2015-01-01

In May-June 2012, macroinvertebrates were investigated at 66 sampling sites in the Huntai River basin in Northeast of China. A total of 72 macrobenthos species were collected, of which, 51 species (70.83%) were aquatic insects, 10 species (13.89%) were mollusks, 7 species (9.72%) were annelids, and 4 species (5.56%) were arthropods. First, 13 candidate metrics (EPT taxa, Dominant taxon%, Ephemeroptera%, Trichoptera%, mollusks%, Heptageniidae/Ephemeroptera; Hydropsychidae/ Trichoptera, Oligochaeta%, intolerant taxon% , tolerant taxon%, Collector%, Clingers%, Shannon-wiener index.) which belonged to six types were chosen to represent macroinvertebrate community structure by correlation analysis. Then, relationships between anthropogenic and physiography pressures and macroinvertebrate community structure variables were measured using redundancy analysis. Then, this study compared the relative influences of anthropogenic and physiographic pressures on macroinvertebrate community structure and the relative influences of anthropogenic pressures at reach, riparian and catchment scales by pRDA. The results showed all environmental factors explained 72.23% of the variation of macroinvertebrate community structure. In addition, a large proportion of the explained variability in macroinvertebrate community structure was related to anthropogenic pressures (48.9%) and to physiographic variables (11.8%), anthropogenic pressures at reach scale influenced most significantly macroinvertebrate community structure which explained 35.3% of the variation of macroinvertebrate community structure. pH, habitat, TN, CODMn, hardness, conductivity, total dissolved particle and ammonia influenced respectively explained 4%, 3.6%, 1.8%, 1.7%, 1.7%, 0.9%, 0.9% and 0.9% of the variation of macroinvertebrate community structure. The land use at riparian and catchment scale respectively explained 10% and 7% of the variation of macroinvertebrate community structure. Finally, the relationships of

Exposure and effects of sediment-spiked fludioxonil on macroinvertebrates and zooplankton in outdoor aquatic microcosms.

PubMed

Yin, Xiao H; Brock, Theo C M; Barone, Lidia E; Belgers, J Dick M; Boerwinkel, Marie-Claire; Buijse, Laura; van Wijngaarden, René P A; Hamer, Mick; Roessink, Ivo

2018-01-01

Information from effects of pesticides in sediments at an ecosystem level, to validate current and proposed risk assessment procedures, is scarce. A sediment-spiked outdoor freshwater microcosm experiment was conducted with fludioxonil (lipophilic, non-systemic fungicide) to study exposure dynamics and treatment-related responses of benthic and pelagic macroinvertebrates and zooplankton. Besides blank control and solvent control systems the experiment had six different treatment levels (1.7-614mga.s./kg dry sediment) based around the reported 28-d No Observed Effect Concentration (NOEC) for Chironomus riparius (40mga.s./kg dry sediment). Twelve systems were available per treatment of which four were sacrificed on each of days 28, 56 and 84 after microcosm construction. Fludioxonil persisted in the sediment and mean measured concentrations were 53-82% of the initial concentration after 84days. The dissipation rate increased with the treatment level. Also exposure concentrations in overlying water were long-term, with highest concentrations 28days after initiation of the experiment. Sediment-dwelling Oligochaeta and pelagic Rotifera and Cladocera showed the most pronounced treatment-related declines. The most sensitive sediment-dwelling oligochaete was Dero digitata (population NOEC 14.2mga.s./kg dry sediment). The same NOEC was calculated for the sediment-dwelling macroinvertebrate community. The most sensitive zooplankton species was the cladoceran Diaphanosoma brachyurum (NOEC of 1.6μga.s./L in overlying water corresponding to 5.0mga.s./kg dry sediment). At the two highest treatments several rotifer taxa showed a pronounced decrease, while the zooplankton community-level NOEC was 5.6μga.s./L (corresponding to 14.2mga.s./kg dry sediment). Zooplankton taxa calanoid Copepoda and Daphnia gr. longispina showed a pronounced treatment-related increase (indirect effects). Consequently, an assessment factor of 10 to the chronic laboratory NOECs of Chironomus riparius

Anti-inflammatory and cytoprotective effects of selected Pakistani medicinal plants in Helicobacter pylori-infected gastric epithelial cells.

PubMed

Zaidi, Syed Faisal; Muhammad, Jibran Sualeh; Shahryar, Saeeda; Usmanghani, Khan; Gilani, Anwarul-Hassan; Jafri, Wasim; Sugiyama, Toshiro

2012-05-07

Helicobacter pylori infection is associated with gastritis, peptic ulcer, and gastric cancer. Due to its high global prevalence and uprising resistance to available antibiotics, efforts are now directed to identify alternative source to treat and prevent associated disorders. In the present study, effect of selected indigenous medicinal plants of Pakistan was evaluated on the secretion of interleukin-8 (IL-8) and generation of reactive oxygen species (ROS) in a bid to rationalize their medicinal use and to examine the anti-inflammatory and cytoprotective effects in gastric epithelial cells. AGS cells and clinically isolated Helicobacter pylori strain (193C) were employed for co-culture experiments. Anti-Helicobacter pylori activity and cytotoxic effects of the selected plants were determined by serial dilution method and DNA fragmentation assay respectively. ELISA and flow cytometry were performed to evaluate the effect on IL-8 secretion and ROS generation in Helicobacter pylori-infected cells. At 100μg/ml, extracts of Alpinia galangal, Cinnamomum cassia, Cinnamomum tamala, Mentha arvensis, Myrtus communis, Oligochaeta ramose, Polygonum bistorta, Rosa damascena, Ruta graveolens, Syzygium aromaticum, Tamarix dioica, and Terminalia chebula exhibited strong inhibitory activity against IL-8 secretion. Of these, four extracts of Cinnamomum cassia, Myrtus communis, Syzygium aromaticum, and Terminalia chebula markedly inhibited IL-8 secretion at both 50 and 100μg/ml. Cinnamomum cassia was further assessed at different concentrations against Helicobacter pylori and TNF-α stimulated IL-8 secretion, which displayed significant suppression of IL-8 in a concentration-dependent-manner. Among the plants examined against ROS generation, Achillea millefolium, Berberis aristata, Coriandrum sativum, Foeniculum vulgare, Matricaria chamomilla and Prunus domestica demonstrated significant suppression of ROS from Helicobacter pylori-infected cells (p<0.01). Results of the study

Trace Elements in Calcifying Marine Invertebrates Indicate Diverse Sensitivities to the Seawater Carbonate System

NASA Astrophysics Data System (ADS)

Doss, W. C.

2015-12-01

Surface ocean absorption of anthropogenic CO2 emissions resulting in ocean acidification may interfere with the ability of calcifying marine organisms to biomineralize, since the drop in pH is accompanied by reductions in CaCO3 saturation state. However, recent experiments show that net calcification rates of cultured benthic invertebrate taxa exhibit diverse responses to pCO2-induced changes in saturation state (Ries et al., 2009). Advancement of geochemical tools as biomineralization indicators will enable us to better understand these results and therefore help predict the impacts of ongoing and future decrease in seawater pH on marine organisms. Here we build upon previous work on these specimens by measuring the elemental composition of biogenic calcite and aragonite precipitated in four pCO2 treatments (400; 600; 900; and 2850 ppm). Element ratios (including Sr/Ca, Mg/Ca, Li/Ca, B/Ca, U/Ca, Ba/Ca, Cd/Ca, and Zn/Ca) were analyzed in 18 macro-invertebrate species representing seven phyla (crustacea, cnidaria, echinoidea, rhodophyta, chlorophyta, gastropoda, bivalvia, annelida), then compared to growth rate data and experimental seawater carbonate system parameters: [CO32-], [HCO3-], pH, saturation state, and DIC. Correlations between calcite or aragonite composition and seawater carbonate chemistry are highly taxa-specific, but do not resemble trends observed in growth rate for all species. Apparent carbonate system sensitivities vary widely by element, ranging from strongly correlated to no significant response. Interpretation of these results is guided by mounting evidence for the capacity of individual species to modulate pH and/or saturation state at the site of calcification in response to ambient seawater chemistry. Such biomineralization pathways and strategies in turn likely influence elemental fractionation during CaCO3 precipitation. Ries, J.B., A.L. Cohen, A.L., and D.C. McCorkle (2009), Marine calcifiers exhibit mixed responses to CO2-induced ocean

Please mind the gap - Visual census and cryptic biodiversity assessment at central Red Sea coral reefs.

PubMed

Pearman, John K; Anlauf, Holger; Irigoien, Xabier; Carvalho, Susana

2016-07-01

Coral reefs harbor the most diverse assemblages in the ocean, however, a large proportion of the diversity is cryptic and, therefore, undetected by standard visual census techniques. Cryptic and exposed communities differ considerably in species composition and ecological function. This study compares three different coral reef assessment protocols: i) visual benthic reef surveys: ii) visual census of Autonomous Reef Monitoring Structures (ARMS) plates; and iii) metabarcoding techniques of the ARMS (including sessile, 106-500 μm and 500-2000 μm size fractions), that target the cryptic and exposed communities of three reefs in the central Red Sea. Visual census showed a dominance of Cnidaria (Anthozoa) and Rhodophyta on the reef substrate, while Porifera, Bryozoa and Rhodophyta were the most abundant groups on the ARMS plates. Metabarcoding, targeting the 18S rRNA gene, significantly increased estimates of the species diversity (p < 0.001); revealing that Annelida were generally the dominant phyla (in terms of reads) of all fractions and reefs. Furthermore, metabarcoding detected microbial eukaryotic groups such as Syndiniophyceae, Mamiellophyceae and Bacillariophyceae as relevant components of the sessile fraction. ANOSIM analysis showed that the three reef sites showed no differences based on the visual census data. Metabarcoding showed a higher sensitivity for identifying differences between reef communities at smaller geographic scales than standard visual census techniques as significant differences in the assemblages were observed amongst the reefs. Comparison of the techniques showed no similar patterns for the visual techniques while the metabarcoding of the ARMS showed similar patterns amongst fractions. Establishing ARMS as a standard tool in reef monitoring will not only advance our understanding of local processes and ecological community response to environmental changes, as different faunal components will provide complementary information but

Reestablishment of Notopygos megalops McIntosh, description of N. caribea sp. n. from the Greater Caribbean and barcoding of “amphiamerican” Notopygos species (Annelida, Amphinomidae)

PubMed Central

Yáñez-Rivera, Beatriz; Carrera-Parra, Luis Fernando

2012-01-01

Abstract The species of the genus Notopygos Grube, 1855 are characterized by an ovate body, a prominent caruncle with three lobes, dendritic branchiae, and double dorsal cirri. Twenty-two species belonging to Notopygos have been described, mostly from the Indo-Pacific region. In America, few species are frequently recorded: Notopygos crinita Grube, 1855 from St. Helena Island (Atlantic) and Notopygos ornata Grube and Ørsted in Grube 1857 from Costa Rica (Pacific). Notopygos crinita is a widely distributed species in the Western Atlantic with additional reports in the Mediterranean Sea (as a questionable alien species) and in the Pacific Ocean. However, only the genus features have been considered, consequently some records could be misidentifications. During a revision of materials from collections and the barcode project, ‘Mexican Barcode of Life, MEXBOL’, we found specimens of Notopygos megalops and an undescribed species from reef zones in the Caribbean; the former had been considered a junior synonym of Notopygos crinita. Herein, Notopygos megalops is reestablished and Notopygos caribea sp. n. is described. A morphological and DNA barcode approach was used to explain the records of Notopygos ornata in the Atlantic and to show the differences with the new species, since both species share features such as complex pigmentation patterns, and circular projections in the median lobe of the caruncle. PMID:23459182

Redescriptions of Nereis oligohalina (Rioja, 1946) and N. garwoodi González-Escalante & Salazar-Vallejo, 2003 and description of N. confusa sp. n. (Annelida, Nereididae).

PubMed

Conde-Vela, Víctor M; Salazar-Vallejo, Sergio I

2015-01-01

Type material of several polychaete species described by Enrique Rioja from Mexican coasts are lost, and the current status of some species is doubtful. Nereis oligohalina (Rioja, 1946) was described from the Gulf of Mexico, but it has been considered a junior synonym of Nereis occidentalis Hartman, 1945, or regarded as a distinct species with an amphiamerican distribution. On the other hand, Nereis garwoodi González-Escalante & Salazar-Vallejo, 2003, described from Chetumal Bay, Caribbean coasts, could be confused with Nereis oligohalina. In order to clarify these uncertainties, Nereis oligohalina is redescribed based on specimens from the Mexican Gulf of Mexico, including a proposed neotype; further, Nereis garwoodi is redescribed including the selection of lectotype and paralectotypes, and Nereis confusa sp. n. is described with material from the Gulf of California. A key for the identification of similar species and some comments about speciation in nereidid polychaetes are also included.

Description of a new species of Eulepethus (Annelida, Eulepethidae) from the northern South China Sea, and comments on the phylogeny of the family.

PubMed

Zhang, Jinghuai; Zhang, Yanjie; Osborn, Karen; Qiu, Jian-Wen

2017-01-30

Eulepethidae is a family of scale-bearing polychaetes. Although members of this family are common inhabitants of tropical and subtropical coastal waters, their diversity is low, with only 22 recognized species in six genera. Here we describe Eulepethus nanhaiensis sp. nov. based on 12 specimens collected from the coastal waters of the northern South China Sea. This new species can be distinguished from Eulepethus hamifer, the only previously described species in this genus, by having up to two spade-shaped lateral processes in some of the anterior elytrae, a blunt-tipped acicular chaeta in the neuropodia of segment 3, and a pair of non-overlapping elytrae in each posterior segment. Phylogenetic analysis indicates that Grubeulepis and Mexieulepis are sister genera, and these two genera form the sister clade of Eulepethus.

Redescriptions of Nereis oligohalina (Rioja, 1946) and N. garwoodi González-Escalante & Salazar-Vallejo, 2003 and description of N. confusa sp. n. (Annelida, Nereididae)

PubMed Central

Conde-Vela, Víctor M.; Salazar-Vallejo, Sergio I.

2015-01-01

Abstract Type material of several polychaete species described by Enrique Rioja from Mexican coasts are lost, and the current status of some species is doubtful. Nereis oligohalina (Rioja, 1946) was described from the Gulf of Mexico, but it has been considered a junior synonym of Nereis occidentalis Hartman, 1945, or regarded as a distinct species with an amphiamerican distribution. On the other hand, Nereis garwoodi González-Escalante & Salazar-Vallejo, 2003, described from Chetumal Bay, Caribbean coasts, could be confused with Nereis oligohalina. In order to clarify these uncertainties, Nereis oligohalina is redescribed based on specimens from the Mexican Gulf of Mexico, including a proposed neotype; further, Nereis garwoodi is redescribed including the selection of lectotype and paralectotypes, and Nereis confusa sp. n. is described with material from the Gulf of California. A key for the identification of similar species and some comments about speciation in nereidid polychaetes are also included. PMID:26448699

Nereis alacranensis, a new species of polychaete (Annelida, Nereididae) from Alacranes Reef, southern Gulf of Mexico, with a key to Nereis from the Grand Caribbean.

PubMed

Ramírez Hernández, Adriana; Hernández-Alcántara, Pablo; Solís-Weiss, Vivianne

2015-09-02

A new species of polychaete, Nereis alacranensis n. sp., was found in dead coral rocks in the intertidal zone of Alacranes reef, southern Gulf of Mexico. N. alacranensis n. sp. can be included in a group of nereidids characterized by the absence of paragnaths in areas I and V of the pharynx, the presence of cones in a single row or absent in areas VII-VIII, and short blades in notopodial homogomph falcigers. The new species can be separated from the other species of the group by the presence of 3-7 cones in area VI and 7 cones arranged in a row in areas VII-VIII, finely dentate blades in notopodial homogomph falcigers, but most of all, by the presence of an unusual brown coarse arc shaped plate on the external ventral region of the peristomium. This structure has not yet been reported, at least in this genus. A taxonomic key of the species of Nereis recorded from the Grand Caribbean region is included.

The biogenic reefs formed by the alien polychaete Hydroides dianthus (Serpulidae, Annelida) favor the polyp stage of Aurelia coerulea (Cnidaria, Scyphozoa) in a coastal artificial lake.

PubMed

Dong, Zhijun; Sun, Tingting; Wang, Lei

2018-04-01

Blooms of the moon jellyfish Aurelia coerulea frequently occur in coastal waters. The increased availability of substrates for the settlement and proliferation of polyps due to the expansion of artificial structures in coastal areas has been proposed as a possible contributing factor in jellyfish blooms. This paper investigates whether a marine artificial lake (Fenghuang Lake) provides additional substrates for A. coerulea polyps and contributes to jellyfish blooms. High densities of A. coerulea ephyrae were discovered in this lake, with a mean density of 41 individuals/m 3 and a maximum measured density of 128 individuals/m 3 . Meanwhile, A. coerulea ephyrae were also found in the two emptying channels outside the lake, with a mean density of 13 individuals/m 3 . Underwater surveys revealed that dense colonies of A. coerulea polyps occurred mainly on biogenic reefs formed by a polychaete, which was identified as an invasive serpulid species Hydroides dianthus, based on the phylogenetic analysis of mitochondrial COI gene sequences. Our study highlights the potential modification of habitats by the alien polychaete H. dianthus, which might provide complex benthic habits suitable for the settlement and proliferation of A. coerulea polyps and may contribute to jellyfish blooms in the marine artificial lake and nearby coastal waters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Entrapped by the uneven central and Middle Eastern terrains: Genetic status of populations of Hirudo orientalis (Annelida, Clitellata, Hirudinida) with a phylogenetic review of the genus Hirudo.

PubMed

Darabi-Darestani, Kaveh; Sari, Alireza; Sarafrazi, Alimorad; Utevsky, Serge

2018-04-01

Phylogenetic relationships between species of the genus Hirudo plus genetic variation in the entire distribution range of Hirudo orientalis were investigated based on mitochondrial (COI and 12S rDNA) and nuclear (ITS1+5.8S+ITS2) genome regions. The sister relationship of Hirudo orientalis and H. medicinalis was revealed with a high posterior probability. A broad and patchy distribution with minor genetic differences was observed in populations of H. orientalis along the central and Middle Eastern parts of Asia. The known distribution range occurred in topographically heterogeneous landscapes around the Caspian Sea. The demographic analysis suggests the selection of the COI locus under unfavourable respiratory conditions, but population size expansion cannot be fully rejected. The genetic variation trend indicated northward dispersal. Higher haplotype diversity in the South Caspian region potentially suggests the area as a historical refugium for the species. The vast dispersal is assumed to occur after the Pleistocene glaciations via vertebrate hosts. Copyright © 2017 Elsevier Inc. All rights reserved.

Food web heterogeneity and succession in created saltmarshes

USGS Publications Warehouse

Nordstrom, M C; Demopoulos, Amanda W.J.; Whitcraft, CR; Rismondo, A.; McMillan, P.; Gonzales, J P; Levin, L A

2015-01-01

1. Ecological restoration must achieve functional as well as structural recovery. Functional metrics for reestablishment of trophic interactions can be used to complement traditional monitoring of structural attributes. In addition, topographic effects on food web structure provide added information within a restoration context; often, created sites may require spatial heterogeneity to effectively match structure and function of natural habitats. 2. We addressed both of these issues in our study of successional development of benthic food web structure, with focus on bottom–up driven changes in macroinvertebrate consumer assemblages in the salt marshes of the Venice Lagoon, Italy. We combined quantified estimates of the changing community composition with stable isotope data (13C:12C and 15N:14N) to compare the general trophic structure between created (2–14 years) marshes and reference sites and along topographic elevation gradients within salt marshes. 3. Macrofaunal invertebrate consumers exhibited local, habitat-specific trophic patterns. Stable isotope-based trophic structure changed with increasing marsh age, in particular with regards to mid-elevation (Salicornia) habitats. In young marshes, the mid-elevation consumer signatures resembled those of unvegetated ponds. The mid elevation of older and natural marshes had a more distinct Salicornia-zone food web, occasionally resembling that of the highest (Sarcocornia-dominated) elevation. In summary, this indicates that primary producers and availability of vascular plant detritus structure consumer trophic interactions and the flow of carbon. 4. Functionally different consumers, subsurface-feeding detritivores (Oligochaeta) and surface grazers (Hydrobia sp.), showed distinct but converging trajectories of isotopic change over time, indicating that successional development may be asymmetric between ‘brown’ (detrital) guilds and ‘green’ (grazing) guilds in the food web. 5. Synthesis and applications

Limnological study of Lake Shastina, Siskiyou County, California

USGS Publications Warehouse

Dong, Alex E.; Beatty, Kenneth W.; Averett, Robert C.

1974-01-01

about 5 million cells per litre.Zooplankton numbers were greatest in March, July, and September, with lesser concentrations in June. Three major zooplankton groups, Cladocera, Copepoda, and Rotifera, were present. The major groups of benthic organisms were Oligochaeta, Chironomidae, and Chaoborus, with numbers ranging from 3350, 890, and 8450 per square metre, respectively.A discussion on algal control is included.

Interrelationships between soil biota and soil physical properties in forest areas of the Pieniny National Park (Poland)

NASA Astrophysics Data System (ADS)

Józefowska, Agnieszka; Zaleski, Tomasz; Sokołowska, Justyna; Dzierwa, Agata

2017-04-01

The study area was located in the Pieniny National Park (PNP) in the Carpathian Mountain (Southern Poland). Investigated soil belonged to Eutric Cambisols and had silt or silt loam texture. The purpose of this research was to investigated relationship between soil biota, such as microbial activity, soil Oligochaeta (Lumbricidae and Enchytraeidae) and soil physical properties, such as water retention or aggregates stability. This research was conducted at six forest monitoring areas of the PNP. Sampling was collected in the September 2016. For each of the 6 places, undisturbed and disturbed soil samples were taken from the 0-15-cm and 15-30-cm layer in 3 to 5 replicates. Undisturbed soil was taken: i) into Kopecky cylinders to determined soil physical properties; ii) a soil cores to determined enchytraeids and fine roots biomass (RB). Disturbed soil was collected in 3 reps and homogenized. Next such soil samples were divided into three parts: i) fresh one to determined dehydrogenase activity (ADh), microbial carbon biomass (MC) and labile carbon (LC); ii) air-dried, passed through a sieve (2-mm mesh size) and used for analysis: pH, organic carbon and bulk density; iii) last part air dried was used to determined stability of different size aggregates. In field, earthworms were collected in 3 reps using hand sorting method. Investigated soils were strongly acidic to neutral (pH 4.8-6.8). Organic carbon (Corg) content was varied from 0.8% to 4.5% and was higher in 0-15-cm layers than in 15-30-cm layers. Higher Corgcontent was connected with lower bulk density. Enchytraeids density was ranged from 1807 ind. m-2 to 88855 ind. m-2 and was correlated with microbial activity (ADh and MB) and RB. Earthworms density (ED) was ranged from 7 ind. m-2to 507 ind. m-2. In investigated soil was 6 genus and 7 species (Octolasion lacteum, Aporrectodea caliginosa, Aporrectodea rosea, Aporrectodea jassyensis, Lumbricus rubellus, Eisenia lucens, and Fitzingeria platyura depressa). ED was

A longitudinal assessment of the aquatic macroinvertebrate community in the channelized lower Missouri River

USGS Publications Warehouse

Poulton, Barry C.; Wildhaber, Mark L.; Charbonneau, Collette S.; Fairchild, James F.; Mueller, Brad G.; Schmitt, Christopher J.

2003-01-01

We conducted an aquatic macroinvertebrate assessment in the channelized reach of the lower Missouri River, and used statistical analysis of individual metrics and multimetric scores to identify community response patterns and evaluate relative biological condition. We examined longitudinal site differences that are potentially associated with water qualityrelated factors originating from the Kansas City metropolitan area, using data from coarse rock substrate in flowing water habitats (outside river bends), and depositional mud substratein slack water habitats (dike fields). Three sites above rivermile (RM) 369 in Kansas City (Nebraska City, RM = 560; St. Joseph, RM = 530; Parkville, RM = 377) and three below (Lexington, RM = 319; Glasgow, RM = 228; Hermann, RM = 94) were sampled with rock basket artificial substrates, a qualitative kicknet method, and the Petite Ponar. We also compared the performance of the methods used. A total of 132 aquatic macroinvertebrate taxa were collected from the lower Missouri River; one third of these taxa belonged to the sensitiveEPOT insect orders (Ephemeroptera, Plecoptera, Odonata, and Trichoptera). Rock baskets had the highest mean efficiency (34.1%) of the methods, and the largest number of taxa was collected by Ponar (n = 69) and kicknet (n = 69) methods. Seven of the 15 metrics calculated from rock basket data, and five ofthe nine metrics calculated from Ponar data showed highly significant differences (ANOVA, P < 0.001) at one or more sitesbelow Kansas City. We observed a substantial reduction in net-spinning Trichoptera in rock habitats below Kansas City (Lexington), an increase in relative dominance of Oligochaeta in depositional habitats at the next site downstream (Glasgow), and lower relative condition scores in rock habitat at Lexingtonand depositional habitat at Glasgow. Collectively, these data indicate that some urban-related impacts on the aquatic macroinvertebrate community are occurring. Our results suggest that

Phylogenomics of Lophotrochozoa with Consideration of Systematic Error.

PubMed

Kocot, Kevin M; Struck, Torsten H; Merkel, Julia; Waits, Damien S; Todt, Christiane; Brannock, Pamela M; Weese, David A; Cannon, Johanna T; Moroz, Leonid L; Lieb, Bernhard; Halanych, Kenneth M

2017-03-01

. Moreover, our systematic approach for dissection of phylogenomic data can be applied to explore sources of incongruence and poor support in any phylogenomic data set. [Annelida; Brachiopoda; Bryozoa; Entoprocta; Mollusca; Nemertea; Phoronida; Platyzoa; Polyzoa; Spiralia; Trochozoa.]. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Biocontrol of the toxigenic plant pathogen Fusarium culmorum by soil fauna in an agroecosystem.

PubMed

Meyer-Wolfarth, Friederike; Schrader, Stefan; Oldenburg, Elisabeth; Weinert, Joachim; Brunotte, Joachim

2017-08-01

In 2011 and 2013, a field experiment was conducted in a winter wheat field at Adenstedt (northern Germany) to investigate biocontrol and interaction effects of important members of the soil food web (Lumbricus terrestris, Annelida; Folsomia candida, Collembola and Aphelenchoides saprophilus, Nematoda) on the phytopathogenic fungus Fusarium culmorum in wheat straw. Therefore, soil fauna was introduced in mesocosms in defined numbers and combinations and exposed to either Fusarium-infected or non-infected wheat straw. L. terrestris was introduced in all faunal treatments and combined either with F. candida or A. saprophilus or both. Mesocosms filled with a Luvisol soil, a cover of different types of wheat straw and respective combinations of faunal species were established outdoors in the topsoil of a winter wheat field after harvest of the crop. After a time span of 4 and 8 weeks, the degree of wheat straw coverage of mesocosms was quantified to assess its attractiveness for the soil fauna. The content of Fusarium biomass in residual wheat straw and soil was determined using a double-antibody sandwich (DAS)-ELISA method. In both experimental years, the infected wheat straw was incorporated more efficiently into the soil than the non-infected control straw due to the presence of L. terrestris in all faunal treatments than the non-infected control straw. In addition, Fusarium biomass was reduced significantly in all treatments after 4 weeks (2011: 95-99%; 2013:15-54%), whereupon the decline of fungal biomass was higher in faunal treatments than in non-faunal treatments and differed significantly from them. In 2011, Fusarium biomass of the faunal treatments was below the quantification limit after 8 weeks. In 2013, a decline of Fusarium biomass was observed, but the highest content of Fusarium biomass was still found in the non-faunal treatments after 8 weeks. In the soil of all treatments, Fusarium biomass was below the quantification limit. The earthworm species

Influence of seabird colonies and other environmental variables on benthic community structure, Lancaster Sound Region, Canadian Arctic

NASA Astrophysics Data System (ADS)

Bouchard Marmen, Mariève; Kenchington, Ellen; Ardyna, Mathieu; Archambault, Philippe

2017-03-01

The Canadian Arctic shelters millions of seabirds each year during the breeding season. By the excretion of important quantities of guano, seabirds locally concentrate nutrient-rich organic matter in the marine areas surrounding colonies. Seabirds, acting as biological vectors of nutrients, can markedly affect terrestrial ecosystems, but their influence on the structure of marine benthic communities is still under-studied. Sessile and long-lived megabenthic species can integrate environmental variation into marine food webs over long time frames. The objectives of this study were (1) to characterize the epifaunal and infaunal communities of the Lancaster Sound Region (LSR) and (2) to test the influence of the presence of seabird colonies and other environmental parameters on the structure of those benthic communities. Our prediction was that benthic diversity, number of taxa, total biomass of infauna and total density of epifauna and infauna, would be higher in areas with colonies present. Photos of the seafloor (data on epifauna) and grab samples (data on infauna) were taken at three control areas and at five areas near seabird colonies, within a depth range of 122 to 442 m. A database of 26 environmental parameters was built to study the environment-benthos relationships. Infauna, which was relatively uniform across the LSR, was numerically dominated by Annelida. Epifauna was much patchier, with each study area having unique epibenthic assemblages. Brittle stars were highly abundant in epifaunal communities, reaching 600 individuals per square meter. The presence of seabird colonies was not a major driver of benthic community structure in the LSR at the depths studied. Negative effects of colonies were detected on the density and number of taxa of infauna, perhaps due to top-down effects transmitted by the seabirds which feed in the water column and can directly reduce the quantity of food reaching the seabed. Sediment concentration of pigment, percent cover of

Composition of abyssal macrofauna along the Vema Fracture Zone and the hadal Puerto Rico Trench, northern tropical Atlantic

NASA Astrophysics Data System (ADS)

Brandt, A.; Frutos, I.; Bober, S.; Brix, S.; Brenke, N.; Guggolz, T.; Heitland, N.; Malyutina, M.; Minzlaff, U.; Riehl, T.; Schwabe, E.; Zinkann, A.-C.; Linse, K.

2018-02-01

We analyzed composition and variations in benthic macrofaunal communities along a transect of the entire length of the Vema-Fracture Zone on board of RV Sonne (SO-237) between December 2014 and January 2015 in order to test whether the Mid-Atlantic Ridge serves as a barrier limiting benthic taxon distribution in the abyssal basins on both sides of the ridge or whether the fracture zone permits the migration of species between the western and eastern abyssal Atlantic basins. The Puerto Rico Trench, much deeper than the surrounding abyssal West Atlantic, was sampled to determine whether the biodiversity of its hadal macrofauna differs from that of the abyssal Atlantic. The composition of the macrofauna from the epibenthic sledge catches yielded a total of 21,332 invertebrates. Crustacea occurred most frequently (59%) with 12,538 individuals followed by Annelida (mostly Polychaeta) (26%) with 5491 individuals, Mollusca (7%) with 1458 individuals, Echinodermata (4%) with 778 individuals, Nematoda (2%) with 502 individuals and Chaetognatha (1%) with 152 and Porifera (1%) with 131 individuals. All other taxa occurred with overall less than ten individuals (Hemichordata, Phoronida, Priapulida, Brachiopoda, invertebrate Chordata, Echiurida, Foraminifera (here refereed to macrofaunal Komokiacea only), Chelicerata, Platyhelminthes). Within the Crustacea, Peracarida (62.6%) with 7848 individuals and Copepoda (36.1%) with 44,526 individuals were the most abundant taxa. Along the abyssal Vema-Fracture Zone macrofaunal abundances (ind./1000 m2) were generally higher on the eastern side, while the highest normalized abundance value was reported in the Puerto Rico Trench at abyssal station 14-1 2313 individuals/1000 m2. The lowest abundance was reported at station 11-4 with 120 ind./1000 m2 located at the western side of the Vema-Fracture Zone. The number of major macrofaunal taxa (phylum, class) ranged between five (stations 12-5, 13-4 and 13-5 at hadal depths in the Puerto Rico

Biodiversity of macrofaunal assemblages from three Portuguese submarine canyons (NE Atlantic)

NASA Astrophysics Data System (ADS)

Cunha, Marina R.; Paterson, Gordon L. J.; Amaro, Teresa; Blackbird, Sabena; de Stigter, Henko C.; Ferreira, Clarisse; Glover, Adrian; Hilário, Ana; Kiriakoulakis, Konstadinos; Neal, Lenka; Ravara, Ascensão; Rodrigues, Clara F.; Tiago, Áurea; Billett, David S. M.

2011-12-01

The macrofaunal assemblages from three Portuguese submarine canyons, Nazaré, Cascais and Setúbal were studied from samples collected at their upper (900-1000 m), middle (3200-3500 m) and lower sections (4200-4500 m) and at the adjacent open slopes (˜1000 m), during the HERMES cruises D297 (R.R.S. Discovery, 2005) CD179 (R.R.S. Charles Darwin, 2006) and 64PE252 (R.V. Pelagia, 2006). The taxonomic composition and patterns in biodiversity, abundance and community structure of the benthic macrofauna were described. Annelida (42.1% of total abundance; 137 species) and Arthropoda (20.6%; 162 species) were, respectively, the most abundant and the most species-rich Phyla among the 342 taxa identified during this study. Multivariate analyses showed significant differences between and within canyons and between canyons and open slope assemblages. At their upper section, canyons supported higher macrofauna abundance but slightly lower biodiversity than the adjacent slopes at similar depth. In all canyons abundance reached the highest value in the middle section and the lowest in the upper section, with marked fluctuations in Nazaré (474-4599 ind. m -2) and lower variability in Cascais (583-1125 ind. m -2). The high abundance and dominance of the assemblages in the middle section of Nazaré and Setúbal was accompanied by depressed biodiversity, while in Cascais, Hurlbert's expected species richness showed increasing values from the upper to the middle canyon, and maintained the high values at the lower section. Overall, the Nazaré Canyon showed the lowest expected species richness (ES (100): 16-39) and the Cascais Canyon the highest (39-54). There was a significant negative Kendall's correlation between total organic carbon concentrations in the superficial sediments and ES (100) and a significant positive correlation between total nitrogen and macrofauna density. The influences of organic enrichment, sediment heterogeneity and hydrodynamic regime on the abundance

Unexpected occurrence of Hemifridericia bivesiculata Christensen & Dózsa-Farkas, 2006 in Hungary, a species presumed to be endemic to Devon Island, Canada, and its comparative analysis with H. parva Nielsen & Christensen, 1959 (Enchytraeidae, Oligochaeta).

PubMed

Dózsa-Farkas, Klára; Felföldi, Tamás

2015-01-27

During the exploration of the enchytraeid fauna in forests and grasslands of Hungarian flat areas, a small enchytraeid species, Hemifridericia bivesiculata Christensen & Dózsa-Farkas, 2006, was found unexpectedly. This species was known previously only from one single location, Bank Island in the Canadian archipelago, and was presumed to be endemic. Here, the distinctive features of the two Hemifridericia species are described based on detailed morphological analyses, which were supported with molecular methods. The results demonstrated that the two Hemifridericia species are very similar morphologically, but can be clearly distinguished from each other by the presence or absence of the oesophageal vesicles and the shape of the brain. Some additional differences were observed between the Hungarian material and the type specimens of H. bivesiculata. The two species were unequivocally separated based on the studied molecular markers, the mitochondrial cytochrome c oxidase subunit I (CO1) gene, the nuclear histon 3 (H3) gene and the nuclear ribosomal ITS region. 

Spring habitat use by stocked one year old European sturgeon Acipenser sturio in the freshwater-oligohaline area of the Gironde estuary

NASA Astrophysics Data System (ADS)

Acolas, M. L.; Le Pichon, C.; Rochard, E.

2017-09-01

for areas with crustacea or nematodea and avoidance for areas with mollusks, insects or oligochaeta occured. We explain our results in light of foraging behavior and adaptation to the wild environment after captivity. For sturgeon population restoration projects in western Europe, these habitat preferences are key-features needed to evaluate the essential habitat availability for A. sturio juveniles in the tidal area at the front of the freshwater/saline transition waters.

Does the different mowing regime affect soil biological activity and floristic composition of thermophilous Pieniny meadow?

NASA Astrophysics Data System (ADS)

Józefowska, Agnieszka; Zaleski, Tomasz; Zarzycki, Jan

2016-04-01

The study area was located in the Pieniny National Park in the Carpathian Mountain (Southern Poland). About 30% of Park's area is covered by meadows. The climax stage of this area is forest. Therefore extensive use is indispensable action to keep semi-natural grassland such as termophilous Pieniny meadows, which are characterized by a very high biodiversity. The purpose of this research was to answer the question, how the different way of mowing: traditional scything (H), and mechanical mowing (M) or abandonment of mowing (N) effect on the biological activity of soil. Soil biological activity has been expressed by microbial and soil fauna activity. Microbial activity was described directly by count of microorganisms and indirectly by enzymatic activity (dehydrogenase - DHA) and the microbial biomass carbon content (MBC). Enchytraeidae and Lumbricidae were chosen as representatives of soil fauna. Density and species diversity of this Oligochaeta was determined. Samples were collected twice in June (before mowing) and in September (after mowing). Basic soil properties, such as pH value, organic carbon and nitrogen content, moisture and temperature, were determined. Mean count of vegetative bacteria forms, fungi and Actinobacteria was higher in H than M and N. Amount of bacteria connected with nitrification and denitrification process and Clostridium pasteurianum was the highest in soil where mowing was discontinued 11 years ago. The microbial activity measured indirectly by MBC and DHA indicated that the M had the highest activity. The soil biological activity in second term of sampling had generally higher activity than soil collected in June. That was probably connected with highest organic carbon content in soil resulting from mowing and the end of growing season. Higher earthworm density was in mowing soil (220 and 208 individuals m-2 in H and M respectively) compare to non-mowing one (77 ind. m-2). The density of Enchytraeidae was inversely, the higher density

Comparative description of ten transcriptomes of newly sequenced invertebrates and efficiency estimation of genomic sampling in non-model taxa

PubMed Central

2012-01-01

Introduction Traditionally, genomic or transcriptomic data have been restricted to a few model or emerging model organisms, and to a handful of species of medical and/or environmental importance. Next-generation sequencing techniques have the capability of yielding massive amounts of gene sequence data for virtually any species at a modest cost. Here we provide a comparative analysis of de novo assembled transcriptomic data for ten non-model species of previously understudied animal taxa. Results cDNA libraries of ten species belonging to five animal phyla (2 Annelida [including Sipuncula], 2 Arthropoda, 2 Mollusca, 2 Nemertea, and 2 Porifera) were sequenced in different batches with an Illumina Genome Analyzer II (read length 100 or 150 bp), rendering between ca. 25 and 52 million reads per species. Read thinning, trimming, and de novo assembly were performed under different parameters to optimize output. Between 67,423 and 207,559 contigs were obtained across the ten species, post-optimization. Of those, 9,069 to 25,681 contigs retrieved blast hits against the NCBI non-redundant database, and approximately 50% of these were assigned with Gene Ontology terms, covering all major categories, and with similar percentages in all species. Local blasts against our datasets, using selected genes from major signaling pathways and housekeeping genes, revealed high efficiency in gene recovery compared to available genomes of closely related species. Intriguingly, our transcriptomic datasets detected multiple paralogues in all phyla and in nearly all gene pathways, including housekeeping genes that are traditionally used in phylogenetic applications for their purported single-copy nature. Conclusions We generated the first study of comparative transcriptomics across multiple animal phyla (comparing two species per phylum in most cases), established the first Illumina-based transcriptomic datasets for sponge, nemertean, and sipunculan species, and generated a tractable

Unexpectedly higher metazoan meiofauna abundances in the Kuril-Kamchatka Trench compared to the adjacent abyssal plains

NASA Astrophysics Data System (ADS)

Schmidt, Christina; Martínez Arbizu, Pedro

2015-01-01

We studied meiofauna standing stocks and community structure in the Kuril-Kamchatka Trench and its adjacent abyssal plains in the northwestern Pacific Ocean. In general, the Nematoda were dominant (93%) followed by the Copepoda (4%). Nematode abundances ranged from 87% to 96%; those of copepods from 2% to 7%. The most diverse deployment yielded 17 taxa: Acari, Amphipoda, Annelida, Bivalvia, Coelenterata, Copepoda, Cumacea, Gastrotricha, Isopoda, Kinorhyncha, Loricifera, Nematoda, Ostracoda, Priapulida, Tanaidacea, Tantulocarida, and Tardigrada. Nauplii were also present. Generally, the trench slope and the southernmost deployments had the highest abundances (850-1392 individuals/cm2). The results of non-metric multidimensional scaling indicated that these deployments were similar to each other in meiofauna community structure. The southernmost deployments were located in a zone of higher particulate organic carbon (POC) flux (g Corg m-2 yr-1), whereas the trench slope should have low POC flux due to depth attenuation. Also, POC and abundance were significantly correlated in the abyssal plains. This correlation may explain the higher abundances at the southernmost deployments. Lateral transport was also assumed to explain high meiofauna abundances on the trench slope. Abundances were generally higher than expected from model results. ANOSIM revealed significant differences between the trench slope and the northern abyssal plains, between the central abyssal plains and the trench slope, between the trench slope and the southern abyssal plains, between the central and the southern abyssal plains, and between the central and northern deployments. The northern and southern abyssal plains did not differ significantly. In addition, a U-test revealed highly significant differences between the trench-slope and abyssal deployments. The taxa inhabited mostly the upper 0-3 cm of the sediment layer (Nematoda 80-90%; Copepoda 88-100%). The trench-slope and abyssal did not differ

BIOLOGY OF THE LEECH ACTINOBDELLA INEQUIANNULATA MOORE, 1901 (ANNELIDA: HIRUDINEA: RHYNCHOBDELLIDA: GLOSSIPHONIIDAE), PARASITIC ON THE WHITE SUCKER, CATOSTOMUS COMMERSONI LACEPEDE, 1803 AND THE LONGNOSE SUCKER, CATOSTOMUS CATOSTOMUS FORSTER, 1773, IN ALGONQUIN PROVINCIAL PARK, ONTARIO, CANADA

EPA Science Inventory

Actinobdella inequiannulata was found on the white sucker, Catostomus commersoni, and less frequently on the longnose sucker, Catostomus catostomus, in Algonquin Provincial Park, Ontario, Canada. Catostomus commersoni parasitized with Act. inequiannulata was collected from July ...

The occurrence of trace elements in bed sediment collected from areas of varying land use and potential effects on stream macroinvertebrates in the conterminous western United States, Alaska, and Hawaii, 1992-2000

USGS Publications Warehouse

Paul, Angela P.; Paretti, Nicholas V.; MacCoy, Dorene E.; Brasher, Anne M.D.

2012-01-01

. Generally, Hg concentrations were below the sediment-quality guideline for this trace element but appeared elevated in urbanized areas and at sites contaminated by historic mining practices. Lastly, although there was no distinctive pattern in Se concentrations with land use, median bed-sediment concentrations were slightly elevated in urbanized areas.Macroinvertebrate community structure was influenced by topographic, geologic, climatic, and in-stream characteristics. To account for inherent distribution patterns resulting from these influences, samples of macroinvertebrates were stratified by ecoregion to assess the influence of trace elements on community structure. Cumulative toxic units (CTUs) were used to evaluate gradients in trace-element concentrations in mixture. Correlation analyses among the trace elements under different land-use conditions indicate that trace-element mixtures vary among bed sediment and can have a marked influence on CTU composition. Macroinvertebrate response to bed-sediment trace-element exposure was evident only at the most highly contaminated sites, notably at sites classified as contaminated by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) as a result of historic mining activities. Results of this study agree with the findings of other studies evaluating trace-element exposure to in-stream macroinvertebrate community structure in that generally lower richness metrics and taxa dominance occur in streams where high trace-element enrichment occurs; however, not all streams in all areas have the same characterizing taxa. In the mountain and xeric ecosystems, the mayfly, Baetis sp.; the Diptera, Simulium sp.; caddisflies in the family Hydropsychiidae; midges in the family Orthocladiinae; and the worms belonging to Turbellaria and Naididae all demonstrated resilience to trace-element exposure and, in some cases, possible changes in physical habitat within stream ecosystems. The taxa characteristics within

Seven new species of Paleanotus (Annelida: Chrysopetalidae) described from Lizard Island, Great Barrier Reef, and coral reefs of northern Australia and the Indo-Pacific: two cryptic species pairs revealed between western Pacific Ocean and the eastern Indian Ocean.

PubMed

Watson, Charlotte

2015-09-18

Morphological investigation into the paleate genus Paleanotus Schmarda 1861 of the family Chrysopetalidae from northern Australian coral reefs, primarily Lizard Island and outlying reefs, included a complex of very small, slender individuals (length < 5 mm). This complex resolved into 7 new species, described herein: Paleanotus inornatus n. sp., P. adornatus n. sp., P. chrysos n. sp., P. aquifolia n. sp., P. latifolia n. sp., P. silus n. sp., and P. silopsis n. sp. A key is provided to the new species and Paleanotus distinguished from Treptopale and Hyalopale, two closely related genera. Diagnostic features of the apical structure and shape of the notochaetal main paleae plus median paleae shape and raised rib pattern, differentiates each species from the other. Gametous states are described. Two cryptic species pairs (Paleanotus silopsis n. sp. and P. silus n. sp.; Paleanotus aquifolia n. sp. and P. latifolia n. sp.) were identified. In each case one species is restricted to either the NE or NW Australian coast. In each pair the most eastern point for the NW Australian species range occurs at Darwin, western Arnhemland, Northern Territory. Additional material for each species pair extends their respective ranges northwards: NW Australia to Thailand, Andaman Sea, eastern Indian Ocean or NE Australia, Great Barrier Reef to the Philippines, western Pacific Ocean. Cryptic morphology and potential genetic diversity is discussed in Paleanotus inornatus n. sp. and P. adornatus n. sp. that possess overlapping widespread distribution patterns across northern Australia and Indo-Pacific reefs. The smallest bodied taxon, Paleanotus chrysos n. sp. is the only species with a Coral Sea range encompassing Lizard Island, Heron Island and New Caledonia.

Technical evaluation of a total maximum daily load model for Upper Klamath and Agency Lakes, Oregon

USGS Publications Warehouse

Wood, Tamara M.; Wherry, Susan A.; Carter, James L.; Kuwabara, James S.; Simon, Nancy S.; Rounds, Stewart A.

2013-01-01

We reviewed a mass balance model developed in 2001 that guided establishment of the phosphorus total maximum daily load (TMDL) for Upper Klamath and Agency Lakes, Oregon. The purpose of the review was to evaluate the strengths and weaknesses of the model and to determine whether improvements could be made using information derived from studies since the model was first developed. The new data have contributed to the understanding of processes in the lakes, particularly internal loading of phosphorus from sediment, and include measurements of diffusive fluxes of phosphorus from the bottom sediments, groundwater advection, desorption from iron oxides at high pH in a laboratory setting, and estimates of fluxes of phosphorus bound to iron and aluminum oxides. None of these processes in isolation, however, is large enough to account for the episodically high values of whole-lake internal loading calculated from a mass balance, which can range from 10 to 20 milligrams per square meter per day for short periods. The possible role of benthic invertebrates in lake sediments in the internal loading of phosphorus in the lake has become apparent since the development of the TMDL model. Benthic invertebrates can increase diffusive fluxes several-fold through bioturbation and biodiffusion, and, if the invertebrates are bottom feeders, they can recycle phosphorus to the water column through metabolic excretion. These organisms have high densities (1,822–62,178 individuals per square meter) in Upper Klamath Lake. Conversion of the mean density of tubificid worms (Oligochaeta) and chironomid midges (Diptera), two of the dominant taxa, to an areal flux rate based on laboratory measurements of metabolic excretion of two abundant species suggested that excretion by benthic invertebrates is at least as important as any of the other identified processes for internal loading to the water column. Data from sediment cores collected around Upper Klamath Lake since the development of the

Fish and Aquatic Invertebrate Communities in Waterways, and Contaminants in Fish, at the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, Louisiana, 1999-2000

USGS Publications Warehouse

Swarzenski, Christopher M.; Mize, Scott V.; Thompson, Bruce A.; Peterson, Gary W.

2004-01-01

, floating rafts of aquatic plants). Individuals from 84 genera belonging to 51 families were identified. Diptera (true flies) was the most diverse group. Malacostraca (crustaceans), especially Amphipoda (scuds and sideswimmers), were the most abundant (36 percent). Total abundance and taxa richness of aquatic invertebrates were comparable during the March and July sampling in 1999, but were lower in samples collected from the same habitat at all three sites in April 2000. About 106 individuals were identified and enumerated from the depositional-targeted habitat (DTH, bottom material). Individuals from 7 genera belonging to 9 families were identified. Diptera was the most diverse group, and Annelida, especially tubificid worms, were the most abundant organisms identified (52 percent). Total abundance and composition of aquatic invertebrate communities differed between RTH and DTH at all three sites in April 2000. Organic compounds in whole fish, and trace elements, iron, and manganese in fillets, were analyzed in bowfin (Amia calva), bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides), and common carp (Cyprinus carpio). Organic compounds were not detected. Mercury was detected in fillets of all four species. Highest concentrations of mercury were detected in fillets from bowfin and largemouth bass. Mercury concentrations increased with increasing weight in the three predatory fish species (bowfin, bluegill, and largemouth bass), but were much lower, relative to weight, in the omnivore, common carp. Chromium concentrations were detected in tissue of the two larger fish, bowfin and common carp. Cadmium and lead were not detected in any samples. Mercury concentrations for larger predatory fish caught in Preserve waterways may be a concern if the fish are frequently consumed by humans. The process of mercury accumulation appears to be natural, and not related to a local source problem. Mercury concentrations in comparable fish tissue at

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Steven W.

most in all four streams. Juvenile bull trout utilized scour pool and run habitat the most in all four streams. YOY bull trout preferred plunge pool and scour pool habitat, as did juvenile bull trout in all four streams. These data show that while in the presence of the putative competitors, bull trout prefer the same habitat as in the absence of the putative competitors. Juvenile bull trout preferred mayflies and stoneflies in Mill Creek, while in the presence of the competitor species they preferred caddisflies, stoneflies, and Oligochaeta. It is felt that this difference is due to the differences in food items available and not species interactions, bull trout consume what is present. Adult bull trout were difficult to capture, and therefore it was difficult to determine the migratory habits in the Tucannon River. It is recommended that future studies use radio telemetry to determine the migratory habitat of these fish. The age, condition, and growth rates of bull trout differed only minimally between streams, indicating that if competitive interactions are occurring between these species it is not reflected by: (1) the length at age of bull trout; (2) the length-weight relationship of bull trout; or (3) the rate of growth of bull trout. The spawning habits of bull trout and spring chinook salmon are similar in the Tucannon River, however it was found that they spawn in different river locations. The salmon spawn below river kilometer 83, while 82% of bull trout spawn above that point. The peak of spawning for salmon occurred 10 days before the peak of bull trout spawning, indicating that very little competition for spawning locations occurs between these species in the Tucannon River. Future species interactions study recommendations include the use of electrofishing to enumerate bull trout populations, snorkeling to identify micro-habitat utilization, seasonal diet analysis, and radio transmitters to identify seasonal migration patterns of bull trout.« less

Benthic processes affecting contaminant transport in Upper Klamath Lake, Oregon

USGS Publications Warehouse

Kuwabara, James S.; Topping, Brent R.; Carter, James L.; Carlson, Rick A; Parchaso, Francis; Fend, Steven V.; Stauffer-Olsen, Natalie; Manning, Andrew J.; Land, Jennie M.

2016-09-30

summers of 2013 and 2014. However, consistently detectable concentrations for all four solutes provide no evidence that they consistently serve as the limiting nutrient for primary production in the lake. In contrast to the four solutes (SRP, ammonia, Fe, and Mn), benthic fluxes of dissolved arsenic (As) were both negative and positive (that is, the lakebed currently serves as both a source and a sink for dissolved As, depending on season). In a further contrast with SRP, ammonia, dissolved Fe, and Mn, dissolved-As riverine loads to UKL were of similar magnitude to benthic loads. A negative relationship between dissolved-As flux and water-column As over the 2014 temporal study provides a potential advantage for the management of water-quality in contrast to solutes, like SRP or ammonia, with consistently positive flux. The mean total benthic invertebrate density during 2013 was 12,610 individuals per square meter (n=63). Although benthic invertebrate density did not change over the study period, it was higher in littoral habitats than open-lake or trench habitats and higher in the northern region compared to the central or southern regions of UKL. Mean total benthic invertebrate density during 2014 was 19,726 individuals m−2 (n=27). Density during the pre-bloom and bloom periods of April 15 to August 13, 2014 (the first two thirds of the 2014 sampling period), were similar to 2013. However, benthic invertebrate density more than doubled during the latter one-third of the study, that is, the post-bloom period between August 20 to October 16, 2014. Oligochaeta, Chironomidae and Hirudinea represented well over 90 percent of the benthic fauna; Oligochaeta were twice as abundant as Chironomidae or Hirudinea, the latter two of which were similar in density. Benthic invertebrates may enhance dissolved-nutrient (or toxicant) transport across the sediment-water interface by (1) modifying diffusion-layer thicknesses and permeability through bioturbation, (2) enhancing advective

Characterization of water quality and biological communities, Fish Creek, Teton County, Wyoming, 2007-2011

USGS Publications Warehouse

Eddy-Miller, Cheryl A.; Peterson, David A.; Wheeler, Jerrod D.; Edmiston, C. Scott; Taylor, Michelle L.; Leemon, Daniel J.

2013-01-01

relative abundance of Ephemeroptera, Plecoptera, and Trichoptera, which tend to be intolerant of water-quality degradation, decreased from April/May to August; the same time period saw a corresponding increase in Diptera and noninsects, particularly Oligochaeta (worms) that are more tolerant. Seasonal changes in macroinvertebrate functional feeding groups were significantly different. The relative abundance of gatherer-collector and scraper feeding groups decreased from April/May to August, accompanied by an increase in filterer-collector and shredders feeding groups. Seasonal changes in feeding groups might be due to the seasonal shift in aquatic plant communities, as indicated by comparison with other streams in the area that had fewer aquatic macrophytes than Fish Creek. Statistical tests of macroinvertebrate metrics indicated few differences between years or biological sampling sites on Fish Creek, although the site farthest upstream sometimes was different not only in terms of macroinvertebrates but also in streamflow, water quality, and aquatic plants. Potential effects of contributions of additional nutrients to the Fish Creek ecosystem beyond the conditions sampled during the study period are not known. However, because virtually all of the detectable dissolved nitrate commonly was consumed by aquatic plants in August (leaving dissolved nitrate less than the reporting level in water samples), it is possible that increased nutrient contributions could cause increased growth of aquatic plants. Additional long-term monitoring of the stream, with concurrent data analysis and interpretation would be needed to determine the effects of additional nutrients on the aquatic plant community and on higher levels of the food chain.