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1

Does crustacean ethoxyresorufin O-deethylase activity vary during the molting cycle?  

PubMed

The authors examined fluctuation in microsomal ethoxyresorufin O-deethylase (EROD) activity in the hepatopancreas during the molting cycle of the fiddler crab, Uca pugilator. Results showed that microsomal EROD activity fluctuates significantly during the molting cycle, with the lowest enzymatic activity occurring in the late premolt stage. These results clearly show that molting physiology influences crustacean EROD activity, suggesting that when using crustacean EROD assays in evaluating pollution, only individuals from the same molt stage should be used. The authors propose that the high level of EROD activity in postmolt and intermolt stages is an additional mechanism crustaceans use to prevent any untimely rise in ecdysteroid levels. PMID:23843096

Hotard, Kate; Zou, Enmin

2013-10-01

2

Regulation of crustacean molting and regeneration  

SciTech Connect

The regulation of molting and regeneration by two antagonistic hormones is discussed. The time course of ecdysteroid titers in crustacean tissues has been followed during molt and regeneration cycles. (ACR)

Skinner, D.M.; Graham, D.E.; Holland, C.A.; Soumoff, C.; Mykles, D.L.

1981-01-01

3

Stage-specific changes in calcium concentration in crustacean (Callinectes sapidus) Y-organs during a natural molting cycle, and their relation to the hemolymphatic ecdysteroid titer.  

PubMed

Secretion of ecdysteroid molting hormones by crustacean Y-organs is suppressed by molt-inhibiting hormone (MIH). The suppressive effect of MIH on ecdysteroidogenesis is mediated by one or more cyclic nucleotide second messengers. In addition, existing data indicate that ecdysteroidogenesis is positively regulated (stimulated) by intracellular Ca(++). Despite the apparent critical role of calcium in regulating ecdysteroidogenesis, the level of Ca(++) in Y-organ cells has not been previously measured during a natural molting cycle for any crustacean species. In studies reported here, a fluorescent calcium indicator (Fluo-4) was used to measure Ca(++) levels in Y-organs during a molting cycle of the blue crab, Callinectes sapidus. Mean calcium fluorescence increased 5.8-fold between intermolt (C4) and stage D3 of premolt, and then dropped abruptly, reaching a level in postmolt (A) that was not significantly different from that in intermolt (P>0.05). The level of ecdysteroids in hemolymph of Y-organ donor crabs (measured by radioimmunoassay) showed an overall pattern similar to that observed for calcium fluorescence, rising from 2.9 ng/mL in intermolt to 357.1 ng/mL in D3 (P<0.05), and then dropping to 55.3 ng/mL in D4 (P<0.05). The combined results are consistent with the hypothesis that ecdysteroidogenesis is stimulated by an increase in intracellular Ca(++). PMID:22683690

Chen, Hsiang-Yin; Dillaman, Richard M; Roer, Robert D; Watson, R Douglas

2012-09-01

4

Carbonic anhydrase activity in a calcium-mobilizing epithelium of the crustacean Orchestia cavimana during molting  

Microsoft Academic Search

We investigated the involvement of the enzyme, carbonic anhydrase, in the calcification-decalcification processes occurring in the posterior caeca of the midgut of the terrestrial crustacean, Orchestia cavimana, before and after exuviation. This enzyme was ultrahistochemically localized throughout the membranes of the caecal epithelium as well as extracellularly, i.e., within pre-exuvial calcareous concretions and postexuvial calcified spherules. During the molt cycle,

J. C. Meyran; F. Graf; J. Fournié

1987-01-01

5

Carbonic anhydrase activity in a calcium-mobilizing epithelium of the crustacean Orchestia cavimana during molting.  

PubMed

We investigated the involvement of the enzyme, carbonic anhydrase, in the calcification-decalcification processes occurring in the posterior caeca of the midgut of the terrestrial crustacean, Orchestia cavimana, before and after exuviation. This enzyme was ultrahistochemically localized throughout the membranes of the caecal epithelium as well as extracellularly, i.e., within pre-exuvial calcareous concretions and postexuvial calcified spherules. During the molt cycle, the pattern of carbonic anhydrase activity in the posterior caeca was correlated with the calcium content at this level. Acetazolamide treatment in vivo inhibited about 50% of the calcium uptake during both pre-exuvial secretion and postexuvial reabsorption. The role of carbonic anhydrase in this mineralizing-demineralizing epithelium is discussed and compared with that of other mechanisms involved in this calcium turnover. PMID:3123431

Meyran, J C; Graf, F; Fournié, J

1987-01-01

6

FIRST-CYCLE MOLTS IN NORTH AMERICAN FALCONIFORMES  

Microsoft Academic Search

I examined 1849 specimens of 20 North American Falconiform species to elucidate the occurrence and nomenclature of partial first-cycle molts. As reported in the literature, American Kestrel (Falco sparverius) and White-tailed Kite (Elanus leucurus) have relatively complete body-feather molts that occur during the first fall; in the kite, this molt can also include up to all rectrices and 2-6 secondaries,

PETER PYLE

7

Magnesium-aspartate-based crystallization switch inspired from shell molt of crustacean  

PubMed Central

Many animals such as crustacean periodically undergo cyclic molt of the exoskeleton. During this process, amorphous calcium mineral phases are biologically stabilized by magnesium and are reserved for the subsequent rapid formation of new shell tissue. However, it is a mystery how living organisms can regulate the transition of the precursor phases precisely. We reveal that the shell mineralization from the magnesium stabilized precursors is associated with the presence of Asp-rich proteins. It is suggested that a cooperative effect of magnesium and Asp-rich compound can result into a crystallization switch in biomineralization. Our in vitro experiments confirm that magnesium increases the lifetime of amorphous calcium carbonate and calcium phosphate in solution so that the crystallization can be temporarily switched off. Although Asp monomer alone inhibits the crystallization of pure amorphous calcium minerals, it actually reduces the stability of the magnesium-stabilized precursors to switch on the transformation from the amorphous to crystallized phases. These modification effects on crystallization kinetics can be understood by an Asp-enhanced magnesium desolvation model. The interesting magnesium-Asp-based switch is a biologically inspired lesson from nature, which can be developed into an advanced strategy to control material fabrications. PMID:20007788

Tao, Jinhui; Zhou, Dongming; Zhang, Zhisen; Xu, Xurong; Tang, Ruikang

2009-01-01

8

Reciprocal changes in calcification of the gastrolith and cuticle during the molt cycle of the red claw crayfish Cherax quadricarinatus.  

PubMed

Mobilization of calcium during the molt cycle from the cuticle to transient calcium deposits is widely spread in crustaceans. The dynamics of calcium transport to transient calcium deposits called gastroliths and to the cuticle over the course of the molt cycle were studied in the crayfish Cherax quadricarinatus. In this species, calcium was deposited in the gastroliths during premolt and transported back to the cuticle during postmolt, shown by digital X-ray radiograph analysis. The predominant mineral in the crayfish is amorphous calcium carbonate embedded in an organic matrix composed mainly of chitin. Scanning electron micrographs of the cuticle during premolt showed that the endocuticle and parts of the exocuticle were the source of most of the labile calcium, while the epicuticle did not undergo degradation and remained mineralized throughout the molt cycle. The gastroliths are made of concentric layers of amorphous calcium carbonate intercalated between chitinous lamella. Measurements of pH and calcium levels during gastrolith deposition showed that calcium concentrations in the gastroliths, stomach, and muscle were about the same (10 to 11 mmol l(-1)). On the other hand, pH varied greatly, from 8.7+/-0.15 in the gastrolith cavity through 7.6+/-0.2 in muscle to 6.9+/-0.5 in the stomach. PMID:18400994

Shechter, Assaf; Berman, Amir; Singer, Alon; Freiman, Aviad; Grinstein, Mor; Erez, Jonathan; Aflalo, Eliahu D; Sagi, Amir

2008-04-01

9

MOLT-RELATED SUSCEPTIBILITY AND REGENERATIVE LIMB GROWTH AS SENSITIVE INDICATORS OF AQUATIC POLLUTANT TOXICITY TO CRUSTACEANS  

EPA Science Inventory

The study evaluated the comparative toxicity of various pollutants to intermolt and molting grass shrimp (Palaemonetes pugio). Most of the tested materials (pentachlorophenol, tetrachlorophenols, trichlorophenols, methylenebis dichlorophenol, dibutyl phthalate, chromium, and dril...

10

The ultrastructure of the oenocytes in the molt/intermolt cycle of an insect.  

PubMed

The structure and development of the permanent oenocytes of Calpodes ethlius (Lepidoptera, Hesperiidae) are described. There are three sorts of oenocyte. The permanent oenocytes are arranged ventral to the last two pairs of spiracles on abdominal segments 7 and 8 in four clusters of about 45 cells each. The molt cycle oenocytes are ventral to the other spiracles and only enlarge at molting. The subdermal oenocytes differentiate from the epidermis in large numbers shortly before pupation. The permanent oenocytes are large polyploid cells characterized by a cytoplasm of densely packed smooth tubular endoplasmic reticulum, and a plasma membrane invaginated in a meshwork of tubes ending in a reticular layer about 12 micro below the surface. There are two sorts of Golgi complex, one small and of conventional form, the other composed of clouds of microvesicles. 'Dense bodies', believed to belong to the microbody class of organelles, arise directly from the STER. There is a variety of membranous and 'crystalline' inclusions. The formation of isolation membranes from the tubular endoplasmic reticulum, and the origin of isolation bodies and autophagic vacuoles are described. Some autophagy takes place at all times in the molt/intermolt cycle, but there are phases of massive autophagy before the 4th-5th molt and the 5th-pupal molt. These phases coincide with pinocytosis of blood proteins and overlap with or are followed by phases of nuclear replication, RNA synthesis (ribosomes) and ER regeneration. Nuclear blebbing occurs before pupation. The morphology of the oenocytes is most like that of vertebrate cells engaged in steroid hormone synthesis. It is pointed out that the oenocytes rather than the prothoracic glands could be the source of ecdysone and the stimulus for molting. PMID:18631462

Locke, M

1969-01-01

11

Cloning of prophenoloxidase from hemocytes of the blue crab, Callinectes sapidus and its expression and enzyme activity during the molt cycle.  

PubMed

The arthropods cuticle undergoes dramatic morphological and biochemical changes from being soft to hardness through each molting process. Prophenoloxidase (PPO) known as a key enzyme in the arthropod innate immune system involved in the melanization reaction, has been related with the initial shell-hardening process, specifically in the sclerotization of the protein matrix in the new cuticle. Since hemocytes have been reported as the main PPO source in arthropods, the transport of hemocyte PPO into the newly laid, soft cuticle has been proposed for shell-hardening occurring during and immediately after ecdysis. In order to define the role of hemocyte PPO in the shell-hardening of crustaceans, the full-length cDNA sequence (2806 nt) of hemocytes PPO of the blue crab Callinectes sapidus (CasPPO-hemo) is isolated using degenerate PCR and 5'-3' RACE. CasPPO-hemo encodes a putative PPO (672 aa) showing three hemocyanin domains: N, M, and C in order and two copper binding sites (CuA & CuB). The sequence analysis identifies the putative CasPPO-hemo as zymogen which requires the cleavage at the N-terminus for its activation. Hemocyte extract (CasHLS) contains the PO, the activity of which depends on the in vitro activation of trypsin. The expression levels of CasPPO-hemo are kept constant during the molt cycle. The increase in the number of hemocytes at early premolt correlates with the elevated PO activity, while at late premolt, the increment in hemocyte numbers does not reflect on the PO activity. The functional importance of the changes in the levels of CasHLS-PO activity during molt cycle is discussed in relation to cuticle hardening process. PMID:23968691

Alvarez, Javier V; Chung, J Sook

2013-11-01

12

The lipid composition of hypodermal membranes from the blue crab (Callinectes sapidus) changes during the molt cycle and alters hypodermal calcium permeability.  

PubMed

Crustaceans are covered by a cuticle that does not grow. In order for an individual to grow, the cuticle must periodically be shed (ecdysis). Replacement of the old cuticle with a new one depends on processes that require precise timing and control, yet the nature and location of these controls remain unclear. A candidate site for them is within the hypodermal microvilli. These cellular structures extend through pore canals deep into the acellular cuticular matrix. Changes in the lipid composition of hypodermal microvilli could modulate water and ion fluxes and enzyme activities during critical stages of the molt cycle; however, the lipid composition of these structures has not been assessed during the molt cycle. Data presented here show that phospholipids isolated from hypodermal microvilli of Callinectes sapidus initially have elevated levels of n-6 fatty acids that decline steadily beginning just after ecdysis. Experiments with liposomes reveal that n-6 fatty acids decrease the calcium permeability of membranes, suggesting that the initially elevated levels in the cuticle may function to reduce calcium flux from the cuticle into the hypodermis. In addition, the ratio of cholesterol to phospholipid and the proportion of oleic acid in membrane phospholipids are maximal at 6 h post-ecdysis. It is known that changes in cholesterol and oleic acid content alter membrane permeability to water. It is, therefore possible that water flux through hypodermal membranes is also modulated in the early post-molt cuticle. Changes in microvillar lipid composition might serve importantly to control biomineralization in the post-ecdysal cuticle. PMID:14990220

Williams, E Eugene; Anderson, Matthew J; Miller, T Justin; Smith, Shaun D

2004-02-01

13

Biomineralizations: insights and prospects from crustaceans  

PubMed Central

Abstract For growing, crustaceans have to molt cyclically because of the presence of a rigid exoskeleton. Most of the crustaceans harden their cuticle not only by sclerotization, like all the arthropods, but also by calcification. All the physiology of crustaceans, including the calcification process, is then linked to molting cycles. This means for these animals to find regularly a source of calcium ions quickly available just after ecdysis. The sources of calcium used are diverse, ranging from the environment where the animals live to endogenous calcium deposits cyclically elaborated by some of them. As a result, crustaceans are submitted to an important and energetically demanding calcium turnover throughout their life. The mineralization process occurs by precipitation of calcium carbonate within an organic matrix network of chitin-proteins fibers. Both crystalline and stabilized amorphous polymorphs of calcium carbonate are found in crustacean biominerals. Furthermore, Crustacea is the only phylum of animals able to elaborate and resorb periodically calcified structures. Notably for these two previous reasons, crustaceans are more and more extensively studied and considered as models of choice in the biomineralization research area. PMID:22536102

Luquet, Gilles

2012-01-01

14

Biomineralizations: insights and prospects from crustaceans.  

PubMed

For growing, crustaceans have to molt cyclically because of the presence of a rigid exoskeleton. Most of the crustaceans harden their cuticle not only by sclerotization, like all the arthropods, but also by calcification. All the physiology of crustaceans, including the calcification process, is then linked to molting cycles. This means for these animals to find regularly a source of calcium ions quickly available just after ecdysis. The sources of calcium used are diverse, ranging from the environment where the animals live to endogenous calcium deposits cyclically elaborated by some of them. As a result, crustaceans are submitted to an important and energetically demanding calcium turnover throughout their life. The mineralization process occurs by precipitation of calcium carbonate within an organic matrix network of chitin-proteins fibers. Both crystalline and stabilized amorphous polymorphs of calcium carbonate are found in crustacean biominerals. Furthermore, Crustacea is the only phylum of animals able to elaborate and resorb periodically calcified structures. Notably for these two previous reasons, crustaceans are more and more extensively studied and considered as models of choice in the biomineralization research area. PMID:22536102

Luquet, Gilles

2012-01-01

15

Zoological detective stories: the case of the facetotectan crustacean life cycle  

PubMed Central

The reconstruction of complete animal life cycles is sometimes a considerable problem, even though the knowledge of the full life cycle may have far-reaching evolutionary implications. A new study published in BMC Biology on artificially induced metamorphosis in an enigmatic crustacean group that was only known from larval stages sheds new light on the evolution of parasitism. PMID:18598383

Scholtz, Gerhard

2008-01-01

16

Ecdysteroids Regulate the Levels of Molt-Inhibiting Hormone (MIH) Expression in the Blue Crab, Callinectes sapidus  

PubMed Central

Arthropod molt is coordinated through the interplay between ecdysteroids and neuropeptide hormones. In crustaceans, changes in the activity of Y-organs during the molt cycle have been regulated by molt-inhibiting hormone (MIH) and crustacean hyperglycemic hormone (CHH). Little has been known of the mode of direct effects of ecdysteroids on the levels of MIH and CHH in the eyestalk ganglia during the molt cycle. This study focused on a putative feedback of ecdysteroids on the expression levels of MIH transcripts using in vitro incubation study with ecdysteroids and in vivo RNAi in the blue crab, Callinectes sapidus. Our results show a specific expression of ecdysone receptor (EcR) in which EcR1 is the major isoform in eyestalk ganglia. The initial elevation of MIH expression at the early premolt stages is replicated by in vitro incubations of eyestalk ganglia with ecdysteroids that mimic the intrinsic conditions of D0 stage: the concentration (75 ng/ml) and composition (ponasterone A and 20-hydroxyecdysone at a 3:1 (w:w) ratio). Additionally, multiple injections of EcR1-dsRNA reduce MIH expression by 67%, compared to the controls. Our data provide evidence on a putative feedback mechanism of hormonal regulation during molting cycle, specifically how the molt cycle is repeated during the life cycle of crustaceans. The elevated concentrations of ecdysteroids at early premolt stage may act positively on the levels of MIH expression in the eyestalk ganglia. Subsequently, the increased MIH titers in the hemolymph at postmolt would inhibit the synthesis and release of ecdysteroids by Y-organs, resulting in re-setting the subsequent molt cycle. PMID:25849453

Techa, Sirinart; Chung, J. Sook

2015-01-01

17

Annual cycle of spawning and molting in the red-claw crayfish, Cherax quadricarinatus, under laboratory conditions  

Microsoft Academic Search

The annual spawning and molting cycles of the Australian red-claw crayfish was studied in the laboratory over a period of 13 months. Sexually mature crayfish were maintained in 140-1 tanks, each containing four females and one male, under a constant temperature (26–28 °C) and either an ambient or a controlled (14 L:10 D) photoperiod. A similar annual pattern of spawning

Assaf Barki; Tal Levi; Gideon Hulata; Ilan Karplus

1997-01-01

18

Calcium bodies of Titanethes albus (Crustacea: Isopoda): molt-related structural dynamics and calcified matrix-associated bacteria.  

PubMed

Crustaceans form a variety of calcium deposits in which they store calcium necessary for the mineralization of their exoskeletons. Calcium bodies, organs containing large amounts of calcium, have been reported in some terrestrial isopod crustaceans, but have not yet been extensively studied. We analyzed the architecture of these organs during the molt cycle in the isopod Titanethes albus. Two pairs of calcium bodies are positioned ventrolaterally in posterior pereonites of T. albus. Individual organs are epithelial sacs that contain material arranged in concentric layers delimited by thin laminae. As demonstrated by electron microscopy and fluorescence in situ hybridization, abundant bacteria are present within the calcium bodies. Regardless of the molt cycle stage, crystalline concretions are present in the central areas of the calcium bodies. Energy dispersive X-ray spectrometry of the concretions demonstrated that they are composed predominantly of calcium and phosphorus and selected area electron diffraction indicated the presence of hydroxyapatite. In molting animals, a glassy layer of mineralized matrix is formed between the envelope and the outermost lamina of the calcium body. This layer consists of an amorphous calcium mineral which contains less phosphorus than the central concretions and is resorbed after molt. Since changes in the mineralized matrix are synchronized with the molt cycle, the calcium bodies likely function as a storage compartment that complements sternal deposits as a source of calcium for the mineralization of the exoskeleton. Bacteria associated with the mineralized matrix of calcium bodies are evidently involved in calcium dynamics. PMID:22651964

Vittori, Miloš; Kostanjšek, Rok; Znidarši?, Nada; Zagar, Kristina; Ceh, Miran; Strus, Jasna

2012-10-01

19

Ecdysone and retinoid-X receptors of the blue crab, Callinectes sapidus: cloning and their expression patterns in eyestalks and Y-organs during the molt cycle.  

PubMed

Crustacean molting is known to be regulated largely by ecdysteroids and crustacean hyperglycemic hormone (CHH) neuropeptide family including molt-inhibiting hormone (MIH) and CHH. The surge of 20-OH ecdysone and/or ponasterone A initiates the molting process through binding to its conserved heterodimeric nuclear receptor: Ecdysone Receptor (EcR) and Ultraspiracle (USP)/Retinoid-X Receptor (RXR). To better understand the role of ecdysteroids in the molt regulation, the full-length cDNAs of the blue crab, Callinectes sapidus EcR1 and RXR1 were isolated from the Y-organs and their expression levels were determined in both Y-organs and eyestalks at various molt stages. Y-organs show the expression of four putative isoforms of CasEcRs and CasRXRs which differ in the length of the open reading frame but share the same domain structures as in typical nuclear receptors: AF1, DBD, HR, LBD, and AF2. The putative CasEcR isoforms are derived from a 27-aa insert in the HR and a 49-aa residue substitution in the LBD. In contrast, an insertion of a 5-aa and/or a 45-aa in the DBD and LBD gives rise to CasRXR isoforms. The eyestalks and Y-organs show the co-expression of CasEcRs and CasRXRs but at the different levels. In the eyestalks, the expression levels of CasRXRs are 3-5 times higher than those of CasEcRs, while in Y-organs, CasRXRs are 2.5-4 times higher than CasEcRs. A tissue-specific response to the changes in the levels of hemolymphatic ecdysteroids indicates that these tissues may have differences in the sensitivity or responsiveness to ecdysteroids. The presence of upstream open reading frame and internal ribosome entry site in 5' UTR sequences of C. sapidus and other arthropod EcR/RXR/USP analyzed by in silico indicates a plausible, strong control(s) of the translation of these receptors. PMID:23764560

Techa, Sirinart; Chung, J Sook

2013-09-15

20

PHYSIOLOGY, ENDOCRINOLOGY, AND REPRODUCTION The Effect of an Induced Molt and a Second Cycle of Lay on Skeletal Integrity of White Leghorns1  

Microsoft Academic Search

The effect of an induced molt and a second egg laying cycle on White Leghorns hen's skeletal integ- rity was investigated in a series of 3 experiments. Using dual-energy X-ray absorptiometry, bone mineral density (BMD) and bone mineral content (BMC) of the left tibia and humerus were measured in live hens and excised bones and correlated with invasive bone measurement

H. Mazzuco; P. Y. Hester

21

Molting Mania  

NSDL National Science Digital Library

Most students are unaware of the process of molting, but it is an animal characteristic they're sure to be interested in and should have the opportunity to observe. Through a two-month long unit on animal molting, kindergarteners observed pill bugs, crayfish, an anole, and an alligator lizard. Through these hands-on adventures, incorporating integrated topics, students observed how different animals grow and began to discover what it means to "be a scientist."

Christina Arce

2006-04-01

22

Intraspecific Deception by Bluffing: A Defense Strategy of Newly Molted Stomatopods (Arthropoda: Crustacea)  

Microsoft Academic Search

After molting, stomatopods can be evicted easily from home cavities by conspecifics because these marine crustaceans lose temporarily their body armor and the use of their raptorial appendages. Some newly molted stomatopods defend their cavities with a meral spread display, a signal correlated with attack when used by animals between molts. The use of the meral spread display actually increases

Rick Steger; Roy L. Caldwell

1983-01-01

23

Depression of synaptic efficacy at intermolt in crayfish neuromuscular junctions by 20-hydroxyecdysone, a molting hormone.  

PubMed

This report demonstrates that ecdysteroids can reduce synaptic transmission at an intermolt stage of a crustacean tonic neuromuscular junction by acting at a presynaptic site. The steroid molting hormone, 20-hydroxyecdysone (20-HE), appears to act through a rapid, nongenomic mechanism that decreases the probability of synaptic vesicle release and reduces the number of release sites. Quantal analysis revealed that fewer vesicles were released for a given stimulus when 20-HE was present, and this in turn accounted for the reduced synaptic efficacy. Reduced synaptic efficacy produced smaller evoked postsynaptic currents and smaller excitatory postsynaptic potentials (EPSPs) across the muscle fiber membrane. The reduction in EPSPs was observed among muscle fibers that were innervated by high- or low-output terminals. The behavior of crustaceans/crayfish during the molt cycle, when 20-HE is high, may be explained by the reduction in synaptic transmission. Crustaceans become quiescent during the premolt periods as do insects. The effects of 20-HE can be reversed with the application of the crustacean neuromodulator serotonin, which enhances synaptic transmission. PMID:9535959

Cooper, R L; Ruffner, M E

1998-04-01

24

Molting Mania  

ERIC Educational Resources Information Center

Most children are unaware of the process of molting, the periodic shedding and replacement of part or all of a coat or an outer covering of an animal, but it is an animal characteristic they are sure to be interested in and should have the opportunity to observe. In this article, the author shares how she and her students observed various…

Arce, Christina

2006-01-01

25

USDA Forest Service Gen. Tech. Rep. PSW-152. 1995. 99 Molts and Plumages in the Annual Cycle of the  

E-print Network

and anthropogenic mortality of juveniles and adult birds. Thus, the adult:juvenile ratio is complex and must information on plumages and molt from published and unpublished sources with three main objectives in mind

Standiford, Richard B.

26

Myostatin from the American lobster, Homarus americanus: Cloning and effects of molting on expression in skeletal muscles.  

PubMed

A cDNA encoding a myostatin (Mstn)-like gene from an astacuran crustacean, Homarus americanus, was cloned and characterized. Mstn inhibits skeletal muscle growth in vertebrates and may play a role in crustacean muscle as a suppressor of protein synthesis. Sequence analysis and three-dimensional modeling of the Ha-Mstn protein predicted a high degree of conservation with vertebrate and other invertebrate myostatins. Qualitative polymerase chain reaction (PCR) demonstrated ubiquitous expression of transcript in all tissues, including skeletal muscles. Quantitative PCR analysis was used to determine the effects of natural molting and eyestalk ablation (ESA) on Ha-Mstn expression in the cutter claw (CT) and crusher claw (CR) closer muscles and deep abdominal (DA) muscle. In intermolt lobsters, the Ha-Mstn mRNA level in the DA muscle was significantly lower than the mRNA levels in the CT and CR muscles. Spontaneous molting decreased Ha-Mstn mRNA during premolt, with the CR muscle, which is composed of slow-twitch (S?) fibers, responding preferentially (82% decrease) to the atrophic signal compared to fast fibers in CT (51% decrease) and DA (69% decrease) muscles. However, acute increases in circulating ecdysteroids caused by ESA had no effect on Ha-Mstn mRNA levels in the three muscles. These data indicate that the transcription of Ha-Mstn is differentially regulated during the natural molt cycle and it is an important regulator of protein turnover in molt-induced claw muscle atrophy. PMID:20696264

MacLea, Kyle S; Covi, Joseph A; Kim, Hyun-Woo; Chao, Erica; Medler, Scott; Chang, Ernest S; Mykles, Donald L

2010-12-01

27

Switching skeletons: hydrostatic support in molting crabs  

NASA Technical Reports Server (NTRS)

Skeletal support systems are essential for support, movement, muscular antagonism, and locomotion. Crustaceans shed their rigid exoskeleton at each molt yet are still capable of forceful movement. We hypothesize that the soft water-inflated body of newly molted crabs may rely on a hydrostatic skeleton, similar to that of worms and polyps. We measured internal hydrostatic pressure and the force exerted during claw adduction and observed a strong correlation between force and hydrostatic pressure, consistent with hydrostatic skeletal support. This alternation between the two basic skeletal types may be widespread among arthropods.

Taylor, Jennifer R A.; Kier, William M.; Walker, I. D. (Principal Investigator)

2003-01-01

28

The lunar-tide cycle viewed by crustacean and mollusc gatherers in the State of Paraíba, Northeast Brazil and their influence in collection attitudes  

Microsoft Academic Search

Traditional human communities have a wide knowledge of their environment. Collection of animals in estuarine and coastal areas are directly influenced by tidal cycles. The aim of this study is to evaluate the understanding of the tides associated with the lunar cycle held by people who gather crustaceans and molluscs in the State of Paraiba. The empirical knowledge of 20

Alberto K Nishida; Nivaldo Nordi; Rômulo RN Alves

2006-01-01

29

Control of molting in crustacea  

SciTech Connect

The single, overriding event that occurs during all proecdysial periods in crustaceans is the synthesis of a new exoskeleton that encompasses an enlarged animal when the old shell is cast off. Regeneration of missing appendages and larval or puberty metamorphoses also occur during proecdysis. Proecdysial periods have been divided into substages defined by the occurrence of specific events. Although a number of factors must be postulated to account for individual proecdysial events, only the molting hormone, 20-hydroxyecdysone, has been identified and isolated. Much evidence indicates that the X-organ sinus glands complex, a neurosecretory tissue located in the eyestalks, is the source of a molt inhibiting hormone (MIH) responsible for maintaining animals in anecdysis. An exuviation factor has been proposed to support the extrication of the animal from the old exoskeleton. There is evidence for a limb growth inhibitory factor (LGIF) that affects the rate of growth of regenerating limbs. We are proposing an anecdysial limb autotomy factor (LAF/sub an/) that propels into precocious molts anecdysial limb autotomy factor (LAF/sub pro/) that interrupts the proecdysial period of animals that lose one or more normal or partially regenerated pereopods before a critical time in proecdysis.

Skinner, D.M.; Graham, D.E.; Holland, C.A.; Mykles, D.L.; Soumoff, C.; Yamaoka, L.H.

1982-01-01

30

Stressed-out lobsters: crustacean hyperglycemic hormone and stress proteins.  

PubMed

Organisms in natural habitats must frequently respond to changes in their environments through various physiological mechanisms. My laboratory has developed several methods for the quantification of stress in crustaceans. An ELISA was developed for the crustacean hyperglycemic hormone (CHH) from the American lobster (Homarus americanus). It is sensitive to as little as 0.2 fmol of peptide. Increases in hemolymph CHH were observed under conditions of acute hypoxia, elevated temperature, and altered salinity. In addition, elevated CHH concentrations were observed in Norway lobsters (Nephrops norvegicus) that were parasitized with the dinoflagellate Hematodinium sp.Stress proteins, also known as heat-shock proteins (HSPs), comprise a highly conserved class of proteins that display elevated transcription during periods of stress. Using homologous molecular probes, my collaborators and I have examined the influence of heat-shock, osmotic stress, and the molt cycle upon HSP expression at the protein and mRNA levels. We observed a significant elevation in HSP mRNA expression after 1 hr of heat-shock or after 0.5 hr of osmotic stress. When comparing claw and abdominal muscles during molting, we observed a tissue-specific HSP response. Quantification of these different stress responses may serve as early indicators of the degradation of environmental health. PMID:21676744

Chang, Ernest S

2005-01-01

31

Differential expression profiling of components associated with exoskeletal hardening in crustaceans  

PubMed Central

Background Exoskeletal hardening in crustaceans can be attributed to mineralization and sclerotization of the organic matrix. Glycoproteins have been implicated in the calcification process of many matrices. Sclerotization, on the other hand, is catalysed by phenoloxidases, which also play a role in melanization and the immunological response in arthropods. Custom cDNA microarrays from Portunus pelagicus were used to identify genes possibly associated with the activation pathways involved in these processes. Results Two genes potentially involved in the recognition of glycosylation, the C-type lectin receptor and the mannose-binding protein, were found to display molt cycle-related differential expression profiles. C-type lectin receptor up-regulation was found to coincide with periods associated with new uncalcified cuticle formation, while the up-regulation of mannose-binding protein occurred only in the post-molt stage, during which calcification takes place, implicating both in the regulation of calcification. Genes presumed to be involved in the phenoloxidase activation pathway that facilitates sclerotization also displayed molt cycle-related differential expression profiles. Members of the serine protease superfamily, trypsin-like and chymotrypsin-like, were up-regulated in the intermolt stage when compared to post-molt, while trypsin-like was also up-regulated in pre-molt compared to ecdysis. Additionally, up-regulation in pre- and intermolt stages was observed by transcripts encoding other phenoloxidase activators including the putative antibacterial protein carcinin-like, and clotting protein precursor-like. Furthermore, hemocyanin, itself with phenoloxidase activity, displayed an identical expression pattern to that of the phenoloxidase activators, i.e. up-regulation in pre- and intermolt. Conclusion Cuticle hardening in crustaceans is a complex process that is precisely timed to occur in the post-molt stage of the molt cycle. We have identified differential expression patterns of several genes that are believed to be involved in biomineralization and sclerotization and propose possible regulatory mechanisms for these processes based on their expression profiles, such as the potential involvement of C-type lectin receptors and mannose binding protein in the regulation of calcification. PMID:19040762

Kuballa, Anna V; Elizur, Abigail

2008-01-01

32

Functional Genomic Analysis of C. elegans Molting  

PubMed Central

Although the molting cycle is a hallmark of insects and nematodes, neither the endocrine control of molting via size, stage, and nutritional inputs nor the enzymatic mechanism for synthesis and release of the exoskeleton is well understood. Here, we identify endocrine and enzymatic regulators of molting in C. elegans through a genome-wide RNA-interference screen. Products of the 159 genes discovered include annotated transcription factors, secreted peptides, transmembrane proteins, and extracellular matrix enzymes essential for molting. Fusions between several genes and green fluorescent protein show a pulse of expression before each molt in epithelial cells that synthesize the exoskeleton, indicating that the corresponding proteins are made in the correct time and place to regulate molting. We show further that inactivation of particular genes abrogates expression of the green fluorescent protein reporter genes, revealing regulatory networks that might couple the expression of genes essential for molting to endocrine cues. Many molting genes are conserved in parasitic nematodes responsible for human disease, and thus represent attractive targets for pesticide and pharmaceutical development. PMID:16122351

Frand, Alison R; Russel, Sascha

2005-01-01

33

Molt cycle related changes and effect of short term starvation on the biochemical constituents of the blue swimmer crab Portunus pelagicus  

PubMed Central

Synthesis and hardening of a new exoskeleton are essential to the arthropod molting process. The present study emphasizes the variations in the levels of hemolymph total free sugars, hepatopancreas glycogen and cuticular proteins during the molting stages of Portunus pelagicus. It also reports the effect of short-term starvation conditions on the biochemical constituents of the hemolymph. Intermolt crabs were subjected to 6 days of starvation and hemolymph samples were taken. Standard biochemical procedures were followed toward the quantification of total proteins, total free sugars and total lipids. The total free sugar level in the hemolymph of P. pelagicus was observed to increase during early premolt D0 (3.108 ± 0.032 g/ml) and a gradual decrease till late postmolt B stage (0.552 ± 0.124 g/ml), suggesting the need for total free sugars to provide energy for the apolysis process. Increase in the levels of hepatopancreas glycogen was observed from 1225 ± 0.04 ?g/mg in early premolt D0 to 1700 ± 0.3 ?g/mg in late premolt D2–3. This is in correlation with the decreased levels of free sugars during premolt stages, suggesting an increase in the storage of glycogen reserves in the hepatopancreas. Cuticular proteins increased during stage B (2.702 ± 0.093 g/ml) and stage C (3.065 ± 0.012 g/ml), indicating exoskeleton hardening and mineralization. Results of the starvation studies clearly showed a steady decline in the level of total free sugars till day 6 (0.099 ± 0.00 g/ml) when compared to the control (8.646 ± 0.08 g/ml). Gradual decrease of total lipids was also observed from the first day of the experiment (6.088 ± 2.44 g/ml) to the last day of the study (0.401 ± 0.20 g/ml) which was 85% lesser than the control (8.450 ± 0.49 g/ml)suggesting the efficient usage of total sugars to consolidate the loss of energy reserves during starvation. The knowledge of Molt-cycle events can be used as a tool for the evaluation of the developmental state providing a morphological reference system for physiological and biochemical studies related to crab aquaculture. Starvation studies enlightens that increasing carbohydrate levels in crab feed together with good protein content could alleviate the natural effects of starvation, improve farm productivity and reduce the deleterious impact of nitrogen pollution generated by rich-protein feeds used in crab farming. PMID:23961226

Sugumar, V.; Vijayalakshmi, G.; Saranya, K.

2012-01-01

34

INTRODUCTION The visual systems of the nearly 50,000 extant crustacean species  

E-print Network

-faceted lenses are composed of modified exoskeleton (Land and Nilsson, 2002). When a crustacean molts, the entire exoskeleton is shed, including the faceted lenses. Prior to molting, the exoskeleton separates from the underlying hypodermis, which then secretes a new epicuticle (Smith and Chang, 2007). The outer exoskeleton

Johnsen, Sönke

35

Qualitative and quantitative changes in exoskeletal proteins synthesized throughout the molt cycle of the Bermuda land crab  

SciTech Connect

During the premolt period in Crustacea, a single layer of epidermal cells that underlies the exoskeleton is thought to be responsible for the degradation of the old exoskeleton and synthesis of a new one. In order to identify molt-specific proteins and their temporal appearance, they cultured epidermis and associated integumentary tissue from the gill chambers of crab in vitro in the presence of one of three radiolabeled amino acids. Autoradiographs of (/sup 35/S)Met-labeled tissues indicate a low level of synthesis in epidermal cells of intermolt animals; synthesis increases during premolt and stage B of postmolt. Label is also found in the innermost layer of the old exoskeleton while it is being degraded and in new exoskeletal layers during their synthesis. Fluorographs of gels of integumentary proteins show marked quantitative changes in 44 and 56 kD proteins late in premolt. Qualitative changes include synthesis of 46 and 48 kD proteins during late premolt and three proteins (all of approx. 170 kD) detectable only in postmolt. Solubilized gel slices of (/sup 3/H)Leu-labeled proteins indicate maximum synthesis at an earlier premolt stage than seen in Met-labeled proteins. Other proteins of 20, 24, 29, 32, and 96 kD are synthesized in a stage-dependent manner while (/sup 3/H)Tyr labels small proteins that appear only in late premolt.

Stringfellow, L.A.; Skinner, D.M.

1987-05-01

36

Testing competing hypotheses for chronology and intensity of lesser scaup molt during winter and spring migration  

USGS Publications Warehouse

We examined chronology and intensity of molt and their relationships to nutrient reserves (lipid and protein) of Lesser Scaup (Aythya affinisK/i>) to test predictions of two competing hypotheses. The "staggered cost" hypothesis states that contour-feather molt is nutritionally costly and should not occur during nutritionally costly periods of the annual cycle unless adequate nutrients are available. The "breeding plumage" hypothesis states that prealternate molt must be complete prior to nesting, regardless of nutrient availability. Males and females were completing prebasic molt during winter (Louisiana) and had similar molt intensities. Females underwent prealternate molt during spring migration (Illinois and Minnesota) and prebreeding (Manitoba) periods; 53% and 93% of females were in moderate to heavy molt in Minnesota and Manitoba, respectively, despite experiencing other substantial nutritional costs. Intensity of prealternate molt was not correlated with lipid reserves even though females, on average, were nutritionally stressed. Molt intensity was not negatively correlated with protein reserves at any location. Chronology and intensity of prealternate molt varied little and were not temporally staggered from other nutritionally costly events. Prealternate molt did not influence nutrient reserves, and nutrient reserves likely were not the ultimate factor influencing chronology or intensity of prealternate molt of females. We surmise that nutrients required for prealternate molt come from exogenous sources and that the "staggered cost" hypothesis does not explain chronology of prealternate molt in female Lesser Scaup; rather, it appears that molt must be complete prior to nesting, consistent with the "breeding plumage" hypothesis.

Anteau, Michael J.; Anteau, Andrea C.E.; Afton, Alan D.

2011-01-01

37

Testing competing hypotheses for chronology and intensity of lesser scaup molt during winter and spring migration  

USGS Publications Warehouse

We examined chronology and intensity of molt and their relationships to nutrient reserves (lipid and protein) of Lesser Scaup (Aythya affinis) to test predictions of two competing hypotheses. The "staggered cost" hypothesis states that contour-feather molt is nutritionally costly and should not occur during nutritionally costly periods of the annual cycle unless adequate nutrients are available. The "breeding plumage" hypothesis states that prealternate molt must be complete prior to nesting, regardless of nutrient availability. Males and females were completing prebasic molt during winter (Louisiana) and had similar molt intensities. Females underwent prealternate molt during spring migration (Illinois and Minnesota) and prebreeding (Manitoba) periods; 53% and 93% of females were in moderate to heavy molt in Minnesota and Manitoba, respectively, despite experiencing other substantial nutritional costs. Intensity of prealternate molt was not correlated with lipid reserves even though females, on average, were nutritionally stressed. Molt intensity was not negatively correlated with protein reserves at any location. Chronology and intensity of prealternate molt varied little and were not temporally staggered from other nutritionally costly events. Prealternate molt did not influence nutrient reserves, and nutrient reserves likely were not the ultimate factor influencing chronology or intensity of prealternate molt of females. We surmise that nutrients required for prealternate molt come from exogenous sources and that the "staggered cost" hypothesis does not explain chronology of prealternate molt in female Lesser Scaup; rather, it appears that molt must be complete prior to nesting, consistent with the "breeding plumage" hypothesis. ?? The Cooper Ornithological Society 2011.

Anteau, M.J.; Anteau, A.C.E.; Afton, A.D.

2011-01-01

38

crustaceans drawer  

NSDL National Science Digital Library

Crustaceans are arthropods with two pairs of antennae in front of the mouth, and one pair grinding or biting limbs (mandibles) behind the mouth. The group includes crabs, lobsters, shrimp and the extinct phyllocarids.

2001-03-01

39

Overview on the sub-grouping of the crustacean hyperglycemic hormone family  

Microsoft Academic Search

The Crustacean hyperglycemic hormones (CHHs) are an ever extending family of crustacean hormones mainly involved in carbohydrate metabolism, molt and reproduction. In this paper, we drew together 32 available CHH sequences, and applied the techniques of multiple sequence alignment, motif searching and amino acid conservation analysis to the characterization of the molecules independently of their biological function. The analysis clearly

C. Lacombe; P. Grève; G. Martin

1999-01-01

40

The lunar-tide cycle viewed by crustacean and mollusc gatherers in the State of Paraíba, Northeast Brazil and their influence in collection attitudes.  

PubMed

Traditional human communities have a wide knowledge of their environment. Collection of animals in estuarine and coastal areas are directly influenced by tidal cycles. The aim of this study is to evaluate the understanding of the tides associated with the lunar cycle held by people who gather crustaceans and molluscs in the State of Paraiba. The empirical knowledge of 20 crab gatherers and 30 mollusc gatherers was recorded through open interviews and structured questionnaires. The results showed that the gatherers have an accurate comprehension of tidal phenomenon based on their exploitation of natural resources, which perpetuates through generations. PMID:16393342

Nishida, Alberto K; Nordi, Nivaldo; Alves, Rômulo R N

2006-01-01

41

The crustacean cuticle: structure, composition and mineralization.  

PubMed

Crustaceans have a rigid exoskeleton, which is made of a layered cuticle, covering the soft body parts for protection from conspecific competitors and/or interspecific predators. Calcium carbonate adds rigidity to the crustacean cuticle, which consequently means that growth only occur at each molt. The current study presents a review of existing literature on crustacean exoskeleton cuticle physiology and biochemistry in relation to the molting process with special reference to calcification. As a result, research matter where knowledge remains limited has been identified during the molting process, including 1) whether the same or different epithelial cells are responsible for the decomposition and/or reconstruction of chitin and proteins, 2) how calcium carbonate levels are regulated at the cellular level during transfer between the cuticle and body organs, and 3) what factors maintain the amorphous state of calcium carbonate following deposition in the exoskeleton and temporary storage organs. The identification of these areas of focus provides a basis on which targeted future research may be developed, and potentially applied to other invertebrate or even vertebrate processes. PMID:22201907

Nagasawa, Hiromichi

2012-01-01

42

Can dietary molting replace feed withdrawal molting?  

Technology Transfer Automated Retrieval System (TEKTRAN)

The aim of this work was to evaluate the efficacy of molting diets at inhibiting egg production in layers (Hy-Line W36). In total, 96, pair-housed, 60-wk-old, hens were assigned to one of four diet treatments (n=12/trt): control (C, 15.4%); low energy (LE, 12.9% CP); low salt (LS, 15.4% CP, 0.05% N...

43

Effects of molting and environmental factors on trace metal body-burdens and hemocyanin concentrations in the American lobster, Homarus americanus.  

PubMed

Hemocyanin concentrations in the hemolymph of marine crustacea are dependent on the molt cycle and on environmental conditions. Studies in our laboratories have found that hemocyanin levels in blue crabs are reduced after ecdysis and under conditions of environmental stress (Engel, Brouwer, & McKenna, 1993. Hemocyanin concentrations in marine crustaceans as a function of environmental conditions. Marine Ecology Progress Series, 93, 233-244). We have extended those studies to include the American lobster, Homarus americanus. Hemolymph and digestive gland tissues from Long Island Sound lobsters were analyzed for hemocyanin, copper, and zinc during different stages of the molt cycle. Hemocyanin, copper and zinc in the hemolymph were highest in premolt stages (D1-D4), and lowest in the postecdysal papershell stages (B1-B2). Concomitantly, copper in digestive glands decreased significantly following ecdysis, but no significant changes in the metals bound to metallothionein (MT) were observed. Copper-MT was the predominant form throughout the molt cycle, presumably because lobsters were obtained from copper-contaminated areas. To examine the effects of environmental factors, intermolt lobsters were collected from locations of different environmental quality along the Atlantic coast, and were analyzed for hemocyanin and trace metals. In general, animals from areas with a history of contamination showed the highest hemocyanin concentrations. PMID:11570806

Engel, D W; Brouwer, M; Mercaldo-Allen, R

2001-09-01

44

Gene Expression Changes of Caenorhabditis elegans Larvae during Molting and Sleep-Like Lethargus  

PubMed Central

During their development, Caenorhabditis elegans larvae go through four developmental stages. At the end of each larval stage, nematodes molt. They synthesize a new cuticle and shed the old cuticle. During the molt, larvae display a sleep-like behavior that is called lethargus. We wanted to determine how gene expression changes during the C. elegans molting cycle. We performed transcriptional profiling of C. elegans by selecting larvae displaying either sleep-like behavior during the molt or wake behavior during the intermolt to identify genes that oscillate with the molting-cycle. We found that expression changed during the molt and we identified 520 genes that oscillated with the molting cycle. 138 of these genes were not previously reported to oscillate. The majority of genes that had oscillating expression levels appear to be involved in molting, indicating that the majority of transcriptional changes serve to resynthesize the cuticle. Identification of genes that control sleep-like behavior during lethargus is difficult but may be possible by looking at genes that are expressed in neurons. 22 of the oscillating genes were expressed in neurons. One of these genes, the dopamine transporter gene dat-1, was previously shown in mammals and in C. elegans to control sleep. Taken together, we provide a dataset of genes that oscillate with the molting and sleep-wake cycle, which will be useful to investigate molting and possibly also sleep-like behavior during lethargus. PMID:25409030

Turek, Michal; Bringmann, Henrik

2014-01-01

45

Molecular analysis of two genes, DD9A and B, which are expressed during the postmolt stage in the decapod crustacean Penaeus japonicus.  

PubMed

In decapod crustaceans, deposition of calcium carbonate crystals (calcification) in the exoskeleton takes place during the postmolt phase of the molt cycle. In an attempt to identify proteins which regulate the calcification process, the differential display technique was used to identify genes which were specifically expressed in the integument during the postmolt stage in the penaeid prawn Penaeus japonicus. One of the genes thus identified, named DD9A, was expressed in the epithelial cells of the tail fan. DD9A encoded a putative precursor of a secreted protein of 113 amino acids which exhibited sequence similarities to a group of crustacean and insect cuticular proteins, suggesting that DD9A was a protein component of the exoskeleton. Another gene, DD9B, which was also transcribed specifically during the postmolt period was identified based on its sequence similarity to DD9A. Potential roles of the DD9A protein in the calcification of the exoskeleton will be discussed. PMID:10840648

Watanabe, T; Persson, P; Endo, H; Kono, M

2000-01-01

46

The Life Cycle of the Parasitic Crustacean, Lernanthropus latis Yamaguti, 1954 (Copepoda: Lernanthropidae), on Marine-Cultured Fish, Lates calcarifer, from Setiu Wetland, Terengganu  

PubMed Central

Parasitic crustaceans of Lernanthropus latis were isolated from the host, the seabass, Lates calcarifer, obtained from a cage culture in Setiu Wetland, Terengganu. The adult females with egg were kept alive in vials containing 20?mL of filtered seawater and incubated at 30°C. The eggs were monitored every hour and the hatching periods were recorded. Three developmental stages were observed, namely, nauplii I, nauplii II, and infective copepodid. The infective copepodids were then transferred into a tank containing 60 litres of seawater with 150 fingerlings for infection purpose. One fish was sacrificed every 24?hr to inspect the next developmental stage. As a result, six more stages were obtained within 298?hrs starting from the infection day. The stages were known as fixed copepodid I, fixed copepodid II, fixed copepodid III, fixed copepodid IV, preadult, and adult. Parasitic L. latis takes a 483?hr period to complete a life cycle. PMID:25574379

Abdul Khalid, Nur Qamarina; Shaharoum-Harrison, Faizah

2014-01-01

47

Biological polarized light reflectors in stomatopod crustaceans  

NASA Astrophysics Data System (ADS)

Body parts that can reflect highly polarized light have been found in several species of stomatopod crustaceans (mantis shrimps). These polarized light reflectors can be grossly divided into two major types. The first type, usually red or pink in color to the human visual system, is located within an animal's cuticle. Reflectors of the second type, showing iridescent blue, are located beneath the exoskeleton and thus are unaffected by the molt cycle. We used reflection spectropolarimetry and transmission electron microscopy (TEM) to study the reflective properties and the structures that reflect highly polarized light in stomatopods. For the first type of reflector, the degree of polarization usually changes dramatically, from less than 20% to over 70%, with a change in viewing angle. TEM examination indicates that the polarization reflection is generated by multilayer thin-film interference. The second type of reflector, the blue colored ones, reflects highly polarized light to all viewing angles. However, these reflectors show a slight chromatic change with different viewing angles. TEM sections have revealed that streams of oval-shaped vesicles might be responsible for the production of the polarized light reflection. In all the reflectors we have examined so far, the reflected light is always maximally polarized at around 500 nm, which is close to the wavelength best transmitted by sea water. This suggests that the polarized light reflectors found in stomatopods are well adapted to the underwater environment. We also found that most reflectors produce polarized light with a horizontal e-vector. How these polarized light reflectors are used in stomatopod signaling remains unknown.

Chiou, Tsyr-Huei; Cronin, Thomas W.; Caldwell, Roy L.; Marshall, Justin

2005-08-01

48

Flexibility and constraints in the molt schedule of long-distance migratory shorebirds: causes and consequences.  

PubMed

Molt is a major component of the annual cycle of birds, the timing and extent of which can affect body condition, survival, and future reproductive success through carry-over effects. The way in which molt is fitted into the annual cycle seems to be a somewhat neglected area which is both of interest and of importance. Study of the causes of annual variation in the timing of molt and its potential consequence in long-distance migratory birds was examined using the Curlew Sandpiper, Calidris ferruginea, as a model species. Using the maximum likelihood molt models of Underhill and Zucchini (1988, Ibis 130:358-372), the relationship between annual variability in the start dates of molt at the population level with conditions on the breeding area was explored. Adult males typically started early in years when temperature in June on the Arctic breeding grounds were high compared to cold years while adult females molted later in years of high breeding success and/or warm July temperature and vice versa. When molt started later, the duration was often shorter, indicating that late completion of molt might have fitness consequences, probably jeopardizing survival. Evidence of this was seen in the low body condition of birds in years when molt was completed late. The results indicate that these migratory shorebirds follow a fine-tuned annual life cycle, and disturbances at a certain stage can alter next biological events through carry-over effects. PMID:23919143

Barshep, Yahkat; Minton, Clive D T; Underhill, Les G; Erni, Birgit; Tomkovich, Pavel

2013-07-01

49

Flexibility and constraints in the molt schedule of long-distance migratory shorebirds: causes and consequences  

PubMed Central

Molt is a major component of the annual cycle of birds, the timing and extent of which can affect body condition, survival, and future reproductive success through carry-over effects. The way in which molt is fitted into the annual cycle seems to be a somewhat neglected area which is both of interest and of importance. Study of the causes of annual variation in the timing of molt and its potential consequence in long-distance migratory birds was examined using the Curlew Sandpiper, Calidris ferruginea, as a model species. Using the maximum likelihood molt models of Underhill and Zucchini (1988, Ibis 130:358–372), the relationship between annual variability in the start dates of molt at the population level with conditions on the breeding area was explored. Adult males typically started early in years when temperature in June on the Arctic breeding grounds were high compared to cold years while adult females molted later in years of high breeding success and/or warm July temperature and vice versa. When molt started later, the duration was often shorter, indicating that late completion of molt might have fitness consequences, probably jeopardizing survival. Evidence of this was seen in the low body condition of birds in years when molt was completed late. The results indicate that these migratory shorebirds follow a fine-tuned annual life cycle, and disturbances at a certain stage can alter next biological events through carry-over effects. PMID:23919143

Barshep, Yahkat; Minton, Clive D T; Underhill, Les G; Erni, Birgit; Tomkovich, Pavel

2013-01-01

50

Glycolytic intermediates induce amorphous calcium carbonate formation in crustaceans.  

PubMed

It has been thought that phosphorus in biominerals made of amorphous calcium carbonate (ACC) might be related to ACC formation, but no such phosphorus-containing compounds have ever been identified. Crustaceans use ACC biominerals in exoskeleton and gastroliths so that they will have easy access to calcium carbonate inside the body before and after molting. We have identified phosphoenolpyruvate and 3-phosphoglycerate, intermediates of the glycolytic pathway, in exoskeleton and gastroliths and found them important for stabilizing ACC. PMID:21336282

Sato, Ai; Nagasaka, Seiji; Furihata, Kazuo; Nagata, Shinji; Arai, Isao; Saruwatari, Kazuko; Kogure, Toshihiro; Sakuda, Shohei; Nagasawa, Hiromichi

2011-04-01

51

The Physiology of Induced Molting  

Microsoft Academic Search

The initiation of seasonal feather molting in wild avian species frequently coincides with incubation of eggs and brooding of offspring. A period of natural inappetence or anorexia usually accompanies this molt. This is particularly true of the jungle fowl, the wild ances- tor of the domestic chicken. Brooding of eggs by the jungle fowl is accompanied by spontaneous anorexia, with

W. D. Berry

52

Reference: Biol. Bull., 153: 145-162. (August, 1977) COCKROACH MOLTING. II. THE NATURE OF REGENERATION-  

E-print Network

145 Reference: Biol. Bull., 153: 145-162. (August, 1977) COCKROACH MOLTING. II. THE NATURE of Ephestia (Pohley, 1965) or autotomy of cockroach legs (O'Farrell and Stock, 1953, 1954; Stock and O of the cockroach molting cycle interact with the regenerating limb (Penzlin, 1965). Although progress has been made

Kunkel, Joseph G.

53

Crustaceans of Southern Australia  

NSDL National Science Digital Library

This intriguing resource on the Crustaceans of Southern Australia is provided by Dr. Gary Poore of the Museum of Victoria. Hundreds of images offer a peak into the diverse and colorful underwaters of Australia; images are accompanied by concise text, offering solid introductory information on the biology of marine crustaceans. Users will find this a worthy educational tool to learn more about Australian crustaceans from barnacles to crabs, ghost shrimps to lobsters.

1998-01-01

54

Least squares estimation of avian molt rates  

USGS Publications Warehouse

A straightforward least squares method of estimating the rate at which birds molt feathers is presented, suitable for birds captured more than once during the period of molt. The date of molt onset can also be estimated. The method is applied to male and female mourning doves.

Johnson, D.H.

1989-01-01

55

Molt regulation in green and red color morphs of the crab Carcinus maenas: gene expression of molt-inhibiting hormone signaling components.  

PubMed

In decapod crustaceans, regulation of molting is controlled by the X-organ/sinus gland complex in the eyestalks. The complex secretes molt-inhibiting hormone (MIH), which suppresses production of ecdysteroids by the Y-organ (YO). MIH signaling involves nitric oxide and cGMP in the YO, which expresses nitric oxide synthase (NOS) and NO-sensitive guanylyl cyclase (GC-I). Molting can generally be induced by eyestalk ablation (ESA), which removes the primary source of MIH, or by multiple leg autotomy (MLA). In our work on Carcinus maenas, however, ESA has limited effects on hemolymph ecdysteroid titers and animals remain in intermolt at 7 days post-ESA, suggesting that adults are refractory to molt induction techniques. Consequently, the effects of ESA and MLA on molting and YO gene expression in C. maenas green and red color morphotypes were determined at intermediate (16 and 24 days) and long-term (~90 days) intervals. In intermediate-interval experiments, ESA of intermolt animals caused transient twofold to fourfold increases in hemolymph ecdysteroid titers during the first 2 weeks. In intermolt animals, long-term ESA increased hemolymph ecdysteroid titers fourfold to fivefold by 28 days post treatment, but there was no late premolt peak (>400 pg ?l(-1)) characteristic of late premolt animals and animals did not molt by 90 days post-ESA. There was no effect of ESA or MLA on the expression of Cm-elongation factor 2 (EF2), Cm-NOS, the beta subunit of GC-I (Cm-GC-I?), a membrane receptor GC (Cm-GC-II) and a soluble NO-insensitive GC (Cm-GC-III) in green morphs. Red morphs were affected by prolonged ESA and MLA treatments, as indicated by large decreases in Cm-EF2, Cm-GC-II and Cm-GC-III mRNA levels. ESA accelerated the transition of green morphs to the red phenotype in intermolt animals. ESA delayed molting in premolt green morphs, whereas intact and MLA animals molted by 30 days post treatment. There were significant effects on YO gene expression in intact animals: Cm-GC-I? mRNA increased during premolt and Cm-GC-III mRNA decreased during premolt and increased during postmolt. Cm-MIH transcripts were detected in eyestalk ganglia, the brain and the thoracic ganglion from green intermolt animals, suggesing that MIH in the brain and thoracic ganglion prevents molt induction in green ESA animals. PMID:24198255

Abuhagr, Ali M; Blindert, Jennifer L; Nimitkul, Sukkrit; Zander, Ian A; Labere, Stefan M; Chang, Sharon A; Maclea, Kyle S; Chang, Ernest S; Mykles, Donald L

2014-03-01

56

Salmon louse (Lepeophtheirus salmonis) transcriptomes during post molting maturation and egg production, revealed using EST-sequencing and microarray analysis  

PubMed Central

Background Lepeophtheirus salmonis is an ectoparasitic copepod feeding on skin, mucus and blood from salmonid hosts. Initial analysis of EST sequences from pre adult and adult stages of L. salmonis revealed a large proportion of novel transcripts. In order to link unknown transcripts to biological functions we have combined EST sequencing and microarray analysis to characterize female salmon louse transcriptomes during post molting maturation and egg production. Results EST sequence analysis shows that 43% of the ESTs have no significant hits in GenBank. Sequenced ESTs assembled into 556 contigs and 1614 singletons and whenever homologous genes were identified no clear correlation with homologous genes from any specific animal group was evident. Sequence comparison of 27 L. salmonis proteins with homologous proteins in humans, zebrafish, insects and crustaceans revealed an almost identical sequence identity with all species. Microarray analysis of maturing female adult salmon lice revealed two major transcription patterns; up-regulation during the final molting followed by down regulation and female specific up regulation during post molting growth and egg production. For a third minor group of ESTs transcription decreased during molting from pre-adult II to immature adults. Genes regulated during molting typically gave hits with cuticula proteins whilst transcripts up regulated during post molting growth were female specific, including two vitellogenins. Conclusion The copepod L.salmonis contains high a level of novel genes. Among analyzed L.salmonis proteins, sequence identities with homologous proteins in crustaceans are no higher than to homologous proteins in humans. Three distinct processes, molting, post molting growth and egg production correlate with transcriptional regulation of three groups of transcripts; two including genes related to growth, one including genes related to egg production. The function of the regulated transcripts is discussed in relation to post molting morphological changes in adult female salmon louse. There is clear evidence that transcription of the major yolk proteins is not induced before some of the post molting growth of abdomen and the genital segment has occurred. A hallmark for the observed growth is transcription of many putative cuticula proteins prior to the size increase. PMID:18331648

Eichner, Christiane; Frost, Petter; Dysvik, Bjarte; Jonassen, Inge; Kristiansen, Bjørn; Nilsen, Frank

2008-01-01

57

Organ weight and serum triglyceride responses of older (80 week) commercial laying hens fed an alfalfa meal molt diet.  

PubMed

Since one of the costs in the commercial egg industry is that of replacement pullets, commercial egg layer managers have opted to induce molt older hens in order to extend their productive life for additional egg laying cycles. Conventional molt induction involves the complete removal of feed for several days. However, this management practice can lead to deleterious physiological responses by the hen and subsequent susceptibility to infection by pathogens. Consequently less stressful molting regimens involving the feeding of low energy diets such as alfalfa have been developed. In this study, 80 week old laying hens that were deprived of feed or fed alfalfa meal during a nine day induced molt. Full fed hens were used as the control. On day 8 serum triglycerides were quantified and on day 9 hens were euthanized and the liver, spleen, heart, intestine, pancreas, ovary, and kidney were collected and weighed. Intestinal weight were highest in the non-molted hens, lower in the hens fed alfalfa, and lower still in the hens deprived of feed. Molted hens exhibited reduced weights of liver, heart, ovary, and pancreas compared to the non-molted hens. Serum triglycerides were highest in the non-molted hens, less in feed deprived hens, and the lowest in alfalfa fed hens. These results suggest that a comparable molt could be achieved with feeding alfalfa meal to 80 week hens compared to feed deprivation. PMID:18164195

Landers, K L; Moore, R W; Herrera, P; Landers, D A; Howard, Z R; McReynolds, J L; Bryd, J A; Kubena, L F; Nisbet, D J; Ricke, S C

2008-09-01

58

Chronologically sampled flight feathers permits recognition of individual molt-migrants due to varying protein sources  

PubMed Central

This is a proof of concept paper based on chronological samples of growing feathers from geese thought to be molt-migrants. When molt-migrant birds initiate molt shortly after migrating to a new isoscape, isotope values measured along the length of their feathers should change continuously. To assess long-term changes and daily cycling in ?15N and ?13C values, we serially sampled a growing primary from three presumed molt-migrant geese. Two showed changing ?15N signatures along the length of their growing primary, indicating they were molt-migrants, while the third, presumably a resident, showed no change. We then resampled these feathers at closer intervals for evidence of the predicted diel cycle in the use of exogenous and endogenous protein for feather growth, generated by the diel feeding cycle of these geese. As predicted, a periodicity of ca. 24 h in ?15N values was found along the primary of the two equilibrating geese, but not in the other goose that was probably a resident. Our results demonstrate that chronological sampling along the length of individual primaries holds great potential for identifying individuals that are molt-migrants. PMID:25649835

Fox, Anthony D.; Daniel, Thomas; Kelly, Jeffrey F.

2015-01-01

59

Orchestin, a calcium-binding phosphoprotein, is a matrix component of two successive transitory calcified biomineralizations cyclically elaborated by a terrestrial crustacean.  

PubMed

Orchestia cavimana is a crustacean that cyclically replaces its calcified cuticle during molting cycles in order to grow. Its terrestrial way of life requires storage of calcium during each premolt period, as calcareous concretions, in tubular diverticula of the midgut. During the postmolt period the stored calcium is reabsorbed and is translocated through the storage organ epithelium as calcified small spherules. In a previous study, we sequenced and characterized a remarkable component of the organic matrix of the premolt storage structures, Orchestin, which is a calcium-binding phosphoprotein. In this paper, we analyzed the spatiotemporal expression of the orchestin gene by Northern blotting and in situ hybridization, and its translated product by immunocytochemistry. We found evidence that the gene and the protein are expressed specifically during premolt in the storage organs. More interestingly, we demonstrated that the protein is synthesized also during the postmolt period, as a component of the organic matrix of the calcium resorption spherules. Thus, Orchestin is a matrix component that is synthesized by the same cells to contribute alternately to the elaboration of two different calcifications. These results, in addition to the physical and chemical features of the protein, suggest that Orchestin is probably a key molecule in the calcium carbonate precipitation process leading to the cyclic elaboration of two transitory calcified mineralizations by the crustacean Orchestia. PMID:15099573

Hecker, Arnaud; Quennedey, Brigitte; Testenière, Olivier; Quennedey, André; Graf, François; Luquet, Gilles

2004-06-01

60

Phenol oxidase is a necessary enzyme for the silkworm molting which is regulated by molting hormone.  

PubMed

Insect molting is an important developmental process of metamorphosis, which is initiated by molting hormone. The molting process includes the activation of dermal cells, epidermal cells separation, molting fluid secretion, the formation of new epidermis and old epidermis excoriation etc. Polyphenol oxidases (PPOs), dopa decarboxylase and acetyltransferase are necessary enzymes for this process. Traditionally, the phenol oxidase was considered as an enzyme for epidermal layer's tanning and melanization. This work suggested that polyphenol oxidases are one set of the key enzymes in molting, which closely related with the role of ecdysone in regulation of molting processes. The data showed that the expression peak of phenol oxidase in silkworm is higher during molting stage, and decreases after molting. The significant increase in the ecdysone levels of haemolymph was observed in the artificially fed silkworm larvae with ecdysone hormone. Consistently, the phenol oxidase expression was significantly elevated compared to the control. PPO1 RNAi induced phenol oxidase expression obviously declined in the silkworm larvae, and caused the pupae incomplete pupation. Overall, the results described that the phenol oxidase expression is regulated by the molting hormone, and is a necessary enzyme for the silkworm molting. PMID:23275200

Wang, Mei-xian; Lu, Yan; Cai, Zi-zheng; Liang, Shuang; Niu, Yan-shan; Miao, Yun-gen

2013-05-01

61

Analysis of the inhibitory mechanism of D-allose on MOLT-4F leukemia cell proliferation.  

PubMed

D-Allose, the C-3 epimer of D-glucose, is one of the rare sugars found in nature. In the present study, we have elucidated for the first time that various leukemia cell lines have different susceptibility to anti-proliferative activity of D-allose, and that this difference is related to the difference in induction of thioredoxin interacting protein (TXNIP) expression. We examined 5 leukemia cell lines (MOLT-4F, IM-9, HL-60, BALL-1 and Daudi), and found that MOLT-4F (T-cell lymphoblastic leukemia) had the highest susceptibility to D-allose, and that Daudi (Burkitt's lymphoma) had the lowest. D-Allose significantly slowed the cell cycle progression without causing apoptosis of MOLT-4F cells. Intracellular TXNIP expression was specifically and markedly enhanced in MOLT-4F cells by D-allose treatment, and subsequent increase of p27(kip1), a cell cycle inhibitor, was observed. On the other hand, D-allose did not increase TXNIP and p27(kip1) levels at all in Daudi cells. These results indicate that D-allose suppresses MOLT-4F cell proliferation possibly by the inhibition of cell cycle progression via induction of TXNIP expression. PMID:19393559

Hirata, Yuko; Saito, Madoka; Tsukamoto, Ikuko; Yamaguchi, Fuminori; Sui, Li; Kamitori, Kazuyo; Dong, Youyi; Uehara, Eisuke; Konishi, Ryoji; Janjua, Najma; Tokuda, Masaaki

2009-05-01

62

Biological clocks and rhythms in intertidal crustaceans.  

PubMed

Animals with habitats within the intertidal zone are exposed to environmental cycles that include the ebb and flow of tidal waters, changes in tidal levels associated with the lunar month, the light-dark cycle and the alternation of seasons. This intricate temporal environment results in the selection of biological timing systems with endogenous clocks that can oscillate with this wide range of periodicities. Whereas great progress has been made in our understanding of the molecular and neural bases of circadian rhythms, that is, endogenous rhythms synchronized to the solar day, there is little understanding on how circatidal rhythms, namely endogenous rhythms synchronized to tides, are generated. Intertidal crustaceans have been a pivotal group for the demonstration of the endogenous nature of circatidal rhythms and their mechanisms of entrainment. We review here some of the classic work using intertidal crustaceans to unmask basic properties of circatidal systems, as well as work from our laboratory that aims to identify putative chemical signals that could be involved in the circatidal systems of decapod crustaceans. PMID:20515812

de la Iglesia, Horacio O; Hsu, Yun-Wei A

2010-01-01

63

Relationship between dose of emamectin benzoate and molting response of ovigerous American lobsters (Homarus americanus).  

PubMed

A widely-prescribed treatment to control sea lice on cultured salmon is the administration of feed medicated with SLICE (active ingredient emamectin benzoate (EMB)). High doses of EMB can disrupt the molt cycle of ovigerous American lobsters, causing them to enter proecdysis prematurely and lose their attached eggs when the shell is cast. To determine the dose response to EMB, lobsters were forced to ingest doses that ranged from 0.05 to 0.39 microg g(-1). A significant proportion of lobsters given doses of 0.39 and 0.22 microg g(-1) (37% and 23%, respectively) molted prematurely, almost a year earlier than the control group. All the lobsters in the 0.05 and 0.12 microg g(-1) groups molted at the normal time and the mean time of molt was similar to that of the control group. Thus, the no-observed-effect level (NOEL) and lowest-observed-effect level (LOEL) of EMB on the molt cycle were 0.12 and 0.22 microg EMB g(-1) lobster, respectively. To acquire the LOEL, a 500-g lobster would have to consume 22 g of salmon feed medicated with SLICE at a level of 5 microg EMB g(-1) feed. PMID:16815547

Waddy, S L; Merritt, V A; Hamilton-Gibson, M N; Aiken, D E; Burridge, L E

2007-05-01

64

When the Seasons Don't Fit: Speedy Molt as a Routine Carry-Over Cost of Reproduction  

PubMed Central

The failure of animals to fit all life-cycle stages into an annual cycle could reduce the chances of successful breeding. In some cases, non-optimal strategies will be adopted in order to maintain the life-cycle within the scope of one year. We studied trade-offs made by a High Arctic migrant shorebird, the red knot Calidris canutus islandica, between reproduction and wing feather molt carried out in the non-breeding period in the Dutch Wadden Sea. We compared primary molt duration between birds undertaking the full migratory and breeding schedule with birds that forego breeding because they are young or are maintained in captivity. Molt duration was ca. 71 days in breeding adults, which was achieved by an accelerated feather replacement strategy. Second-year birds and captive adults took ca. 22% and 27% longer, respectively. Second-year birds start molt in late June, more than four weeks before captive adults, and almost seven weeks before adults that return from breeding in late July–August. Adults finish molt in October when steeply increasing thermostatic costs and reductions in food availability occur. Primary molt duration was longer in female than in male knots (all ages), which was accordance with the somewhat larger body size of females. Since fast growth leads to lower quality feathers, the speedy wing molt shown by Arctic-breeding birds may represent a time constraint that is an unavoidable and routine cost of reproduction. So far it was hypothesized that only birds over 1 kg would have difficulty fitting molt within a year. Here we show that in birds an order of magnitude smaller, temporal imperatives may impose the adoption of non-optimal life-cycle routines in the entire actively breeding population. PMID:23349758

Dietz, Maurine W.; Rogers, Ken G.; Piersma, Theunis

2013-01-01

65

When the seasons don't fit: speedy molt as a routine carry-over cost of reproduction.  

PubMed

The failure of animals to fit all life-cycle stages into an annual cycle could reduce the chances of successful breeding. In some cases, non-optimal strategies will be adopted in order to maintain the life-cycle within the scope of one year. We studied trade-offs made by a High Arctic migrant shorebird, the red knot Calidris canutus islandica, between reproduction and wing feather molt carried out in the non-breeding period in the Dutch Wadden Sea. We compared primary molt duration between birds undertaking the full migratory and breeding schedule with birds that forego breeding because they are young or are maintained in captivity. Molt duration was ca. 71 days in breeding adults, which was achieved by an accelerated feather replacement strategy. Second-year birds and captive adults took ca. 22% and 27% longer, respectively. Second-year birds start molt in late June, more than four weeks before captive adults, and almost seven weeks before adults that return from breeding in late July-August. Adults finish molt in October when steeply increasing thermostatic costs and reductions in food availability occur. Primary molt duration was longer in female than in male knots (all ages), which was accordance with the somewhat larger body size of females. Since fast growth leads to lower quality feathers, the speedy wing molt shown by Arctic-breeding birds may represent a time constraint that is an unavoidable and routine cost of reproduction. So far it was hypothesized that only birds over 1 kg would have difficulty fitting molt within a year. Here we show that in birds an order of magnitude smaller, temporal imperatives may impose the adoption of non-optimal life-cycle routines in the entire actively breeding population. PMID:23349758

Dietz, Maurine W; Rogers, Ken G; Piersma, Theunis

2013-01-01

66

Instar growth and molt increments in Lepeophtheirus salmonis (Copepoda: Caligidae) chalimus larvae.  

PubMed

The salmon louse (Lepeophtheirus salmonis) is an ectoparasitic copepod causing severe problems to the fish farming industry and to wild salmonids. Morphologically, all stages in the life cycle of L. salmonis have been described in detail based on successive samples from host populations. However, the rate of development differs between males and females as well as between individuals. It has therefore been difficult to observe development within stages, and this has led to a longstanding misinterpretation of the number of chalimus stages. Here samples of chalimi obtained for 12 consecutive days were observed daily in incubators. Chalimus 1 was able to molt in incubators only when fully grown and close to molting, whereas chalimus 2 was able to molt at about 60% of total instar growth. Total length instar growth was about 35% in both chalimus 1 and chalimus 2 and about equal among males and females; the cephalothorax increased by about 12% and the posterior body by about 80%. Instar growth was probably the main factor that led to the former belief that L. salmonis had four chalimus stages. Relative total length increase at molting was at the same order of magnitude as instar growth, but total length of females increased significantly more than that of males at molting. Consequently, a sexual size dimorphism was established upon molting to chalimus 2 and males were about 10% smaller than females. While growth by molting was mainly caused by cephalothorax increase, instar growth was mainly due to increase of the posterior body. The cephalothorax/total length ratio decreased from beginning to end of the instar phase suggesting that it may be used as an instar age marker. Male and female chalimus 2 can almost uniquely be identified by cephalothorax length. Chalimus 1 lasted between 5 and 6 days for males and between 6 and 7 days for females at 10°C. Chalimus 2 males lasted between 6 and 7 days and females between 7 and 8 days. PMID:25451218

Eichner, Christiane; Hamre, Lars Are; Nilsen, Frank

2015-02-01

67

Digestive proteinases of red shrimp Pleoticus muelleri (Decapoda, Penaeoidea): partial characterization and relationship with molting.  

PubMed

The present study describes the activity and some characteristics of proteinases in the hepatopancreas of red shrimp Pleoticus muelleri during the different stages of the molting cycle. Proteolytic activity was highest between pH 7.5 and 8. The hepatopancreatic protein content in the premolt stage was higher than in the other stages of the molting cycle (P<0.05). No significant differences were found in total proteolytic activity in the hepatopancreas when comparing molting stages. The proteolytic activity of the P. muelleri hepatopancreas enzyme preparations is the main responsibility of serine proteinases. TLCK, a trypsin inhibitor, reduced azocasein hydrolysis between 26% (intermolt) and 37% (premolt). TPCK, a chymotrypsin inhibitor, did not decrease hydrolytic activity, except for in postmolt. Low trypsin and chymotrypsin activities were found during intermolt, and increased in postmolt. The electrophoretogram of the enzyme extracts shows 12 bands of activity during intermolt (from 16.6 to 53.1 kDa). Some fractions were not detected in the postmolt and premolt stages. Three low molecular weight trypsin forms (17.4, 19.1 and 20 kDa) were found in all molting stages. One band of chymotrypsin (21.9 kDa) was observed in all molting stages. High molecular mass active bands (66-205 kDa) could not be characterized with inhibitors. Comparison of the protease-specific activity of the hepatopancreas of some species indicated a relationship between digestive enzyme activity and feeding habits of the shrimp. Omnivorous shrimp, such as Penaeus vannamei (syn: Litopenaeus vannamei) and Penaeus monodon, showed higher protease activity than the carnivorous shrimp, Penaeus californiensis (syn: Farfantepenaeus californiensis) and P. muelleri. In fact, the enzymatic activity in the hepatopancreas of P. muelleri showed variations in relation to feeding habit and molting cycle. PMID:11567895

Fernández Gimenez, A V; García-Carreño, F L; Navarrete del Toro, M A; Fenucci, J L

2001-10-01

68

Lunar-Rhythmic Molting in Laboratory Populations of the Noble Crayfish Astacus astacus (Crustacea, Astacidea): An Experimental Analysis  

PubMed Central

Juvenile noble crayfish, Astacusastacus (Crustacea, Astacidea) in the second year of age were kept in the laboratory for a twelve-month period under continuing “summer conditions” (LD 16:8, 19°C). Molting processes in this population could be synchronized by artificial moonlight cycles. Peaks of exuviations occurred at “new moons”. Males showed a slightly higher degree of synchronization than females. A phase-shift of the artificial lunar cycle in relation to the natural cycle resulted in a corresponding shift of the molting cycle. This clearly demonstrates that changes in the nocturnal light regime provide the primary external information for the lunar-monthly molting rhythm. There is a first indication that lunar photic stimuli do not act directly but as a zeitgeber which entrains an endogenous molting rhythm to the lunar cycle. Moreover, the results of the long-term experiments suggest that the hibernal resting period of A. astacus in the field (no molts between October and April) may also involve some endogenous programming. Continuing artificial summer conditions can delay but not completely suppress this resting period. The adaptive significance of the phenomena and how the findings may be applied to improve the management of crowded crayfish stocks are discussed. PMID:23840899

Franke, Robert; Hoerstgen-Schwark, Gabriele

2013-01-01

69

Lunar-rhythmic molting in laboratory populations of the noble crayfish Astacus astacus (Crustacea, Astacidea): an experimental analysis.  

PubMed

Juvenile noble crayfish, Astacusastacus (Crustacea, Astacidea) in the second year of age were kept in the laboratory for a twelve-month period under continuing "summer conditions" (LD 16:8, 19°C). Molting processes in this population could be synchronized by artificial moonlight cycles. Peaks of exuviations occurred at "new moons". Males showed a slightly higher degree of synchronization than females. A phase-shift of the artificial lunar cycle in relation to the natural cycle resulted in a corresponding shift of the molting cycle. This clearly demonstrates that changes in the nocturnal light regime provide the primary external information for the lunar-monthly molting rhythm. There is a first indication that lunar photic stimuli do not act directly but as a zeitgeber which entrains an endogenous molting rhythm to the lunar cycle. Moreover, the results of the long-term experiments suggest that the hibernal resting period of A. astacus in the field (no molts between October and April) may also involve some endogenous programming. Continuing artificial summer conditions can delay but not completely suppress this resting period. The adaptive significance of the phenomena and how the findings may be applied to improve the management of crowded crayfish stocks are discussed. PMID:23840899

Franke, Robert; Hoerstgen-Schwark, Gabriele

2013-01-01

70

Chemical Communication in Peracarid Crustaceans  

Microsoft Academic Search

\\u000a Chemical communication plays an important role during the life of peracarid crustaceans, where the two main taxa, the amphipods\\u000a and isopods, have representatives in both aquatic and terrestrial habitats. As in other crustaceans, the antennae bear the\\u000a most important chemosensory structures, which are used for food-finding, predator detection and intraspecific interactions.\\u000a The chemical nature of peracarid pheromones is unknown, but

Martin Thiel

71

Ionotropic Crustacean Olfactory Receptors  

PubMed Central

The nature of the olfactory receptor in crustaceans, a major group of arthropods, has remained elusive. We report that spiny lobsters, Panulirus argus, express ionotropic receptors (IRs), the insect chemosensory variants of ionotropic glutamate receptors. Unlike insects IRs, which are expressed in a specific subset of olfactory cells, two lobster IR subunits are expressed in most, if not all, lobster olfactory receptor neurons (ORNs), as confirmed by antibody labeling and in situ hybridization. Ligand-specific ORN responses visualized by calcium imaging are consistent with a restricted expression pattern found for other potential subunits, suggesting that cell-specific expression of uncommon IR subunits determines the ligand sensitivity of individual cells. IRs are the only type of olfactory receptor that we have detected in spiny lobster olfactory tissue, suggesting that they likely mediate olfactory signaling. Given long-standing evidence for G protein-mediated signaling in activation of lobster ORNs, this finding raises the interesting specter that IRs act in concert with second messenger-mediated signaling. PMID:23573266

Corey, Elizabeth A.; Bobkov, Yuriy; Ukhanov, Kirill; Ache, Barry W.

2013-01-01

72

Ionotropic crustacean olfactory receptors.  

PubMed

The nature of the olfactory receptor in crustaceans, a major group of arthropods, has remained elusive. We report that spiny lobsters, Panulirus argus, express ionotropic receptors (IRs), the insect chemosensory variants of ionotropic glutamate receptors. Unlike insects IRs, which are expressed in a specific subset of olfactory cells, two lobster IR subunits are expressed in most, if not all, lobster olfactory receptor neurons (ORNs), as confirmed by antibody labeling and in situ hybridization. Ligand-specific ORN responses visualized by calcium imaging are consistent with a restricted expression pattern found for other potential subunits, suggesting that cell-specific expression of uncommon IR subunits determines the ligand sensitivity of individual cells. IRs are the only type of olfactory receptor that we have detected in spiny lobster olfactory tissue, suggesting that they likely mediate olfactory signaling. Given long-standing evidence for G protein-mediated signaling in activation of lobster ORNs, this finding raises the interesting specter that IRs act in concert with second messenger-mediated signaling. PMID:23573266

Corey, Elizabeth A; Bobkov, Yuriy; Ukhanov, Kirill; Ache, Barry W

2013-01-01

73

Molt patterns and weight changes of the American woodcock  

USGS Publications Warehouse

A study of molt and changes in body weight of American Woodcock was conducted to better understand the summer and fall behavior of these birds and to indicate periods of physiological stress. The postnuptial molt of adults was a complete molt beginning in late June and ending by the middle of October. In contrast, the postjuvenal molt was a less intensive partial molt beginning in mid-July but also extending to the middle of October. Both male and female adult birds experienced weight loss in August during peak molt. Young birds gradually gained weight throughout the summer. Fat deposition was negatively correlated with molt while fall body weights were positively correlated with fat deposition. The data indicated that the majority of Maine woodcock are not physiologically prepared for migration until mid-October. Weights of adult males during the spring suggested that this is an important period of stress for these birds.

Owen, R.B.; Krohn, W.B.

1973-01-01

74

Depression of synaptic efficacy in high- and low-output Drosophila neuromuscular junctions by the molting hormone (20-HE).  

PubMed

The molt-related steroid hormone, 20-hydroxyecdysone (20-HE), was applied to muscles 6 and 7 of third instar larval of Drosophila melanogaster neuromuscular junction preparations to examine if rapid, nongenomic responses could be observed as was shown recently to occur in crustacean neuromuscular junctions. At a dose of 10 microM, the excitatory junction potentials were reduced in amplitude within minutes. To elucidate the site of action of the hormone, focal-macropatch recordings of synaptic currents were obtained over the neuromuscular junctions. The results showed that the high-output (Is) and the low-output (Ib) motor nerve terminals, which innervate muscles 6 and 7, released fewer synaptic vesicles for each stimulation while exposed to 20-HE. Because the size and shape of synaptic currents from spontaneous releases did not change, the effects of the 20-HE are presynaptic. The rapid effects of this hormone may account in part for the quiescent behavior associated with molts among insects and crustaceans. PMID:10036278

Ruffner, M E; Cromarty, S I; Cooper, R L

1999-02-01

75

Expression of cytoskeletal and molt-related genes is temporally scheduled in the hypodermis of the crayfish Procambarus clarkii during premolt.  

PubMed

The rigid crustacean exoskeleton, the cuticle, is composed of the polysaccharide chitin, structural proteins and mineral deposits. It is periodically replaced to enable growth and its construction is an energy-demanding process. Ecdysis, the shedding event of the old cuticle, is preceded by a preparatory phase, termed premolt, in which the present cuticle is partially degraded and a new one is formed underneath it. Procambarus clarkii (Girard 1852), an astacid crustacean, was used here to comprehensively examine the changing patterns of gene expression in the hypodermis underlying the cuticle of the carapace at seven time points along ~14 premolt days. Next generation sequencing was used to construct a multi-tissue P. clarkii transcript sequence assembly for general use in a variety of transcriptomic studies. A reference transcriptome was created here in order to perform digital transcript expression analysis, determining the gene expression profiles in each of the examined premolt stages. The analysis revealed a cascade of sequential expression events of molt-related genes involved in chitin degradation, synthesis and modification, as well as synthesis of collagen and four groups of cuticular structural genes. The new description of major transcriptional events during premolt and the determination of their timing provide temporal markers for future studies of molt progress and regulation. The peaks of the expression of the molt-related genes were preceded by expression peaks of cytoskeletal genes that are hypothesized to be essential for premolt progress through regulating protein synthesis and/or transport, probably by remodeling the cytoskeletal structure. PMID:25278476

Tom, Moshe; Manfrin, Chiara; Chung, Sook J; Sagi, Amir; Gerdol, Marco; De Moro, Gianluca; Pallavicini, Alberto; Giulianini, Piero G

2014-12-01

76

Changes in digestive enzymes through developmental and molt stages in the spiny lobster, Panulirus argus.  

PubMed

Changes in major digestive enzymes through developmental and molt stages were studied for the spiny lobster Panulirus argus. There were significant positive relationships between specific activity of trypsin and amylase enzymes and lobster size, whereas esterase and lipase specific activities decreased as lobsters aged. No relationship was found between amylase/trypsin ratio and lobster size. Positive trends were found, however, for trypsin/lipase and amylase/lipase ratios. Results suggest that changes in enzyme activity respond to the lobsters' physiological needs for particular dietary components although multivariate analysis suggested that enzyme activities could be not totally independent of diet. On the other hand, the pattern of changes of major enzyme activities through molt cycle was similar for most enzymes studied. Following molt, trypsin, chymotrypsin, amylase, and lipase activities gradually increased to maximal levels at late intermolt (C4) and premolt (D). There were no variations in the electrophoretic pattern of digestive enzymes through developmental and molt stages and thus, it is demonstrated that regulation is exerted quantitatively rather than qualitatively. Further studies on the effect of other intrinsic and extrinsic factors on digestive enzyme activities are needed to fully understand digestive abilities and regulation mechanisms in spiny lobsters. PMID:18692150

Perera, Erick; Moyano, F J; Díaz, M; Perdomo-Morales, R; Montero-Alejo, V; Rodriguez-Viera, L; Alonso, E; Carrillo, O; Galich, G S

2008-11-01

77

Flightlessness and the energetic cost of wing molt in a large sea duck.  

PubMed

Although the replacement of feathers apparently represents the major event of somatic production in the annual cycle of wild birds, knowledge about the energetics of molt has always been hampered by logistical and technical difficulties, which are exacerbated by the fact that birds are able to compensate behaviorally to buffer any variation in energy demand. During wing molt, sea ducks (Mergini) and other diving birds lose all of their wing feathers at once, leading to a period of temporary flightlessness of variable duration, a condition that considerably restricts their movements and increases the probability of predation. In the present study, we present the first results aimed at quantifying the duration of flightlessness, energy expenditure, and foraging effort during molt of a wing-propelled diving bird, the Common Eider (Somateria mollissima). Data loggers were implanted in the body cavity of 13 females to record heart rate and hydrostatic pressure (depth) every two seconds for a period of 220 days. Flight frequency and duration were assessed from elevated and constant heart rate, and the absence of flight was used to quantify the duration of flightlessness, which lasted, on average, 36 +/- 8 days (mean +/- SD). Using a period of four weeks before and four weeks after the flightless period, we found that dive depth (ranging from 1 to 2 m, on average) and daily diving time did not vary during the course of the study. Daily metabolic rate increased by 9%, and resting metabolic rate by 12% from the pre-molt period to the flightless period and remained high during the post-molt period. This study indicates that the energetic costs of replacing flight remiges in female eiders are substantial, although this is not associated with any change in foraging effort, which suggests that female Common Eiders lose mass during wing molt. Finally, estimates of energy savings associated with the total absence of flights during wing molt represent 6% of daily metabolic rate or 14% of resting metabolic rate. This finding contrasts with the classical view that little or no benefit is associated with a flightless condition. We suggest that such energy savings may have favored the evolution of temporary flightlessness in diving birds. PMID:18051662

Guillemette, Magella; Pelletier, David; Grandbois, Jean-Marc; Butler, Patrick J

2007-11-01

78

Hemolymph proteins in marine crustaceans  

PubMed Central

This study is done with the aim to bring together the various antimicrobial peptides that are present in the crustacean hemolymph and their sources along with its characteristics. Invertebrates lack immune systems that involve antigen-antibody reactions and do not have an immune memory, therefore most invertebrate species show no evidence of acquired immunity. Crustaceans possess an open circulatory system, where nutrients, oxygen, hormones, and cells are distributed in the hemolymph. They lack adaptive immune system and rely exclusively on their innate immune mechanisms that include both cellular and humoral responses. Antimicrobial peptides and proteins form an important means of host defense in eukaryotes. In addition to their role as endogenous antibiotics, antimicrobial peptides have functions in inflammation, wound repair and regulation of the adaptive immune system. Over the past several years, many antimicrobial peptides have been found and characterized in crabs. PMID:23569958

Fredrick, W Sylvester; Ravichandran, S

2012-01-01

79

Tyrosinases from crustaceans form hexamers.  

PubMed Central

Tyrosinases, which are widely distributed among animals, plants and fungi, are involved in many biologically essential functions, including pigmentation, sclerotization, primary immune response and host defence. In the present study, we present a structural and physicochemical characterization of two new tyrosinases from the crustaceans Palinurus elephas (European spiny lobster) and Astacus leptodactylus (freshwater crayfish). In vivo, the purified crustacean tyrosinases occur as hexamers composed of one subunit type with a molecular mass of approx. 71 kDa. The tyrosinase hexamers appear to be similar to the haemocyanins, based on electron microscopy. Thus a careful purification protocol was developed to discriminate clearly between tyrosinases and the closely related haemocyanins. The physicochemical properties of haemocyanins and tyrosinases are different with respect to electronegativity and hydrophobicity. The hexameric nature of arthropod tyrosinases suggests that these proteins were the ideal predecessors from which to develop the oxygen-carrier protein haemocyanin, with its allosteric and co-operative properties, later on. PMID:12466021

Jaenicke, Elmar; Decker, Heinz

2003-01-01

80

The King of Crustaceans: Lobsters  

NSDL National Science Digital Library

In the north Atlantic, the American Lobster is the undisputed king of crustaceans. It’s also a tremendously important commercial catch. While all the other fisheries are collapsing, why are lobsters resisting the trend? In this video, Jonathan goes out with a Maine lobsterman to learn why, and he dives down below to find the biggest lobsters he has ever seen. This segment won a New England Emmy Award! Please see the accompanying study guide for educational objectives and discussion points.

2012-07-28

81

The frontal eyes of crustaceans.  

PubMed

Frontal eyes of crustaceans (previously called nauplius eye and frontal organs) are usually simple eyes that send their axons to a medial brain centre in the anterior margin of the protocerebrum. Investigations of a large number of recent species within all major groups of the Crustacea have disclosed four kinds of frontal eyes correlated with taxonomic groups and named after them as the malacostracan, ostracod-maxillopodan, anostracan, and phyllopodan frontal eyes. The different kinds of eyes have been established using the homology concept coined by Owen [Owen, R., 1843. Lectures on the comparative anatomy and physiology of the invertebrate animals. Longman, Brown, Green, Longmans, London] and the criteria for homology recommended by Remane [Remane, A., 1956. Die Grundlagen des natürlichen Systems, der vergleichenden Anatomie und der Phylogenetik. 2nd ed. Akademische Verlagsgesellschaft, Geest und Portig, Leipzig]. Common descent is not used as a homology criterion. Frontal eyes bear no resemblance to compound eyes and in the absence of compound eyes, as in the ostracod-maxillopodan group, frontal eyes develop into complicated mirror, lens-mirror, and scanning eyes. Developmental studies demonstrate widely different ways to produce frontal eyes in phyllopods and malacostracans. As a result of the studies of recent frontal eyes in crustaceans, it is concluded by extrapolation that in crustacean ancestors four non-homologous frontal eye types evolved that have remained functional in spite of concurrent compound eyes. PMID:18089076

Elofsson, Rolf

2006-12-01

82

Movements of flightless long-tailed ducks during wing molt  

USGS Publications Warehouse

We examined the movements of flightless Long-tailed Ducks (Clangula hyemalis) during the wing molt in the near-shore lagoons of the Beaufort Sea in Alaska. Estimates of site fidelity during the 21-day flightless period ranged from 1-100%, with considerable variation among locations and within locations among years. There was no effect of low-level experimental disturbance or an underwater seismic survey on site fidelity of molting Long-tailed Ducks. Birds molting along a relatively consistent habitat gradient were more likely to move than those molting in a fragmented habitat. While flocks of birds are consistently observed in the same locations, these data suggest considerable turnover within these aggregations. These results, in conjunction with other studies, suggest that forage is relatively uniformly distributed within lagoons. We conclude that habitat selection by molting Long-tailed Ducks is likely influenced by protection from wind and associated waves.

Flint, P.L.; Lacroix, D.L.; Reed, J.A.; Lanctot, Richard B.

2004-01-01

83

RELATIONSHIP OF DIET, FEED CONSUMPTION, AND ENVIRONMENT OF THE GASTROINTESTINAL TRACT TO SUSCEPTILITY OF LAYING HENS TO SALMONELLA ENTERITIDIS DURING FORCED MOLT  

Technology Transfer Automated Retrieval System (TEKTRAN)

The use of feed deprivation to induce molting and stimulate multiple egg-laying cycles in laying hens is a common practice in commercial egg production. Unfortunately, this method causes an increased risk of Salmonella enteritidis (SE). Methods to stimulate multiple egg-laying cycles without increas...

84

ECCENTRIC FIRST-YEAR MOLT PATrERNS IN CERTAIN TYRANNID FLYCATCHE!.S  

Microsoft Academic Search

Most passerines follow a similar sequence of remex molt, replacement of the primaries commencing with the innermost and proceeding distally, while that of the secondaries (except for the tertials, S7-S9) begins with the outermost and proceeds proximally (Ginn and Melville 1983). During the first- year molts (here defined as all periods of molting before the second prebasic molt), many passerines

PETER PYLE

85

Role of molting on the biodistribution of CeO2 nanoparticles within Daphnia pulex.  

PubMed

As all arthropods, microcrustaceans shed their chitinous exoskeleton (cuticule, peritrophic membrane) to develop and grow. While the molting is the most crucial stage in their life cycle, it remains poorly investigated in term of pollutant biodistribution within the organisms. In this paper, we used optical, electronic, and X ray-based microscopies to study the uptake and release of CeO2 nanoparticles by/from Daphnia pulex over a molting stage. We measured that D. pulex molts every 59 ± 21 h (confidence interval) with growth rates about 1.1 or 1.8 ?m per stage as a function of the pieces measured. Ingestion via food chain was the main route of CeO2 nanoparticles uptake by D. pulex. The presence of algae during the exposure to nanoparticles (sub-lethal doses) enhanced by a factor of 3 the dry weight concentration of Ce on the whole D. pulex. Nanoparticles were localized in the gut content, in direct contact with the peritrophic membrane, and on the cuticle. Interestingly, the depuration (24 h with Chlorella pseudomonas) was not efficient to remove the nanoparticles from the organisms. From 40% to 100% (depending on the feeding regime during exposure) of the CeO2 taken up by D. pulex is not release after the depuration process. However, we demonstrated for the first time that the shedding of the chitinous exoskeleton was the crucial mechanism governing the released of CeO2 nanoparticles regardless of the feeding regime during exposure. PMID:23664411

Auffan, Mélanie; Bertin, Delphine; Chaurand, Perrine; Pailles, Christine; Dominici, Christian; Rose, Jérôme; Bottero, Jean-Yves; Thiery, Alain

2013-08-01

86

Primary feather molt of adult mourning doves in North and South Carolina  

USGS Publications Warehouse

Examination of 8,141 adult mourning doves (Zenaida macroura) in North and South Carolina revealed that substantial numbers complete primary feather molt in September. Adult mourning doves shed primaries at the rate of 1 per 14 days. No difference was found in this rate between sexes or among years, 1969-74. The initiation of molt differed from year to year, and female molt always preceded male molt. Available data show that southern doves complete primary molt a month earlier than northern doves. Therefore, age based on primary molt can be biased upward if all molt-complete wings from southern hunting samples are considered immature.

Haas, G.H.; Amend, S.R.

1979-01-01

87

Molt and taxonomy of red-breasted nuthatches  

USGS Publications Warehouse

The postnuptial and postjuvenal molts of Red-breasted Nuthatches occur from middle June to late September. Some birds may be nearly finished with the complete molt before other individuals begin, so that specimens taken at any given time may differ by as much as two months in the age of their plumage. No characters useful in ageing birds after the completion of the autumn molt were found.....The proposed racial subdivision of Sitta canadensis was based on misleading evidence resulting from variation of plumage age in birds assumed to be seasonally comparable, sooting of birds in industrialized parts of the country, and variation in quality of prepared specimens.

Banks, R.C.

1970-01-01

88

Induction of intrinsic and extrinsic apoptosis pathways in the human leukemic MOLT-4 cell line by terpinen-4-ol.  

PubMed

Terpinen-4-ol is a terpene found in the rhizome of Plai (Zingiber montanum (Koenig) Link ex Dietr.). In this study apoptogenic activity and mechanisms of cell death induced by terpinen-4-ol were investigated in the human leukemic MOLT-4 cell line. Terpinen-4-ol exhibited cytotoxicity in MOLT-4 cells, with characteristic morphological features of apoptosis by Wright's staining. The mode of cell death was confirmed to be apoptosis by flow cytometric analysis after staining with annexin V-FITC and propidium iodide. A sub-G1 peak in DNA histograms of cell cycle assays was observed. Terpinen-4-ol induced-MOLT-4 cell apoptosis mediated through an intrinsic pathway involving the loss of mitochondrial transmembrane potential (MTP) and release of cytochrome c into the cytosol. In addition, terpinen-4-ol also induced apoptosis via an extrinsic pathway by caspase-8 activation resulting in the cleavage of cytosolic Bid. Truncated-Bid (tBid) translocated to mitochondria and activated the mitochondrial pathway in conjunction with down-regulation of Bcl-2 protein expression. Caspase-3 activity also increased. In conclusion, terpinen-4-ol can induce human leukemic MOLT-4 cell apoptosis via both intrinsic and extrinsic pathways. PMID:22994712

Khaw-on, Patompong; Banjerdpongchai, Ratana

2012-01-01

89

California condor plumage and molt as field study aids  

USGS Publications Warehouse

An analysis is made of the reliability of plumage and molt characteristics of the California condor for estimating age and identifying individual birds. Neither character seems sufficiently reliable to use in more than a general way.

Wilbur, S.R.

1975-01-01

90

Neural mechanism of optimal limb coordination in crustacean swimming  

PubMed Central

A fundamental challenge in neuroscience is to understand how biologically salient motor behaviors emerge from properties of the underlying neural circuits. Crayfish, krill, prawns, lobsters, and other long-tailed crustaceans swim by rhythmically moving limbs called swimmerets. Over the entire biological range of animal size and paddling frequency, movements of adjacent swimmerets maintain an approximate quarter-period phase difference with the more posterior limbs leading the cycle. We use a computational fluid dynamics model to show that this frequency-invariant stroke pattern is the most effective and mechanically efficient paddling rhythm across the full range of biologically relevant Reynolds numbers in crustacean swimming. We then show that the organization of the neural circuit underlying swimmeret coordination provides a robust mechanism for generating this stroke pattern. Specifically, the wave-like limb coordination emerges robustly from a combination of the half-center structure of the local central pattern generating circuits (CPGs) that drive the movements of each limb, the asymmetric network topology of the connections between local CPGs, and the phase response properties of the local CPGs, which we measure experimentally. Thus, the crustacean swimmeret system serves as a concrete example in which the architecture of a neural circuit leads to optimal behavior in a robust manner. Furthermore, we consider all possible connection topologies between local CPGs and show that the natural connectivity pattern generates the biomechanically optimal stroke pattern most robustly. Given the high metabolic cost of crustacean swimming, our results suggest that natural selection has pushed the swimmeret neural circuit toward a connection topology that produces optimal behavior. PMID:25201976

Zhang, Calvin; Guy, Robert D.; Mulloney, Brian; Zhang, Qinghai; Lewis, Timothy J.

2014-01-01

91

Neural mechanism of optimal limb coordination in crustacean swimming.  

PubMed

A fundamental challenge in neuroscience is to understand how biologically salient motor behaviors emerge from properties of the underlying neural circuits. Crayfish, krill, prawns, lobsters, and other long-tailed crustaceans swim by rhythmically moving limbs called swimmerets. Over the entire biological range of animal size and paddling frequency, movements of adjacent swimmerets maintain an approximate quarter-period phase difference with the more posterior limbs leading the cycle. We use a computational fluid dynamics model to show that this frequency-invariant stroke pattern is the most effective and mechanically efficient paddling rhythm across the full range of biologically relevant Reynolds numbers in crustacean swimming. We then show that the organization of the neural circuit underlying swimmeret coordination provides a robust mechanism for generating this stroke pattern. Specifically, the wave-like limb coordination emerges robustly from a combination of the half-center structure of the local central pattern generating circuits (CPGs) that drive the movements of each limb, the asymmetric network topology of the connections between local CPGs, and the phase response properties of the local CPGs, which we measure experimentally. Thus, the crustacean swimmeret system serves as a concrete example in which the architecture of a neural circuit leads to optimal behavior in a robust manner. Furthermore, we consider all possible connection topologies between local CPGs and show that the natural connectivity pattern generates the biomechanically optimal stroke pattern most robustly. Given the high metabolic cost of crustacean swimming, our results suggest that natural selection has pushed the swimmeret neural circuit toward a connection topology that produces optimal behavior. PMID:25201976

Zhang, Calvin; Guy, Robert D; Mulloney, Brian; Zhang, Qinghai; Lewis, Timothy J

2014-09-23

92

DNA Damage in Dihydroartemisinin-resistant Molt-4 Cells.  

PubMed

Artemisinin generates carbon-based free radicals when it reacts with iron, and induces molecular damage and apoptosis. Its toxicity is more selective toward cancer cells because cancer cells contain a higher level of intracellular free iron. Dihydroartemisinin (DHA), an analog of artemisinin, has selective cytotoxicity toward Molt-4 human lymphoblastoid cells. A major concern is whether cancer cells could develop resistance to DHA, thus limiting its therapeutic efficacy. We have developed a DHA-resistant Molt-4 cell line (RTN) and found out that these cells exhibited resistance to DHA but no significant cross- resistance to artemisinin-tagged holotransferrin (ART-TF), a synthetic artemisinin compound. In the present study, we investigated DNA damage induced by DHA and ART-TF in both Molt-4 and RTN cells using the comet assay. RTN cells exhibited a significantly lower level of basal and X-ray-induced DNA damage compared to Molt-4 cells. Both DHA and ART-TF induced DNA damage in Molt-4 cells, whereas DNA damage was induced in RTN cells by ART-TF, and not DHA. The result of this study shows that by the cell selection method, it is possible to generate a Molt-4 cell line which is not sensitive to DHA, but sensitive to ART-TF, as measured by DNA damage. PMID:25750283

Park, Jungsoo; Lai, Henry C; Sasaki, Tomikazu; Singh, Narendra P

2015-03-01

93

Changes in Timing, Duration, and Symmetry of Molt of Hawaiian Forest Birds  

PubMed Central

Food limitation greatly affects bird breeding performance, but the effect of nutritive stress on molt has barely been investigated outside of laboratory settings. Here we show changes in molting patterns for an entire native Hawaiian bird community at 1650–1900 m elevation on the Island of Hawaii between 1989–1999 and 2000–2006, associated with severe food limitation throughout the year beginning in 2000. Young birds and adults of all species took longer to complete their molt, including months never or rarely used during the 1989–1999 decade. These included the cold winter months and even the early months of the following breeding season. In addition, more adults of most species initiated their molt one to two months earlier, during the breeding season. Suspended molt, indicated by birds temporarily not molting primary flight feathers during the months of peak primary molt, increased in prevalence. Food limitation reached the point where individuals of all species had asymmetric molt, with different primary flight feathers molted on each wing. These multiple changes in molt, unprecedented in birds, had survival consequences. Adult birds captured during January to March, 2000–2004, had lower survival in four of five species with little effect of extended molt. Extended molt may be adaptive for a nutrient stressed bird to survive warm temperatures but not cool winter temperatures that may obliterate the energy savings. The changing molt of Hawaiian birds has many implications for conservation and for understanding life history aspects of molt of tropical birds. PMID:22279547

Freed, Leonard A.; Cann, Rebecca L.

2012-01-01

94

Identification and developmental expression of mRNAs encoding crustacean cardioactive peptide (CCAP) in decapod crustaceans.  

PubMed

Full-length cDNAs encoding crustacean cardioactive peptide (CCAP) were isolated from several decapod (brachyuran and astacuran) crustaceans: the blue crab Callinectes sapidus, green shore crab Carcinus maenas, European lobster Homarus gamarus and calico crayfish Orconectes immunis. The cDNAs encode open reading frames of 143 (brachyurans) and 139-140 (astacurans) amino acids. Apart from the predicted signal peptides (30-32 amino acids), the conceptually translated precursor codes for a single copy of CCAP and four other peptides that are extremely similar in terms of amino acid sequence within these species, but which clearly show divergence into brachyuran and astacuran groups. Expression patterns of CCAP mRNA and peptide were determined during embryonic development in Carcinus using quantitative RT-PCR and immunohistochemistry with whole-mount confocal microscopy, and showed that significant mRNA expression (at 50% embryonic development) preceded detectable levels of CCAP in the developing central nervous system (CNS; at 70% development). Subsequent CCAP gene expression dramatically increased during the late stages of embryogenesis (80-100%), coincident with developing immunopositive structures. In adult crabs, CCAP gene expression was detected exclusively in the eyestalk, brain and in particular the thoracic ganglia, in accord with the predominance of CCAP-containing cells in this tissue. Measurement of expression patterns of CCAP mRNA in Carcinus and Callinectes thoracic ganglia throughout the moult cycle revealed only modest changes, indicating that previously observed increases in CCAP peptide levels during premoult were not transcriptionally coupled. Severe hypoxic conditions resulted in rapid downregulation of CCAP transcription in the eyestalk, but not the thoracic ganglia in Callinectes, and thermal challenge did not change CCAP mRNA levels. These results offer the first tantalising glimpses of involvement of CCAP in environmental adaptation to extreme, yet biologically relevant stressors, and perhaps suggest that the CCAP-containing neurones in the eyestalk might be involved in adaptation to environmental stressors. PMID:16985202

Chung, J S; Wilcockson, D C; Zmora, N; Zohar, Y; Dircksen, H; Webster, S G

2006-10-01

95

Evaluation of the Bacterial Diversity in Cecal Contents of Laying Hens Fed Various Molting Diets Using Bacterial Tag-Encoded FLX Amplicon Pyrosequencing (bTEFAP)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Laying hens are typically induced to molt in order to begin a new egg-laying cycle by withdrawing feed for up to 12-14 d. Fasted hens are more susceptible to colonization and tissue invasion by Salmonella Enteriditis. Much of this increased incidence in fasted hens is thought to be due to changes ...

96

EFFECTS OF ZINC COMPOUNDS ON THE ENVIRONMENT OF THE GASTROINTESTINAL TRACT AND SUSCEPTIBILITY OF LAYING HENS TO SALMONELLA ENTERITIDIS DURING FORCED MOLT  

Technology Transfer Automated Retrieval System (TEKTRAN)

The method most commonly used to induce molting and stimulate multiple egg-laying cycles in laying hens for commercial egg production is feed deprivation. Unfortunately, an increased risk of Salmonella enteritidis (SE) may result from the use of this method. Methods to stimulate multiple egg-layi...

97

ALTERATIONS IN THE GROWTH, REPRODUCTION AND ENERGY METABOLISM OF ESTUARINE CRUSTACEANS AS INDICATORS OF POLLUTANT STRESS  

EPA Science Inventory

An estuarine mysid (Mysidopsis bahia) has been identified as one of the most sensitive members of the estuarine community to pollutant stress (for a review see Nimmo and Hamaker, 1982). n the majority of life-cycle toxicity tests using this planktonic estuarine crustacean, sublet...

98

Complex Population Responses to Food Resources in the Marine Crustacean Americamysis Bahia  

EPA Science Inventory

Most observations of stressor effects on marine crustaceans are made on individuals or even-aged cohorts. Results of these studies are difficult to translate into ecological predictions, either because life cycle models are incomplete, or because stressor effects on mixed age po...

99

Inverse Demographic Analysis of Compensatory Responses to Resource Limitation in the Mysid Crustacean Americamysis bahia  

EPA Science Inventory

Most observations of stressor effects on marine crustaceans are made on individuals or even-aged cohorts. Results of these studies are difficult to translate into ecological predictions, either because life cycle models are incomplete, or because stressor effects on mixed age po...

100

Neurobiology of the Crustacean Swimmeret System  

PubMed Central

The crustacean swimmeret system includes a distributed set of local circuits that individually control movements of one jointed limb. These modular local circuits occur in pairs in each segmental ganglion, and normally operate synchronously to produce smoothly coordinated cycles of limb movements on different body segments. The system presents exceptional opportunities for computational and experimental investigation of neural mechanisms of coordination because: a. The system will express in vitro the periodic motor pattern that normally drives cycles of swimmeret movements during forward swimming. b. The intersegmental neurons which encode information that is necessary and sufficient for normal coordination have been identified, and their activity can be recorded. c. The local commissural neurons that integrate this coordinating information and tune the phase of each swimmeret are known. d. The complete set of synaptic connections between coordinating neurons and these commissural neurons have been described. e. The synaptic connections onto each local pattern-generating circuit through which coordinating information tunes the circuit's phase have been discovered. These factors make possible for the first time a detailed, comprehensive cellular and synaptic explanation of how this neural circuit produces an effective, behaviorally-significant output. This paper is the first comprehensive review of the system's neuroanatomy and neurophysiology, its local and intersegmental circuitry, its transmitter pharmacology, its neuromodulatory control mechanisms, and its interactions with other motor systems. Each of these topics is covered in detail in an attempt to provide a complete review of the literature as a foundation for new research. The series of hypotheses that have been proposed to account for the system's properties are reviewed critically in the context of experimental tests of their validity. PMID:22270044

Mulloney, Brian; Smarandache-Wellmann, Carmen

2012-01-01

101

Mineral Deposition in Bacteria-Filled and Bacteria-Free Calcium Bodies in the Crustacean Hyloniscus riparius (Isopoda: Oniscidea)  

PubMed Central

Crustacean calcium bodies are epithelial sacs which contain a mineralized matrix. The objectives of this study were to describe the microscopic anatomy of calcium bodies in the terrestrial isopod Hyloniscus riparius and to establish whether they undergo molt-related structural changes. We performed 3D reconstruction of the calcium bodies from paraffin sections and analyzed their structure with light and electron microscopy. In addition, we analyzed the chemical composition of their mineralized matrices with micro-Raman spectroscopy. Two pairs of these organs are present in H. riparius. One pair is filled with bacteria while the other pair is not. In non-molting animals, the bacteria-filled calcium bodies contain apatite crystals and the bacteria-free calcium bodies enclose CaCO3-containing concretions with little organic matrix. During preparation for molt, an additional matrix layer is deposited in both pairs of calcium bodies. In the bacteria-filled calcium bodies it contains a mixture of calcium carbonate and calcium phosphate, whereas only calcium carbonate is present in bacteria-free calcium bodies. After ecdysis, all mineral components in bacteria-free calcium bodies and the additional matrix layer in bacteria-filled calcium bodies are completely resorbed. During calcium resorption, the apical surface of the calcium body epithelium is deeply folded and electron dense granules are present in spaces between epithelial cells. Our results indicate that the presence of bacteria might be linked to calcium phosphate mineralization. Calcium bodies likely provide a source of calcium and potentially phosphate for the mineralization of the new cuticle after molt. Unlike other terrestrial isopods, H. riparius does not form sternal CaCO3 deposits and the bacteria-free calcium bodies might functionally replace them in this species. PMID:23554963

Vittori, Miloš; Rozman, Alenka; Grdadolnik, Jože; Novak, Urban; Štrus, Jasna

2013-01-01

102

Topographical and typological comparison of the rodlike setae of ambulatory dactylopodites in decapod crustaceans  

SciTech Connect

The arrangement and external morphology of the rodlike setae and associated structures located on the dactylopodites of the walking legs of six species of decapod crustaceans are compared. The dactyls of littoral species, represented by the rock crab, Cancer antennarius, and the spiny lobster, Panulirus interruptus, have dense tufts and bands of rodlike setae, as is typical of many decapods, and additionally only a few small plumed setae. The arrangement of setae on the dactyls of the recently discovered Galapagos vent crab. Bythograea thermydron, closely resembles that of C. antennarius. Rodlike and long plumed setae occur in about equal numbers on the dactyls of the pelagic anomuran, Pleuroncodes planipes. The dactyls having the fewest rodlike setae are those of the terrestrial hermit crab, Coenobita perlatus, and those of the kelp crab, Pugettia producta, where flat setae typical of Majidae have replace most rodlike setae. The presence and structures of the terminal pores in rodlike setae vary intra- and interspecifically, possibly as a function of molt stage. Variations in some features of rodlike setae, such as tip acuity and presence of microsetae and surface sculpting, appear to be related to development. Serrated setae occur on the dactyls of megalopal P. producta but not in later stages. The topography and typolgy of setae located on the ambulatory dactyls of decapod crustaceans are considered in light of recent interest in using seta characteristics to determine the sensory functions of sensilla and to clarify the phylogeny of arthropod groups.

Hamilton, K.A.

1983-01-01

103

Hormonal treatment and flight feather molt in immature Sandhill Cranes  

USGS Publications Warehouse

Molt, the production of a new generation of feathers, is a poorly understood physiological phenomenon in nondomestic birds. Often in large birds like geese, flight is restricted by clipping the primary remiges on 1 wing and flight is restored after the molt when the primaries are replaced. A similar technique would be desirable for use with cranes conditioned for release to the native habitat. However, immature sandhill cranes (Grus canadensis) did not appear to replace their primaries annually; therefore, we studied their flight feather molt (from 4 months to 3.5 years of age) and attempted to influence molting. Under natural conditions tail feathers (rectrices) were replaced annually and all secondaries replaced in 2.5-year-old birds. However, replacement of primaries in immature sandhill cranes appears to be a gradual process beginning the 2nd year; about 33% of the original primaries (present at 10 months of age) persisted in the 3.5-year-oId birds. Pulling out the primaries of immature sandhill cranes induces the growth of new primaries, as is true of many other birds. However, the new primaries were incapable of supporting flight, fell out repeatedly, and those that remained were often deformed. Pulling the primaries, under the influence of tranquilizers and anesthetics to relax the feather papillae, also did not induce normal growth of the replacement primaries. Progesterone (including excessively high doses), thyroxine, and follicle stimulating hormone, although effective in inducing feather replacement in domestic poultry, had no effect on crane molt.

Gee, G.F.

1982-01-01

104

DISCRIMINATION OF CONSPECIFIC MALE MOLT ODOR SIGNALS BY MALE CRAYFISH, ORCONECTES RUSTICUS  

E-print Network

molting. A Y-maze experimental design was used to test for differential responses to various molt such as crushed conspecific cues (Hazlett, 1990; Rittschof, 1992; Hazlett, 1994; Pijanowska, 1997). Mate or sex concentrations of hormones, inclu

Moore, Paul A.

105

Calcium-calmodulin dependent protein kinase I from Macrobrachium nipponense: cDNA cloning and involvement in molting.  

PubMed

Calcium-calmodulin dependent protein kinase I is a component of a calmodulin-dependent protein kinase cascade and involved in many physiological processes. The full-length cDNA of calcium-calmodulin dependent protein kinase I (MnCaMKI) was cloned from the freshwater prawn Macrobrachium nipponense and its expression pattern during the molt cycle and after eyestalk ablation is described. The full-length cDNA of MnCaMKI is 3,262 bp in length and has an open reading frame (ORF) of 1,038 bp, encoding a 345 amino acid protein. The expression of MnCaMKI in three examined tissues was upregulated in the premolt stage of the molt cycle. Its expression was induced after eyestalk ablation (ESA): the highest expression level was reached 1 day after ESA in hepatopancreas, and 3 days after ESA in muscle. By dsRNA-mediated RNA interference assay, expression of MnCaMKI and ecydone receptor gene (MnEcR) was significantly decreased in prawns treated by injection of dsMnCaMKI, while expression of these two genes was also significantly decreased in prawns treated by injection of dsMnEcR, demonstrating a close correlation between the expression of these two genes. These results suggest that CaMKI in M. nipponense is involved in molting. PMID:24491503

Shen, Huaishun; Hu, Yacheng; Zhang, Yuanqin; Zhou, Xin; Xu, Zenghong

2014-04-01

106

Molecular cloning and characterization of lipopolysaccharide- and beta-1,3-glucan-binding protein from the giant freshwater prawn Macrobrachium rosenbergii and its transcription in relation to foreign material injection and the molt stage.  

PubMed

Lipopolysaccharide (LPS)- and beta-1,3-glucan-binding protein (LGBP) complementary (c)DNA was cloned from the hepatopancreas of the giant freshwater prawn Macrobrachium rosenbergii using oligonucleotide primers and a reverse-transcription polymerase chain reaction (RT-PCR). Both 3'- and 5'-regions were isolated by the rapid amplification of cDNA ends (RACE) method. Analysis of the nucleotide sequence revealed that the cDNA clone has an open reading frame of 1389 bp encoding a protein of 378 amino acids (aa) including a 15-aa signal peptide. The calculated molecular mass of the mature protein (363 aa) was 41.2 kDa with an estimated pI of 4.73. The M. rosenbergii LGBP sequence contains (1) three putative integrin-binding motifs, (2) a glucanase motif, (3) a putative N-glycosylation site, (4) four protein kinase C phosphorylation sites, (5) four casein kinase II phosphorylation sites, and (6) a putative recognition motif. Sequence comparison showed that the deduced amino acids of LGBP of M. rosenbergii had overall similarities of 60-71% to those of known crustacean LGBPs and beta-1,3-glucan-binding proteins (BGBPs). The LGBP of M. rosenbergii was mainly expressed in the hepatopancreas. The LGBP transcript of M. rosenbergii was downregulated in haemocytes, but was upregulated in the hepatopancreas when injected with LPS and poly:IC after 12 h. The LGBP messenger (m)RNA expression of prawns in the postmolt stage was significantly upregulated in haemocytes, but downregulated in the hepatopancreas, which revealed a complementary relationship between haemocytes and the hepatopancreas in the molt cycle. PMID:19766194

Yeh, Maw-Sheng; Chang, Chin-Chyuan; Cheng, Winton

2009-12-01

107

Rheb, an activator of target of rapamycin, in the blackback land crab, Gecarcinus lateralis: cloning and effects of molting and unweighting on expression in skeletal muscle.  

PubMed

Molt-induced claw muscle atrophy in decapod crustaceans facilitates exuviation and is coordinated by ecdysteroid hormones. There is a 4-fold reduction in mass accompanied by remodeling of the contractile apparatus, which is associated with an 11-fold increase in myofibrillar protein synthesis by the end of the premolt period. Loss of a walking limb or claw causes a loss of mass in the associated thoracic musculature; this unweighting atrophy occurs in intermolt and is ecdysteroid independent. Myostatin (Mstn) is a negative regulator of muscle growth in mammals; it suppresses protein synthesis, in part, by inhibiting the insulin/metazoan target of rapamycin (mTOR) signaling pathway. Signaling via mTOR activates translation by phosphorylating ribosomal S6 kinase (s6k) and 4E-binding protein 1. Rheb (Ras homolog enriched in brain), a GTP-binding protein, is a key activator of mTOR and is inhibited by Rheb-GTPase-activating protein (GAP). Akt protein kinase inactivates Rheb-GAP, thus slowing Rheb-GTPase activity and maintaining mTOR in the active state. We hypothesized that the large increase in global protein synthesis in claw muscle was due to regulation of mTOR activity by ecdysteroids, caused either directly or indirectly via Mstn. In the blackback land crab, Gecarcinus lateralis, a Mstn-like gene (Gl-Mstn) is downregulated as much as 17-fold in claw muscle during premolt and upregulated 3-fold in unweighted thoracic muscle during intermolt. Gl-Mstn expression in claw muscle is negatively correlated with hemolymph ecdysteroid level. Full-length cDNAs encoding Rheb orthologs from three crustacean species (G. lateralis, Carcinus maenas and Homarus americanus), as well as partial cDNAs encoding Akt (Gl-Akt), mTOR (Gl-mTOR) and s6k (Gl-s6k) from G. lateralis, were cloned. The effects of molting on insulin/mTOR signaling components were quantified in claw closer, weighted thoracic and unweighted thoracic muscles using quantitative polymerase chain reaction. Gl-Rheb mRNA levels increased 3.4-fold and 3.9-fold during premolt in claw muscles from animals induced to molt by eyestalk ablation (ESA) and multiple leg autotomy (MLA), respectively, and mRNA levels were positively correlated with hemolymph ecdysteroids. There was little or no effect of molting on Gl-Rheb expression in weighted thoracic muscle and no correlation of Gl-Rheb mRNA with ecdysteroid titer. There were significant changes in Gl-Akt, Gl-mTOR and Gl-s6k expression with molt stage. These changes were transient and were not correlated with hemolymph ecdysteroids. The two muscles differed in terms of the relationship between Gl-Rheb and Gl-Mstn expression. In thoracic muscle, Gl-Rheb mRNA was positively correlated with Gl-Mstn mRNA in both ESA and MLA animals. By contrast, Gl-Rheb mRNA in claw muscle was negatively correlated with Gl-Mstn mRNA in ESA animals, and no correlation was observed in MLA animals. Unweighting increased Gl-Rheb expression in thoracic muscle at all molt stages; the greatest difference (2.2-fold) was observed in intermolt animals. There was also a 1.3-fold increase in Gl-s6k mRNA level in unweighted thoracic muscle. These data indicate that the mTOR pathway is upregulated in atrophic muscles. Gl-Rheb, in particular, appears to play a role in the molt-induced increase in protein synthesis in the claw muscle. PMID:22279066

MacLea, Kyle S; Abuhagr, Ali M; Pitts, Natalie L; Covi, Joseph A; Bader, Brandon D; Chang, Ernest S; Mykles, Donald L

2012-02-15

108

Food Color Preferences of Molting House Finches (Carpodacus mexicanus) in Relation to Sex and Plumage Coloration  

E-print Network

Food Color Preferences of Molting House Finches (Carpodacus mexicanus) in Relation to Sex with drabber coloration. Here, we examine food color preferences in house finches (Carpodacus mexicanus coloration during molt. We captured wild, molting juvenile house finches over 4 wk in late summer/ early fall

McGraw, Kevin J.

109

SEX PHEROMONE ACTIVITY OF THE MOLTING HORMONE, CRUSTECDYSONE, ON MALE CRABS  

E-print Network

SEX PHEROMONE ACTIVITY OF THE MOLTING HORMONE, CRUSTECDYSONE, ON MALE CRABS (Pa~hygrapsus ~rassipes' ABSTRACT The pheromone released by premolt female Pachygrapsu8 cras.~ipes is a heat stable non-ionic polar lipid. The coincidence of the release of the pheromone and the nubial molt suggested that the molting

110

THE TIMING OF WING MOLT IN TUNDRA SWANS: ENERGETIC AND NON-ENERGETIC CONSTRAINTS  

Microsoft Academic Search

Date of wing molt initiation, based on the regression of tenth primary length on capture date, was calculated for breeding and nonbreeding Tundra Swans (Cygnus colum- bianus columbiunus) on the Colville River Delta, Alaska. Breeding females initiated wing molt significantly later than breeding males and nonbreeding males and females; the molt of breeding females was correlated with the date on

SUSAN L. EARNST

111

VITELLOGENISIS AND IT'S ENDOCRINE CONTROL IN DECAPOD CRUSTACEANS  

EPA Science Inventory

Vitellogenesis, the production of vitellin (major yolk protein), is controlled in decapod crustaceans by several hormones. With increasing efforts world-wide to successfully culture economically important crustaceans, such as shrimp, there is growing interest in attaining a bette...

112

Primary feather molt of juvenile mourning doves in Texas  

E-print Network

. Silvy During 1981 and 1982, known-age nestling mourning doves (Zenaida macroura) were banded on the Texas AM University Campus. Information on post-juvenal primary molt was obtained from recapture of 60 of these nestlings. Wide range in the age...

Morrow, Michael Eugene

1983-01-01

113

MORPHOLOGICAL AND PHYSIOLOGICAL RESPONSES TO INDUCED MOLTING IN LAYING HENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Induced molting in laying hens by feed withdrawal (FW) is a common practice in the U.S., which has led to public concern regarding their well-being, and there is a pressing need to evaluate physiological changes resulting from prolonged feed withdrawal (FW). A total of 168 hens from Hy-line W-92 li...

114

Behavior of laying hens on alfalfa crumble molt diets  

Technology Transfer Automated Retrieval System (TEKTRAN)

Induced molting by feed withdrawal has been a common practice in the commercial layer industry and usually involves the removal of feed for a period of up to 14 days. However, this is a practice that is believed to adversely influence the welfare of the hens and there is a need to examine behavoria...

115

Bacteria-Induced Dscam Isoforms of the Crustacean, Pacifastacus leniusculus  

E-print Network

Bacteria-Induced Dscam Isoforms of the Crustacean, Pacifastacus leniusculus Apiruck Watthanasurorot amino acid sequence of Dscam in the crustacean Pacifastacus leniusculus (PlDscam), encodes 9(Ig)-4(FNIII (2011) Bacteria-Induced Dscam Isoforms of the Crustacean, Pacifastacus leniusculus. PLoS Pathog 7(6): e

Uppsala Universitet

116

The effects of polychlorinated biphenyls (Aroclor 1242) on thyroxine, estradiol, molt, and plumage characteristics in the American kestrel (Falco sparverius).  

PubMed

The purpose of this experiment was to determine the effects of Aroclor 1242, a mixture of polychlorinated biphenyls (PCBs), on plumage characteristics and molt in the American kestrel, Falco sparverius. Several characteristics of plumage, including color and molt schedule, are modulated by hormonal signals and hence may be modified by endocrine-active contaminants. If so, the functions of plumage (e.g., communication for mating or territorial defense) may be compromised by exposure to such compounds. Captive American kestrels were fed Aroclor 1242 at 0, 6.0, and 60.0 ppm (n = 6 males and 6 females per treatment) mixed in their normal diet. Concentrations of plasma estradiol and thyroxine were measured weekly from the beginning of treatment. Measured plumage characteristics included width of the black subterminal band on the tail, color (a composite index of hue and saturation), reflectance from 230 to 800 nm. pattern of feather loss and regrowth on the tail and wing, and timing of onset and duration of molt. Aroclor 1242 depressed plasma thyroxine. Plasma estradiol levels remained low due to the phase of the breeding cycle. Treatments did not disrupt the measured plumage characteristics. This may be due to timing or dose of exposure or to genetic factors. PMID:12109742

Quinn, Michael J; French, John B; McNabb, F M Anne; Ottinger, Mary Ann

2002-07-01

117

The effects of polychlorinated biphenyls (Aroclor 1242) on thyroxine, estradiol, molt, and plumage characteristics in the American kestrel (Falco sparverius)  

USGS Publications Warehouse

The purpose of this experiment was to determine the effects of Aroclor 1242, a mixture of polychlorinated biphenyls (PCBs), on plumage characteristics and molt in the American kestrel, Falco sparverills. Several characteristics of plumage. including color and molt schedule, are modulated by hormonal signals and hence may be modified by endocrine-active contaminants. If so, the functions of plumage (e.g. communication for mating or territorial defense) may be compromised by exposure to such compounds. Captive American kestrels were fed Aroclor 1242 at 0. 6.0. and 60.0 ppm (n = 6 males and 6 females per treatment) mixed in their normal diet. Concentrations of plasma estradiol and thyroxine were measured weekly from the beginning of treatment. Measured plumage characteristics included width of the black subterminal band on the tail, color (a composite index of hue and saturation), reflectance from 230 to 800 min. pattern of feather loss and regrowth on the tail and wing. and timing of onset and duration of molt. Aroclor 1242 depressed plasma thyroxine. Plasma estradiol levels remained low due to the phase of the breeding cycle. Treatments did not disrupt the measured plumage characteristics. This may be due to timing or dose of exposure or to genetic factors.

Quinn, M.J.; French, J.B.; McNabb, F.M.A.; Ottinger, M.A.

2002-01-01

118

Conserved behavioral and genetic mechanisms in the pre-hatching molt of the nematode Pristionchus pacificus  

PubMed Central

Background During development, juvenile nematodes undergo four molts. Although the number of molts appears to be constant within the Nematoda, the timing of the first molt can occur either before or after hatching. A previous study indicates that, as in some parasitic nematode lineages, a pre-hatching juvenile stage also exists in Diplogastrid nematodes. A detailed description of these sequence of events has yet to be shown for any single species. Findings To delineate the timing of the pre-hatching molt in the beetle-associated Pristionchus pacificus, we tracked individual mid-J1 stage worms inside the eggshell through the J1-J2 transition and hatching. We found that active movement ended 21 hours after egg-laying, followed by lethargus and hatching. We inferred that lethargus behavior represents the onset of the first molt, which precedes each post-hatching molt in C. elegans and P. pacificus. The onset of the J1-J2 molt was also marked by the upregulation of the P. pacificus molting marker Ppa-pnhr-1. We further corroborated the pre-hatching molt with the isolation of two genetic mutants that exhibited aberrant molting both inside the egg and after hatching, as characterized by protracted and often-aborted shedding of the old cuticle. Conclusion Our results describe in detail the pre-hatching juvenile molt in P. pacificus, provide strong visual evidence of a pre-hatching molt, and show support for common genetic mechanisms regulating molting in the pre-hatching and post-hatching developmental stages. Our findings support the hypothesis that the evolution of pre-hatching development in Diplogastrid nematodes is likely due to a heterochronic shift between the timing of the first molt and hatching. PMID:25276336

2014-01-01

119

Identification and developmental expression of mRNAs encoding crustacean cardioactive peptide (CCAP) in decapod crustaceans  

Microsoft Academic Search

Full-length cDNAs encoding crustacean cardioactive peptide (CCAP) were isolated from several decapod (brachyuran and astacuran) crustaceans: the blue crab Callinectes sapidus, green shore crab Carcinus maenas, European lobster Homarus gamarus and calico crayfish Orconectes immunis. The cDNAs encode open reading frames of 143 (brachyurans) and 139-140 (astacurans) amino acids. Apart from the predicted signal peptides (30-32 amino acids), the conceptually

J. S. Chung; D. C. Wilcockson; N. Zmora; Y. Zohar; H. Dircksen; S. G. Webster

2006-01-01

120

Identifiable Cells in the Crustacean Stomatogastric Ganglion  

NSDL National Science Digital Library

Neural circuits rely on slight physiological differences between the component cells for proper function. When any circuit is analyzed, it is important to characterize the features that distinguish one cell type from another. This review describes the methods used to identify the neurons of the crustacean stomatogastric ganglion.

Amber E Hudson (Georgia Institute of Technology)

2010-10-01

121

EFFECT OF DIFLUBENZURON ON AN ESTUARINE CRUSTACEAN  

EPA Science Inventory

Data are reported for tests exposing a small, estuarine crustacean, Mysidopsis bahia, to diflubenzuron (Dimilin, TH-6040, (1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea)) in flowing seawater. Tests were conducted in intermittent flows from a diluter or continuous flowing water i...

122

Crustacean biodiversity as an important factor for mosquito larval control.  

PubMed

Newly established ponds, which are highly dynamic systems with changing levels of biological interactions among species, are common larval mosquito habitats. We investigated the impact of crustacean abundance and taxa diversity on mosquito oviposition and larval development. The effects of the biological larvicide Bacillus thuringiensis israelensis (Bti) on mosquito larvae were monitored according to fluctuations in crustacean communities. Populations of the mosquito Culex pipiens colonized artificial ponds that contained crustacean communities at different time points of colonization by crustaceans: 1) 'no colonization' (no crustaceans), 2) 'simultaneous colonization' by crustaceans and mosquitoes, and 3) 'head-start colonization' by crustaceans (preceding colonization by mosquitoes). All types of ponds were treated with three concentrations of Bti (10, 100, or 1,000 µg/liter). Colonization of all ponds by Cx. pipiens (in terms of oviposition, larval abundance, and larval development) decreased significantly with increasing diversity of crustacean taxa. The total abundance of crustaceans had a minor effect on colonization by Cx. pipiens. The presence of crustaceans increased the sensitivity of Cx. pipiens larvae to Bti treatment by a factor of 10 and delayed the time of recolonization. This effect of Bti was relevant in the short term. In the long term, the presence of Cx. pipiens was determined by crustacean biodiversity. PMID:24581370

Kroeger, Iris; Duquesne, Sabine; Liess, Matthias

2013-12-01

123

Gene Silencing in Crustaceans: From Basic Research to Biotechnologies  

PubMed Central

Gene silencing through RNA interference (RNAi) is gaining momentum for crustaceans, both in basic research and for commercial development. RNAi has proven instrumental in a growing number of crustacean species, revealing the functionality of novel crustacean genes essential among others to development, growth, metabolism and reproduction. Extensive studies have also been done on silencing of viral transcripts in crustaceans, contributing to the understanding of the defense mechanisms of crustaceans and strategies employed by viruses to overcome these. The first practical use of gene silencing in aquaculture industry has been recently achieved, through manipulation of a crustacean insulin-like androgenic gland hormone. This review summarizes the advancements in the use of RNAi in crustaceans, and assesses the advantages of this method, as well as the current hurdles that hinder its large-scale practice. PMID:24705266

Sagi, Amir; Manor, Rivka; Ventura, Tomer

2013-01-01

124

Cuticular Biominerals of the Terrestrial Crustacean Oniscus asellus (Isopoda, Linnaeus 1758)  

NASA Astrophysics Data System (ADS)

Biomineralization is a phenomenon observed in many eukaryotic organisms and evidence suggests this process began relatively early in the evolution of multicellular life (Marin F et al. 1996). Crustaceans form a large fraction of all eukaryotic biomineralizers by incorporating calcium carbonate (CaCO3) into their cuticle. Terrestrial species are challenged in their production of CaCO3 by the absence of calcium-rich waters. To cope with this limitation, the terrestrial crustacean Oniscus asellus recycles up to 80% (Auzou G 1953) of its total calcium during the molting process. This feat is accomplished by separate molting of the front and back cuticle, with temporary storage of the calcium carbonate as amorphous calcium carbonate (ACC) in the front half (Ziegler A 1997). These processes infer a highly efficient and regulated mechanism for biomineralization that is most likely orchestrated by a myriad of proteins (Ziegler A et al. 2012). Until recently, investigations of biomineralization were largely directed toward understanding morphology and large-scale chemistry of the minerals, ignoring the mechanistic roles of biomacromolecules in mineralization processes. More recent work suggests a high involvement of these compounds on the formation of biominerals and, in some cases, the specific polymorphs thereof (Keene EC et al. 2010). This study focuses on identifying the components of the biological mineralization matrix at each stage of the process. Using chemical demineralization of the stored ACC, all biomacromolecules can be separated and purified for subsequent analysis by MALDI-TOF mass spectrometry. To link the localized biochemistry more intimately to the polymorph of calcium carbonate that forms in the animal, the inorganic phase (';the mineral') will be monitored at each life stage using XRD and TEM. This analysis will reveal the organic components of a very precise biomineralization mechanism and may shed insight on its evolutionary origin. References: Marin F, Westbroek P et al., 1996, Proc Nat Acad Sci 93:1554-1559 Auzou G, 1953, L Ann Sci Nat 15:71-98 Ziegler A, 1997, Zoomorphology 117:181-187 Ziegler A et al., 2012, Cryst Growth Des 12:646-655 Keene EC et al., 2010, Cryst Growth Des 10:1383-1389

Mergelsberg, S. T.; Mukhopadhyay, B.; Dove, P. M.

2013-12-01

125

Expression and functions of dopa decarboxylase in the silkworm, Bombyx mori was regulated by molting hormone.  

PubMed

Insect molting is an important developmental process of metamorphosis, which is initiated by molting hormone. Molting includes the activation of dermal cells, epidermal cells separation, molting fluid secretion, the formation of new epidermis and old epidermis shed and other series of continuous processes. Polyphenol oxidases, dopa decarboxylase and acetyltransferase are necessary enzymes for this process. Traditionally, the dopa decarboxylase (BmDdc) was considered as an enzyme for epidermal layer's tanning and melanization. This work suggested that dopa decarboxylase is one set of the key enzymes in molting, which closely related with the regulation of ecdysone at the time of biological molting processes. The data showed that the expression peak of dopa decarboxylase in silkworm is higher during molting stage, and decreases after molting. The significant increase in the ecdysone levels of haemolymph was also observed in the artificially fed silkworm larvae with ecdysone hormone. Consistently, the dopa decarboxylase expression was significantly elevated compared to the control. BmDdc RNAi induced dopa decarboxylase expression obviously declined in the silkworm larvae, and caused the pupae appeared no pupation or incomplete pupation. BmDdc was mainly expressed and stored in the peripheral plasma area near the nucleus in BmN cells. In larval, BmDdc was mainly located in the brain and epidermis, which is consisted with its function in sclerotization and melanization. Overall, the results described that the dopa decarboxylase expression is regulated by the molting hormone, and is a necessary enzyme for the silkworm molting. PMID:23640098

Wang, Mei-xian; Cai, Zi-zheng; Lu, Yan; Xin, Hu-Hu; Chen, Rui-ting; Liang, Shuang; Singh, Chabungbam Orville; Kim, Jong-Nam; Niu, Yan-shan; Miao, Yun-gen

2013-06-01

126

Temporal and spatial shifts in habitat use by Black Brant immediately following flightless molt  

USGS Publications Warehouse

Each year thousands of Pacific Black Brant (Branta bernicla nigricans) undergo flightless wing molt in the Teshekpuk Lake Special Area (TLSA), Alaska, in two distinct habitats: inland, freshwater lakes and coastal, brackish wetlands. Brant lose body mass during wing molt and likely must add reserves upon regaining flight to help fuel their 2,500 km migration to autumn staging areas. We characterized movements and habitat use by Brant during post-molt (the period immediately following the recovery of flight) by (1) marking individual Brant with GPS (global positioning system) transmitters, and (2) conducting a series of replicate aerial surveys. Individuals molting in inland habitats promptly abandoned their molt wetland during the post-molt and moved into coastal habitats. Consequently, inland habitats were nearly deserted by early August when Brant had regained flight, a decrease of >5,000 individuals from the flightless period of early July. Conversely, coastal molting Brant largely remained in coastal habitats during the post-molt and many coastal wetlands were occupied by large flocks (>1,000 birds). Our results indicate that inland, freshwater wetlands were less suitable post-molt habitats for Brant, while coastal wetlands were preferred as they transitioned from flightless molt. The immediacy with which Brant vacated inland habitats upon regaining flight suggests that food may be limiting during molt and they are not selecting inland molt sites strictly for food resources, but rather a balance of factors including predator avoidance and acquisition of protein for feather growth. Our data clearly demonstrate that patterns of habitat use by Brant in the TLSA change over the course of the molt season, an important consideration for management of future resource development activities in this area.

Lewis, Tyler L.; Flint, Paul L.; Schmutz, Joel A.; Derksen, Dirk V.

2010-01-01

127

Survival and movements of molting male black ducks in Labrador  

USGS Publications Warehouse

We marked 26 flightless male American black ducks with transmitters during the post-nuptial molt in northern Labrabor to determine survival and movements. Twelve ducks remained in the watershed where marked and 11 ducks moved to different watersheds. The period survival rate (PSR) for these flightless males was 0.89 using the Kaplan-Meier estimator. Only 2 ducks were killed by predators. Death of these 2 ducks might have been influenced by our disturbance, thus we considered the PSR minimal.

Bowman, T.D.; Longcore, J.R.

1989-01-01

128

Induced metamorphosis in crustacean y-larvae: Towards a solution to a 100-year-old riddle  

PubMed Central

Background The y-larva, a crustacean larval type first identified more than 100 years ago, has been found in marine plankton samples collected in the arctic, temperate and tropical regions of all oceans. The great species diversity found among y-larvae (we have identified more than 40 species at our study site alone) indicates that the adult organism may play a significant ecological role. However, despite intense efforts, the adult y-organism has never been identified, and nothing is therefore known about its biology. Results We have successfully and repeatedly induced metamorphosis of y-larvae into a novel, highly reduced juvenile stage by applying the crustacean molting hormone 20-HE. The new stage is slug-like, unsegmented and lacks both limbs and almost all other traits normally characterizing arthropods, but it is capable of vigorous peristaltic motions. Conclusion From our observations on live and preserved material we conclude that adult Facetotecta are endoparasitic in still to be identified marine hosts and with a juvenile stage that represents a remarkable convergence to that seen in parasitic barnacles (Crustacea Cirripedia Rhizocephala). From the distribution and abundance of facetotectan y-larvae in the world's oceans we furthermore suggest that these parasites are widespread and could play an important role in the marine environment. PMID:18492233

Glenner, Henrik; Høeg, Jens T; Grygier, Mark J; Fujita, Yoshihisa

2008-01-01

129

Toxicity of cadmium to six species in two genera of crayfish and the effect of cadmium on molting success.  

PubMed

Nine acute (96-h) toxicity tests were conducted on six species of crayfish (Cambaridae). Six tests focused on adults, and three tests examined juveniles. Lethal concentration to 50% of a population (LC50) and lethal concentration to 10% of a population (LC10) values, respectively, for the adults of individual test species were as follows: Orconectes juvenilis, 2.44 and 0.623 mg Cd/L; Orconectes placidus, 0.487 and 0.092 mg Cd/L; Orconectes virilis, 3.30 and 0.947 mg Cd/L; Procambarus acutus, 0.368 and 0.048 mg Cd/L; Procambarus alleni, 3.07 and 0.386 mg Cd/L; and Procambarus clarkii, 2.66 and 0.486 mg Cd/L. The Orconectes LC50 genus mean acute value (GMAV) was 1.57 mg Cd/L, whereas the LC50 GMAV for Procambarus was 1.44 mg Cd/L. The LC10 GMAVs were 0.379 and 0.208 mg Cd/L, respectively. Family mean acute values (FMAVs) also were calculated for the Cambaridae using all species data (LC50, 1.51 mg Cd/L; LC10, 0.281 mg Cd/L). For tests with juvenile crayfish, the LC50 and LC10 values, respectively, were as follows: O. juvenilis, 0.060 and 0.014 mg Cd/L; O. placidus, 0.037 and 0.002 mg Cd/L; and P. clarkii, 0.624 and 0.283 mg Cd/L. The GMAVs were calculated for juvenile Orconectes (LC50, 0.047 mg Cd/L; LC10, 0.005 mg Cd/L). Additionally, FMAVs were calculated for juvenile crayfish (LC50, 0.111 mg Cd/L; LC10, 0.020 mg Cd/L). Crayfish sensitivity to Cd varied by a factor of nine among species tested as adults and by a factor of 17 among species tested as juveniles. Molting was a sensitive life stage for crayfish. Most individuals that molted shortly before or during exposure to Cd died, whereas all controls that molted in the adult assays survived. Because molting is a sensitive, recurring life-cycle event, molting individuals should be included in toxicological analysis despite some contrary recommendations. PMID:17373521

Wigginton, Andrew J; Birge, Wesley J

2007-03-01

130

Progress of primary feather molt of adult mourning doves in Missouri  

USGS Publications Warehouse

The examination of 7,892 adult doves in Missouri between 1953 and 1965 showed that less than 2.5% of adult doves completed their molt before October 1. Adult doves of both sexes began molting their primary feathers during early June in Missouri and lost the last (tenth) primary during the latter half of October. Approximately 140-150 days were required to complete the molt. Thus, early-hatched immatures, which begin their primary molt 25-30 days after hatching, contributed the bulk of the wings with completed molts in September. By correctly classifying September samples of dove wings with a completed molt as young-of-the-year a more accurate young:adult ratio is obtained.

Sadler, K.C.; Tomlinson, R.E.; Wight, H.M.

1970-01-01

131

Crustacean hematopoiesis and the astakine cytokines.  

PubMed

Major contributions to research in hematopoiesis in invertebrate animals have come from studies in the fruit fly, Drosophila melanogaster, and the freshwater crayfish, Pacifastacus leniusculus. These animals lack oxygen-carrying erythrocytes and blood cells of the lymphoid lineage, which participate in adaptive immune defense, thus making them suitable model animals to study the regulation of blood cells of the innate immune system. This review presents an overview of crustacean blood cell formation, the role of these cells in innate immunity, and how their synthesis is regulated by the astakine cytokines. Astakines are among the first invertebrate cytokines shown to be involved in hematopoiesis, and they can stimulate the proliferation, differentiation, and survival of hematopoietic tissue cells. The astakines and their vertebrate homologues, prokineticins, share similar functions in hematopoiesis; thus, studies of astakine-induced hematopoiesis in crustaceans may not only advance our understanding of the regulation of invertebrate hematopoiesis but may also provide new evolutionary perspectives about this process. PMID:21444913

Lin, Xionghui; Söderhäll, Irene

2011-06-16

132

Ancient androdioecy in the freshwater crustacean Eulimnadia  

PubMed Central

Among the variety of reproductive mechanisms exhibited by living systems, one permutation—androdioecy (mixtures of males and hermaphrodites)—is distinguished by its rarity. Models of mating system evolution predict that androdioecy should be a brief stage between hermaphroditism and dioecy (separate males and females), or vice versa. Herein we report evidence of widespread and ancient androdioecy in crustaceans in the genus Eulimnadia, based on observations of over 33?000 shrimp from 36 locations from every continent except Antarctica. Using phylogenetic, biogeographical and palaeontological evidence, we infer that androdioecy in Eulimnadia has persisted for 24–180 million years and has been maintained through multiple speciation events. These results suggest that androdioecy is a highly successful aspect of the life history of these freshwater crustaceans, and has persisted for orders of magnitude longer than predicted by current models of this rare breeding system. PMID:16608693

Weeks, Stephen C; Sanderson, Thomas F; Reed, Sadie K; Zofkova, Magdalena; Knott, Brenton; Balaraman, Usha; Pereira, Guido; Senyo, Diana M; Hoeh, Walter R

2005-01-01

133

Hormonal correlates and thermoregulatory consequences of molting on metabolic rate in a northerly wintering shorebird.  

PubMed

Even though molt involves both endocrine and energetic changes in bird bodies, this study is among the first to combine assessments of energy costs together with thyroid hormone variations in molting birds. Individual shorebirds (red knots Calidris canutus islandica) were measured while in full summer and winter plumage as well as during peak of molt. Molt was associated with a 9.8% increase in average mass-independent basal metabolic rate (BMR) above nonmolting levels. Individual plasma levels of thyroxine (T(4)) were correlated with individual rate of body feather renewal, confirming that T(4) is related to body molt but also showing that it is potentially regulating its rate. Across seasons, mass-independent average heat loss measured as conductance gradually declined with conductance during molt falling between measured values for summer and winter. During the molting period, however, body molting rate was positively correlated with thermal conductance, indicating that for a given ambient temperature below thermoneutrality, the fastest molting birds were losing more body heat. Across seasons, triiodothyronine (T(3)), a hormone typically upregulated in response to a cold stimulus, was correlated with individual thermal conductance and BMR. We suggest that the increased heat loss of fast-molting birds leads to a cold-acclimatization response that may be partly responsible for the elevated BMR measured during molt. This could be mediated through a stimulatory effect of T(3) on BMR in response to increased heat loss. Our interpretation is supported by a positive relationship between the individual changes in conductance and the change in BMR from summer to the molting period. PMID:19199554

Vézina, François; Gustowska, Anna; Jalvingh, Kirsten M; Chastel, Olivier; Piersma, Theunis

2009-01-01

134

ISOTOPIC EVALUATION OF INTERRUPTED MOLT IN NORTHERN BREEDING POPULATIONS OF THE LOGGERHEAD SHRIKE  

Microsoft Academic Search

2 Environment Canada, 11 Innovation Boulevard, Saskatoon, SK S7N 3H5, Canada Abstract. The Loggerhead Shrike (Lanius ludovicianus) breeds throughout North America and various populations apparently exhibit diverse molt strategies. However, molt in this species and how it may vary geographically is generally poorly known. We investigated molt sequence in 27 breeding Loggerhead Shrikes using stable hydrogen (dD) isotope analysis of

Guillermo E. Pérez; Keith A. Hobson

2006-01-01

135

Molt-related and size-dependent differences in the escape response and post-threat behavior of the American lobster, Homarus americanus.  

PubMed

Videotaped recordings of adult lobsters of different molt stages were analyzed. The escape response of adults was compared with that of juveniles recorded in an earlier study. Juvenile lobsters always respond to a threat with escape behavior irrespective of their molt stage, but in adults the probability of eliciting a response was a function of molt stage: more hard-shelled (intermolt stage C) and (premolt stage D) animals tailflipped than did soft-shelled (postmolt stages A and B) animals. The number, frequency, and duration of tailflips, and the average distance swum by animals in each molt stage were measured for the entire escape response, for the initial power swim, and for the subsequent swims. These measurements were used to compute several parameters: velocity, acceleration, force, and work; average distance traveled in a tailflip for each kilogram of body weight (distance/kg/tailflip); and average distance traveled for each bodylength (distance/bodylength). Among adults, intermolt (stage C) lobsters traveled significantly farther and faster than postmolt animals (stages A and B). Among juveniles, late postmolt (stage B) animals traveled farther. Among adults, although the total number of tailflips and the duration of the response were not significantly different among molt stages, the number of tailflips/second (frequency) and distance traveled/kg/tailflip were greater for intermolt animals. In juvenile intermolts, however, frequency and distance/kg/tailflip were markedly lower than in the premolt stages. Although values were lower than intermolts and premolts, postmolt adults sustained their swimming frequency, distance/kg/tailflip, and distance/bodylength for the entire escape distance (as did postmolt juveniles). These parameters then dropped off sharply for both adult and juvenile intermolt and premolt animals in the second half of the escape distance. Post-threat behaviors reveal that stage D animals have the highest aggression index and often attack the presented stimulus, whereas stage A animals are the least likely to approach the stimulus and typically back away in a non-aggressive posture. Thus, although effects of the molt cycle on adult and juvenile escape behavior are similar in some ways, other physical characteristics of adults, such as weight, allometry, and physiology, seem to become important in determining the likelihood of escape behavior and the characteristics of the escape swim in each molt stage. PMID:11147707

Cromarty, S I; Mello, J; Kass-Simon, G

2000-12-01

136

Changes in the blood and plasma volume of Harris' sparrows during postnuptial molt.  

PubMed

In captive Harris' sparrows (Zonotrichia querula), plasma and blood volume increased significantly during stages 2 and 3 of postnuptial molt, when extensive feather replacement was taking place in the wings, tail and body tracts. Erythrocyte number did not increase significantly until molt was essentially complete. Consequently the 6% mean maximum reduction in hematocrit that was observed during molt appeared to be largely the result of plasma volume expansion. This plasma volume expansion was not due to changes in the osmolality or concentration of proteins within the blood plasma since both decreased significantly during intense molt. PMID:2863078

deGraw, W A; Kern, M D

1985-01-01

137

Body molt of male long-tailed ducks in the nearshore waters of the north slope, Alaska  

USGS Publications Warehouse

We examined the timing and intensity of body molt in relation to stage of remige growth for postbreeding adult male Long-tailed Ducks (Clangula hyemalis) off the coast of northern Alaska. During this period, remige and rectrix feathers are molted simultaneously with body feathers during the prebasic molt, which results in a period of increased energetic and nutritional demands. We collected birds from late July through mid-August and recorded intensity of molt in eight regions: head and neck, back and rump, greater coverts, lesser coverts, flank and sides, breast, belly, and tail. Using nonlinear regression, we estimated the peak intensity and variation for each region in relation to ninth primary length. We found little evidence of molt in the head and neck region. The greater and lesser coverts, and back and rump reached peak molt intensities earliest and were followed by tail, breast, and belly. Molt intensity in the flank and side region was highly variable and indicated a more prolonged molting pattern in relation to other regions. While body molt occurs simultaneously with wing molt, we found that molt among regions occurred in a staggered pattern. Long-tailed Ducks may employ this staggered molting pattern to minimize the energetic and nutritional requirements of molt.

Howell, M.D.; Grand, J.B.; Flint, P.L.

2003-01-01

138

Effects of temperature on mean molt interval, molting and mortality of red swamp crawfish 1 1 “Crayfish” is a more popular name than “crawfish”. However, the common name for Procambarus clarkii is “red swamp crawfish”. Because Procambarus clarkii is the main species used in soft-shell crayfish culture, the term “crawfish” is used in this paper for consistency. ( Procambarus clarkii)  

Microsoft Academic Search

The operation of soft-shell crawfish culture is based upon crawfish molting behavior. Mean molt interval and molting percentage are the main factors determining the production rate of a culture facility. Effects of temperature on mean molt interval and molting percentage of red swamp crawfish (Procambarus clarkii) were investigated in laboratory-scale recirculating culture system in two seasons. In this study, higher

Shulin Chen; Jingwei Wu; Ronald F. Malone

1995-01-01

139

Inexplicable Inefficiency of Avian Molt? Insights from an Opportunistically Breeding Arid-Zone Species, Lichenostomus penicillatus  

PubMed Central

The majority of bird species studied to date have molt schedules that are not concurrent with other energy demanding life history stages, an outcome assumed to arise from energetic trade-offs. Empirical studies reveal that molt is one of the most energetically demanding and perplexingly inefficient growth processes measured. Furthermore, small birds, which have the highest mass-specific basal metabolic rates (BMRm), have the highest costs of molt per gram of feathers produced. However, many small passerines, including white-plumed honeyeaters (WPHE; Lichenostomus penicillatus), breed in response to resource availability at any time of year, and do so without interrupting their annual molt. We examined the energetic cost of molt in WPHE by quantifying weekly changes in minimum resting metabolic rate (RMRmin) during a natural-molt period in 7 wild-caught birds. We also measured the energetic cost of feather replacement in a second group of WPHEs that we forced to replace an additional 25% of their plumage at the start of their natural molt period. Energy expenditure during natural molt revealed an energy conversion efficiency of just 6.9% (±0.57) close to values reported for similar-sized birds from more predictable north-temperate environments. Maximum increases in RMRmin during the molt of WPHE, at 82% (±5.59) above individual pre-molt levels, were some of the highest yet reported. Yet RMRmin maxima during molt were not coincident with the peak period of feather replacement in naturally molting or plucked birds. Given the tight relationship between molt efficiency and mass-specific metabolic rate in all species studied to date, regardless of life-history pattern (Efficiency (%) ?=?35.720•10?0.494BMRm; r2?=?0.944; p?=?<0.0001), there appears to be concomitant physiological costs entrained in the molt period that is not directly due to feather replacement. Despite these high total expenditures, the protracted molt period of WPHE significantly reduces these added costs on a daily basis. PMID:21311594

Hoye, Bethany J.; Buttemer, William A.

2011-01-01

140

Alfalfa as a nutritive modulator in maintaining the innate immune response during the molting process  

Technology Transfer Automated Retrieval System (TEKTRAN)

Force molting of laying hens increases enteric foodborne pathogens in the reproductive tract, leading to contaminated eggs and progeny of infected hens. Currently, we lack a complete understanding of how conditions such as molting affect the immune system. Previous reports show that alfalfa is eff...

141

INTRODUCTION: CURRENT AND FUTURE PROSPECTS FOR INDUCED MOLTING IN LAYING HENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Induced molting to revive the productivity of aging laying flocks has been widely practiced by the commercial egg industry in the United States for many years. Recently, the induction of molting by feed deprivation has been the focus of vigorous criticism on the basis of both animal welfare implicat...

142

Stages of Embryonic Development in the Amphipod Crustacean, Parhyale hawaiensis  

E-print Network

. Crustaceans are an enormously successful group of arthropods and extant species demonstrate a wide diversity- logical diversity has been reinvigorated by new techni- ques in genetics and molecular biology. However development among crustaceans in particular, as well as between different arthropod groups. In addition

Browne, William E.

143

Calcium transport mechanism in molting crayfish revealed by microanalysis  

SciTech Connect

Crayfish provide a good model in which to study the transport mechanism of Ca ions. During the molting stage, decalcified Ca ions are transferred into the blood and accumulate in the gastrolith epithelium, after which a gastrolith is formed on the surface of the epithelium. The gastrolith is dissolved in the stomach after molting, and the Ca is reabsorbed and redistributed throughout the newly formed exoskeleton. We studied the mechanism of Ca transport by cytochemical precipitation of Ca ions and by electron microanalysis, including X-ray microanalysis (EDX) and electron energy-loss spectroscopy (EELS), with a computer. In EDX analysis, the fine precipitates of K-antimonate in the gastrolith mitochondria clearly defined Ca with antimony; we also observed a large amount of Ca-oxalate in the mitochondria, and Ca-K X-ray pulses were clearly defined. Ca-K X-rays were also detected from fresh freeze-substituted mitochondria. Finally, we succeeded in taking a Ca-L EELS image from the mitochondria of fresh freeze-substituted thin sections. Only a very small amount of Ca was detected from the cell membrane and other organelles. Ca-adenosine triphosphatase (ATPase) and Mg-ATPase activity was also very clearly demonstrated in the mitochondria. These enzymes may play an important role in Ca metabolism.

Mizuhira, V.; Ueno, M.

1983-01-01

144

Skin lipid structure controls water permeability in snake molts.  

PubMed

The role of lipids in controlling water exchange is fundamentally a matter of molecular organization. In the present study we have observed that in snake molt the water permeability drastically varies among species living in different climates and habitats. The analysis of molts from four snake species: tiger snake, Notechis scutatus, gabon viper, Bitis gabonica, rattle snake, Crotalus atrox, and grass snake, Natrix natrix, revealed correlations between the molecular composition and the structural organization of the lipid-rich mesos layer with control in water exchange as a function of temperature. It was discovered, merging data from micro-diffraction and micro-spectroscopy with those from thermal, NMR and chromatographic analyses, that this control is generated from a sophisticated structural organization that changes size and phase distribution of crystalline domains of specific lipid molecules as a function of temperature. Thus, the results of this research on four snake species suggest that in snake skins different structured lipid layers have evolved and adapted to different climates. Moreover, these lipid structures can protect, "safety", the snakes from water lost even at temperatures higher than those of their usual habitat. PMID:24157843

Torri, Cristian; Mangoni, Alfonso; Teta, Roberta; Fattorusso, Ernesto; Alibardi, Lorenzo; Fermani, Simona; Bonacini, Irene; Gazzano, Massimo; Burghammer, Manfred; Fabbri, Daniele; Falini, Giuseppe

2014-01-01

145

Genomic identification of a putative circadian system in the cladoceran crustacean Daphnia pulex  

PubMed Central

Essentially nothing is known about the molecular underpinnings of crustacean circadian clocks. The genome of Daphnia pulex, the only crustacean genome available for public use, provides a unique resource for identifying putative circadian proteins in this species. Here, the Daphnia genome was mined for putative circadian protein genes using Drosophila melanogaster queries. The sequences of core clock (e.g. CLOCK, CYCLE, PERIOD, TIMELESS and CRYPTOCHROME 2), clock input (CRYPTOCHROME 1) and clock output (PIGMENT DISPERSING HORMONE RECEPTOR) proteins were deduced. Structural analyses and alignment of the Daphnia proteins with their Drosophila counterparts revealed extensive sequence conservation, particularly in functional domains. Comparisons of the Daphnia proteins with other sequences showed that they are, in most cases, more similar to homologs from other species, including vertebrates, than they are to those of Drosophila. The presence of both CRYPTOCHROME 1 and 2 in Daphnia suggests the organization of its clock may be more similar to that of the butterfly Danaus plexippus than to that of Drosophila (which possesses CRYPTOCHROME 1 but not CRYPTOCHROME 2). These data represent the first description of a putative circadian system from any crustacean, and provide a foundation for future molecular, anatomical and physiological investigations of circadian signaling in Daphnia. PMID:21798832

Tilden, Andrea R.; McCoole, Matthew D.; Harmon, Sarah M.; Baer, Kevin N.; Christie, Andrew E.

2011-01-01

146

Significant fluctuations in ecdysteroid receptor gene (EcR) expression in relation to seasons of molt and reproduction in the grapsid crab, Metopograpsus messor (Brachyura: Decapoda).  

PubMed

Metopograpsus messor, a brachyuran crab inhabiting the estuaries of North Kerala (India), is a prolific breeder releasing approximately 14-16 broods a year. The present paper reports the sequence information on the DNA binding domain (C domain, DBD), linker (D domain) and ligand binding domain (E domain, LBD) of M. messor ecdysteroid receptor (MmEcR) gene, the first grapsid brachyuran crab EcR examined. We have also measured MmEcR transcript levels in the ovary and the hepatopancreas throughout the annual cycle, with special reference to seasons of molt and reproduction. MmEcR expression in both the tissues is found to be at its peak (P<0.05) in late premolt crabs (January/May, molt/reproduction season); the expression levels are lowest (P<0.05) during June/July, when the females would neither molt nor reproduce (season for molt/reproduction repose). Intermediate levels of expression were found during the breeding season (August/December). Interestingly, this pattern of gene expression is in concordance with the fluctuating ecdysteroid levels of the hemolymph and Y organ secretory activity. The significant levels of fluctuation in the ovarian expression of MmEcR strongly suggest the ovary as a potential target for ecdysteroid action. A season-wise comparison of the gene expression reveals that ovarian MmEcR transcript levels are higher in breeding crabs (August/December) than the non-breeding animals (June/July), implicating a possible ecdysteroid role in reproduction in M. messor. PMID:25448252

Shyamal, Sharmishtha; Anilkumar, G; Bhaskaran, R; Doss, G P; Durica, D S

2015-01-15

147

Neuroactive steroids modulate crustacean locomotor activity.  

PubMed

We examined the effects of neuroactive steroids known to modulate gamma-aminobutyric acid(A) (GABA)(A) receptor activity, on locomotor activity in a submerged circular open-field apparatus. Juvenile male lobsters, Homarus americanus, were treated with a single administration of an agonist, 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone, 3alpha,5alpha-TH PROG), an antagonist, pregnenolone sulfate (PREGS), or vehicle alone. 3alpha,5alpha-TH PROG treatment (125 and 250 microg) significantly reduced while PREGS significantly elevated locomotor activity in a dose-dependent manner similar to diazepam. PREGS increased locomotor activity at 30 and 60 microg, while diminishing such activity and altering locomotor patterns at 120 microg. These results suggest that neuroactive steroids may affect crustacean GABA receptors in a fashion similar to the GABA(A) type found in the vertebrates, and that they may be involved in the regulation of locomotor behavior. PMID:11684341

Snyder, M J; Peeke, H V

2001-11-01

148

Composite forces shape population dynamics of copepod crustaceans.  

PubMed

Understanding the processes that control species abundance and distribution is a major challenge in ecology, yet for a large number of potentially important organisms, we know little about the biotic and abiotic factors that influence population size. One group of aquatic organisms that defies traditional demographic analyses is the Crustacea, particularly those with complex life cycles. We used likelihood techniques and information theoretics to evaluate a suite of models representing alternative hypotheses on factors controlling the abundance of two copepod crustaceans in a small, tropical floodplain lake. Quantitative zooplankton samples were collected at three stations in a Venezuelan floodplain lake from June through December 1984; the average sampling interval was two days. We constructed a series of models with stage structure that incorporated six biotic and abiotic covariates in various combinations to account for temporal changes in abundance of these target species and in their population growth rates. Our analysis produced several novel insights into copepod population dynamics. We found that multiple forces affected the abundance of particular stages, that these factors differed between species as well as among stages within each species, and that biotic processes had the largest effects on copepod population dynamics. Density dependence had a large effect on the survival of Oithona amazonica copepodites and on population growth rate of Diaptomus negrensis. PMID:17503594

Twombly, S; Wang, Guiming; Hobbs, N Thompson

2007-03-01

149

Blood chemistry of wild Brazilian Coscoroba Swans during molt.  

PubMed

The Coscoroba Swan (Coscoroba coscoroba) is an unusual member of the Anatidae found in South America, from the Falkland Islands and Tierra del Fuego through Chile and Argentina, Uruguay, and Paraguay as far north as Mato Grosso do Sul in Brazil. The species is not threatened globally, but some local populations have declined and the status of others is unknown. The objective of this study was to quantify the plasma chemistry of a wild population of Coscoroba Swans in southern Brazil during their molting period. We captured 12 chicks, 14 juveniles, and 31 mature birds. The following blood parameters were measured: glucose, cholesterol, triglycerides, HDL cholesterol, uric acid, creatine-kinase, aspartate amino transferase, alanine-aminotransferase, alkaline phosphatase, amylase, and pancreatic amylase. Significant differences between males and females were not observed for any of the parameters, and only the levels of alkaline phosphatase differed significantly among age groups. PMID:20688656

Calabuig, Cecilia Pérez; Ferrer, Miguel; Muriel, Roberto

2010-04-01

150

Allometry of the Duration of Flight Feather Molt in Birds  

PubMed Central

We used allometric scaling to explain why the regular replacement of the primary flight feathers requires disproportionately more time for large birds. Primary growth rate scales to mass (M) as M0.171, whereas the summed length of the primaries scales almost twice as fast (M0.316). The ratio of length (mm) to rate (mm/day), which would be the time needed to replace all the primaries one by one, increases as the 0.14 power of mass (M0.316/M0.171?=?M0.145), illustrating why the time required to replace the primaries is so important to life history evolution in large birds. Smaller birds generally replace all their flight feathers annually, but larger birds that fly while renewing their primaries often extend the primary molt over two or more years. Most flying birds exhibit one of three fundamentally different modes of primary replacement, and the size distributions of birds associated with these replacement modes suggest that birds that replace their primaries in a single wave of molt cannot approach the size of the largest flying birds without first transitioning to a more complex mode of primary replacement. Finally, we propose two models that could account for the 1/6 power allometry between feather growth rate and body mass, both based on a length-to-surface relationship that transforms the linear, cylindrical growing region responsible for producing feather tissue into an essentially two-dimensional structure. These allometric relationships offer a general explanation for flight feather replacement requiring disproportionately more time for large birds. PMID:19529759

Rohwer, Sievert; Ricklefs, Robert E.; Rohwer, Vanya G.; Copple, Michelle M.

2009-01-01

151

Effects of predictable and unpredictable food restriction on the stress response in molting and non-molting European starlings (Sturnus vulgaris).  

PubMed

This study tested whether an ethologically relevant stressor, a three-week period of food restriction where food was unavailable for four hours a day, caused chronic stress in molting and non-molting captive European starlings. Although all birds increased weight during the Food Restriction period, only non-molting birds increased food intake. Morning baseline heart rates increased during the Food Restriction period and all birds showed a decrease in heart rate when food was absent from the cage. In non-molting birds, there were no differences in either baseline or stress-induced corticosterone (CORT) concentrations, whereas molting birds showed attenuated baseline CORT, stress-induced CORT, and fecal glucocorticoid metabolite levels over the Food Restriction period. Although several parameters, such as increased morning heart rate, are consistent with chronic stress, the majority of these data suggest that restricting food availability is not chronically stressful. Furthermore, making the timing of food removal less predictable by randomizing when food was removed during the day did not enhance any of the above responses, but did alter the frequency of maintenance and feeding behaviors. In conclusion, starlings appear resistant to developing symptoms of chronic stress from repeated food restriction. PMID:21801846

Bauer, Carolyn M; Glassman, Laura W; Cyr, Nicole E; Romero, L Michael

2011-11-01

152

EFFECTS OF CHLORINATED SEAWATER ON DECAPOD CRUSTACEANS AND 'MULINIA' LARVAE  

EPA Science Inventory

Eggs and larvae of decapod crustaceans and embryos of Mulinia lateralis were exposed to chlorinated seawater for varying periods in continuous flow systems. Mortality, developmental rate, and general behavior were recorded. Panopeus herbstii zoeae were more sensitive to chlorine-...

153

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved  

Code of Federal Regulations, 2012 CFR

50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC...

2012-10-01

154

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved  

Code of Federal Regulations, 2010 CFR

50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2010-10-01

155

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved  

Code of Federal Regulations, 2014 CFR

50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC...

2014-10-01

156

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved  

Code of Federal Regulations, 2010 CFR

50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2010-10-01

157

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved  

Code of Federal Regulations, 2012 CFR

50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2012-10-01

158

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved  

Code of Federal Regulations, 2012 CFR

50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2012-10-01

159

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved  

Code of Federal Regulations, 2011 CFR

50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2011-10-01

160

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved  

Code of Federal Regulations, 2013 CFR

50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC...

2013-10-01

161

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved  

Code of Federal Regulations, 2013 CFR

50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2013-10-01

162

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved  

Code of Federal Regulations, 2011 CFR

50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC...

2011-10-01

163

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved  

Code of Federal Regulations, 2011 CFR

50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2011-10-01

164

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved  

Code of Federal Regulations, 2013 CFR

50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2013-10-01

165

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved  

Code of Federal Regulations, 2012 CFR

50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2012-10-01

166

50 CFR 665.640 - PRIA crustacean fisheries. [Reserved  

Code of Federal Regulations, 2014 CFR

50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false PRIA crustacean fisheries. [Reserved] 665.640 Section 665.640 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2014-10-01

167

50 CFR 665.140 - American Samoa Crustacean Fisheries. [Reserved  

Code of Federal Regulations, 2010 CFR

50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false American Samoa Crustacean Fisheries. [Reserved] 665.140 Section 665.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC...

2010-10-01

168

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved  

Code of Federal Regulations, 2013 CFR

50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2013-10-01

169

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved  

Code of Federal Regulations, 2010 CFR

50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2010-10-01

170

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved  

Code of Federal Regulations, 2014 CFR

50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2014-10-01

171

50 CFR 665.240 - Hawaii crustacean fisheries. [Reserved  

Code of Federal Regulations, 2014 CFR

50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Hawaii crustacean fisheries. [Reserved] 665.240 Section 665.240 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2014-10-01

172

50 CFR 665.440 - Mariana crustacean fisheries. [Reserved  

Code of Federal Regulations, 2011 CFR

50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Mariana crustacean fisheries. [Reserved] 665.440 Section 665.440 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND...

2011-10-01

173

Crustacean-derived biomimetic components and nanostructured composites.  

PubMed

Over millions of years, the crustacean exoskeleton has evolved into a rigid, tough, and complex cuticle that is used for structural support, mobility, protection of vital organs, and defense against predation. The crustacean cuticle is characterized by a hierarchically arranged chitin fiber scaffold, mineralized predominately by calcium carbonate and/or calcium phosphate. The structural organization of the mineral and organic within the cuticle occurs over multiple length scales, resulting in a strong and tough biological composite. Here, the ultrastructural details observed in three species of crustacean are reviewed: the American lobster (Homarus americanus), the edible crab (Cancer pagurus), and the peacock mantis shrimp (Odontodactylus scyllarus). The Review concludes with a discussion of recent advances in the development of biomimetics with controlled organic scaffolding, mineralization, and the construction of nanoscale composites, inspired by the organization and formation of the crustacean cuticle. PMID:24833136

Grunenfelder, Lessa Kay; Herrera, Steven; Kisailus, David

2014-08-27

174

THE GROWTH-PROMOTING ACTION OF CRUSTACEAN EYESTALK EXTRACT  

Microsoft Academic Search

From the eye-stalks of such crustaceans as Pala'i'nonetes, Callinectes, Cancer, etc., there can be obtained by water extraction a substance (or mixture of substances), which, distributed by the blood stream, will lead to contraction of the chromatophores of crustaceans (Perkins, 1928; Koller, 1928), contraction of the chromatophores of fishes (Kol ler and Meyer, 1930; Kropp and Perkins, 1933b), and expansion

A. E. NAVEZ; B. KROPP

175

BODY WEIGHT AND FEATHER GROWTH OF MALE BARROW'S GOLDENEYE DURING WING MOLT  

Microsoft Academic Search

We studied the timing, duration, and rate of wing molt of male Barrow's Goldeneye (Bucephala islandica). The mean daily change in primary feather length was 2.6%, which is consistent with rates re- ported for other waterfowl species. The mean length of the flightless period was 31 days (range: 27-34 days), excluding the pre-shedding interval. Wing molt extended from early July

Debbie van de Wetering; Fred Cooke

2000-01-01

176

Trade-offs between molt and immune activity in two populations of house sparrows ( Passer domesticus )  

Microsoft Academic Search

Molt and immune defense are critical activities in which all birds must invest. Because each is costly, wild passerines may have to decrease their investment in one activity if they are to increase investments to others. Here, I studied such molt-immune trade-offs in one neotropical and one north-temperate population of house sparrows (Passer domesticus (L., 1758)). I included two populations

Lynn B. Martin II

2005-01-01

177

Crustacean intersexuality is feminization without demasculinization: implications for environmental toxicology.  

PubMed

The dysfunction associated with intersexuality in vertebrates and molluscs is often a serious threat to ecosystems. Although poorly understood, crustacean intersexuality is associated with contamination and includes forms linked to increased sex-ratio distorting parasites at polluted sites. Despite the importance of crustaceans for monitoring vulnerable aquatic habitats, little is known about the molecular basis of this abnormal sexual differentiation and any associated sexual dysfunction. To increase the relevance of crustaceans to environmental toxicologists, we comprehensively analyzed gene expression in amphipods presenting parasite- and nonparasite-associated intersexuality. Our findings reveal existing vertebrate biomarkers of feminization should not be applied to crustaceans, as orthologous genes are not induced in feminized amphipods. Furthermore, in contrast to vertebrates, where feminization and intersexuality is often associated with deleterious demasculinization, we find males maintain masculinity even when unambiguously feminized. This reveals a considerable regulatory separation of the gene pathways responsible for male and female characteristics and demonstrates that evidence of feminization (even if detected with appropriate biomarkers) is not a proxy for demasculinization in crustaceans. This study has also produced a comprehensive spectrum of potential molecular biomarkers that, when combined with our new molecular understanding, will greatly facilitate the use of crustaceans to monitor aquatic habitats. PMID:25343324

Short, Stephen; Yang, Gongda; Guler, Yasmin; Green Etxabe, Amaia; Kille, Peter; Ford, Alex T

2014-11-18

178

The sensory dorsal organs of crustaceans.  

PubMed

The cuticle of crustaceans bears numerous organs, of which the functions of many are unknown. One of these, the sensory dorsal organ (SDO), is present in a wide diversity of taxa. Here we critically review the variability, ultrastructure, distribution, and possible function of this enigmatic cuticular organ. Previous data are complemented by new observations on larvae and adults of various malacostracans. The SDO is composed of four sensors arranged as the corners of a square, the centre of which is occupied by a gland. Pores or pegs surrounding this central complex may also form part of the organ. The arrangement and the external aspect of the five main elements varies greatly, but this apparently has little impact on their ultrastructural organisation. The sensors and the gland are associated with a particularly thin cuticle. Each sensor contains four outer dendritic segments and the central gland is made of a single large cell. It is not yet known what this large cell secretes. The SDO is innervated from the tritocerebrum and therefore belongs to the third cephalic segment. A similar organ, here called the posterior SDO, has been repeatedly observed more posteriorly on the carapace. It resembles the SDO but has a greater number of sensors (usually six, but up to ten) apparently associated with only two outer dendritic segments. The SDO and the posterior SDO are known in the Eumalacostraca, the Hoplocarida, and the Phyllocarida. Some branchiopods also possess a 'dorsal organ' resembling both the SDO and the ion-transporting organ more typical of this group. This may indicate a common origin for these two functionally distinct groups of organs. New observations on the posterior SDO support the hypothesis that the SDO and the posterior SDO are homologous to the lattice organ complexes of the costracans. However, the relationship between the SDO and the dorsal cephalic hump of calanoid copepods remains unclear. No correlation can be demonstrated between the presence of a SDO and a particular ecological or biological trait. In fossils, the most convincing examples of SDO-like organs are found in some Late Cambrian arthropods from the Alum Shale of southern Sweden. They suggest that related organs might have been present in non-crustacean Cambrian arthropods. The distribution of the SDO and posterior SDO in extant and fossil crustaceans strongly suggests that these organs originated early in the history of the group, and are crucial to the functioning of these organisms. However, except for knowing that the sensors are chemoreceptors and that in a given organ a functional relationship probably exists between them and the gland, little is known about this function. The description of a SDO in freshwater carideans, which can be easily reared in a laboratory, opens the way for behavioural and physiological experiments to be undertaken that could prove crucial for the determination of this function. PMID:23279348

Lerosey-Aubril, Rudy; Meyer, Roland

2013-05-01

179

Abundance and distribution of the common eider in eastern North America during the molting season  

USGS Publications Warehouse

Like most other sea ducks, male common eiders (Somateria mollissima) concentrate in large groups to molt following the breeding season. Although Maine conducted surveys in the 1980s, little was known of eider molting sites in Atlantic Canada until recently, when surveys and research conducted in Quebec, Newfoundland, Labrador, Nova Scotia and Maine revealed a number of important molting sites. Sites vary in importance from a few hundred males to tens of thousands. Important sites include the western and southern coastal areas of Anticosti island (40,000 birds), Baie des Milles Vaches (9,000) in Quebec, southwestern Nova Scotia (40,000), Petit Manan Island archipelago (7,000), and Metinic Island archipelago (10,000) in Maine. Molting eider surveys conducted in Maine during the early 1980s and in the St. Lawrence in 2003-2004 revealed large flock sizes, commonly over 2,000 birds, in consistent locations annually. An estimated 40,000 males molt in Nova Scotia and 28,400 in Maine (1981 data). Surveys indicate that important sites are used consistently between years and that local movements occur. Recoveries from banded birds suggest that eiders breeding on the lower North Shore of the St. Lawrence, New Brunswick, Nova Scotia, and even Newfoundland appear to concentrate at the Petit Manan site in Maine. They also suggest inter annual movements between the Nova Scotia and Petit Manan sites. Greater understanding of the relationships between breeding, wintering, and molting sites will facilitate management of this heavily exploited sea duck.

Savard, Jean-Pierre L.; Allen, B.; McAuley, D.; Milton, G.R.; Gililand, S.

2005-01-01

180

Broad antiviral activity in tissues of crustaceans.  

PubMed

Innate antiviral substances occur in vertebrates and may function as host defenses. Virus infections are common among invertebrates, but little is known about the ability of invertebrates to control viral infections. Pre-existing antiviral substances may be particularly important, since invertebrates lack the antiviral defense conferred by specific immunity. In our study, we found that tissue extracts of blue crab (Callinectes sapidus), shrimp (Penaeus setiferus), and crayfish (Procambarus clarkii) contained antiviral activities that inhibit a variety of DNA and RNA viruses, i.e. Sindbis virus (SB), vaccinia virus (VAC), vesicular stomatitis virus (VS), mengo virus (MENGO), banzi virus (BANZI) and poliomyelitis (POLIO). The concentration of inhibitory activity was relatively high, ranging from 102 to 216 U/g tissue for Sindbis virus, using the various tissue extracts. The other viruses were somewhat less sensitive to the inhibitor. The main antiviral activity in the inhibitor preparation from blue crab resided in an approximately 440 kDa fraction. It was inactivated significantly by lipid extraction, but not by proteinase K or glycosidases. The antiviral mechanism of the inhibitor from the blue crab was inhibition of virus attachment to eukaryotic cells, as evidenced by inhibitory activity at 4 degrees C. These studies are among the first to show the existence of broadly active antiviral activities in aquatic crustaceans. These antiviral substances may function as innate host defenses in these species that lack specific antibody immunity and, therefore, merit further study. PMID:11080539

Pan, J; Kurosky, A; Xu, B; Chopra, A K; Coppenhaver, D H; Singh, I P; Baron, S

2000-10-01

181

Insect molting hormone and sterol biosynthesis in spinach  

SciTech Connect

Insect molting hormones, which are produced by plants and are effective molecules in the control of insect crop pests, are biosynthesized in developing spinach leaves (Spinacia oleracea L.). The major sterols biosynthesized by spinach are avenasterol (24{alpha}-ethyl-5{alpha}-cholesta-7,24(28)-dien-3{beta}-ol), spinasterol (24{alpha}-ethyl-5{alpha}-cholesta-7,22-dien-3{beta}-ol), and 22-dihydrospinasterol (24{alpha}-ethyl-5{alpha}-cholest-7-en-3{beta}-ol). The major ecdysteroids biosynthesized are ecdysterone (2{beta},3{beta},14{alpha},20R,22R,25-hexahydroxy-5{beta}-cholest-7-en-6-one) and polypodine B (2{beta},3{beta},5{beta},14{alpha},20R,22R,25-heptahycroxycholest-7-en-6-one) and polypodine B (2{beta},3{beta},5{beta},14{alpha},20R,22R,25-heptahydroxycholest-7-en-6-one). When labeled 2-{sup 14}C-mevalonic acid was incorporated into young leaves isolated squalene, sterols and ecdysteroids contained the label. During a short (16 h) incorporation period in intact young leaves of 100 day old plants, the avenasterol has the highest specific activity in counts per minute per {mu}g of sterol followed by 22-dihydrospinasterol which is more highly labeled than spinasterol. The ecdysteroids synthesized, on an entire plant basis, account for 20% of the total steroid (sterol and ecdysteroid) isolated from the plant.

Grebenok, R.J.; Adler, J.H. (Michigan Technological Univ., Houghton (USA))

1990-05-01

182

Timing of feather molt related to date of spring migration in male white-throated sparrows, Zonotrichia albicollis.  

PubMed

In migratory birds, the ability to depart wintering grounds at the appropriate time is an important determinant of fitness. Understanding the regulation of this timing will be essential for predicting whether timing of bird migration keeps up with global climate change. We examined whether the timing of the late-winter molt, in which white-throated sparrows (Zonotrichia albicollis) replace head and body feathers in advance of mating, may constrain the timing of northward migratory departure. In an observational study, we found a significant correlation between timing of molt and the date on which free-living male white-throated sparrows disappeared from our study site during migration. The following year, we tested whether experimentally manipulating molt date by advancing photoperiod during temporary captivity would subsequently advance disappearance date once the birds were released. Sparrows that were experimentally induced to molt early disappeared from the wintering site before controls. However, the captive control birds also molted and disappeared from the site earlier than free-living controls, suggesting that the diet during captivity had played a role. In the third winter we completed the study by advancing or delaying molt using only dietary manipulation. Together, these results show that the ability to molt early in spring is related to early disappearance from the wintering site. Early molt likely has carry-over effects on reproduction and the requirements of molt may prevent populations from adjusting migration timing in response to global climate change. PMID:25287905

Cristol, Daniel Aaron; Johnson, Karen Michelle; Jenkins, Kendell Daly; Hawley, Dana Michelle

2014-12-01

183

Primary feather molt and serum luteinizing hormone concentration in chukar partridge (Alectoris chukar) during a photoperiodically induced molt with or without fasting.  

PubMed

In two experiments, 135 adult chukar partridge of two genetic lines, one selected for high egg production and a random-bred control line, were induced to molt by reducing photoperiod from 16 hr light/day to 8 hr light/day on Day 0. In Experiment 1, feed was removed from approximately half the birds on Day 0 and returned on Day 7. Birds in Experiment 2 were not fasted. Photoperiod was increased to 16 hr light/day on Day 56. Primary feather molt scores, body weights, and, in Experiment 2, serum luteinizing hormone (LH) levels were monitored weekly through Day 85. Prior to the short day period, birds selected for high egg production and females had lower molt scores than controls or males, respectively. Fasting had no effect on molt scores, egg production, or body weights (except during the fasting period). Selected-line birds returned to lay approximately 3 days earlier and laid approximately 16 more eggs during the second production period than controls. Six days before photoperiod was reduced, immunoreactive serum LH levels were 5 to 8 ng/ml; they declined during short days to about 4 ng/ml. Within 8 days after relighting, LH levels increased to approximately 33 ng/ml in males and 18 ng/ml in females. Luteinizing hormone levels remained elevated in males throughout the subsequent 4 weeks but declined in females as egg production resumed. PMID:3588482

Meyer, W E; Millam, J R

1986-08-01

184

Multiple parasitic crustacean infestation on belonid fish Strongylura strongylura  

PubMed Central

Abstract Simultaneous multiple infestation of parasitic crustacean species involving a cymothoid isopod, Cymothoa frontalis Milne Edward, 1840 and four species of copepods such as Lernanthropus tylosuri Richiardi, 1880, Caligodes lacinatus Kroyer, 1863, Bomolochus bellones Burmeister, 1833 and Dermoergasilus coleus Cressey & Collette, 1970 was frequently noticed on spot-tail needlefish, Strongylura strongylura (Belonidae) captured from the Malabar coast (Kerala, India) during the period from April 2011 to March 2012. All the 43 fishes (Strongylura strongylura) collected, were under the hyper-infection with parasitic crustaceans; a total of 388 parasitic crustaceans including 57 Cymothoa frontalis, 252 Lernanthropus tylosuri, 31 Caligodes lacinatus, 24 Bomolochus bellones and 32 Dermoergasilus coleus were recovered from the host fish. 4 members (9.30%) of host fish were under quadruple parasitism, in two different combinations. Seventeen (39.53%) host fishes showed triple parasitism and 20 (46.51%) members exhibited double parasitism, with four and five parasitic combinations respectively. Remaining two (4.65%) fishes were parasitized only by the copepod, Lernanthropus tylosuri. The infestations by all recovered parasitic crustaceans were highly site specific. The damage caused by the parasitic crustaceans was also discussed. PMID:25561846

Aneesh, Panakkool-Thamban; Sudha, Kappalli; Helna, Ameri Kottarathil; Anilkumar, Gopinathan; Trilles, Jean-Paul

2014-01-01

185

Development of a dihydroartemisinin-resistant Molt-4 leukemia cell line.  

PubMed

Artemisinin generates cytotoxic free radicals when it reacts with iron. Its toxicity is more selective toward cancer cells because cancer cells contain a higher level of intracellular-free iron. We previously reported that dihydroartemisinin (DHA), an active metabolite of artemisinin, has selective cytotoxicity toward Molt-4 human lymphoblastoid cells. A concern is whether cancer cells could develop resistance to DHA after repeated administration, thus limiting its therapeutic efficacy. In the present study, we developed a DHA-resistant Molt-4 cell line (RTN) by exposing Molt-4 cells to gradually increasing concentrations of DHA in vitro. The half-maximal inhibitory concentration (IC50) of DHA for RTN cells is 7.1-times higher than that of Molt-4 cells. RTN cells have a higher growth rate than Molt-4 cells. In addition, we investigated the toxicities of two more potent synthetic artemisinin compounds, artemisinin dimer-alcohol and artemisinin-tagged holotransferrin toward RTN cells; RTN cells showed no significant cross-resistance to these compounds. PMID:24922643

Park, Jungsoo; Lai, Henry C; Singh, Mallika; Sasaki, Tomikazu; Singh, Narendra P

2014-06-01

186

Body condition, food habits, and molt status of late-wintering ruddy ducks in California  

USGS Publications Warehouse

We studied body condition, food habits, and molt status of late-wintering ruddy ducks (Oxyura jamaicensis) using drainwater evaporation ponds in the southern San Joaquin Valley, California. Levels of body fat and protein were similar by sex but varied by age (adults greater than immatures). Masses of breast and leg muscle protein were greatest in adult males and lowest in immature males, but similar in adult and immature females. Fat and protein levels in late-wintering ruddy ducks were independent of their body size. We detected no differences among sex-age classes in the proportion of animal foods consumed. Aquatic invertebrates composed 85% of the diet; midge larvae (Diptera: Chironomidae) and brine flies (Diptera: Ephydridae) were the principal taxa consumed. Molt score by feather region and overall molt score did not vary by sex or age. Light to moderate molt (25 to 50% molting feathers) was recorded in all feather regions. High levels of body fat and protein were attributed to premigratory hyperphagia and consumption of foods with a high protein:energy ratio.

Hohman, W.L.; Ankney, C.D.; Roster, D.L.

1992-01-01

187

MAPS BANDING Sheet Location Band Size Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS BANDING Sheet Location Band Size Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP New Band N Local 4 Skull NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR

DeSante, David F.

188

MAPS RECAPTURES Sheet Location Band Size R Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS RECAPTURES Sheet Location Band Size R Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture R Local 4 Skull ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI

DeSante, David F.

189

MAPS UNBANDED Sheet Location Band Size U Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS UNBANDED Sheet Location Band Size U Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U' for Local 4 Skull HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI.COVS SEC

DeSante, David F.

190

MAPS UNBANDED Sheet Location Band Size U Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS UNBANDED Sheet Location Band Size U Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U' for Local 4 Skull HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI.COVS SEC

DeSante, David F.

191

MAPS RECAPTURES Sheet Location Band Size R Year Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS RECAPTURES Sheet Location Band Size R Year Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture R Local 4 Skull ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI

DeSante, David F.

192

MAPS UNBANDED Sheet Location Band Size U Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS UNBANDED Sheet Location Band Size U Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U' for Local 4 Skull BAND NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT

DeSante, David F.

193

MAPS RECAPTURES Sheet Location Band Size R Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS RECAPTURES Sheet Location Band Size R Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture R Local 4 Skull ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI

DeSante, David F.

194

MAPS BANDING Sheet Location Band Size Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS BANDING Sheet Location Band Size Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP New Band N Local 4 Skull NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR

DeSante, David F.

195

MAPS BANDING Sheet Location Band Size Year Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS BANDING Sheet Location Band Size Year Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP New Band N Local 4 Skull S Feather NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR

DeSante, David F.

196

MAPS UNBANDED Sheet Location Band Size U Year 2014 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS UNBANDED Sheet Location Band Size U Year 2014 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U' for Local 4 Skull HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI.COVS SEC

DeSante, David F.

197

MAPS RECAPTURES Sheet Location Band Size R Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MAPS RECAPTURES Sheet Location Band Size R Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture R Local 4 Skull BANDER'S INITIALS CODE BAND NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR

DeSante, David F.

198

MoSI BANDING Sheet Location Band Size Season (e.g. 2009-10) Page # CODE SEX AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MoSI BANDING Sheet Location Band Size Season (e.g. 2009-10) Page # CODE SEX AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP New Band N Male L Leave blank if you didn't look Predation P Dead D at that feather tract. DATE BANDER'S INITIALS

DeSante, David F.

199

Crustacean Hyperglycemic Hormone (cHH) as a Modulator of Aggression in Crustacean Decapods  

PubMed Central

Biogenic amines, particularly serotonin, are recognised to play an important role in controlling the aggression of invertebrates, whereas the effect of neurohormones is still underexplored. The crustacean Hyperglycemic Hormone (cHH) is a multifunctional member of the eyestalk neuropeptide family. We expect that this neuropeptide influences aggression either directly, by controlling its expression, or indirectly, by mobilizing the energetic stores needed for the increased activity of an animal. Our study aims at testing such an influence and the possible reversion of hierarchies in the red swamp crayfish, Procambarus clarkii, as a model organism. Three types of pairs of similarly sized males were formed: (1) ‘control pairs’ (CP, n?=?8): both individuals were injected with a phosphate saline solution (PBS); (2) ‘reinforced pairs’ (RP, n?=?9): the alpha alone was injected with native cHH, and the beta with PBS; (3) ‘inverted pairs’ (IP, n?=?9): the opposite of (2). We found that, independently of the crayfish’s prior social experience, cHH injections induced (i) the expression of dominance behaviour, (ii) higher glycemic levels, and (iii) lower time spent motionless. In CP and RP, fight intensity decreased with the establishment of dominance. On the contrary, in IP, betas became increasingly likely to initiate and escalate fights and, consequently, increased their dominance till a temporary reversal of the hierarchy. Our results demonstrate, for the first time, that, similarly to serotonin, cHH enhances individual aggression, up to reverse, although transitorily, the hierarchical rank. New research perspectives are thus opened in our intriguing effort of understanding the role of cHH in the modulation of agonistic behaviour in crustaceans. PMID:23166815

Aquiloni, Laura; Giulianini, Piero G.; Mosco, Alessandro; Guarnaccia, Corrado; Ferrero, Enrico; Gherardi, Francesca

2012-01-01

200

Carotenoprotein complexes in entomostracan crustaceans (Streptocephalus dichotomus and Moina micrura).  

PubMed

The carotenoprotein complexes of a freshwater fairy shrimp (Streptocephalus dichotomus) and a daphnid (Moina micrura) were characterised and compared. Based on thin layer chromatography and mass spectral analysis, a variety of cartenoprotein complexes such as astaxanthin, canthaxanthin, antheraxanthin, lutein, beta-cryptoxanthin and violaxanthin were found. Both crustaceans had astaxanthin and canthaxanthin as predominant prosthetic groups. Amino acid analysis of the complexes further revealed high levels of asparagine, glutamine and glycine in both species. Our study highlights the presence of naturally available carotenoid species in both crustaceans and their possible inter-conversion in anostracans. PMID:12781971

Velu, C S; Czeczuga, B; Munuswamy, N

2003-05-01

201

Role of Rho-ROCK signaling in MOLT4 cells metastasis induced by CCL25.  

PubMed

Our previous research has revealed that binding of the chemokine CCL25 to the CCR9 provides chemotactic cues guiding leukemic cells to specific tissues and organs. The RhoA-ROCK pathway might be involved in cancer migration. The purpose of this study was to explore the role of the RhoA-ROCK-MLC axis in leukemic cell migration following exposure to CCL25. The results showed that CCL25 could increase the amount of the GTPase RhoA and activate MLC in MOLT4 cells in a time-dependent manner. C3 exoenzyme and Y-27632 could block MOLT4 cell migration and chemotaxis. Thus, the RhoA-ROCK-MLC axis might play an important role in MOLT4 cell metastasis induced by CCL25. PMID:20855113

Zhang, Li; Yu, Beibei; Hu, Meng; Wang, Zhan; Liu, Dongying; Tong, Xiaoling; Leng, Jun; Zhou, Beibei; Hu, Yi; Wu, Ranran; Ding, Qianshan; Zhang, Qiuping

2011-01-01

202

The Role of Prolactin in the Development of Reproductive Photorefractoriness and Postnuptial Molt in the European Starling (Sturnus vulgaris)  

Microsoft Academic Search

Seasonal breeding in many birds, including the European starling, is terminated by the development of absolute reproductive photore- fractoriness, followed by a postnuptial molt, when photo-induced PRL secretion is at its seasonal maximum. To determine whether this photo-induced increase in PRL secretion has a causal role in the development of photorefractoriness or molt, European starlings were actively immunized against vasoactive

ALISTAIR DAWSON; PETER J. SHARP

2010-01-01

203

Molt-induced muscle atrophy decreases the zinc content of the pectoralis of the Giant Canada Goose ( Branta canadensis maxima )  

Microsoft Academic Search

Summary During molt-induced atrophy of the pectoralis muscle of the Giant Canada Goose (Branta canadensis maxima), the zinc content of the muscle was significantly reduced (p?0.0139), though the concentration of zinc per unit weight of muscle appeared higher (p?0.0232). Zinc lost from the muscle during molt could be utilized for growth of the new flight feathers.

B. W. C. Rosser; J. C. George

1986-01-01

204

DETECTION BY DGGE OF MODIFICATIONS IN CROP AND CECAL BACTERIAL POPULATIONS FOLLOWING FEED WITHDRAWAL AND FORCED MOLT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Spent laying hens often are subjected to forced molt in order to prolong their laying status. One popular method of forced molt involves the removal of access to feed during periods of reduced light. A negative result of total feed withdrawal is increased susceptibility to colonization and infecti...

205

MOTIVATION OF HENS TO OBTAIN FEED DURING A MOLT INDUCED BY EITHER FEED WITHDRAWAL, WHEAT MIDDLINGS OR MELENGESTROL ACETATE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Traditionally, molting had been done by withdrawing feed, which leads to weight loss and increased mortality. Public criticism of feed withdrawal, based on the perception that it inhumanely increases hunger, has led the industry to ban the practice. Thus far, alternatives result in poor post-molt p...

206

Mechanistic target of rapamycin (mTOR) signaling genes in decapod crustaceans: cloning and tissue expression of mTOR, Akt, Rheb, and p70 S6 kinase in the green crab, Carcinus maenas, and blackback land crab, Gecarcinus lateralis.  

PubMed

Mechanistic target of rapamycin (mTOR) controls global translation of mRNA into protein by phosphorylating p70 S6 kinase (S6K) and eIF4E-binding protein-1. Akt and Rheb, a GTP-binding protein, regulate mTOR protein kinase activity. Molting in crustaceans is regulated by ecdysteroids synthesized by a pair of molting glands, or Y-organs (YOs), located in the cephalothorax. During premolt, the YOs hypertrophy and increase production of ecdysteroids. Rapamycin (1?M) inhibited ecdysteroid secretion in Carcinus maenas and Gecarcinus lateralis YOs in vitro, indicating that ecdysteroidogenesis requires mTOR-dependent protein synthesis. The effects of molting on the expression of four key mTOR signaling genes (mTOR, Akt, Rheb, and S6K) in the YO was investigated. Partial cDNAs encoding green crab (C. maenas) mTOR (4031bp), Akt (855bp), and S6K (918bp) were obtained from expressed sequence tags. Identity/similarity of the deduced amino acid sequence of the C. maenas cDNAs to human orthologs were 72%/81% for Cm-mTOR, 58%/73% for Cm-Akt, and 77%/88% for Cm-S6K. mTOR, Akt, S6K, and elongation factor 2 (EF2) in C. maenas and blackback land crab (G. lateralis) were expressed in all tissues examined. The two species differed in the effects of molting on gene expression in the YO. In G. lateralis, Gl-mTOR, Gl-Akt, and Gl-EF2 mRNA levels were increased during premolt. By contrast, molting had no effect on the expression of Cm-mTOR, Cm-Akt, Cm-S6K, Cm-Rheb, and Cm-EF2. These data suggest that YO activation during premolt involves up regulation of mTOR signaling genes in G. lateralis, but is not required in C. maenas. PMID:24269559

Abuhagr, Ali M; Maclea, Kyle S; Chang, Ernest S; Mykles, Donald L

2014-02-01

207

Molting success of Ixodes scapularis varies among individual blood meal hosts and species.  

PubMed

The blacklegged tick (Ixodes scapularis) is an important vector of emerging human pathogens. It has three blood-feeding stages, as follows: larva, nymph, and adult. Owing to inefficient transovarial transmission, at least for the Lyme disease agent (Borrelia burgdorferi), larval ticks rarely hatch infected, but they can acquire infection during their larval blood meal. Nymphal ticks are primarily responsible for transmitting pathogens to hosts, including humans. The transition from uninfected host-seeking larva to infectious host-seeking nymph is therefore a key aspect of human risk of infection. It can be divided into a series of steps, as follows: finding a host, taking a blood meal, becoming infected, molting, and overwintering. The chance of succeeding in each of these steps may depend on the species identity of the blood meal host. We used a Bayesian method to estimate the molting success of larval I. scapularis collected from four commonly parasitized species of birds and eight commonly parasitized small and mid-sized mammals found in the forests of Dutchess County, New York. We show that molting success varies substantially among host species; white-footed mice, veeries, and gray catbirds support particularly high molting success, whereas ticks feeding on short-tailed shrews, robins, and wood thrushes were less successful. We also show that larval molting success varies substantially between individual blood meal hosts, and that this intraspecific variability is much higher in some species than in others. The causes of both inter- and intraspecific variation in molting success remain to be determined. PMID:21845946

Brunner, Jesse L; Cheney, Laura; Keesing, Felicia; Killilea, Mary; Logiudice, Kathleen; Previtali, Andrea; Ostfeld, Richard S

2011-07-01

208

TESTOSTERONE AND AVIAN LIFE HISTORIES: EFFECTS OF EXPERIMENTALLY ELEVATED TESTOSTERONE ON PREBASIC MOLT AND SURVIVAL IN MALE DARK-EYED JUNCOS  

Microsoft Academic Search

Male Dark-eyed Juncos (Junco hyemalis) that breed in Virginia begin their prebasic molt after breeding has ended, usually in August. Almost all males caught in late October have completed the molt. In 1989, we obtained anecdotal evidence that males whose testosterone (T) we maintained at artificially elevated levels beyond the end of the breeding season postponed or suppressed prebasic molt.

VAL NOLAN; CHARLES ZIEGENFUS; DANIEL P. CULLEN; C. RAY CHANDLER

209

Short-term oscillations in avian molt intensity: evidence from the golden eagle Aquila chrysaetos  

USGS Publications Warehouse

From a year-long study of molt in the golden eagle Aquila chrysaetos, we recorded 2069 contour feathers replaced in 137 d (6 May-19 September). Very few contour feathers were lost outside this period. From precise daily counts of feathers lost, and using time series analysis, we identified short-term fluctuations (i.e., 19-d subcycles) around a midsummer peak (i.e., a left-skewed normal distribution). Because these subcycles have never before been reported and because the physiological basis for many aspects of avian molt is poorly known, we offer only hypothetical explanations for the controls responsible for the subcycles.

Ellis, D.H.; Lish, J.W.; Kery, M.; Redpath, S.M.

2006-01-01

210

Short-term oscillations in avian molt intensity: Evidence from the golden eagle Aquila chrysaetos  

USGS Publications Warehouse

From a year-long study of molt in the golden eagle Aquila chrysaetos, we recorded 2069 contour feathers replaced in 137 d (6 May-19 September). Very few contour feathers were lost outside this period. From precise daily counts of feathers lost, and using time series analysis, we identified short-term fluctuations (i.e., 19-d subcycles) around a midsummer peak (i.e., a left-skewed normal distribution). Because these subcycles have never before been reported and because the physiological basis for many aspects of avian molt is poorly known, we offer only hypothetical explanations for the controls responsible for the subcycles. ?? Journal of Avian Biology.

Ellis, D.H.; Lish, J.W.; Kery, M.; Redpath, S.M.

2006-01-01

211

Hair color, molt, and testis size in male, short-tailed weasels treated with melatonin.  

PubMed

Melatonin in beeswax was implanted in male weasels (Mustela erminea). Brown weasels and white animals undergoing the spring change to the brown pelage and reproductive activity molted, grew a new white coat, and became reproductively quiescent after treatment. Controls retained or acquired the brown coat and developed or maintained enlarged testes. Treated weasels with pituitary autografts under the kidney capsule grew brown hair after hair growth was initiated by plucking. It is suggested that the pineal gland product, melatonin, initiates changes in the central nervous system and endocrines which result in molting, growth of the white winter pelage, and reproductive quiescence in the weasel. PMID:5816328

Rust, C C; Meyer, R K

1969-08-29

212

Haste Makes Waste but Condition Matters: Molt Rate–Feather Quality Trade-Off in a Sedentary Songbird  

PubMed Central

Background The trade-off between current and residual reproductive values is central to life history theory, although the possible mechanisms underlying this trade-off are largely unknown. The ‘molt constraint’ hypothesis suggests that molt and plumage functionality are compromised by the preceding breeding event, yet this candidate mechanism remains insufficiently explored. Methodology/Principal Findings The seasonal change in photoperiod was manipulated to accelerate the molt rate. This treatment simulates the case of naturally late-breeding birds. House sparrows Passer domesticus experiencing accelerated molt developed shorter flight feathers with more fault bars and body feathers with supposedly lower insulation capacity (i.e. shorter, smaller, with a higher barbule density and fewer plumulaceous barbs). However, the wing, tail and primary feather lengths were shorter in fast-molting birds if they had an inferior body condition, which has been largely overlooked in previous studies. The rachis width of flight feathers was not affected by the treatment, but it was still condition-dependent. Conclusions/Significance This study shows that sedentary birds might face evolutionary costs because of the molt rate–feather quality conflict. This is the first study to experimentally demonstrate that (1) molt rate affects several aspects of body feathers as well as flight feathers and (2) the costly effects of rapid molt are condition-specific. We conclude that molt rate and its association with feather quality might be a major mediator of life history trade-offs. Our findings also suggest a novel advantage of early breeding, i.e. the facilitation of slower molt and the condition-dependent regulation of feather growth. PMID:22808221

Vágási, Csongor I.; Pap, Péter L.; Vincze, Orsolya; Benk?, Zoltán; Marton, Attila; Barta, Zoltán

2012-01-01

213

Use of plant protein sources in crustacean diets  

Technology Transfer Automated Retrieval System (TEKTRAN)

World production of crustaceans has experienced a steady expansion that is expected to continue as world population increases and demand for quality sea food continues to rise. Paralleling the growth of industry has been an expansion in feed production, which has been primarily dominated by marine s...

214

INTRODUCTION Crayfish as well as other crustaceans form social dominance  

E-print Network

1210 INTRODUCTION Crayfish as well as other crustaceans form social dominance hierarchies (Bovbjerg populations. When two previously unacquainted crayfish encounter each other, conflict occurs immediately such as size and weight are the major determining factor for victory as the larger crayfish usually wins

Nagayama, Toshiki

215

Changes in the Lake Superior Crustacean Zooplankton Community  

Microsoft Academic Search

We examined crustacean zooplankton densities at five locations in two regions of Lake Superior during a time period that spanned two decades, for three years in the early 1970's and again for three years in the early 1990's. We used coupled multivariate and univariate analyses to find whether the zooplankton community had changed over these decades, and to determine if

Jason Link; James H. Selgeby; Robert E. Keen

2004-01-01

216

Insect Pheromones: Useful Lessons for Crustacean Pheromone Programs?  

E-print Network

Chapter 27 Insect Pheromones: Useful Lessons for Crustacean Pheromone Programs? Thomas C. Baker Abstract Insect pheromones, especially sex pheromones, have successfully con- tributed to pest management programs around the world since the 1970s. In this chapter I examine some of the ways in which pheromones

217

Biological effects of the anti-parasitic chemotherapeutant emamectin benzoate on a non-target crustacean, the spot prawn (Pandalus platyceros Brandt, 1851) under laboratory conditions.  

PubMed

The potential impact of commercial salmon aquaculture along the coast of British Columbia on the health of non-target marine wildlife is of growing concern. In the current initiative, the biological effects on gene expression within spot prawn (Pandalus platyceros) exposed to the sea lice controlling agent, emamectin benzoate (EB; 0.1-4.8 mg/kg sediment), were investigated. A mean sediment/water partitioning coefficient (K(p)) was determined to be 21.81 and significant levels of EB were detected in the tail muscle tissue in all exposed animals. Animals selected for the experiment did not have eggs and were of similar weight. Significant mortality was observed within 8 days of EB treatment at concentrations between 0.1 and 0.8 mg/kg and there was no effect of EB on molting. Twelve spot prawn cDNA sequences were isolated from the tail muscle either by directed cloning or subtractive hybridization of control versus EB exposed tissues. Three of the transcripts most affected by EB exposure matched sequences encoding the 60S ribosomal protein L22, spliceosome RNA helicase WM6/UAP56, and the intracellular signal mediator histidine triad nucleotide binding protein 1 suggesting that translation, transcription regulation, and apoptosis pathways were impacted. The mRNA encoding the molting enzyme, ?-N-acetylglucosaminidase, was not affected by EB treatment. However, the expression of this transcript was extremely variable making it unsuitable for effects assessment. The results suggest that short-term exposure to EB can impact biological processes within this non-target crustacean. PMID:22088864

Veldhoen, Nik; Ikonomou, Michael G; Buday, Craig; Jordan, Jameson; Rehaume, Vicki; Cabecinha, Melissa; Dubetz, Cory; Chamberlain, Jon; Pittroff, Sabrina; Vallée, Kurtis; van Aggelen, Graham; Helbing, Caren C

2012-02-01

218

Demecology in the Cambrian: synchronized molting in arthropods from the Burgess Shale  

PubMed Central

Background The Burgess Shale is well known for its preservation of a diverse soft-bodied biota dating from the Cambrian period (Series 3, Stage 5). While previous paleoecological studies have focused on particular species (autecology) or entire paleocommunities (synecology), studies on the ecology of populations (demecology) of Burgess Shale organisms have remained mainly anecdotal. Results Here, we present evidence for mass molting events in two unrelated arthropods from the Burgess Shale Walcott Quarry, Canadaspis perfecta and a megacheiran referred to as Alalcomenaeus sp. Conclusions These findings suggest that the triggers for such supposed synchronized molting appeared early on during the Cambrian radiation, and synchronized molting in the Cambrian may have had similar functions in the past as it does today. In addition, the finding of numerous juvenile Alalcomenaeus sp. molts associated with the putative alga Dictyophycus suggests a possible nursery habitat. In this nursery habitat a population of this animal might have found a more protected environment in which to spend critical developmental phases, as do many modern species today. PMID:23721223

2013-01-01

219

Effect of vitamins, probiotics and protein on semen traits in post-molt male broiler breeders.  

PubMed

The study aimed to investigate the comparative effect of vitamins E and C, probiotics, lower than normal protein level and the combination of these treatments in male broiler breeders after Zn-induced molting. One hundred and eighty birds at 65 weeks of age were divided into six groups (five replicates per group) in a completely randomized block design. Birds were induced to molt by mixing zinc oxide in feed at the rate of 3000 mg/kg of feed. Upon completion of molting, birds were fed different supplements. One group was kept as a control, while the other groups were fed: vitamin E (100 IU/kg), vitamin C (500 IU/kg), probiotics (50 mg/L of water), lower dietary protein level (14%) or the combination of these treatments. Results revealed that vitamins (E and C) supplementation increased (P<0.05) semen volume, however, sperm motility and egg fertility were significantly higher only in vitamin E supplemented group compared to control. The dead sperm percentage decreased (P<0.05) in vitamin C fed group, whereas, sperm concentration did not differ (P>0.05) between the control and treated groups. The results validate the key role of antioxidant vitamins in male broiler breeders' fertility after Zn-induced molting. PMID:23078867

Khan, R U; Rahman, Zia-ur; Javed, I; Muhammad, F

2012-11-01

220

Carotenoid-based plumage coloration and aggression during molt in male house finches  

E-print Network

Carotenoid-based plumage coloration and aggression during molt in male house finches Kevin J. Mc than or dominant to those with drab or small color patches. Male House Finches (Carpodacus mexicanus and in winter. One hypothesis for this `negatively correlated handicap' is that drab male house finches, being

McGraw, Kevin J.

221

Influence of exogenous melatonin administration on Salmonella enteritidis colonization in molted layers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two studies were conducted to evaluate the effects of exogenous melatonin on Salmonella enteritidis (SE) infection in experimentally-challenged laying hens subjected to a forced molt. Single Comb White Leghorn hens (W-36) over 50-wk-of-age were randomly placed in one of two rooms, allowed to acclima...

222

Annual survival and site fidelity of Stellar's Eiders molting along the Alaska Peninsula  

USGS Publications Warehouse

Populations of Steller?s eiders (Polysticta stelleri) molting and wintering along the Alaska Peninsula have declined since the 1960's. We captured and marked a large sample of Steller's eiders molting in 2 lagoons along the Alaska Peninsula between 1975-97. We used mark-recapture analysis techniques to estimate annual survival and movement probabilities within and among lagoons for male and female eiders. Estimates of annual survival (?SE) were 0.899 ? 0.032 for females and 0.765 ? 0.044 for males. Both sexes showed high rates of fidelity to specific molting locations (>95%) within lagoons; yet we found no evidence that annual probability of survival differed among groups molting in different locations either within or among lagoons. We found weak evidence that annual survival decreased between the periods 1975-81 and 1991-97. The lower survival of males compared to females is unusual for waterfowl and may result in a female-biased sex ratio. We conclude that a decrease in adult survival may have initiated the long-term population decline. Further, a shortage of males may be limiting reproductive potential.

Flint, P.L.; Petersen, M.R.; Dau, C.P.; Hines, J.E.; Nichols, J.D.

2000-01-01

223

Annual survival and site fidelity of Steller's eiders molting along the Alaska Peninsula  

USGS Publications Warehouse

Populations of Steller's eiders (Polysticta stelleri) molting and wintering along the Alaska Peninsula have declined since the 1960's. We captured and marked a large sample of Steller's eiders molting in 2 lagoons along the Alaska Peninsula between 1975-97. We used mark-recapture analysis techniques to estimate annual survival and movement probabilities within and among lagoons for male and female eiders. Estimates of annual survival (??SE) were 0.899 ?? 0.032 for females and 0.765 ?? 0.044 for males. Both sexes showed high rates of fidelity to specific molting locations (>95%) within lagoons; yet we found no evidence that annual probability of survival differed among groups molting in different locations either within or among lagoons. We found weak evidence that annual survival decreased between the periods 1975-81 and 1991-97. The lower survival of males compared to females is unusual for waterfowl and may result in a female-biased sex ratio. We conclude that a decrease in adult survival may have initiated the long-term population decline. Further, a shortage of males may be limiting reproductive potential.

Flint, P.L.; Petersen, M.R.; Dau, C.P.; Hines, J.E.; Nichols, J.D.

2000-01-01

224

Dietary mercury exposure causes decreased escape takeoff flight performance and increased molt rate in European starlings  

E-print Network

Dietary mercury exposure causes decreased escape takeoff flight performance and increased molt rate 2014 Ó Springer Science+Business Media New York 2014 Abstract Mercury is a widespread and persistent that forage from primarily terrestrial sources have shown evidence of bioaccumula- tion of mercury, but little

Swaddle, John

225

Changes in immunocompetence and other physiological measures during molt in Brown-headed Cowbirds (Molothrus ater)  

Microsoft Academic Search

We tested one of the foundational hypotheses of the field of ecological immunology: that it is difficult for animals to simultaneously carry out two or more especially demanding physiological processes at optimal levels because of energy needs or other factors that cause tradeoffs among competing components of life history. We investigated possible effects of molt (a costly life-history stage that

Vincenzo A. Ellis; Loren Merrill; John C. Wingfield; Adrian L. O'Loghlen; Stephen I. Rothstein

2012-01-01

226

Molt Migration in Relation to Breeding Success in Greater Snow Geese  

Microsoft Academic Search

We describe summer migratory movements by female greater snow geese (Chen caerulescens atlantica) breeding on Bylot Island, Nunavut. We followed 121 radio-collared females between 1997 and 2001 to determine the frequency and timing of their departure from the colony in relation to breeding status, nesting success, and molting chronology. We found that 90% (n = 51) of non-breeders (no nest

ERIC T. REED; JOËL BÊTY; JULIEN MAINGUY; GILLES GAUTHIER; JEAN-FRANÇOIS GIROUX

2003-01-01

227

Reference: Biol. Bull., 148: 259-273. (April 1975) COCKROACH MOLTING. I. TEMPORAL ORGANIZATION OF  

E-print Network

Reference: Biol. Bull., 148: 259-273. (April 1975) 259 COCKROACH MOLTING. I. TEMPORAL ORGANIZATION an approach to the study of cockroach development using feeding (Kunkel, 1966) and regeneration (O'Farrell and Stock, 1953) as extrinsically controllable cues for regulating the development of cockroach cultures

Kunkel, Joseph G.

228

High fidelity does not preclude colonization: range expansion of molting Black Brant on the Arctic coast of Alaska  

USGS Publications Warehouse

High rates of site fidelity have been assumed to infer static distributions of molting geese in some cases. To test this assumption, we examined movements of individually marked birds to understand the underlying mechanisms of range expansion of molting Black Brant (Branta bernicla nigricans) on the Arctic Coastal Plain (ACP) of Alaska. The Teshekpuk Lake Special Area (TLSA) on the ACP was created to protect the primary molting area of Brant. When established in 1977, the TLSA was thought to include most, if not all, wetlands used by molting Brant on the ACP. From 2010 to 2013, we surveyed areas outside the TLSA and counted an average of 9800 Brant per year, representing 29–37% of all molting Brant counted on the ACP. We captured and banded molting Brant in 2011 and 2012 both within the TLSA and outside the TLSA at the Piasuk River Delta and Cape Simpson to assess movements of birds among areas across years. Estimates of movement rates out of the TLSA exceeded those into the TLSA, demonstrating overall directional dispersal. We found differences in sex and age ratios and proportions of adult females with brood patches, but no differences in mass dynamics for birds captured within and outside the TLSA. Overall fidelity rates to specific lakes (0.81, range = 0.49–0.92) were unchanged from comparable estimates obtained in the early 1990s. We conclude that Brant are dispersing from the TLSA into new molting areas while simultaneously redistributing within the TLSA, likely as a consequence of changes in relative habitat quality. Shifts in distribution resulted from colonization of new areas by young birds as well as low levels of directional dispersal of birds that previously molted in the TLSA. Based on combined counts, the overall number of molting Brant across the ACP has increased substantially.

Flint, Paul L.; Meixell, Brandt W.; Mallek, Edward J.

2014-01-01

229

Effects of starvation and molting on the metabolic rate of the bed bug (Cimex lectularius L.).  

PubMed

The bed bug (Cimex lectularius L.) is a common hematophagous pest in the urban environment and is capable of surviving extended periods of starvation. However, the relationship between starvation and metabolism in bed bugs is not well understood. To better understand this relationship, we measured the metabolism of all life stages for >900 h after feeding (starvation) using closed-system respirometry. Measurements were made around molting for the immature life stages, which occurs only after a blood meal. In addition, both mated and unmated adults were measured. Starvation and molting had significant effects on the metabolism of the bed bug. Mass-specific metabolic rate (V(O2); mL g(-1) h(-1)) declined in a curvilinear fashion with the period of starvation for adults and with the postmolting period for immature bed bugs (used to standardize all immature life stages). A standard curve was developed to depict the generalized pattern of metabolic decline observed in all life stages that molted. Individual metabolic comparisons among life stages that molted revealed some differences in metabolic rate between unmated males and females. In addition, the mass scaling coefficient was found to decline with starvation time (postmolting time) for all life stages that molted. In most life stages, the ratio of V(CO2) to V(O2) (respiratory exchange ratio) declined over time, indicating a change in metabolic substrate with starvation. Finally, daily percent loss in body mass declined in a pattern similar to that of V(O2). The observed patterns in metabolic decline are evaluated in relation to the life history of bed bugs. In addition, the evolutionary development of these patterns is discussed. The metabolic pattern after feeding was also found to share several similarities with that of other ectothermic species. PMID:25590593

DeVries, Zachary C; Kells, Stephen A; Appel, Arthur G

2015-01-01

230

Effect of novel dinuclear platinum(II) complexes on redox status of MOLT-4 leukemic cells.  

PubMed

As the alkylating agents metabolism is accompanied by reactive oxygen species (ROS) generation, the aim of this study has been to compare the effect of cisplatin and novel platinum(II) complexes, Pt2(isopropylamine)4(berenil)2, Pt2(piperazine)4(berenil)2, Pt2(2-picoline)4(berenil)2, Pt2(3-picoline)4(berenil)2, Pt2(4-picoline)4(berenil)2, on the redox state of human leukemic T-cells line Molt-4. Treatment of Molt-4 with the novel complexes has shown that all compounds enhance total ROS and superoxide anion generation as well as change the activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. Moreover, all the above-mentioned compounds cause a decrease in the level of non-enzymatic antioxidants such as GSH as well as vitamin C, E and A. Such a situation is conducive to oxidative stress formation and oxidative modifications of cellular macromolecules. DNA damage of MOLT-4 leukemic cells is connected with 8-hydroxy-2'-deoxyguanosine and N7-methyldeoxyguanosine generation. The increased level of protein carbonyl groups and dityrosine indicates enhanced protein oxidative modifications, while an increase in the level of lipid peroxidation products, MDA, 4-HNE and isoprostanes proves the significant lipid peroxidation after treatment of Molt-4 cells with the complexes. Moreover, the complexes enhance expression of Bax and cytochrome c as well as decrease the expression of Bcl-2 and p53 protein. The novel platinum(II) complexes in comparison with cisplatin disturb redox status more intensively and lead to oxidative stress in Molt-4 cells. The enhanced oxidative modifications of macromolecules of human leukemic cancer cells lead to a shift in the proapoptotic-antiapoptotic balance into the proapoptotic direction. PMID:23859055

Jarocka, Iwona; G?gotek, Agnieszka; Bielawska, Anna; Bielawski, Krzysztof; ?uczaj, Wojciech; Hodun, Tomasz; Skrzydlewska, El?bieta

2013-11-01

231

Cloning of genomic sequences of three crustacean hyperglycemic hormone superfamily genes and elucidation of their roles of regulating insulin-like androgenic gland hormone gene.  

PubMed

The insulin-like androgenic gland hormone (IAG) gene in crustaceans plays an important role in male sexual differentiation, metabolism, and growth. However, the upstream regulation of IAG signaling schemes remains poorly studied. In the present study, we cloned the 5' flanking sequence of IAG and full-length genomic sequences of gonad-inhibiting hormone (Mn-GIH), molt-inhibiting hormone (Mn-MIH) and crustacean hyperglycemic hormone (Mn-CHH) in Macrobrachium nipponense. We identified the transcription factor-binding sites in the 5' flanking sequence of IAG and investigated the exon-intron patterns of the three CHH superfamily genes. Each CHH superfamily gene consisted of two introns separating three exons. Mn-GIH and Mn-MIH shared the same intron insertion sites, which differed from Mn-CHH. We provided DNA-level evidence for the type definition. We also identified two cAMP response elements in the 5' untranslated region. We further investigated the regulatory relationships between Mn-GIH, Mn-MIH, and Mn-CHH and IAG at the transcriptional level by injection of double-stranded RNA (dsRNA). IAG transcription levels were significantly increased to 660.2%, 472.9%, and 112.4% of control levels in the Mn-GIH dsRNA, Mn-MIH dsRNA, and Mn-CHH dsRNA groups, respectively. The results clearly demonstrated that Mn-GIH and Mn-MIH, but not Mn-CHH, negatively regulate the expression of the IAG gene. PMID:25680292

Li, Fajun; Bai, Hongkun; Zhang, Wenyi; Fu, Hongtuo; Jiang, Fengwei; Liang, Guoxia; Jin, Shubo; Sun, Shengming; Qiao, Hui

2015-04-25

232

Detection of tropomyosin and determination of proteins in crustacean oils.  

PubMed

Tropomyosin is known to be the main allergen in crustaceans and the objective of this study was to investigate if this protein could be detected in commercial crustacean oils from Antarctic krill (Euphausia superba) and the zooplankton Calanus finmarchicus. We also examined the possibility of determining the protein content in the oils by direct amino acid analysis. Western blotting showed that a commercial antibody against shrimp tropomyosin cross-reacted with a protein of similar size in Antarctic krill and C. finmarchicus. The protein tentatively identified as tropomyosin, was also detected in krill oil products, but not in oils from C. finmarchicus. The acetone-heptane method used for extracting proteins in the oils is however not optimal. Other extraction methods should therefore be considered when investigating the presence of allergenic proteins in oils. Direct amino acid analysis on oils should be further explored as a method for determining the total amount of proteins present. PMID:23768329

Vang, Birthe; Mæhre, Hanne K; Jensen, Ida-J; Olsen, Ragnar L

2013-11-01

233

Phylogenetic position of the pentastomida and [pan]crustacean relationships  

SciTech Connect

Pentastomids are a small group of vermiform animals with unique morphology and parasitic lifestyle. They are generally recognized as being related to the Arthropoda, however the nature of this relationship is controversial. We have determined the complete sequence of the mitochondrial DNA (mtDNA) of the pentastomid Armillifer armillatus and complete, or nearly complete, mtDNA sequences from representatives of four previously unsampled groups of Crustacea: Remipedia (Speleonectes tulumensis), Cephalocarida (Hutchinsoniella macracantha), Cirripedia (Pollicipes polymerus), and Branchiura (Argulus americanus). Analyses of the mtDNA gene arrangements and sequences determined in this study indicate unambiguously that pentastomids are a group of modified crustaceans likely related to branchiurans. In addition, gene arrangement comparisons strongly support an unforeseen assemblage of pentastomids with maxillopod and cephalocarid crustaceans, to the exclusion of remipedes, branchiopods, malacos tracans and insects.

Lavrov, Dennis V.; Brown, Wesley M.; Boore, Jeffrey L.

2004-01-31

234

Alien Marine Crustaceans of Japan: A Preliminary Assessment  

Microsoft Academic Search

\\u000a Although invasions may have commenced in the 1500s, our record of invasions of alien marine and estuarine species in Japan\\u000a begins largely in the 1930s. We expand the previous inventory of 10 alien species to 31 alien and cryptogenic species, underscoring\\u000a that this, too, may be a striking underestimate. Most of the marine crustacean invasions into Japan have occurred along

Wataru Doi; Seiichi Watanabe; James T. Carlton

235

The ecdysteroid titer in the female prawn, Macrobrachium rosenbergii during the molt cycle  

E-print Network

~ g of 20-hydroxyecdysone were injected onto the HPLC column. Fractions were collected from 5 to 18 min. , evaporated by vacuum centrifugation, and assayed. Data from three runs are shown in Figure 10. It is clear that. both ecdysone and 20... of labeled and unlabeled ecdysone through purification. Experiment 49: Ecdysteroid titer of prawn carcasses with determination of recovery. 38 39 TABLE 5. Experiment 410: HPLC analysis of zone E from TLC separations 45 TABLE 6. Experiment iI11...

Newitt, Richard Allen

1981-01-01

236

Horizontal transfer of transposons between and within crustaceans and insects  

PubMed Central

Background Horizontal transfer of transposable elements (HTT) is increasingly appreciated as an important source of genome and species evolution in eukaryotes. However, our understanding of HTT dynamics is still poor in eukaryotes because the diversity of species for which whole genome sequences are available is biased and does not reflect the global eukaryote diversity. Results In this study we characterized two Mariner transposable elements (TEs) in the genome of several terrestrial crustacean isopods, a group of animals particularly underrepresented in genome databases. The two elements have a patchy distribution in the arthropod tree and they are highly similar (>93% over the entire length of the element) to insect TEs (Diptera and Hymenoptera), some of which were previously described in Ceratitis rosa (Crmar2) and Drosophila biarmipes (Mariner-5_Dbi). In addition, phylogenetic analyses and comparisons of TE versus orthologous gene distances at various phylogenetic levels revealed that the taxonomic distribution of the two elements is incompatible with vertical inheritance. Conclusions We conclude that the two Mariner TEs each underwent at least three HTT events. Both elements were transferred once between isopod crustaceans and insects and at least once between isopod crustacean species. Crmar2 was also transferred between tephritid and drosophilid flies and Mariner-5 underwent HT between hymenopterans and dipterans. We demonstrate that these various HTTs took place recently (most likely within the last 3 million years), and propose iridoviruses and/or Wolbachia endosymbionts as potential vectors of these transfers. PMID:24472097

2014-01-01

237

Cloning and characterization of a calmodulin gene (CaM) in crayfish Procambarus clarkii and expression during molting.  

PubMed

Calmodulin (CaM) is a highly conserved calcium (Ca(2+)) binding protein that transduces Ca(2+) signals into downstream effects influencing a range of cellular processes, including Ca(2+) homeostasis. The present study explores CaM expression when Ca(2+) homeostasis is challenged during the mineralization cycle of the freshwater crayfish (Procambarus clarkii). In this paper we report the cloning of a CaM gene from axial abdominal crayfish muscle (referred to as pcCaM). The pcCaM mRNA is ubiquitously expressed but is far more abundant in excitable tissue (muscle, nerve) than in any epithelia (gill, antennal gland, digestive) suggesting that it plays a greater role in the biology of excitation than in epithelial ion transport. In muscle cells the pcCaM was colocalized on the plasma membrane with the Ca(2+) ATPase (PMCA) known to regulate intracellular Ca(2+) through basolateral efflux. While PMCA exhibits a greater upregulation in epithelia (than in non-epithelial tissues) during molting stages requiring transcellular Ca(2+) flux (pre- and postmolt compared with intermolt), expression of pcCaM exhibited a uniform increase in epithelial and non-epithelial tissues alike. The common increase in expression of CaM in all tissues during pre- and postmolt stages (compared with intermolt) suggests that the upregulation is systemically (hormonally) mediated. Colocalization of CaM with PMCA confirms physiological findings that their regulation is linked. PMID:19095075

Gao, Yongping; Gillen, Christopher M; Wheatly, Michele G

2009-03-01

238

Immunolocalisation of crustacean-SIFamide in the median brain and eyestalk neuropils of the marbled crayfish  

Microsoft Academic Search

Crustacean-SIFamide (GYRKPPFNGSIFamide) is a novel neuropeptide that was recently isolated from crayfish nervous tissue. We\\u000a mapped the localisation of this peptide in the median brain and eyestalk neuropils of the marbled crayfish (Marmorkrebs),\\u000a a parthenogenetic crustacean. Our experiments showed that crustacean-SIFamide is strongly expressed in all major compartments\\u000a of the crayfish brain, including all three optic neuropils, the lateral protocerebrum

M. A. Polanska; A. Yasuda; S. Harzsch

2007-01-01

239

Endocrine regulation of the reproduction in crustaceans: Identification of potential targets for toxicants and environmental contaminants  

Microsoft Academic Search

Progress in ecotoxicological research documents that crustaceans are highly vulnerable to diverse chemicals and toxicants\\u000a in the environment. In particular, pollutants affecting endocrine homeostasis in crustaceans (i.e., endocrine disruptors)\\u000a are intensively studied, and serious reproductive disorders have been documented. In this review, current knowledge about\\u000a the endocrine regulation of the crustacean reproduction is put together with the published ecotoxicological data

Edita Mazurová; Klára Hilscherová; Rita Triebskorn; Heinz-R. Köhler; Blahoslav Maršálek; Lud?k Bláha

2008-01-01

240

Using body mass dynamics to examine long-term habitat shifts of arctic-molting geese: evidence for ecological change  

Microsoft Academic Search

From 1976 onward, molting brant geese (Branta bernicla) within the Teshekpuk Lake Special Area, Alaska, shifted from inland, freshwater lakes toward coastal wetlands. Two hypotheses\\u000a explained this redistribution: (1) ecological change: redistribution of molting brant reflects improvements in coastal foraging\\u000a habitats, which have undergone a succession toward salt-tolerant plants due to increased coastal erosion and saltwater intrusion\\u000a as induced by

Tyler L. Lewis; Paul L. Flint; Dirk V. Derksen; Joel A. Schmutz; Eric J. Taylor; Karen S. Bollinger

241

Metamorphosis in the Cirripede Crustacean Balanus amphitrite  

PubMed Central

Stalked and acorn barnacles (Cirripedia Thoracica) have a complex life cycle that includes a free-swimming nauplius larva, a cypris larva and a permanently attached sessile juvenile and adult barnacle. The barnacle cyprid is among the most highly specialized of marine invertebrate larvae and its settlement biology has been intensively studied. By contrast, surprisingly few papers have dealt with the critical series of metamorphic events from cementation of the cyprid to the substratum until the appearance of a suspension feeding juvenile. This metamorphosis is both ontogenetically complex and critical to the survival of the barnacle. Here we use video microscopy to present a timeline and description of morphological events from settled cyprid to juvenile barnacle in the model species Balanus amphitrite, representing an important step towards both a broader understanding of the settlement ecology of this species and a platform for studying the factors that control its metamorphosis. Metamorphosis in B. amphitrite involves a complex sequence of events: cementation, epidermis separation from the cypris cuticle, degeneration of cypris musculature, rotation of the thorax inside the mantle cavity, building of the juvenile musculature, contraction of antennular muscles, raising of the body, shedding of the cypris cuticle, shell plate and basis formation and, possibly, a further moult to become a suspension feeding barnacle. We compare these events with developmental information from other barnacle species and discuss them in the framework of barnacle settlement ecology. PMID:22666355

Maruzzo, Diego; Aldred, Nick; Clare, Anthony S.; Høeg, Jens T.

2012-01-01

242

The First Complete Mitochondrial Genome Sequences for Stomatopod Crustaceans: Implications for Phylogeny  

SciTech Connect

We report the first complete mitochondrial genome sequences of stomatopods and compare their features to each other and to those of other crustaceans. Phylogenetic analyses of the concatenated mitochondrial protein-coding sequences were used to explore relationships within the Stomatopoda, within the malacostracan crustaceans, and among crustaceans and insects. Although these analyses support the monophyly of both Malacostraca and, within it, Stomatopoda, it also confirms the view of a paraphyletic Crustacea, with Malacostraca being more closely related to insects than to the branchiopod crustaceans.

Swinstrom, Kirsten; Caldwell, Roy; Fourcade, H. Matthew; Boore, Jeffrey L.

2005-09-07

243

Widespread Wolbachia infection in terrestrial isopods and other crustaceans 123 Widespread Wolbachia infection in terrestrial isopods  

E-print Network

range of crustacean hosts. Given the ability of isopod Wolbachia strains to induce feminization such as cytoplasmic incompatibility, male killing, thelytokous parthenogenesis and feminization of genetic males (O

Richard, Cordaux,

244

76 FR 77214 - Hawaii Crustacean Fisheries; 2012 Northwestern Hawaiian Islands Lobster Harvest Guideline  

Federal Register 2010, 2011, 2012, 2013, 2014

...DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA838 Hawaii Crustacean Fisheries; 2012 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries...

2011-12-12

245

Soldiers of a European gall aphid, Pemphigus spyrotecae (Homoptera: Aphidoidea): Why do they molt?  

Microsoft Academic Search

A non-migratory aphid,Pemphigus spyrothecae, produces 1 st-instar larvae of 2 types in the gall: thick-legged ones and normal-legged ones. It was found that the thick-legged\\u000a larvae play a defensive role, hence they may be called soldiers. Unlike the soldiers of other species hitherto reported, at\\u000a least some soldiers of this species molt and become adults. Their incomplete sterility is explained

Shigeyuki Aoki; Utako Kurosu

1986-01-01

246

Immunohistochemical localization and morphometry of somatotrophs and lactotrophs in protein, probiotic and symbiotic supplemented molted layers  

PubMed Central

Two hundred Single Comb White Leg-Horn spent hens at the age of 70 weeks were purchased from a commercial layer farm. The birds were shifted to the Poultry Research Station, Department of Physiology and Pharmacology, University of Agriculture, Faisalabad, Pakistan. High dietary zinc (3 g/kg feed/day) was used to induce molting in all the birds after one week of acclimatization. Thereafter, birds were divided in groups of 50 birds each, with the following treatments: G1 [control; crude protein (CP)16%, no other supplement], G2 (CP18%, no other supplement), G3 (CP16%, Symbiotic, 85 mg/L drinking water) and G4 (CP16%, Probiotic, 85 mg/L in drinking water). Fifteen birds were slaughtered at 5% of peak of production for each group to collect their pituitary glands. Better egg production was seen in all the supplemented groups as compared to the control. Especially an earlier post molt production recovery and delayed decline was seen in G2 as compared to all other groups. The immunohistochemistry of the pituitary gland reveals the decrease (P?0.01) in the cell and nucleus size as well as area of somatotrophs in G2 and G4 as compared to G1. The cell and nucleus size as well as area of lactotrophs decreased (P?0.01) in G2, G3 and G4 as compared to G1. The better and earlier post molt production in G2 highlights the potential role of protein supplementation in connection with the decreased lactotroph size and area in molted birds. PMID:23027344

Anwar, H.; Rahman, Z.U.; Javed, I.; Muhammad, F.

2012-01-01

247

Effects of a new molt-inducing insecticide, tebufenozide, on zooplankton communities in lake enclosures  

Microsoft Academic Search

A potent ecdysone agonist, tebufenozide, has recently been developed as a molt-inducing insecticide to control defoliating lepidopterans. As part of continuing research efforts to assess the effectiveness and environmental safety of this material for insect pest management in Canadian forests, tebufenozide (RH-5992-2F) was applied to large lake enclosures and the effects on zooplankton communities were evaluated. There were significant treatment

David P. Kreutzweiser; David R. Thomas

1995-01-01

248

Proteolytic cleavage of phospholipase Cg1 during apoptosis in Molt4 cells  

Microsoft Academic Search

Apoptosis is a cell suicide mechanism that requires the activation of cellular death pro- teases for its induction. We examined whether the progress of apoptosis involves cleavage of phospho- lipase C-g1 (PLC-g1), which plays a pivotal role in mitogenic signaling pathway. Pretreatment of T leu- kemic Molt-4 cells with PLC inhibitors such as U-73122 or ET-18-OCH3 potentiated etoposide-in- duced apoptosis

SUN SIK BAE; DAVID K. PERRY; YONG SEOK OH; JANG HYUN CHOI; SEHAMUDDIN H. GALADARI; TARIQ GHAYUR; SUNG HO RYU; YUSUF A. HANNUN; PANN-GHILL SUH

249

NHR-23 dependent collagen and hedgehog-related genes required for molting  

SciTech Connect

Highlights: {yields} NHR-23 is a critical regulator of nematode development and molting. {yields} The manuscript characterizes the loss-of-function phenotype of an nhr-23 mutant. {yields} Whole genome expression analysis identifies new potential targets of NHR-23. {yields} Hedgehog-related genes are identified as NHR-23 dependent genes. {yields} New link between sterol mediated signaling and regulation by NHR-23 is found. -- Abstract: NHR-23, a conserved member of the nuclear receptor family of transcription factors, is required for normal development in Caenorhabditis elegans where it plays a critical role in growth and molting. In a search for NHR-23 dependent genes, we performed whole genome comparative expression microarrays on both control and nhr-23 inhibited synchronized larvae. Genes that decreased in response to nhr-23 RNAi included several collagen genes. Unexpectedly, several hedgehog-related genes were also down-regulated after nhr-23 RNAi. A homozygous nhr-23 deletion allele was used to confirm the RNAi knockdown phenotypes and the changes in gene expression. Our results indicate that NHR-23 is a critical co-regulator of functionally linked genes involved in growth and molting and reveal evolutionary parallels among the ecdysozoa.

Kouns, Nathaniel A.; Nakielna, Johana; Behensky, Frantisek [Laboratory of Model Systems, Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague (Czech Republic)] [Laboratory of Model Systems, Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague (Czech Republic); Krause, Michael W. [Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (United States)] [Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (United States); Kostrouch, Zdenek [Laboratory of Model Systems, Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague (Czech Republic)] [Laboratory of Model Systems, Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague (Czech Republic); Kostrouchova, Marta, E-mail: marta.kostrouchova@lf1.cuni.cz [Laboratory of Model Systems, Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague (Czech Republic)] [Laboratory of Model Systems, Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague (Czech Republic)

2011-10-07

250

The effects of ethidium bromide induced loss of mitochondrial DNA on mitochondrial phenotype and ultrastructure in a human leukemia T-cell line (MOLT4 cells)  

Microsoft Academic Search

Mitochondrial DNA-deficient (?0) cells were generated following a 26-day incubation of MOLT-4 lymphoblastoid T cells in ethidium bromide (3,8-diamino-5-ethyl-6-phenylphenanthridinium bromide). The absence of mitochondrial DNA (mtDNA) in the resultant MOLT-4 ?0 cells was confirmed by Southern analysis and quantitative polymerase chain reaction (PCR). MOLT-4 ?0 cells proliferated more slowly than parental cells (wild type) and produced significantly more lactate (approximately

Ray Armand; Jacqueline Y Channon; Jennifer Kintner; Kristina A White; Kristin A Miselis; Raymond P Perez; Lionel D Lewis

2004-01-01

251

The impact of pathogens on exploited populations of decapod crustaceans.  

PubMed

Several crustacean fisheries have experienced significant outbreaks of disease that have damaged their industries. Not only do fisheries suffer from direct losses to pathogens, such as disease-induced mortalities or reduced product value, but they can also incur indirect losses such as stunting, castration, and increased risk of predation. In some cases, the indirect losses can be substantial, yet they are often overlooked by the fishing industry as their primary focus is on recruits to the fishery, and not on the affected juvenile pre-recruits. Low levels of pathogens are to be expected in natural populations of commercial species, but baseline data on the prevalence and intensity of even the most common agents is often lacking. It is important to establish baselines for two reasons. First, it is important to know what pathogens exist in heavily exploited populations so as to gauge their potential to damage the industry; and second, during outbreaks, it is important to know whether an outbreak is a newly emergent event or whether it is a component of a cyclical phenomenon. Pathogens frequently act in concert with environmental stressors, and a variety of stressors have contributed to outbreaks of emerging agents in crustacean fisheries. Pollution, poor water quality, hypoxia, temperature extremes, and overexploitation have all been implicated as stressors in various outbreaks. This review focuses on epidemic diseases of commercially fished crustaceans. Outbreaks in cultured stocks are not covered. Disease epizootics have occurred in fished populations of crayfish and shrimp but they are less well known than the issues arising from extensive aquaculture of these species. PMID:22434001

Shields, Jeffrey D

2012-06-01

252

Adult neurogenesis in the decapod crustacean brain: A hematopoietic connection?  

PubMed Central

New neurons are produced and integrated into circuits in the adult brains of many organisms, including crustaceans. In some crustacean species, the 1st- generation neuronal precursors reside in a niche exhibiting characteristics analogous to mammalian neurogenic niches. However, unlike mammalian niches where several generations of neuronal precursors coexist, the lineage of precursor cells in crayfish is spatially separated allowing the influence of environmental and endogenous regulators on specific generations in the neuronal precursor lineage to be defined. Experiments also demonstrate that the 1st-generation neuronal precursors in the crayfish Procambarus clarkii are not self-renewing. A source external to the neurogenic niche must therefore provide cells that replenish the 1st-generation precursor pool, because although these cells divide and produce a continuous efflux of 2nd-generation cells from the niche, the population of 1st-generation niche precursors is not diminished with growth and aging. In vitro studies show that cells extracted from the hemolymph, but not other tissues, are attracted to and incorporated into the neurogenic niche, a phenomenon that appears to involve serotonergic mechanisms. We propose that in crayfish, the hematopoietic system may be a source of cells that replenish the niche cell pool. These and other studies reviewed here establish decapod crustaceans as model systems in which the processes underlying adult neurogenesis, such as stem cell origins and transformation, can be readily explored. Studies in diverse species where adult neurogenesis occurs will result in a broader understanding of fundamental mechanisms and how evolutionary processes may have shaped the vertebrate/mammalian condition. PMID:21929622

Beltz, Barbara S.; Zhang, Yi; Benton, Jeanne L.; Sandeman, David C.

2011-01-01

253

C. elegans NIMA-related kinases NEKL-2 and NEKL-3 are required for the completion of molting.  

PubMed

Caenorhabditis elegans molting is a process during which the apical extracellular matrix of the epidermis, the cuticle, is remodeled through a process of degradation and re-synthesis. Using a genetic approach, we identified nekl-3 as essential for the completion of molting. NEKL-3 is highly similar to the mammalian NEK kinase family members NEK6 and NEK7. Animals homozygous for a hypomorphic mutation in nekl-3, sv3, had a novel molting defect in which the central body region, but not the head or tail, was unable to shed the old cuticle. In contrast, a null mutation in nekl-3, gk506, led to complete enclosure within the old cuticle. nekl-2, which is most similar to mammalian NEK8, was also essential for molting. Mosaic analyses demonstrated that NEKL-2 and NEKL-3 were specifically required within the large epidermal syncytium, hyp7, to facilitate molting. Consistent with this, NEKL-2 and NEKL-3 were expressed at the apical surface of hyp7 where they localized to small spheres or tubular structures. Inhibition of nekl-2, but not nekl-3, led to the mislocalization of LRP-1/megalin, a cell surface receptor for low-density lipoprotein (LDL)-binding proteins. In addition, nekl-2 inhibition led to the mislocalization of several other endosome-associated proteins. Notably, LRP-1 acts within hyp7 to facilitate completion of molting, suggesting at least one mechanism by which NEKL-2 may influence molting. Notably, our studies failed to reveal a requirement for NEKL-2 or NEKL-3 in cell division, a function reported for several mammalian NEKs including NEK6 and NEK7. Our findings provide the first genetic and in vivo evidence for a role of NEK family members in endocytosis, which may be evolutionarily conserved. PMID:25523392

Yochem, John; Lažeti?, Vladimir; Bell, Leslie; Chen, Lihsia; Fay, David

2015-02-15

254

Crustacean diseases in European legislation: Implications for importing and exporting nations  

Microsoft Academic Search

EC Council Directive 2006\\/88\\/EC, adopted during 2008, has for the first time introduced controls for crustacean diseases to be applied across all Member States of the European Union. It lists three crustacean diseases, all of which are caused by viral pathogens and primarily associated with the production of marine penaeid shrimp: White Spot Disease (WSD) caused by the White Spot

G. D. Stentiford; B. Oidtmann; A. Scott; E. J. Peeler

2010-01-01

255

Crustaceans associated with Cnidaria, Bivalvia, Echinoidea and Pisces at São Tomé and Príncipe islands  

Microsoft Academic Search

Symbiotic crustaceans were searched for at sea anemones (Actiniaria), encrusting anemones (Zoantharia), horny coral (Gorgonaria), black coral (Antipatharia), bivalves (Bivalvia), and sea urchins (Echinoidea) at São Tomé and Príncipe Islands (Gulf of Guinea, eastern central Atlantic). Sixteen species of crustaceans were found in association with these invertebrate hosts; eleven of them were new records for the area and two species,

PETER WIRTZ

256

Compound eyes and ocular pigments of crustacean larvae (Stomatopoda and decapoda, brachyura)  

Microsoft Academic Search

Larvae of decapod and stomatopod crustaceans possess paired compound eyes not unlike those of adult crustaceans. However, the visual demands of larval and adult life differ considerably. Furthermore, the eyes of adult stomatopods appear to be far more specialized than those of the larvae. We examined eyes of several stomatopod species just before and after larval metamorphosis. At this time,

Thomas W. Cronin; N. Justin Marshall; Roy L. Caldwell; Dmitriy Pales

1995-01-01

257

Does the accumulation of trace metals in crustaceans affect their ecology—the amphipod example?  

Microsoft Academic Search

Crustaceans, like all aquatic invertebrates, take up and accumulate metals from a wide range of sources and the trace metal concentrations within their tissues and bodies show great variability. Trace metal uptake in crustaceans occurs from the water and food, either of which may be affected by the physico-chemical properties of the sediment. Accumulated metal concentrations in amphipods are contrasted

I. D Marsden; P. S Rainbow

2004-01-01

258

Seasonal dynamics of rotifer and crustacean zooplankton populations in a eutrophic, monomictic lake with a note on rotifer sampling techniques  

Microsoft Academic Search

The abundances, biomass, and seasonal succession of rotifer and crustacean zooplankton were examined in a man-made, eutrophic lake, Lake Oglethorpe, over a 13 month period. There was an inverse correlation between the abundance of rotifers and crustaceans. Rotifers were most abundant and dominated (>69%) the rotifer-crustacean biomass during summer months (June–September) while crustacean zooplankton dominated during the remainder of the

John D. Orcutt; Michael L. Pace

1984-01-01

259

Pancrustacean phylogeny: hexapods are terrestrial crustaceans and maxillopods are not monophyletic.  

PubMed

Recent molecular analyses indicate that crustaceans and hexapods form a clade (Pancrustacea or Tetraconata), but relationships among its constituent lineages, including monophyly of crustaceans, are controversial. Our phylogenetic analysis of three protein-coding nuclear genes from 62 arthropods and lobopods (Onychophora and Tardigrada) demonstrates that Hexapoda is most closely related to the crustaceans Branchiopoda (fairy shrimp, water fleas, etc.) and Cephalocarida + Remipedia, thereby making hexapods terrestrial crustaceans and the traditionally defined Crustacea paraphyletic. Additional findings are that Malacostraca (crabs, isopods, etc.) unites with Cirripedia (barnacles, etc.) and they, in turn, with Copepoda, making the traditional crustacean class Maxillopoda paraphyletic. Ostracoda (seed shrimp)--either all or a subgroup--is associated with Branchiura (fish lice) and likely to be basal to all other pancrustaceans. A Bayesian statistical (non-clock) estimate of divergence times suggests a Precambrian origin for Pancrustacea (600 Myr ago or more), which precedes the first unambiguous arthropod fossils by over 60 Myr. PMID:15734694

Regier, Jerome C; Shultz, Jeffrey W; Kambic, Robert E

2005-02-22

260

Pancrustacean phylogeny: hexapods are terrestrial crustaceans and maxillopods are not monophyletic  

PubMed Central

Recent molecular analyses indicate that crustaceans and hexapods form a clade (Pancrustacea or Tetraconata), but relationships among its constituent lineages, including monophyly of crustaceans, are controversial. Our phylogenetic analysis of three protein-coding nuclear genes from 62 arthropods and lobopods (Onychophora and Tardigrada) demonstrates that Hexapoda is most closely related to the crustaceans Branchiopoda (fairy shrimp, water fleas, etc.) and Cephalocarida+Remipedia, thereby making hexapods terrestrial crustaceans and the traditionally defined Crustacea paraphyletic. Additional findings are that Malacostraca (crabs, isopods, etc.) unites with Cirripedia (barnacles, etc.) and they, in turn, with Copepoda, making the traditional crustacean class Maxillopoda paraphyletic. Ostracoda (seed shrimp)—either all or a subgroup—is associated with Branchiura (fish lice) and likely to be basal to all other pancrustaceans. A Bayesian statistical (non-clock) estimate of divergence times suggests a Precambrian origin for Pancrustacea (600 Myr ago or more), which precedes the first unambiguous arthropod fossils by over 60 Myr. PMID:15734694

Regier, Jerome C.; Shultz, Jeffrey W.; Kambic, Robert E.

2005-01-01

261

Null point of discrimination in crustacean polarisation vision.  

PubMed

The polarisation of light is used by many species of cephalopods and crustaceans to discriminate objects or to communicate. Most visual systems with this ability, such as that of the fiddler crab, include receptors with photopigments that are oriented horizontally and vertically relative to the outside world. Photoreceptors in such an orthogonal array are maximally sensitive to polarised light with the same fixed e-vector orientation. Using opponent neural connections, this two-channel system may produce a single value of polarisation contrast and, consequently, it may suffer from null points of discrimination. Stomatopod crustaceans use a different system for polarisation vision, comprising at least four types of polarisation-sensitive photoreceptor arranged at 0, 45, 90 and 135 deg relative to each other, in conjunction with extensive rotational eye movements. This anatomical arrangement should not suffer from equivalent null points of discrimination. To test whether these two systems were vulnerable to null points, we presented the fiddler crab Uca heteropleura and the stomatopod Haptosquilla trispinosa with polarised looming stimuli on a modified LCD monitor. The fiddler crab was less sensitive to differences in the degree of polarised light when the e-vector was at -45 deg than when the e-vector was horizontal. In comparison, stomatopods showed no difference in sensitivity between the two stimulus types. The results suggest that fiddler crabs suffer from a null point of sensitivity, while stomatopods do not. PMID:24737768

How, Martin J; Christy, John; Roberts, Nicholas W; Marshall, N Justin

2014-07-15

262

Shrimps that pay attention: saccadic eye movements in stomatopod crustaceans  

PubMed Central

Discovering that a shrimp can flick its eyes over to a fish and follow up by tracking it or flicking back to observe something else implies a ‘primate-like’ awareness of the immediate environment that we do not normally associate with crustaceans. For several reasons, stomatopods (mantis shrimp) do not fit the general mould of their subphylum, and here we add saccadic, acquisitional eye movements to their repertoire of unusual visual capabilities. Optically, their apposition compound eyes contain an area of heightened acuity, in some ways similar to the fovea of vertebrate eyes. Using rapid eye movements of up to several hundred degrees per second, objects of interest are placed under the scrutiny of this area. While other arthropod species, including insects and spiders, are known to possess and use acute zones in similar saccadic gaze relocations, stomatopods are the only crustacean known with such abilities. Differences among species exist, generally reflecting both the eye size and lifestyle of the animal, with the larger-eyed more sedentary species producing slower saccades than the smaller-eyed, more active species. Possessing the ability to rapidly look at and assess objects is ecologically important for mantis shrimps, as their lifestyle is, by any standards, fast, furious and deadly. PMID:24395969

Marshall, N. J.; Land, M. F.; Cronin, T. W.

2014-01-01

263

Structural marsh management effects on coastal fishes and crustaceans  

NASA Astrophysics Data System (ADS)

Structural marsh management, using levees and water-control structures, is used in the coastal zone for many objectives, for example, to reduce marsh loss, to enhance waterfowl habitat, to revegetate open-water areas, and to reduce saltwater intrusion. The literature was evaluated to categorize structural marsh management and to determine some of its effects on fishes and crustaceans. Structural marsh management had positive effects on standing stock of most resident organisms and negative effects on marine-transient organisms. Emigration was negatively affected for both resident and marine-transient organisms. Techniques such as opening structures at critical migration times, designing structures that offer the greatest management flexibility, and using structures to create a flow-through system could reduce these impacts. More effort should be put into monitoring managed areas to determine if the objectives are being met and to evaluate the effects on fishes and crustaceans. Although frequent manipulation could reduce these impacts, the costs and problems incurred may outweigh the anticipated benefits.

Rogers, Donna R.; Rogers, Barton D.; Herke, William H.

1994-05-01

264

Recrudescence Mechanisms and Gene Expression Profile of the Reproductive Tracts from Chickens during the Molting Period  

PubMed Central

The reproductive system of chickens undergoes dynamic morphological and functional tissue remodeling during the molting period. The present study identified global gene expression profiles following oviductal tissue regression and regeneration in laying hens in which molting was induced by feeding high levels of zinc in the diet. During the molting and recrudescence processes, progressive morphological and physiological changes included regression and re-growth of reproductive organs and fluctuations in concentrations of testosterone, progesterone, estradiol and corticosterone in blood. The cDNA microarray analysis of oviductal tissues revealed the biological significance of gene expression-based modulation in oviductal tissue during its remodeling. Based on the gene expression profiles, expression patterns of selected genes such as, TF, ANGPTL3, p20K, PTN, AvBD11 and SERPINB3 exhibited similar patterns in expression with gradual decreases during regression of the oviduct and sequential increases during resurrection of the functional oviduct. Also, miR-1689* inhibited expression of Sp1, while miR-17-3p, miR-22* and miR-1764 inhibited expression of STAT1. Similarly, chicken miR-1562 and miR-138 reduced the expression of ANGPTL3 and p20K, respectively. These results suggest that these differentially regulated genes are closely correlated with the molecular mechanism(s) for development and tissue remodeling of the avian female reproductive tract, and that miRNA-mediated regulation of key genes likely contributes to remodeling of the avian reproductive tract by controlling expression of those genes post-transcriptionally. The discovered global gene profiles provide new molecular candidates responsible for regulating morphological and functional recrudescence of the avian reproductive tract, and provide novel insights into understanding the remodeling process at the genomic and epigenomic levels. PMID:24098561

Ahn, Suzie E.; Lim, Chul-Hong; Lee, Jin-Young; Bae, Seung-Min; Kim, Jinyoung; Bazer, Fuller W.; Song, Gwonhwa

2013-01-01

265

The effect of dietary erythromycin and force molting on the reproductive performance of heavy breed hens  

E-print Network

"tality /0 1F 2F 3F 4. F 5F 6F 7F BF Control Control ? Molted 100 ? Intermittently 100 ? Continuously 200 ? Intermittently 200 ? Continuously 500 ? Intermittently 500 ? Cont'nuously 421 410 432 461 411 431 434 447 l. 69 1 ~ 77 1.... and Ned. 77:209-213. Zlam, J. F. , L. I. Gee, and. J. R. Couch, 1951b. Function and metabolic significance of peni- cillin and bacitracin in the chick. I'bid. . 78:832-836. 39 Elam, J. F. , R. L. Jacobs, and J. R. Couch, 1953. The effect of prolonged...

Noriega Coello, Carlos

1969-01-01

266

[The infradian rhythm in changes of thyroxine level and related periodicity of feather replacement during the molting in passerine birds].  

PubMed

In the course of 15 days, the thyroxine and corticosterone level was measured daily in blood serum of molting starlings, Sturnus vulgaris, by use of enzyme immunodetection method. Revealed are three-day rhythm in changes of thyroxine level and four-day one in changes of corticosterone level, both rhythms being synchronized in different birds. A beginning of growth of new oar feathers coincides with maximum thyroxine concentration in blood serum and also demonstrates a three-day period. In free-living passerine birds (Passer montamus, Parus major, Chloris chloris) a three-day rhythm is found in the dynamics of feather replacement. This rhythm is manifested synchronously in the studied species that differ in timing of post-nuptial molting. Established is the synchronous manifestation of three-day rhythm in changes of thyroxine level and feather replacement during molting in different passerine species and different birds of the same species. PMID:25508100

2013-01-01

267

[The infradian rhythm in changes of thyroxine level and related periodicity of feather replacement during the molting in passerine birds].  

PubMed

In the course of 15 days, the thyroxine and corticosterone level was measured daily in blood serum of molting starlings, Sturnus vulgaris, by use of enzyme immunodetection method. Revealed are three-day rhythm in changes of thyroxine level and four-day one in changes of corticosterone level, both rhythms being synchronized in different birds. A beginning of growth of new oar feathers coincides with maximum thyroxine concentration in blood serum and also demonstrates a three-day period. In free-living passerine birds (Passer montamus, Parus major, Chloris chloris) a three-day rhythm is found in the dynamics of feather replacement. This rhythm is manifested synchronously in the studied species that differ in timing of post-nuptial molting. Established is the synchronous manifestation of three-day rhythm in changes of thyroxine level and feather replacement during molting in different passerine species and different birds of the same species. PMID:25438569

Diatroptov, M E

2013-01-01

268

Size Dimorphism, Molt Status, and Body Mass Variation of Prairie Falcons Nesting in the Snake River Birds of Prey National Conservation Area  

Microsoft Academic Search

Birds face challenges in how they allocate energy during the reproductive season. Most temperate zone species do not breed and molt at the same time, presumably because of the high energy demands of these two activities (Espie et al. 1996 and citations therein). However, representatives of at least four raptor genera are known to molt during the nesting season (Schmutz

Karen Steenhof; James O. McKinley; Cheryl R. Dykstra

2006-01-01

269

Plumage development and molt in Long-tailed Manakins (Chiroxiphia linearis): Variation according to sex and age  

USGS Publications Warehouse

Lek-mating Long-tailed Manakins (Chiroxiphia linearis) exhibit an unusual pattern of delayed plumage maturation. Each year, males progress through a series of predefinitive plumages before attaining definitive plumage in their fifth calendar year. Females also exhibit variation in plumage coloration, with some females displaying male-like plumage characteristics. Using data from mist-net captures in northwest Costa Rica (n = 1,315) and museum specimens from throughout the range of Long-tailed Manakins (n = 585), we documented the plumage sequence progression of males, explored variation in female plumage, and described the timing of molt in this species. Males progressed through a series of age-specific predefinitive plumages, which enabled the accurate aging of predefinitive-plumaged males in the field; this preclefinitive plumage sequence is the basis for age-related status- signaling in these males. Females tended to acquire red coloration in the crown as they aged. However, colorful plumage in females may be a byproduct of selection on bright male plumage. Females exhibited an early peak of molt activity from February to April, little molt from May through July, and a second, more pronounced peak of molt activity in October. By contrast, males in older predefinitive-plumage stages and males in definitive plumage exhibited comparable unimodal distributions in molt activity beginning in June and peaking between July and October. Our data are consistent with selective pressure to avoid the costs of molt-breeding overlap in females and older males. Our findings have important implications for social organization and signaling in Longtailed Manakins, and for the evolution of delayed plumage maturation in birds.

Doucet, S.M.; McDonald, D.B.; Foster, M.S.; Clay, R.P.

2007-01-01

270

Multiple forms of calcium-dependent proteinase in crustacean muscle  

SciTech Connect

Four calcium-dependent proteinase (CDP) activities in lobster muscles have been resolved by high performance liquid chromatography. These activities differ in molecular weight and net charge. Though optimum activity occurred at high (5 and 10 mM) calcium at pH 6.8, the enzymes differ in activation at lower calcium concentrations. Only one of the CDPs is active at 100 ..mu..M calcium; none are active at 10 ..mu..M and below. Although all four CDPs are inhibited by the cysteine proteinase inhibitors leupeptin, E-64, and iodoacetamide, they show a differential response to the aspartic proteinase inhibitor pepstatin and the serine proteinase inhibitor PMSF. In contrast to CDPs from vertebrate tissues, crustacean muscles contain multiple forms that require calcium at millimolar levels. 17 refs., 6 figs.

Mykles, D.L.; Skinner, D.M.

1986-01-01

271

Crustacean zooplankton in aerated wastewater treatment lagoons as a potential feedstock for biofuel.  

PubMed

Zooplankton biomass productivity was estimated for two 64,000 m3 (1.7 ha) facultative aerated wastewater treatment lagoons to evaluate potential biodiesel production from zooplankton biomass. Lagoons were monitored bi-weekly during summer 2010. Lipid accumulated by crustacean zooplankton was considered the most efficient means by which to collect lipid produced by phytoplankton owing to the greater ease in the collection of these organisms (>0.153mm) compared with unicellular algae (size <0.06 mm). In terms of biomass, the cladoceran Daphnia and the copepod Cyclops were the dominant zooplankton in these hypereutrophic lagoons, while unicellular chlorophytes dominated the phytoplankton community. Secondary productivity of these lagoons (250 g of dry weight m(-2) yr(-1)) is comparable to the secondary productivity of other sewage lagoons. The potential biodiesel production for one lagoon was estimated to be 0.04 +/- 0.02 L m(-2) yr(-1), which results in a total of 1120 +/- 560 L from two lagoons. This study showed that there are organisms present in wastewater lagoons, besides algae, that can serve as a biofuel feedstock. Additionally, this research expands the current knowledge of facultative aerated wastewater lagoon ecology and waste stream-derived biofuel. Future research should include complete life cycle and economic analyses to determine if harvesting zooplankton from wastewater lagoons is a sustainable endeavour. PMID:24350451

Kring, Stefanie A; Xia, Xiaoyan; Powers, Susan E; Twiss, Michael R

2013-01-01

272

Arthropod phylogeny revisited, with a focus on crustacean relationships.  

PubMed

Higher-level arthropod phylogenetics is an intensely active field of research, not least as a result of the hegemony of molecular data. However, not all areas of arthropod phylogenetics have so far received equal attention. The application of molecular data to infer a comprehensive phylogeny of Crustacea is still in its infancy, and several emerging results are conspicuously at odds with morphology-based studies. In this study, we present a series of molecular phylogenetic analyses of 88 arthropods, including 57 crustaceans, representing all the major lineages, with Onychophora and Tardigrada as outgroups. Our analyses are based on published and new sequences for two mitochondrial markers, 16S rDNA and cytochrome c oxidase subunit I (COI), and the nuclear ribosomal gene 18S rDNA. We designed our phylogenetic analyses to assess the effects of different strategies of sequence alignment, alignment masking, nucleotide coding, and model settings. Our comparisons show that alignment optimization of ribosomal markers based on secondary structure information can have a radical impact on phylogenetic reconstruction. Trees based on optimized alignments recover monophyletic Arthropoda (excluding Onychophora), Pancrustacea, Malacostraca, Insecta, Myriapoda and Chelicerata, while Maxillopoda and Hexapoda emerge as paraphyletic groups. Our results are unable to resolve the highest-level relationships within Arthropoda, and none of our trees supports the monophyly of Myriochelata or Mandibulata. We discuss our results in the context of both the methodological variations between different analyses, and of recently proposed phylogenetic hypotheses. This article offers a preliminary attempt to incorporate the large diversity of crustaceans into a single molecular phylogenetic analysis, assessing the robustness of phylogenetic relationships under varying analysis parameters. It throws into sharp relief the relative strengths and shortcomings of the combined molecular data for assessing this challenging phylogenetic problem, and thereby provides useful pointers for future studies. PMID:19854296

Koenemann, Stefan; Jenner, Ronald A; Hoenemann, Mario; Stemme, Torben; von Reumont, Björn M

2010-01-01

273

REPRODUCTIVE AND DEVELOPMENTAL SCREENING PROTOCOLS FOR ENDOCRINE DISRUPTORS USING ESTUARINE CRUSTACEANS  

EPA Science Inventory

The objective of this research is to develop in vivo screening protocols for endocrine disruption in marine crustaceans, invertebrates of ecological and economic importance. A series of comparative developmental and reproductive studies were performed on several species of estuar...

274

THE INFLUENCE OF INSECT JUVENILE HORMONE AGONISTTS ON METAMORPHOSIS AND REPRODUCTION IN ESTUARINE CRUSTACEANS  

EPA Science Inventory

Comparative developmental and reproductive studies were performed on several species of estuarine crustaceans in response to three juvenile hormone agonists (JHAs) (methoprene, fenoxycarb, and pyriproxyfen). Larval development of the grass shrimp, Palaemonetes pugio, was greater ...

275

POLYCLONAL ANTISERA AGAINST ESTUARINE CRUSTACEAN VITELLINS: A MOLECULAR APPROACH TO REPRODUCTIVE ENDOCRINOLOGY AND TOXICOLOGY  

EPA Science Inventory

To fully elucidate the action of crustacean hormones, or their agonists, on reproduction and vitellogenesis it has become increasingly important to develop sensitive assays that indicate a stimulatory or inhibitory effect on easily measured endpoints. Because of the relative abun...

276

76 FR 4551 - Hawaii Crustacean Fisheries; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline  

Federal Register 2010, 2011, 2012, 2013, 2014

...DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 665 RIN 0648-XA159 Hawaii Crustacean Fisheries; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries...

2011-01-26

277

78 FR 9327 - Hawaii Crustacean Fisheries; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline  

Federal Register 2010, 2011, 2012, 2013, 2014

...DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 665 RIN 0648-XC453 Hawaii Crustacean Fisheries; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries...

2013-02-08

278

Chemical Communication in Crustaceans: Research Challenges for the Twenty-First Century  

Microsoft Academic Search

\\u000a Chemical signals play an important role during various life stages of crustaceans. Settling of larvae, parent–offspring communication,\\u000a mate finding, mate choice, aggressive contests, and dominance hierarchies are all mediated by chemical signals. Enormous advances\\u000a have been made on understanding the function of chemical signals in crustaceans and we are on the doorstep of major advances\\u000a in chemical characterization of pheromones.

Martin Thiel; Thomas Breithaupt

279

Neurogenesis in the central olfactory pathway of adult decapod crustaceans: development of the neurogenic niche in the brains of procambarid crayfish  

PubMed Central

Background In the decapod crustacean brain, neurogenesis persists throughout the animal's life. After embryogenesis, the central olfactory pathway integrates newborn olfactory local and projection interneurons that replace old neurons or expand the existing population. In crayfish, these neurons are the descendants of precursor cells residing in a neurogenic niche. In this paper, the development of the niche was documented by monitoring proliferating cells with S-phase-specific markers combined with immunohistochemical, dye-injection and pulse-chase experiments. Results Between the end of embryogenesis and throughout the first post-embryonic stage (POI), a defined transverse band of mitotically active cells (which we will term 'the deutocerebral proliferative system' (DPS) appears. Just prior to hatching and in parallel with the formation of the DPS, the anlagen of the niche appears, closely associated with the vasculature. When the hatchling molts to the second post-embryonic stage (POII), the DPS differentiates into the lateral (LPZ) and medial (MPZ) proliferative zones. The LPZ and MPZ are characterized by a high number of mitotically active cells from the beginning of post-embryonic life; in contrast, the developing niche contains only very few dividing cells, a characteristic that persists in the adult organism. Conclusions Our data suggest that the LPZ and MPZ are largely responsible for the production of new neurons in the early post-embryonic stages, and that the neurogenic niche in the beginning plays a subordinate role. However, as the neuroblasts in the proliferation zones disappear during early post-embryonic life, the neuronal precursors in the niche gradually become the dominant and only mechanism for the generation of new neurons in the adult brain. PMID:22225949

2012-01-01

280

Growth versus molting time of caterpillars as a function of temperature, nutrient concentration and the phenolic rutin  

Microsoft Academic Search

A factorial experiment tested the effects of varying nutrient concentration (normal versus diluted), presence or absence of the phenolic allelochemical rutin and daytime temperature (20, 25 and 30° C) on growth, molting and food utilization efficiencies of tobacco hornworms (Manduca sexta). Two of the utilization efficiencies (approximate digestibility and efficiency of conversion of ingested food) were unaffected by temperature; the

Nancy E. Stamp

1990-01-01

281

Immunological cell and serum metabolite response of sixty-week old commercial laying hens to an alfalfa meal molt diet  

Technology Transfer Automated Retrieval System (TEKTRAN)

The practice of inducing molt in commercial poultry involves light restriction, feed removal, and limiting water for five to fourteen days. Many animal welfare groups are concerned about this issue due to the stresses that feed and water deprivation cause. With this in mind, alternative diets have...

282

Molt-Related and Size-Dependent Differences in the Escape Response and Post-Threat Behavior of the  

E-print Network

Molt-Related and Size-Dependent Differences in the Escape Response and Post-Threat Behavior Department, University of Rhode Island, Kingston, Rhode Island 02881 Abstract. Videotaped recordings of adult stage: more hard-shelled (intermolt stage C) and (premolt stage D) animals tailflipped than did soft

Cromarty, Stuart I.

283

762 shorT commUnicaTions AN IMPROVED EXTRACTION METHOD TO INCREASE DNA YIELD FROM MOLTED FEATHERS  

E-print Network

- vasive source of DNA for genetic studies of Northern Goshawks (Accipiter gentilis), we isolated words: Accipiter gentilis, DNA extraction, DNA yield, molted feathers, noninvasive genetic sampling ADN en estudios de Accipiter gentilis, aislamos y cuantificamos ADN de plumas mudadas y comparamos la

284

EFFECTS OF SIZE AND MIGRATORY BEHAVIOR ON THE EVOLUTION OF WING MOLT IN TERNS (STERNAE): A PHYLOGENETIC-COMPARATIVE STUDY  

Microsoft Academic Search

Approximately 60% of the 45 species of terns (Sternae) have an unusual form of wing molt in which a variable number of inner primaries and outer secondaries are replaced two or three times in a single year—a process that has been called \\

Eli S. Bridge; Gary Voelker; Christopher W. Thompson; Andrew W. Jones; Allan J. Baker

2007-01-01

285

Plasma biochemistry values in emperor geese (Chen canagica) in Alaska: comparisons among age, sex, incubation, and molt.  

USGS Publications Warehouse

Reduced populations of emperor geese (Chen canagica), a Bering Sea endemic, provided the need to assess plasma biochemistry values as indicators of population health. A precursory step to such an investigation was to evaluate patterns of variability in plasma biochemistry values among age, sex, and reproductive period. Plasma from 63 emperor geese was collected on their breeding grounds on the Yukon-Kuskokwim Delta in western Alaska, USA. The geese sampled included 18 incubating adult females captured, in mid June, on their nests by using bow nets, and 30 adults and 15 goslings captured in corral traps in late July and early August, when the adults were molting their wing feathers and the goslings were 5-6 weeks old. Plasma was evaluated for 15 biochemical parameters, by comparing results among age, sex, and sampling period (incubation versus wing-feather molt). Ten of the 15 biochemical parameters assayed differed among adults during incubation, the adults during molt, and the goslings at molt, whereas sex differences were noted in few parameters.

Franson, J.C.; Hoffman, D.J.; Schmutz, J.A.

2009-01-01

286

HumanWildlife Conflicts 3(2):260270, Fall 2009 Molt migration by giant Canada geese in  

E-print Network

Human­Wildlife Conflicts 3(2):260­270, Fall 2009 Molt migration by giant Canada geese in eastern, Valley City State University Valley City, ND 58072, USA Abstract: We captured giant Canada geese (Branta (1997) for giant Canada geese banded in eastern South Dakota from 1955 to 1995. We believe it is likely

287

The relationship between circulating ecdysteroids and chela allometry in male tanner crabs: Evidence for a terminal molt in the genus Chionoecetes  

USGS Publications Warehouse

Whether male Tanner crabs, Chionoecetes bairdi, undergo a terminal molt associated with a change in claw allometry has long been debated. We measured molting hormone levels in captured male C. bairdi to assess the potential for molting. We plotted a frequency histogram of chela height to carapace width ratios and found a bimodal distribution of crabs with a ratio of approximately 0.18 separating the two modes. Male crabs with a ratio less than 0.18 were classified as "small-clawed" (SC) while crabs with a ratio greater than 0.18 were classified as "large-clawed" (LC). Circulating molting hormones between SC and LC crabs were compared. Significantly lower ecdysteroid levels were found in LC crabs, indicating that this morphotype had negligible potential for molting. Circulating ecdysteroids were measured in SC males of different shell conditions (soft, new, old, and very old) and no significant differences were found. This research suggests that the molt to LC morphology is a terminal molt. The results from this study have important implications for fisheries management because sub-legal LC males will not recruit into the fishery and removal of larger males may have long term effects on population size structure.

Tamone, S.L.; Taggart, S.J.; Andrews, A.G.; Mondragon, J.; Nielsen, J.K.

2007-01-01

288

Global diversity of marine isopods (except Asellota and crustacean symbionts).  

PubMed

The crustacean order Isopoda (excluding Asellota, crustacean symbionts and freshwater taxa) comprise 3154 described marine species in 379 genera in 37 families according to the WoRMS catalogue. The history of taxonomic discovery over the last two centuries is reviewed. Although a well defined order with the Peracarida, their relationship to other orders is not yet resolved but systematics of the major subordinal taxa is relatively well understood. Isopods range in size from less than 1 mm to Bathynomus giganteus at 365 mm long. They inhabit all marine habitats down to 7280 m depth but with few doubtful exceptions species have restricted biogeographic and bathymetric ranges. Four feeding categories are recognised as much on the basis of anecdotal evidence as hard data: detritus feeders and browsers, carnivores, parasites, and filter feeders. Notable among these are the Cymothooidea that range from predators and scavengers to external blood-sucking micropredators and parasites. Isopods brood 10-1600 eggs depending on individual species. Strong sexual dimorphism is characteristic of several families, notably in Gnathiidae where sessile males live with a harem of females while juvenile praniza stages are ectoparasites of fish. Protandry is known in Cymothoidae and protogyny in Anthuroidea. Some Paranthuridae are neotenous. About half of all coastal, shelf and upper bathyal species have been recorded in the MEOW temperate realms, 40% in tropical regions and the remainder in polar seas. The greatest concentration of temperate species is in Australasia; more have been recorded from temperate North Pacific than the North Atlantic. Of tropical regions, the Central Indo-Pacific is home to more species any other region. Isopods are decidedly asymmetrical latitudinally with 1.35 times as many species in temperate Southern Hemisphere than the temperate North Atlantic and northern Pacific, and almost four times as many Antarctic as Arctic species. More species are known from the bathyal and abyssal Antarctic than Arctic GOODS provinces, and more from the larger Pacific than Atlantic oceans. Two areas with many species known are the New Zealand-Kermadec and the Northern North Pacific provinces. Deep hard substrates such as found on seamounts and the slopes are underrepresented in samples. This, the documented numbers of undescribed species in recent collections and probable cryptic species suggest a large as yet undocumented fauna, potentially an order of magnitude greater than presently known. PMID:22952700

Poore, Gary C B; Bruce, Niel L

2012-01-01

289

Fine scale movements and habitat use of black brant during the flightless Wing Molt in Arctic Alaska  

USGS Publications Warehouse

Thousands of Black Brant (Branta bernicla nigricans) migrate annually to the Teshekpuk Lake Special Area (TLSA), Alaska, to undergo the flightless wing molt on tundra lakes and wetlands. GPS transmitters were attached to Brant over two summers (2007â€"2008) to examine patterns of movement and habitat use of molting Brant, including variation by habitat type, year and body mass. Molting Brant were located an average of 31 ±1 m (SE) from shore and this distance did not vary across any of the explanatory variables. Brant moved an average of 123 ±3 m hr -1 while flightless. Movement rates varied by year, averaging 22 ±12 m hr -1 faster in 2008, and across habitat types, averaging 22 ±13 m hr -1 faster in inland versus coastal and estuarine habitats. Two kernel home ranges were estimated: entire home range, which encompassed the complete 95% probability contour, and shoreline home range, which included only shoreline areas used by molting Brant. Entire home range (x bar = 15.1 ±2.2 km 2) was negatively correlated with body mass, suggesting that heavier individuals have more body reserves to contribute to feather growth and thereby require less food and smaller home ranges. Conversely, shoreline home range (x bar = 4.3 ±0.6 km 2) did not vary by body mass, but rather by habitat type, being larger in estuarine habitats. The complex shorelines and numerous deltaic islands of estuarine habitats offer more shoreline per area than either coastal or inland habitats. Brant appear to have limited ability to adjust their home range size or forage further from shore in response to variable food resources across years or habitats, instead altering their movement rate. Given this apparent lack of behavioral flexibility, Brant may be sensitive to development-related disturbances or habitat losses at molt sites in the TLSA.

Lewis, Tyler L.; Flint, Paul L.; Derksen, Dirk V.; Schmutz, Joel A.

2011-01-01

290

Fine scale movements and habitat use of black brant during the flightless Wing Molt in Arctic Alaska  

USGS Publications Warehouse

Thousands of Black Brant (Branta bernicla nigricans) migrate annually to the Teshekpuk Lake Special Area (TLSA), Alaska, to undergo the flightless wing molt on tundra lakes and wetlands. GPS transmitters were attached to Brant over two summers (2007?????"2008) to examine patterns of movement and habitat use of molting Brant, including variation by habitat type, year and body mass. Molting Brant were located an average of 31 ??1 m (SE) from shore and this distance did not vary across any of the explanatory variables. Brant moved an average of 123 ??3 m hr-1 while flightless. Movement rates varied by year, averaging 22 ??12 m hr-1 faster in 2008, and across habitat types, averaging 22 ??13 m hr-1 faster in inland versus coastal and estuarine habitats. Two kernel home ranges were estimated: entire home range, which encompassed the complete 95% probability contour, and shoreline home range, which included only shoreline areas used by molting Brant. Entire home range (x bar = 15.1 ??2.2 km2) was negatively correlated with body mass, suggesting that heavier individuals have more body reserves to contribute to feather growth and thereby require less food and smaller home ranges. Conversely, shoreline home range (x bar = 4.3 ??0.6 km2) did not vary by body mass, but rather by habitat type, being larger in estuarine habitats. The complex shorelines and numerous deltaic islands of estuarine habitats offer more shoreline per area than either coastal or inland habitats. Brant appear to have limited ability to adjust their home range size or forage further from shore in response to variable food resources across years or habitats, instead altering their movement rate. Given this apparent lack of behavioral flexibility, Brant may be sensitive to development-related disturbances or habitat losses at molt sites in the TLSA.

Lewis, T.L.; Flint, P.L.; Derksen, D.V.; Schmutz, J.A.

2011-01-01

291

MoSI RECAPTURES Sheet Location Band Size R Season (e.g. 2009-10) Page # CODE SEX AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MoSI RECAPTURES Sheet Location Band Size R Season (e.g. 2009-10) Page # CODE SEX AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture if you didn't look Predation P Dead D at that feather tract. DATE BANDER'S INITIALS CODE BAND NUMBER

DeSante, David F.

292

MoSI UNBANDED Sheet Location Band Size U Season (e.g. 2009-10) Page # CODE SEX AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

MoSI UNBANDED Sheet Location Band Size U Season (e.g. 2009-10) Page # CODE SEX AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U P Dead D at that feather tract. DATE BANDER'S INITIALS CODE BAND NUMBER SPECIES NAME SPECIES ALPHA

DeSante, David F.

293

Exploiting the Polypharmacology of ß-Carbolines to Disrupt O. volvulus Molting.  

PubMed

Onchocerciasis is an infection caused by the filarial worm Onchocerca volvulus, which can eventually result in blindness. The lack of an effective macrofilaricide and the possible development of ivermectin-resistant strains of O. volvulus necessitate the need for alternative treatment strategies. We have shown that targeting the L3-stage-specific chitinase OvCHT1 impairs the shedding of the filarial cuticle. In our continued efforts to discover OvCHT1 inhibitors, we identified the ?-carboline alkaloid scaffolding as a chitinase inhibitor that is capable of penetrating the worm cuticle. Herein, we disclose the rich polypharmacology of the ?-carboline class of compounds as an approach to abrogate the molting of the parasite and thus the initiation of infection in the human host. PMID:25815157

Gooyit, Major; Tricoche, Nancy; Javor, Sacha; Lustigman, Sara; Janda, Kim D

2015-03-12

294

Evolution and development in cave animals: from fish to crustaceans  

PubMed Central

Cave animals are excellent models to study the general principles of evolution as well as the mechanisms of adaptation to a novel environment: the perpetual darkness of caves. In this article, two of the major model systems used to study the evolution and development (evo–devo) of cave animals are described: the teleost fish Astyanax mexicanus and the isopod crustacean Asellus aquaticus. The ways in which these animals match the major attributes expected of an evo–devo cave animal model system are described. For both species, we enumerate the regressive and constructive troglomorphic traits that have evolved during their adaptation to cave life, the developmental and genetic basis of these traits, the possible evolutionary forces responsible for them, and potential new areas in which these model systems could be used for further exploration of the evolution of cave animals. Furthermore, we compare the two model cave animals to investigate the mechanisms of troglomorphic evolution. Finally, we propose a few other cave animal systems that would be suitable for development as additional models to obtain a more comprehensive understanding of the developmental and genetic mechanisms involved in troglomorphic evolution. PMID:23580903

Protas, Meredith; Jeffery, William R.

2013-01-01

295

Bacteria-Induced Dscam Isoforms of the Crustacean, Pacifastacus leniusculus.  

PubMed

The Down syndrome cell adhesion molecule, also known as Dscam, is a member of the immunoglobulin super family. Dscam plays an essential function in neuronal wiring and appears to be involved in innate immune reactions in insects. The deduced amino acid sequence of Dscam in the crustacean Pacifastacus leniusculus (PlDscam), encodes 9(Ig)-4(FNIII)-(Ig)-2(FNIII)-TM and it has variable regions in the N-terminal half of Ig2 and Ig3 and the complete Ig7 and in the transmembrane domain. The cytoplasmic tail can generate multiple isoforms. PlDscam can generate more than 22,000 different unique isoforms. Bacteria and LPS injection enhanced the expression of PlDscam, but no response in expression occurred after a white spot syndrome virus (WSSV) infection or injection with peptidoglycans. Furthermore, PlDscam silencing did not have any effect on the replication of the WSSV. Bacterial specific isoforms of PlDscam were shown to have a specific binding property to each tested bacteria, E. coli or S. aureus. The bacteria specific isoforms of PlDscam were shown to be associated with bacterial clearance and phagocytosis in crayfish. PMID:21695245

Watthanasurorot, Apiruck; Jiravanichpaisal, Pikul; Liu, Haipeng; Söderhäll, Irene; Söderhäll, Kenneth

2011-06-01

296

Crustacean fish parasites from Segara Anakan Lagoon, Java, Indonesia.  

PubMed

The present study is the first investigation on ectoparasites of commercial important fish from Segara Anakan, a brackish water lagoon located at the southern coast of Java, Indonesia. Eight economically important marine fish species (Mugil cephalus, Siganus javus, Scatophagus argus, Caranx sexfasciatus, Lutjanus johnii, Eleutheronema tetradactylum, Johnius coitor, and Epinephelus coioides) were examined for crustacean parasites. Prevalence and intensity data for each parasite species are given, together with an analysis of the origin and possible transmission pathways. A highly divers copepod fauna consisting of 23 different species and two isopods was found. All fish species were at least infested with two copepod species, with the exception of L. johnii, S. argus, and M. cephalus. With seven and six species, respectively, they harboured the most species-rich ectoparasite fauna. The copepods Ergasilus sp. 3 and Caligus acanthopagri on S. argus showed the highest prevalence (78.6) and intensity [17.8 (1-233) and 5.3 (1-22)] of infestation. The recorded parasite fauna is represented by marine, brackish water, and probably also freshwater components. The brackish water environment of Segara Anakan does not prevent disease outbreaks due to parasitic copepods by preventing pathogenic marine or freshwater species to enter the lagoon. This might cause fish health problems if the Segara Anakan Lagoon would be developed for finfish mariculture in future. PMID:17219222

Yuniar, Asri T; Palm, Harry W; Walter, Thorsten

2007-05-01

297

Remarkable Diversity of Endogenous Viruses in a Crustacean Genome  

PubMed Central

Recent studies in paleovirology have uncovered myriads of endogenous viral elements (EVEs) integrated in the genome of their eukaryotic hosts. These fragments result from endogenization, that is, integration of the viral genome into the host germline genome followed by vertical inheritance. So far, most studies have used a virus-centered approach, whereby endogenous copies of a particular group of viruses were searched in all available sequenced genomes. Here, we follow a host-centered approach whereby the genome of a given species is comprehensively screened for the presence of EVEs using all available complete viral genomes as queries. Our analyses revealed that 54 EVEs corresponding to 10 different viral lineages belonging to 5 viral families (Bunyaviridae, Circoviridae, Parvoviridae, and Totiviridae) and one viral order (Mononegavirales) became endogenized in the genome of the isopod crustacean Armadillidium vulgare. We show that viral endogenization occurred recurrently during the evolution of isopods and that A. vulgare viral lineages were involved in multiple host switches that took place between widely divergent taxa. Furthermore, 30 A. vulgare EVEs have uninterrupted open reading frames, suggesting they result from recent endogenization of viruses likely to be currently infecting isopod populations. Overall, our work shows that isopods have been and are still infected by a large variety of viruses. It also extends the host range of several families of viruses and brings new insights into their evolution. More generally, our results underline the power of paleovirology in characterizing the viral diversity currently infecting eukaryotic taxa. PMID:25084787

Thézé, Julien; Leclercq, Sébastien; Moumen, Bouziane; Cordaux, Richard; Gilbert, Clément

2014-01-01

298

Cadmium uptake and accumulation by the decapod crustacean Penaeus indicus.  

PubMed

Juveniles of the dendrobranchiate decapod Penaeus indicus take up radiolabelled cadmium from solution over the exposure concentration range of 1.8-31.5 microg L(-1), with an uptake rate constant of 0.090 L g(-1)d(-1) at 15 salinity and 25 degrees C. New cadmium taken up is added to the existing cadmium content of the prawn with no significant excretion, and the rate of accumulation of radiolabelled cadmium is a measure of the absolute cadmium uptake rate from solution. Moulting had no significant effect on the accumulation of cadmium. Newly accumulated cadmium is distributed to all organs with the highest proportions of body content being found in the hepatopancreas, exoskeleton, gills and remaining soft tissues, the hepatopancreas and gills containing the highest labelled cadmium concentrations. Like other crustaceans, penaeid prawns inhabiting anthropogenically contaminated coastal waters with raised cadmium bioavailabilities can be expected to contain raised body concentrations of cadmium. Cadmium concentrations of most field-collected adult penaeids are relatively low, as a probable consequence of the growth dilution of their cadmium contents as a result of the rapid growth rates of penaeid prawns. PMID:15769503

Nuñez-Nogueira, Gabriel; Rainbow, Philip S

2005-09-01

299

Detritivorous crustaceans become herbivores on jasmonate-deficient plants  

PubMed Central

The jasmonate signal pathway is known to control defenses against herbivores, such as leaf eaters (folivores). Does the reach of the pathway extend to defense against other types of animal? Among the arthropods attracted to seed baits placed below flowering Arabidopsis thaliana plants are 2 largely nocturnal isopod crustaceans generally considered as detritivores: Porcellio scaber and Armadillidium vulgare. Parallel laboratory experiments identified the isopods as being capable of predation on intact plants. Isopod feeding was strongly facilitated in jasmonate-deficient Arabidopsis and rice plants. The feeding activity of isopods revealed potentially detritivore-sensitive, jasmonate-protected Achilles' heels in these architecturally different plants (petioles and inflorescence stems in Arabidopsis, and lower stem and mesocotyl in rice). The work addresses the question of what stops 2 detritivores from attacking living plants and provides evidence that it is, in part, the jasmonate signal pathway. Furthermore, senescent leaves from an Arabidopsis jasmonate mutant were consumed more rapidly than senescent wild-type leaves, suggesting that past activity of the jasmonate signal pathway in leaves may slow carbon recycling through detritivory. PMID:19139394

Farmer, Edward E.; Dubugnon, Lucie

2009-01-01

300

MTPA: a crustacean metallothionein that affects hepatopancreatic mitochondrial functions.  

PubMed

Metallothioneins are cysteine-rich proteins, with a high capacity to bind metallic ions, and for which a precise biological role has not been established. Here we investigated the effects of MTPA, a metallothionein from the lobster Panulirus argus, on mitochondrial oxygen consumption and ROS production. An HPLC-RP-ESI-MS analysis of recombinant MTPA showed that despite its extra Cys, MTPA binds 6 Zn2+ per molecule akin to other crustacean metallothioneins with 18 Cys. The extra Cys is not involved in zinc binding, since its side-chain would be oriented to the outside of the molecule according to a preliminary model of the tridimensional structure of MTPA. MTPA-Zn2+(6) is imported into the hepatopancreatic mitochondria intermembrane space and inhibits mitochondrial oxygen consumption, increasing thereby ROS production. Nevertheless, the stimulation of ROS production by MT-bound Zn2+ is weaker compared to equivalent amounts of free Zn2+, suggesting that MTPA protects against oxidative stress. This constitutes the first report on metallothioneins effects on mitochondrial function in invertebrates and agrees with the results described for mammals, suggesting a connection between metallothioneins and energy metabolism. PMID:17889825

Moltó, Eduardo; Bonzón-Kulichenko, Elena; Gallardo, Nilda; Andrés, Antonio

2007-11-01

301

Crustacean social behavioral changes in response to isolation.  

PubMed

Periods of isolation during which animals have no social contact are common in the design of behavioral experiments. They are used, for example, to test memory and recognition responses, or to ensure a baseline condition before experimental manipulations commence. We investigated the effect of isolation periods on the aggressive behavior of matched pairs of the crayfish Cherax destructor in two contexts. The first experiment tested the effects of a period of isolation between two encounters. The second experiment tested the effects of isolation before an encounter by pairing one crayfish from a communal living environment with another crayfish from an isolated one. Fight outcome and aggression levels were analyzed, resulting in three conclusions about the social biology of C. destructor. First, encounters between familiar opponents are influenced by the outcome of the familiarization fight for about 2 weeks. Second, the level of aggression and the outcome of an encounter are affected over different time frames. Third, individuals that are isolated before an encounter can be disadvantaged. These data suggest that isolation, or events that occur during periods of isolation, affect multiple elements of social behavior in C. destructor. This suggestion has implications for the interpretation of previous results and future studies in crustaceans and other taxa. PMID:17928525

Hemsworth, Robert; Villareal, Wil; Patullo, Blair W; MacMillan, David L

2007-10-01

302

Phylogenetic evidence for a single long-lived clade of crustacean cyclic parthenogens and its implications for the evolution of sex  

PubMed Central

The short-term advantages of sexual reproduction are unclear, but the existence of groups that are capable of producing either meiotic or ameiotic eggs (cyclic parthenogenesis, CP) might indicate that short-term advantages to sex exist. Alternatively, CP might be an unstable transitory stage between asexuality and sex, or a phylogenetically favoured life cycle (i.e. clade selection). The extensive knowledge of breeding systems and population genetics in branchiopod crustaceans makes them a useful group to test phylogenetic predictions of these hypotheses. Several proponents favour the hypothesis that CP has evolved multiple times in five orders of branchiopod crustaceans. We inferred the first robust branchiopod phylogeny from nuclear rRNA sequence (SSU and LSU), morphology, and complex rRNA stem–loop structures to assess the phylogenetic distribution of cyclic parthenogenesis. The sequence-based, structural rRNA and total evidence phylogenies are concordant and suggest that cyclic parthenogenesis arose once in the branchiopods, that this clade is long-lived (at least since the Permian), and that it has radiated extensively into nearly every aqueous habitat without reverting to strict sexuality and only rarely transforming to strict asexuality. These results are consistent with the clade selection hypothesis but inconsistent with the predictions of the hypothesis that CP is a transitory stage that leads to strict sexual reproduction. The evidence also indicates that clade selection for CP is a viable alternative explanation for the maintenance of sex in CP life cycles.

Taylor, D. J.; Crease, T. J.; Brown, W. M.

1999-01-01

303

Gene expression profiling of cuticular proteins across the moult cycle of the crab Portunus pelagicus  

PubMed Central

Background Crustaceans represent an attractive model to study biomineralization and cuticle matrix formation, as these events are precisely timed to occur at certain stages of the moult cycle. Moulting, the process by which crustaceans shed their exoskeleton, involves the partial breakdown of the old exoskeleton and the synthesis of a new cuticle. This cuticle is subdivided into layers, some of which become calcified while others remain uncalcified. The cuticle matrix consists of many different proteins that confer the physical properties, such as pliability, of the exoskeleton. Results We have used a custom cDNA microarray chip, developed for the blue swimmer crab Portunus pelagicus, to generate expression profiles of genes involved in exoskeletal formation across the moult cycle. A total of 21 distinct moult-cycle related differentially expressed transcripts representing crustacean cuticular proteins were isolated. Of these, 13 contained copies of the cuticle_1 domain previously isolated from calcified regions of the crustacean exoskeleton, four transcripts contained a chitin_bind_4 domain (RR consensus sequence) associated with both the calcified and un-calcified cuticle of crustaceans, and four transcripts contained an unannotated domain (PfamB_109992) previously isolated from C. pagurus. Additionally, cryptocyanin, a hemolymph protein involved in cuticle synthesis and structural integrity, also displays differential expression related to the moult cycle. Moult stage-specific expression analysis of these transcripts revealed that differential gene expression occurs both among transcripts containing the same domain and among transcripts containing different domains. Conclusion The large variety of genes associated with cuticle formation, and their differential expression across the crustacean moult cycle, point to the complexity of the processes associated with cuticle formation and hardening. This study provides a molecular entry path into the investigation of the gene networks associated with cuticle formation. PMID:17925039

Kuballa, Anna V; Merritt, David J; Elizur, Abigail

2007-01-01

304

[Diversity and faunal analysis of crustaceans in Potatso National Park, Shangri-La, China].  

PubMed

Potatso National Park was the first national park in mainland China, preceded by the earlier Bitahai Nature Reserve. Located in the northwest of Yunnan and on the southeast of Qinghai-Tibet plateau, Potatso is a typical low latitude and high elevation wetland nature reserve, with large areas of coniferous forest around alpine lakes and both wetland and water area ecosystems. In August, 2011, we undertook a survey of crustaceans in the park, sampling lakes, ponds, streams, and rivers throughout Potatso. We found a total of 29 species (including varieties) belonging to 24 genera and 11 families. Notable discoveries include Parartemiopsis sp, Arctodiaptomus parvispinus and Simocephalus congener, which are the first examples of these species to be recorded in China. Likewise, Gammarus bitaensis is a unique crustacean found only in Potatso National Park and Thermocyclops dumonti and Gammarus paucispinus are both endemic species to northwestern Yunnan. The overall faunal characteristics of crustaceans in the park also revealed several things about Potatso: (1) Cosmopolitan and Palaearctic elements reach 48.27% and 37.93%, clearly showing the Palaearctic element as the dominant fauna; (2) most of the crustacean, such as Arctodiaptomus parvispinus and Gammarus, are typical alpine types, confirming that Potatso has feature typical of alpine and plateau fauna; and (3) the proportion of endemic and rare crustacean species in Potatso National Park is approximately 10%, suggesting that the Potatso National Park in particular and the northwest of Yunnan in general have a unique geological and evolutionary history. PMID:23775996

Shu, Shu-Sen; Chen, Fei-Zhou; Yang, Jun-Xing; Yang, Xiao-Jun; Chen, Xiao-Yong

2013-06-01

305

Scale-dependent analysis of an otter-crustacean system in Argentinean Patagonia.  

PubMed

The Southern river otter or 'huillin', Lontra provocax, is an endangered species endemic of the Andean Patagonian region of Argentina and Chile. It feeds almost exclusively on the genera of macro-crustacea: Aegla and Sammastacus. The aim of this study was to analyse the role of food availability on the huillin's distribution using a scale-dependent analysis of crustacean and otter distributions. We compared the distributions of otters and macro-crustaceans along a north-south regional gradient, between river basins of northern Patagonia, in an altitudinal gradient within a river basin, and between habitat types within a lake. We investigated the distribution of otters by sign surveys along lake shores, river banks and marine coasts, and of crustaceans using surveys in the water, undigested remains in mink (Mustela vison) scats, presence of external skeletons at the waterside and through interviews with local people. Our results show that there were heterogeneities in the distributions of macro-crustaceans at four scales and these were generally reflected in the distributions of freshwater otters. We conclude that the main factor limiting the distributions of L. provocax in freshwater environments is the availability of macro-crustaceans. This paper shows how scale-dependent type analyses of population distribution serves as a method for identifying key environmental factors for species for which the use of long-term demographies is unfeasible. PMID:19225749

Cassini, Marcelo H; Fasola, Laura; Chehébar, Claudio; Macdonald, David W

2009-05-01

306

Scale-dependent analysis of an otter-crustacean system in Argentinean Patagonia  

NASA Astrophysics Data System (ADS)

The Southern river otter or ‘huillin’, Lontra provocax, is an endangered species endemic of the Andean Patagonian region of Argentina and Chile. It feeds almost exclusively on the genera of macro-crustacea: Aegla and Sammastacus. The aim of this study was to analyse the role of food availability on the huillin’s distribution using a scale-dependent analysis of crustacean and otter distributions. We compared the distributions of otters and macro-crustaceans along a north-south regional gradient, between river basins of northern Patagonia, in an altitudinal gradient within a river basin, and between habitat types within a lake. We investigated the distribution of otters by sign surveys along lake shores, river banks and marine coasts, and of crustaceans using surveys in the water, undigested remains in mink ( Mustela vison) scats, presence of external skeletons at the waterside and through interviews with local people. Our results show that there were heterogeneities in the distributions of macro-crustaceans at four scales and these were generally reflected in the distributions of freshwater otters. We conclude that the main factor limiting the distributions of L. provocax in freshwater environments is the availability of macro-crustaceans. This paper shows how scale-dependent type analyses of population distribution serves as a method for identifying key environmental factors for species for which the use of long-term demographies is unfeasible.

Cassini, Marcelo H.; Fasola, Laura; Chehébar, Claudio; MacDonald, David W.

2009-05-01

307

Ultrastructural and cytological changes in the muscle fibers of the pectoralis of the giant Canada goose ( Branta canadensis maxima ) in disuse atrophy during molt  

Microsoft Academic Search

Adult male Branta canadensis maxima were collected from a nonmigratory feral population during their premolt, molt and postmolt phases. Lean dry weight of the pectoralis muscle decreased significantly (p=0.0001) during molt, as a result of disuse atrophy. Histochemical analysis revealed that the region of the pectoralis muscle sampled consisted of Red (fast-twitch oxidative-glycolytic) and White (fast-twitch glycolytic) muscle fiber types,

B. W. C. Rosser; J. C. George

1987-01-01

308

Activation of Caspase3 in Molt4 Cells by Apoptosis-Inducing Nucleosides from CD57 +HLA-DR bright Natural Suppressor Cell Line  

Microsoft Academic Search

Apoptosis-inducing nucleosides (AINs), which were released and isolated from CD57+HLA-DRbright natural suppressor (57.DR-NS) cell line derived from human decidual tissue, induced apoptosis in Molt4 cells. The addition of caspase-3 inhibitor into the reaction blocked the cleavage of caspase-3 and apoptosis in Molt4 cells treated with AINs, detected by flow cytometrical or spectrofluorometrical analysis and DNA fragmentation assay. Furthermore, by means

Xiang Li; Maowu Guo; Etsuko Mori; Tsuneatsu Mori

2000-01-01

309

Gill structure and relationships of the Triassic cycloid crustaceans.  

PubMed

Unusually well-preserved fossils of a Halicyne-like cycloid crustacean frequently occur in the early Late Triassic lacustrine clay bed at Krasiejów in Opole Silesia, southern Poland. Its gill-like structures form a horseshoe-shaped pair of units composed of numerous calcified blades with reverse U-shaped cross-section. Originally, these were parallel slits opening on the ventral surface of the carapace. Lobation of the posterior margin of the carapace, of unusually large mature size for the group, make the animal different from other members of Halicynidae, and the new name Opolanka decorosa gen. et sp. nov. is proposed for it. More completely preserved specimens of cycloids from Vosges, France, and Madagascar show that the slit openings were located above radially arranged coxae of the walking appendages and a reduced abdomen. The disposition and arrangement of the cycloid gills suggest at least close analogy, and possibly homology, with the "respiratory areas" of the Branchiura, serving mostly as ion-exchange organs. It is proposed that they originated, in connection with the body size increase and adaptation to fresh-water environment, as radially arranged infoldings of the respiratory areas cuticle, with strongly calcified rigid dorsal parts suspended from the carapace. At least three ecologically and anatomically distinct lineages were represented in the order Cyclida, which was probably initially confined to marine environments and gradually adapted to life in continental waters. New taxa Schraminidae fam. nov. (with Schramine gen. nov.) and Americlidae fam. nov. (with Americlus gen. nov.) are proposed. PMID:18690662

Dzik, Jerzy

2008-12-01

310

MAPS BANDING Sheet Location Band Size Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP  

E-print Network

Not attempt X Dead D DATE BANDER'S INITIALS CODE BAND NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXEDMAPS BANDING Sheet Location Band Size Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL Excessive 5 Mixed Basic M Tong j yue In ur T SEX A rfter Third Yea 8 Molt M Fully p.Com 6 Gr. Bulg gin 6 >1

DeSante, David F.

311

Cytotoxicity of dihydroartemisinin toward Molt-4 cells attenuated by N-tert-butyl-alpha-phenylnitrone and deferoxamine.  

PubMed

Derivatives of artemisinin, a compound extracted from the wormwood Artemisia annua L, have potent anticancer properties. The anticancer mechanisms of artemisinin derivatives have not been fully-elucidated. We hypothesize that the cytotoxicity of these compounds is due to the free radicals formed by interaction of their endoperoxide moiety with intracellular iron in cancer cells. The effects of N-tert-butyl-alpha-phenylnitrone (PBN), a spin-trap free radical scavenger, and deferoxamine (DX), an iron chelating agent, on the in vitro cytotoxicity of dihyroartemisinin (DHA) toward Molt-4 human T-lymphoblastoid leukemia cells were investigated in the present study. Dihydroartemisinin effectively killed Molt-4 cells in vitro. Its cytotoxicity was significantly attenuated by PBN and DX. Based on the data of our present and previous studies, we conclude that one anticancer mechanism of dihydroartemisinin is the formation of toxic-free radicals via an iron-mediated process. PMID:24123007

Chan, Ho Wing; Singh, Narendra P; Lai, Henry C

2013-10-01

312

The cryptocephal Gene (ATF4) Encodes Multiple Basic-Leucine Zipper Proteins Controlling Molting and Metamorphosis in Drosophila  

Microsoft Academic Search

The cryptocephal (crc) mutation causes pleiotropic defects in ecdysone-regulated events during Drosophila molting and metamorphosis. Here we report that crc encodes a Drosophila homolog of vertebrate ATF4, a member of the CREB\\/ATF family of basic-leucine zipper (bZIP) transcription factors. We identified three putative protein isoforms. CRC-A and CRC-B contain the bZIP domain, and CRC-D is a C-terminally truncated form. We

Randall S. Hewes; Anneliese M. Schaefer; Paul H. Taghert

313

Changes in abundance and spatial distribution of geese molting near Teshekpuk Lake, Alaska: interspecific competition or ecological change?  

Microsoft Academic Search

Goose populations molting in the Teshekpuk Lake Special Area of the National Petroleum Reserve—Alaska have changed in size\\u000a and distribution over the past 30 years. Black brant (Branta bernicla nigricans) are relatively stable in numbers but are shifting from large, inland lakes to salt marshes. Concurrently, populations of\\u000a greater white-fronted geese (Anser albifrons frontalis) have increased seven fold. Populations of Canada

Paul L. Flint; Edward J. Mallek; Rodney J. King; Joel A. Schmutz; Karen S. Bollinger; Dirk V. Derksen

2008-01-01

314

Anti-proliferative activity of 6-O-acyl-D-allose against the human leukemia MOLT-4F cell line.  

PubMed

The anti-proliferative activities of the 6-O-acyl derivatives of D-allose against the human leukemia MOLT-4F cell line were examined. The activity of the 6-O-dodecanoyl derivative (3) was approximately 30 times stronger than that of D-allose. An evaluation of the derivatives of 3 that occurred in a furanose form revealed the pyranose forms of 3 to be important for the anti-proliferative activity. PMID:25036670

Yanagita, Ryo C; Kobashi, Katsuya; Ogawa, Chisa; Ashida, Yoshiki; Yamaashi, Haruka; Kawanami, Yasuhiro

2014-01-01

315

Size and temperature-dependent variations in intermolt duration and size increment at molt of Northern Shrimp, Pandalus borealis  

Microsoft Academic Search

Growth of Pandalus borealis post-larval stages was measured in relation to size and temperature. Growth characteristics, including intermolt period (IP),\\u000a molt increment (MI) in size and mass, and tissue allocation in juvenile, male, and female shrimp, were evaluated at 2, 5,\\u000a and 8°C, the temperature range where this species is generally found in the Northwest Atlantic. Significant variations in\\u000a growth

Dounia Daoud; Yvan Lambert; Céline Audet; Denis Chabot

2010-01-01

316

Neurogenesis in the water flea Daphnia magna (Crustacea, Branchiopoda) suggests different mechanisms of neuroblast formation in insects and crustaceans  

Microsoft Academic Search

Within euarthropods, the morphological and molecular mechanisms of early nervous system development have been analysed in insects and several representatives of chelicerates and myriapods, while data on crustaceans are fragmentary. Neural stem cells (neuroblasts) generate the nervous system in insects and in higher crustaceans (malacostracans); in the remaining euarthropod groups, the chelicerates (e.g. spiders) and myriapods (e.g. millipedes), neuroblasts are

Petra Ungerer; Bo Joakim Eriksson; Angelika Stollewerk

2011-01-01

317

39A new species of the subterranean amphipod genus Stygobromus A new species of the subterranean amphipod crustacean genus  

E-print Network

39A new species of the subterranean amphipod genus Stygobromus A new species of the subterranean amphipod crustacean genus Stygobromus (Crangonyctidae) from a cave in Nevada, USA Steven J. TAYLOR(1, a new stygobiotic amphipod crustacean species in the family Crangonyctidae, is described from two pools

Taylor, Steven J.

318

The fate of isolated blastomeres with respect to germ cell formation in the amphipod crustacean Parhyale hawaiensis  

E-print Network

The fate of isolated blastomeres with respect to germ cell formation in the amphipod crustacean. In this paper, I use immunodetection of Vasa protein to study germ cell development in the amphipod crustacean amphipod development, including timing and symmetry of cell division, the transition from holoblastic

Extavour, Cassandra

319

Proc. Okla. Acad. Sci. 86: pp 65-74 (2006) Annotated Checklist of the Amphipod Crustaceans of  

E-print Network

Proc. Okla. Acad. Sci. 86: pp 65-74 (2006) Annotated Checklist of the Amphipod Crustaceans Summarized here for the first time are all known records of amphipod crustaceans in Oklahoma. Data sources. The majority of Oklahoman amphipods are closely associated with groundwater or cave habitats and seven species

Fenolio, Danté

320

Cross-species amplification of microsatellite markers in Mycteria leucocephala Pennant 1769: molted feathers as successful DNA source.  

PubMed

DNA from molted feathers is being increasingly used for genetic studies on birds. However, the DNA obtained from such non-invasive sources is often not of enough quantity and quality for isolation of new microsatellite markers. The present study examined the potential of shed feathers of near threatened Painted Stork as a source of its DNA for cross-species amplification of microsatellites. Thirty-one shed feathers of varying conditions ('good' and 'deteriorated') and sizes ('large', 'intermediate' and 'small') collected in a north Indian population were used to isolate DNA by a standard isopropanol method and 11 microsatellite markers already developed in the Wood Stork were screened for amplification. Nine plucked feathers from two dead Painted Storks were also used to compare the DNA yield and amplification success. The DNA yield of feathers varied significantly in relation to the calamus size and condition. Among molted feathers, 'good' and 'large' samples provided more DNA than 'deteriorated' and 'small' ones, respectively. 'Large' plucked feathers yielded more DNA than 'large' molted feathers. DNA was almost degraded in all the samples and ratio of absorbance at 260/280 nm varied from 1.0 to 1.8, indicating impurity in many samples. Independent of DNA yields, all microsatellites were cross-amplified in all kinds of feathers, with > 80% success in different feather categories. It is concluded that the shed feathers can be successfully used to isolate DNA in the Painted Stork and for cross-species amplification of microsatellites. PMID:25345251

Sharma, Bharat Bhushan; Mustafa, Mohd; Sharma, Tusha; Banerjee, Basu Dev; Urfi, Abdul Jamil

2014-10-01

321

Mechanisms of population genetic heterogeneity among molting common mergansers on Kodiak Island, Alaska: implications for assessments of migratory connectivity  

USGS Publications Warehouse

Quantifying population genetic heterogeneity within nonbreeding aggregations can inform our understanding of patterns of site fidelity, migratory connectivity, and gene flow between breeding and nonbreeding areas. However, characterizing mechanisms that contribute to heterogeneity, such as migration and dispersal, is required before site fidelity and migratory connectivity can be assessed accurately. We studied nonbreeding groups of Common Mergansers (Mergus merganser) molting on Kodiak Island, Alaska, from 2005 to 2007, using banding data to assess rates of recapture, mitochondrial (mt) DNA to determine natal area, and nuclear microsatellite genotypes to assess dispersal. Using baseline information from differentiated mtDNA haplogroups across North America, we were able to assign individuals to natal regions and document population genetic heterogeneity within and among molting groups. Band-recovery and DNA data suggest that both migration from and dispersal among natal areas contribute to admixed groups of males molting on Kodiak Island. A lack of differentiation in the Common Merganser's nuclear, bi-parentally inherited DNA, observed across North America, implies that dispersal can mislead genetic assessments of migratory connectivity and assignments of nonbreeding individuals to breeding areas. Thus multiple and independent data types are required to account for such behaviors before accurate assessments of migratory connectivity can be made.

Pearce, John M.; Zwiefelhofer, Denny; Maryanski, Nate

2009-01-01

322

Annotated list of species of marine crustaceans (Decapoda and Stomatopoda) from Golfo Dulce, Costa Rica.  

PubMed

The present study is an annotated list of the marine crustaceans (Decapoda and Stomatopoda) from Golfo Dulce, Costa Rica, collected during the RV Victor Hensen Cruise 1993-1994, at depths ranging from 20 to 260 m. Stomatopoda was represented by one family and two species. Decapoda was represented by 12 families and 21 species. Two new records for Costa Rica, Cancer johngarthi and Lysmata californica are reported. This increases the reported marine crustaceans of Golfo Dulce to three species of Stomatopoda and sixty-six of Decapoda (a complete checklist in included). A list of species reported in the literature from the gulf is also included. PMID:9393646

Castro, M; Vargas, R

1996-12-01

323

The Salmon Louse Lepeophtheirus salmonis (Copepoda: Caligidae) Life Cycle Has Only Two Chalimus Stages  

PubMed Central

Each year the salmon louse (Lepeophtheirussalmonis Krøyer, 1838) causes multi-million dollar commercial losses to the salmon farming industry world-wide, and strict lice control regimes have been put in place to reduce the release of salmon louse larvae from aquaculture facilities into the environment. For half a century, the Lepeophtheirus life cycle has been regarded as the only copepod life cycle including 8 post-nauplius instars as confirmed in four different species, including L. salmonis. Here we prove that the accepted life cycle of the salmon louse is wrong. By observations of chalimus larvae molting in incubators and by morphometric cluster analysis, we show that there are only two chalimus instars: chalimus 1 (comprising the former chalimus I and II stages which are not separated by a molt) and chalimus 2 (the former chalimus III and IV stages which are not separated by a molt). Consequently the salmon louse life cycle has only six post-nauplius instars, as in other genera of caligid sea lice and copepods in general. These findings are of fundamental importance in experimental studies as well as for interpretation of salmon louse biology and for control and management of this economically important parasite. PMID:24069203

Dalvin, Sussie T.; Bron, James E.; Nilsen, Frank; Boxshall, Geoff; Skern-Mauritzen, Rasmus

2013-01-01

324

Vertical and temporal distribution of pelagic decapod crustaceans over the shelf-break and middle slope in two contrasting zones around Mallorca (western Mediterranean Sea)  

NASA Astrophysics Data System (ADS)

The pelagic decapod crustacean fauna of two different zones (Sóller and Cabrera) with different hydrographic dynamics and oligotrophy levels was studied around Mallorca (western Mediterranean), the latter with a higher degree of oligotrophy than the former. Samples were taken with a Pelagic Trawl and an IKMT in the upper 600 m of the water column, targeting larger and middle-sized nektonic species, respectively. Fourteen species were collected: five dendrobranchiate shrimps, eight caridean shrimps and one scyllarid lobster. Some species were restricted to the shelf-break: Chlorotocus crassicornis and Plesionika heterocarpus. Others were exclusive of the middle slope: Pasiphaea multidentata, and Sergia robusta. Pasiphaea sivado and Gennadas elegans occurred in all pelagic strata. Multivariate analyses showed several distinct assemblages related to bathymetry and sampling depth. No significant differences were found concerning zone or sampled seasons. Bathymetrically, Deep Scattering Layers showed the highest diversity. No decapod crustaceans occurred in epipelagic daytime samples. The pelagic decapod community sampled was structured by both the geomorphology (and associated hydrographic characteristics over the shelf-break) and the influence of light in the water column. Size analysis showed species-specific patterns concerning size/age movements into the water column throughout the day-night cycle.

Simão, Daniela S.; Torres, Asvin P.; Olivar, M. Pilar; Abelló, Pere

2014-10-01

325

Ontogenesis, gender, and molting influence the venom yield in the spider Coremiocnemis tropix (Araneae, Theraphosidae)  

PubMed Central

The demand for spider venom increases along with the growing popularity of venoms-based research. A deeper understanding of factors that influence the venom yield in spiders would therefore be of interest to both commercial venom suppliers and research facilities. The present study addresses the influence of several factors on the venom yield by systematically analyzing the data obtained from 1773 electrical milkings of the Australian theraphosid spider Coremiocnemis tropix. Gender and ontogenesis were found to cause a major effect on the venom yield, as adult female C. tropix yielded significantly more venom than adult males. During ontogenesis, the venom yield increased with increasing size of the spiders. Furthermore, a significant reduction in the venom yield during the 50-day time interval preceding a molt was found. On the other hand, extended milking intervals (up to 449 days) and different states of nutrition (as an indication of how well the spider was fed) did not significantly affect the venom yield. Overall, the present findings suggest that venom production in spiders is carefully balanced between the demand for venom and the energy costs associated with its production. It can therefore be concluded that, in line with the venom optimization hypothesis, venom is a precious resource for spiders, which have implemented control mechanisms to ensure economical venom production and usage. PMID:21544186

Herzig, Volker

2010-01-01

326

Immunization of cattle with Ra86 impedes Rhipicephalus appendiculatus nymphal-to-adult molting.  

PubMed

Commercial vaccines based on the tick gut protein Bm86 have been successful in controlling the one-host tick Rhipicephalus (Boophilus) microplus and provide heterologous protection against certain other non-target ixodid tick species. This cross protection, however, does not extend to the three-host tick R. appendiculatus, the vector of the protozoan parasite Theileria parva. When transmitted to cattle, T. parva causes the often fatal disease East Coast fever. Here, we used insect cell-expressed recombinant versions of the R. appendiculatus homologs of Bm86, named Ra86, to vaccinate cattle. We measured multiple fitness characteristics for ticks that were fed on cattle Ra86-vaccinated or unvaccinated. The Ra86 vaccination of cattle significantly decreased the molting success of nymphal ticks to the adult stage. Modeling simulations based on our empirical data suggest that repeated vaccinations using Ra86 could reduce tick populations over successive generations. Vaccination with Ra86 could thus form a component of integrated control strategies for R. appendiculatus leading to a reduction in use of environmentally damaging acaricides. PMID:22658857

Olds, Cassandra; Mwaura, Stephen; Crowder, David; Odongo, David; van Oers, Monique; Owen, Jeb; Bishop, Richard; Daubenberger, Claudia

2012-06-01

327

CHANGES IN NUCLEIC ACIDS OVER THE MOLT CYCLE IN RELATION TO FOOD AVAILABILITY AND TEMPERATURE IN HOMARUS AMERICANUS POSTLARVAE  

EPA Science Inventory

Postlarval lobsters Homarus americanus Milne Edwards hatched from three females collected in 1989 fr m Block Island Sound, Rhode Island were reared individually in the laboratory under nine treatment combinations of temperature (15, 18 and 200C) and feeding(starved, low ration, a...

328

Use of Crustacean Shells for Uptake and Removal of Metal Ions in Solution  

Microsoft Academic Search

The use of crustacean shells, in particular crab shells, for the removal of metal ions in solution is described. Research studies found in the literature on the ability of the shells, effect of particle size, pH, competitive studies in mixtures of metals, application to real samples such as acid mine drainage, and use of the shells in a column are

Anita Morris; Joseph Sneddon

2011-01-01

329

DETERMINATION OF LETHAL DISSOLVED OXYGEN LEVELS FOR SELECTED MARINE AND ESTUARINE FISHES, CRUSTACEANS AND A BIVALVE  

EPA Science Inventory

The objective of this study was to provide a database of the incipient lethal concentrations for reduced dissolved oxygen (DO) for selected marine and estuarine species including 12 species of fish, 9 crustaceans, and 1 bivalve. All species occur in the Virginian Province, USA, w...

330

MYSID CRUSTACEANS AS POTENTIAL TEST ORGANISMS FOR THE EVALUATION OF ENVIRONMENTAL ENDOCRINE DISRUPTORS: A REVIEW  

EPA Science Inventory

Verslycke, Tim A., Nancy Fockedey, Charles L. McKenney, Jr., Stephen D. Roast, Malcolm B. Jones, Jan Mees and Colin R. Janssen. 2004. Mysid Crustaceans as Potential Test Organisms for the Evaluation of Environmental Endocrine Disruption: A Review. Environ. Toxicol. Chem. 23(5):12...

331

Transglutaminase activity in the hematopoietic tissue of a crustacean, Pacifastacus leniusculus, importance in hemocyte homeostasis  

Microsoft Academic Search

BACKGROUND: Transglutaminases (TGases) form a group of enzymes that have many different substrates and among the most well known are fibrin for Factor XIIIa and the clotting protein in crustaceans. We also found that TGase is an abundant protein in the hematopoietic tissue (Hpt) cells of crayfish and hence we have studied the possible function of this enzyme in hematopoiesis.

Xionghui Lin; Kenneth Söderhäll; Irene Söderhäll

2008-01-01

332

The Membrane Components of Crustacean Neuromuscular Systems II. Analysis of interactions among the electrogenic components  

E-print Network

ABSTRACT The present work provides additional evidence for the occurrence of a number of electrogenic components in crustacean and particularly crayfish muscle fibers. It demonstrates that these different components are independent. One or another can be eliminated or modified by various procedures

Masahiro Ozeki; Alan R. Freeman

333

Charles Darwin and Joseph de Bosquet – Brothers in barnacles: How diminutive crustaceans helped shape a theory  

Microsoft Academic Search

Ten years after his return to England on board ‘The Beagle’ in 1836, Charles Robert Darwin (1809–1882) started collecting, dissecting, describing and interpreting both extant and fossil acorn and goose barnacles (cirripedes). In all, he spent eight years on this animal group and, between 1851 and 1855, published four authoritative and admirably illustrated volumes on these sessile crustaceans; a highly

John W. M. Jagt

2011-01-01

334

Reef-associated crustacean fauna: biodiversity estimates using semi-quantitative sampling and DNA barcoding  

NASA Astrophysics Data System (ADS)

The cryptofauna associated with coral reefs accounts for a major part of the biodiversity in these ecosystems but has been largely overlooked in biodiversity estimates because the organisms are hard to collect and identify. We combine a semi-quantitative sampling design and a DNA barcoding approach to provide metrics for the diversity of reef-associated crustacean. Twenty-two similar-sized dead heads of Pocillopora were sampled at 10 m depth from five central Pacific Ocean localities (four atolls in the Northern Line Islands and in Moorea, French Polynesia). All crustaceans were removed, and partial cytochrome oxidase subunit I was sequenced from 403 individuals, yielding 135 distinct taxa using a species-level criterion of 5% similarity. Most crustacean species were rare; 44% of the OTUs were represented by a single individual, and an additional 33% were represented by several specimens found only in one of the five localities. The Northern Line Islands and Moorea shared only 11 OTUs. Total numbers estimated by species richness statistics (Chao1 and ACE) suggest at least 90 species of crustaceans in Moorea and 150 in the Northern Line Islands for this habitat type. However, rarefaction curves for each region failed to approach an asymptote, and Chao1 and ACE estimators did not stabilize after sampling eight heads in Moorea, so even these diversity figures are underestimates. Nevertheless, even this modest sampling effort from a very limited habitat resulted in surprisingly high species numbers.

Plaisance, L.; Knowlton, N.; Paulay, G.; Meyer, C.

2009-12-01

335

Absence of preserved glucosamine and amino acids in fossil crustacean exoskeletons  

SciTech Connect

No glucosamine and only traces of amino acids were detected in kerogen prepared from fossil crustacean exoskeletons. The elemental C/N ratios of the kerogen samples were above 20, indicating that most of the organic nitrogen was eliminated from the chitin biopolymer during diagenesis. The results contradict earlier reports of the stability of chitin during fossilization.

Schimmelmann, A.; Krause, R.G.F.; DeNiro, M.J.

1988-01-01

336

Fine structure and optical properties of biological polarizers in crustaceans and cephalopods  

E-print Network

Fine structure and optical properties of biological polarizers in crustaceans and cephalopods Tsyr signals, especially those based on color. To escape this problem, certain cephalopod mollusks types of polarizers found in cephalopods and stomatopods. Although all the polarizers share a somewhat

Caldwell, Roy

337

The role of crustacean fisheries and aquaculture in global food security: past, present and future.  

PubMed

The 1996 World Food Summit defined food security as "Food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life". This paper looks at the status of production from both shrimp capture fisheries and shrimp aquaculture, as well as trade, in order to understand the contribution of the crustacean sector to overall fish production and thus to global food security. This paper also examines some sustainability issues that will potentially affect the contribution of the crustacean sector (particularly shrimp) to food security. These include sustainable shrimp capture fisheries, sustainable shrimp trade and sustainable shrimp aquaculture. The paper concludes that crustaceans are an important source of aquatic food protein. Production (as food and ornamental) and trade are extremely important for developing countries. It provides both economic development and empowerment in terms of contribution to GDP, consumption, employment, catch value and exports. The crustacean sector generates high value export products which enables producers to buy lower value products in the world market - thus a positive contribution to food security in both producing and exporting countries. PMID:22433997

Bondad-Reantaso, Melba G; Subasinghe, Rohana P; Josupeit, Helga; Cai, Junning; Zhou, Xiaowei

2012-06-01

338

Health management during handling and live transport of crustaceans: A review  

Microsoft Academic Search

Best practice approaches used in the live transport of commercial crustacean species groups are reviewed and the physiological responses to handling practices are described. Codes of practice aimed at providing technological guidelines in handling and transportation of live prawns, lobsters, crabs and freshwater crayfish are examined. While some handling and transport practices are common across species groups, for example purging

S. Fotedar; L. Evans

2011-01-01

339

Crustacean Hyperglycemic Hormone, a possible endocrine regulator of ecdysis in the tobacco hornworm, Manduca sexta  

E-print Network

ecdysis because (i) its endocrine system is well characterized, (ii) it has identifiable cells fromCrustacean Hyperglycemic Hormone, a possible endocrine regulator of ecdysis in the tobacco hornworm State University, San Francisco, CA 94132 Fig. 3: Paired endocrine cells of the Third thoracic ganglia

Fuse, Megumi

340

Genetic basis of eye and pigment loss in the cave crustacean, Asellus aquaticus  

E-print Network

Genetic basis of eye and pigment loss in the cave crustacean, Asellus aquaticus Meredith E. Protasa and the loss of eyes and pigmentation, have evolved multiple times in a diverse assemblage of cave animals to be involved in pigmen- tation, eye, and appendage development, was used to identify loci of large effect

Patel, Nipam H.

341

Insecticidal juvenile hormone analogs stimulate the production of male offspring in the crustacean Daphnia magna.  

PubMed Central

Juvenile hormone analogs (JHAs) represent a class of insecticides that were designed specifically to disrupt endocrine-regulated processes relatively unique to insects. Recently we demonstrated that the crustacean juvenoid hormone methyl farnesoate programs oocytes of the crustacean Daphnia magna to develop into males. We hypothesized that insecticidal JHAs might mimic the action of methyl farnesoate, producing altered sex ratios of offspring. Daphnids were exposed chronically (3 weeks) to sublethal concentrations of methyl farnesoate, the JHA pyriproxyfen, and several nonjuvenoid chemicals to discern whether excess male offspring production is a generic response to stress or a specific response to juvenoid hormones. Only methyl farnesoate and pyriproxyfen increased the percentage of males produced by exposed maternal organisms. As previously reported with methyl farnesoate, acute exposure (24 hr) to either pyriproxyfen or the JHA methoprene caused oocytes maturing in the ovary to develop into males. We performed experiments to determine whether combined effects of a JHA and methyl farnesoate conformed better to a model of concentration addition (indicative of same mechanism of action) or independent joint action (indicative of different mechanisms of action). Combined effects conformed better to the concentration-addition model, although some synergy, of unknown etiology, was evident between the insecticides and the hormone. These experiments demonstrate that insecticidal JHAs mimic the action of the crustacean juvenoid hormone methyl farnesoate, resulting in the inappropriate production of male offspring. The occurrence of such an effect in the environment could have dire consequences on susceptible crustacean populations. PMID:12782492

Olmstead, Allen W; LeBlanc, Gerald A

2003-01-01

342

Insect protein as a partial replacement of fishmeal in the diets of juvenile fish and crustaceans  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter represents a review of the published literature to determine if insect protein is an important supplement to - or even a replacement for - fishmeal in diets for juvenile fish and crustaceans. Fishmeal is becoming a finite resource. This chapter highlights areas of opportunity for produc...

343

BAC library for the amphipod crustacean, Parhyale hawaiensis Ronald J. Parchem a,1  

E-print Network

from genomic DNA isolated from whole adult animals and comprises 129,024 individual clones. The median large fragments of DNA and have become an invaluable tool for studying genome biology. To fill) and arthropods (e.g. insects, crustaceans) are ecdysozoans. Of these groups, the ecdysozoans contain the vast

Patel, Nipam H.

344

A structure-function analysis of ion transport in crustacean gills and excretory organs.  

PubMed

Osmotic and ionic regulation in the Crustacea is mostly accomplished by the multifunctional gills, together with the excretory organs. In addition to their role in gas exchange, the gills constitute organs of active, transepithelial, ion transport, an activity of major importance that underlies many essential physiological functions like osmoregulation, calcium homeostasis, ammonium excretion and extracellular pH regulation. This review focuses on structure-function relationships in crustacean gills and excretory effectors, from the organ to molecular levels of organization. We address the diversity of structural architectures encountered in different crustacean gill types, and in constituent cell types, before examining the physiological mechanisms of Na(+), Cl(-), Ca(2+) and NH(4)(+) transport, and of acid-base equivalents, based on findings obtained over the last two decades employing advanced techniques. The antennal and maxillary glands constitute the principal crustacean excretory organs, which have received less attention in functional studies. We examine the diversity present in antennal and maxillary gland architecture, highlighting the structural similarities between both organ types, and we analyze the functions ascribed to each glandular segment. Emphasis is given to volume and osmoregulatory functions, capacity to produce dilute urine in freshwater crustaceans, and the effect of acclimation salinity on urine volume and composition. The microanatomy and diversity of function ascribed to gills and excretory organs are appraised from an evolutionary perspective, and suggestions made as to future avenues of investigation that may elucidate evolutionary and adaptive trends underpinning the invasion and exploitation of novel habitats. PMID:17604200

Freire, Carolina A; Onken, Horst; McNamara, John C

2008-11-01

345

Sexual Contests in Aquatic Crustaceans: What's Physiology Got To Do with It?  

ERIC Educational Resources Information Center

Describes a science laboratory on reproductive behavior and studies the dynamics in Lirceus, an aquatic crustacean of which the females evaluate the males' quality through mating contests. Explains collecting isopods and developing colonies in the lab environment. Investigates food deprivation, locomotor activity, and behavioral trials to…

Keogh, Daniel P.; Sparkes, Timothy C.

2003-01-01

346

Variability in trophic dominance of crustaceans along a gradient of urban and industrial contamination  

Microsoft Academic Search

The trophic organization of the crustacean fauna belonging to a photophilic assemblage exposed to an urban and industrial contamination gradient in the Gulf of Fos (South of France) was studied over a period of 16 mo (May 1974 to August 1975). An increasing destabilization of the four major trophic groups from clean waters towards those most polluted was noted. Carnivores

G. Desrosiers; D. Bellan-Santini; J.-C. F. Brêthes; A. Willsie

1990-01-01

347

Z .Journal of Neuroscience Methods 69 1996 5158 Assessing ultrastructure of crustacean and insect neuromuscular  

E-print Network

to experimentation. The attractive features of the arthropod motor nerve termi- nals are the relatively large size of crustaceans and Drosophila show various forms of physiological plasticity, such as short-term Zand long; .Weiler et al., 1995 . The use of Drosophila affords an opportunity to investigate genetic influences

Cooper, Robin L.

348

Differential expression profiling of components associated with exoskeletal hardening in crustaceans  

Microsoft Academic Search

BACKGROUND: Exoskeletal hardening in crustaceans can be attributed to mineralization and sclerotization of the organic matrix. Glycoproteins have been implicated in the calcification process of many matrices. Sclerotization, on the other hand, is catalysed by phenoloxidases, which also play a role in melanization and the immunological response in arthropods. Custom cDNA microarrays from Portunus pelagicus were used to identify genes

Anna V Kuballa; Abigail Elizur

2008-01-01

349

Chemical composition and buoyancy of midwater crustaceans as function of depth of occurrence off Southern California  

Microsoft Academic Search

Water, ash, C, H, N, lipid, carbohydrate, chitin and protein contents were determined for 28 species of midwater crustaceans. Variation of these components as a function of depth of occurrence, relative buouancy and respiratory rate of these species was examined. Vertical distribution data for 10 of the species based on discrete depth crawls is provided. The relative bouyancies of 16

J. J. Childress; M. Nygaard

1974-01-01

350

DETERMINATION OF BIOACTIVITY OF CHEMICAL FRACTIONS OF LIQUID WASTES USING FRESHWATER AND SALTWATER ALGAE AND CRUSTACEANS  

EPA Science Inventory

A method is described for analysis of complex industrial and municipal wastes. The method uses chemical fractionation and subfractionation combined with laboratory toxicity tests on marine and freshwater algae and crustaceans to determine toxicity of whole waste and to identify i...

351

Exceptionally preserved crustaceans from western Canada reveal a cryptic Cambrian radiation  

PubMed Central

The early history of crustaceans is obscured by strong biases in fossil preservation, but a previously overlooked taphonomic mode yields important complementary insights. Here we describe diverse crustacean appendages of Middle and Late Cambrian age from shallow-marine mudstones of the Deadwood Formation in western Canada. The fossils occur as flattened and fragmentary carbonaceous cuticles but provide a suite of phylogenetic and ecological data by virtue of their detailed preservation. In addition to an unprecedented range of complex, largely articulated filtering limbs, we identify at least four distinct types of mandible. Together, these fossils provide the earliest evidence for crown-group branchiopods and total-group copepods and ostracods, extending the respective ranges of these clades back from the Devonian, Pennsylvanian, and Ordovician. Detailed similarities with living forms demonstrate the early origins and subsequent conservation of various complex food-handling adaptations, including a directional mandibular asymmetry that has persisted through half a billion years of evolution. At the same time, the Deadwood fossils indicate profound secular changes in crustacean ecology in terms of body size and environmental distribution. The earliest radiation of crustaceans is largely cryptic in the fossil record, but “small carbonaceous fossils” reveal organisms of surprisingly modern aspect operating in an unfamiliar biosphere. PMID:22307616

Harvey, Thomas H. P.; Vélez, Maria I.; Butterfield, Nicholas J.

2012-01-01

352

Determination of bioactivity of chemical fractions of liquid wastes using freshwater and saltwater algae and crustaceans  

Microsoft Academic Search

Complex wastes from industrial and municipal outfalls were fractionated chemically and tested for toxicity with freshwater and saltwater algae and crustaceans. The organic fraction of each waste was subfractionated into acid-, base-, and neutral-extractable portions, and the inorganic fraction was subfractionated into its anion and cation components. All wastes affected growth of the algae Skeletonema costatum (saltwater) and Monoraphidium capricornutum

Gerald E. Walsh; Richard L. Garnas

1983-01-01

353

Fish and macro-crustacean communities and their dynamics in the Severn Estuary.  

PubMed

The species of fish and macro-crustacean living within the Severn Estuary are reviewed. The fish community is notably species rich and exceeds 100 species in total for the estuary. Standardised long-term sampling at Hinkley Point in Bridgwater Bay gives a total complement of 83 for a single locality and this number is increasing by about one new species every two years. Most of these new species are moving in from centres of population lying to the south of the estuary. Almost all species of fish and macro-crustacean living within the estuary undertake regular migrations so that they tend to move seasonally in waves up and down the estuary. For fish, both species richness and the total abundance reach a maximum in late summer and autumn. The timing of this peak varies between the upper and lower estuary. This seasonal maximum is primarily caused by the arrival of the new recruits which use the estuary as a nursery. In contrast, crustaceans tend to be at their most diverse and abundant in early to mid summer. Using a 30-year time series of fish and crustacean abundance collected at Hinkley Point it is shown that major changes in the structure of the community are now underway and there are considerable recent changes in the abundance. However, some abundant species, including sand goby, Pomatoschistus spp., whiting, Merlangius merlangus and sprat, Sprattus sprattus, the three most abundant species in the estuary, have shown no long-term trend. At present, approximately 20% of the fish and macro-crustaceans observed in Bridgwater Bay are undergoing rapid, typically exponential, change in abundance. For a numerically abundant, diverse, fauna composed of approximately 90 species such levels of change are unexpected and suggest that the system is presently far from equilibrium. In some cases, the observed changes can be related to recent warming and the North Atlantic Oscillation. The overall increase in fish abundance observed may reflect a general improvement in water quality and a reduction in other anthropogenic impacts such as mortality in cooling-water intakes. The potential impacts of tidal power generation in the Severn Estuary are reviewed. There is considerable potential for any major installation to impact the fish and crustacean populations as they migrate and also alter the nature of the habitat resulting in changes in community composition. A particular difficulty in predicting the future impact of harnessing tidal energy is that the present community is already changing rapidly. The ability of fish and crustaceans to pass through the turbines unharmed will be a key issue in an assessment of the impact of tidal power generation. PMID:20074757

Henderson, P A; Bird, D J

2010-01-01

354

[Morphofunctional changes in the midgut of ticks of the genus Ixodes (Acarina: Ixodidae) during life cycle].  

PubMed

Morphofunctional investigations of five Ixodes species (Ixodes pacificus, I. pavlovsky, I. persulcatus, I. ricinus and I. scapularis) were carried out. It was established, that the change of midgut epithelium lags at the each next developmental stage, and it is not synchronized with general processes of metamorphosis and organogenesis during molts. The midgut epithelium of a previous phase of the life cycle persists and functions during the feeding stage at the next phase. PMID:19957908

Grigor'eva, L A

2009-01-01

355

Crustaceans from a tropical estuarine sand-mud flat, Pacific, Costa Rica, (1984-1988) revisited.  

PubMed

The availability of data sets for time periods of more than a year is scarce for tropical environments. Advances in hardware and software speed-up the re-analysis of old data sets and facilitates the description of population oscillations. Using recent taxonomic literature and software we have updated and re-analized the information on crustacean diversity and population fluctuations from a set of cores collected at a mud-sand flat in the mid upper Gulf of Nicoya estuary, Pacific coast of Costa Rica (1984-1988). A total of 112 morphological species of macroinvertebrates was found, of which 29 were crustaceans. Taxonomic problems, maily with the peracarids, prevented the identification of a group of species. The abundance patterns of the crab Pinnixa valerii, the ostracod Cyprideis pacifica, and the cumacean Coricuma nicoyensis were analized with the Generalized Additive Models of the free software R. The models evidenced a variety of population oscillations during the sampling period. These oscillations probably included perturbations induced by external factors, like the strong red tide events of 1985. In additon, early on 1984 the populations might have been at an altered state due to the inpact of El Niño 1982-83. Thus, the oscillations observed during the study period departed from the expected seasonality (dry vs rainy) pattern and are thus considered atypical for this tropical estuarine tidal-flat. Crustacean diversity and population peaks were within the range of examples found in worldwide literature. However, abundances of the cumacean C. nicoyensis, an endemic species, are the highest reported for a tropical estuary. Comparative data from tropical tidal flat crustaceans continues to be scarce. Crustaceans (total vs groups) had population changes in response to the deployment of predator exclusion cages during the dry and rainy seasons of 1985. Temporal and spatial patchiness characterized the abundances of P. valeri, C. pacifica and C. nicoyenis. PMID:23342527

Vargas-Zamora, José A; Sibaja-Cordero, Jeffrey A; Vargas-Castillo, Rita

2012-12-01

356

Effect of withdrawing long days from male American tree sparrows (Spizella arborea): implications for understanding thyroid-dependent programming of seasonal reproduction and postnuptial molt.  

PubMed

In previous studies, we withdrew thyroid hormones by thyroidectomy before, at, or after the onset of photostimulation and showed that male American tree sparrows (Spizella arborea) are programmed for seasonal reproduction and postnuptial molt by or before Week 3 on long days. In this corollary study, we withdrew long days before or after the control circuits had been programmed. After 1 day to 4 wk on long days, groups of thyroid-intact males were returned to short days until Week 7, when they were moved to constant light and evaluated for photosensitivity or photorefractoriness and postnuptial molt. Long-day controls held 7 wk on long days showed robust testicular growth through Week 6 and then spontaneous testicular regression. Testes of short-day controls and of males photostimulated for 1 day remained small. In all other groups, photostimulation induced testicular growth, which gave way to regression during exposure to short days. Long-day controls tested photorefractory at Week 7 and initiated molt by Week 10. All other groups tested photosensitive and did not molt. Our demonstration that long days are required for expression of seasonal reproduction and postnuptial molt in thyroid-intact male tree sparrows previously programmed for these events suggests that long days create a milieu that is permissive for expression. PMID:9472917

Wilson, F E; Reinert, B D

1998-01-01

357

Characterization and spatiotemporal expression of orchestin, a gene encoding an ecdysone-inducible protein from a crustacean organic matrix.  

PubMed Central

We report the characterization of a new gene encoding an acidic protein named Orchestin. This protein is a component of the organic matrix of calcium storage structures (calcareous concretions) elaborated during the moulting cycles of the terrestrial crustacean Orchestia cavimana. The deduced molecular mass of Orchestin is estimated to be 12.4 kDa and the pI to be 4.4, whereas the native protein extracted from the calcium deposits migrates as a 23 kDa band on SDS/PAGE. This discrepancy is probably due to the richness of this protein in acidic amino acids (approx. 30%). The protein obtained by expressing the Orchestin cDNA in Escherichia coli presents an electrophoretic mobility of 25 kDa. Antibodies raised against the recombinant protein recognize the 23 kDa native protein exclusively among the organic-matrix components. Spatiotemporal analysis of the expression of the orchestin gene shows that it is expressed only in the storage organ cells when the concretions are elaborated during the premoult period and also, to a smaller extent, during the postmoult period. The translation products are expressed in accordance with the transcript expression during both the premoult and postmoult periods. Study of the hormonal stimulation of orchestin reveals that 20-hydroxyecdysone induces this gene as a secondary-response or late-response gene. PMID:11772404

Testenière, Olivier; Hecker, Arnaud; Le Gurun, Sabine; Quennedey, Brigitte; Graf, François; Luquet, Gilles

2002-01-01

358

`Akohekohe response to flower availability: seasonal abundance, foraging, breeding, and molt  

USGS Publications Warehouse

We studied the relationship of flower availability to the seasonality of life history events of the `Akohekohe (Palmeria dolei), a primarily nectarivorous and endangered Hawaiian honeycreeper from montane rain forests on Maui, Hawai`i. For comparison, we also investigated temporal bird density and foraging behavior of three other competing Hawaiian honeycreepers: `Apapane (Himatione sanguinea), `I`iwi (Vestiaria coccinea), and Hawai`i `Amakihi (Hemignathus virens). All species except `Amakihi fed primarily on nectar of `Ohi?a-lehua (Metrosideros polymorpha), which produced flowers year-round but had an annual flowering peak in January. Flowers of several subcanopy shrubs and trees were important components of the diet for all nectarivores, and these were available seasonally depending upon the species. `Akohekohe densities did not change temporally, suggesting a relatively stable population residing above 1,700 m. Monthly densities of `Apapane, `I`iwi, and Hawai`i `Amakihi were positively correlated with monthly `Ohi?a-lehua flower abundance, and 50-80% of these populations departed temporarily from our high-elevation site in July. There was a positive correlation with the timing of Akohekohe breeding and high abundance of `Ohi?a-lehua bloom. Molt followed breeding. From a conservation perspective, these results show that `Akohekohe maintain a relatively stable population above the mid-elevation zone of disease transmission, particularly during the fall when `Ohi?a-lehua bloom decreases and mosquitoes increase. `Akohekohe remain on their territories partly by switching their foraging to subcanopy trees and shrubs, most of which require protection from feral pigs (Sus scrofa).

Berlin, K.E.; Simon, J.C.; Pratt, T.K.; Kowalsky, J.R.; Hatfield, J.S.

2001-01-01

359

Biological Surface Coating and Molting Inhibition as Mechanisms of TiO2 Nanoparticle Toxicity in Daphnia magna  

PubMed Central

The production and use of nanoparticles (NP) has steadily increased within the last decade; however, knowledge about risks of NP to human health and ecosystems is still scarce. Common knowledge concerning NP effects on freshwater organisms is largely limited to standard short-term (?48 h) toxicity tests, which lack both NP fate characterization and an understanding of the mechanisms underlying toxicity. Employing slightly longer exposure times (72 to 96 h), we found that suspensions of nanosized (?100 nm initial mean diameter) titanium dioxide (nTiO2) led to toxicity in Daphnia magna at nominal concentrations of 3.8 (72-h EC50) and 0.73 mg/L (96-h EC50). However, nTiO2 disappeared quickly from the ISO-medium water phase, resulting in toxicity levels as low as 0.24 mg/L (96-h EC50) based on measured concentrations. Moreover, we showed that nTiO2 (?100 nm) is significantly more toxic than non-nanosized TiO2 (?200 nm) prepared from the same stock suspension. Most importantly, we hypothesized a mechanistic chain of events for nTiO2 toxicity in D. magna that involves the coating of the organism surface with nTiO2 combined with a molting disruption. Neonate D. magna (?6 h) exposed to 2 mg/L nTiO2 exhibited a “biological surface coating” that disappeared within 36 h, during which the first molting was successfully managed by 100% of the exposed organisms. Continued exposure up to 96 h led to a renewed formation of the surface coating and significantly reduced the molting rate to 10%, resulting in 90% mortality. Because coating of aquatic organisms by manmade NP might be ubiquitous in nature, this form of physical NP toxicity might result in widespread negative impacts on environmental health. PMID:21647422

Dabrunz, André; Duester, Lars; Prasse, Carsten; Seitz, Frank; Rosenfeldt, Ricki; Schilde, Carsten; Schaumann, Gabriele E.; Schulz, Ralf

2011-01-01

360

Biological surface coating and molting inhibition as mechanisms of TiO2 nanoparticle toxicity in Daphnia magna.  

PubMed

The production and use of nanoparticles (NP) has steadily increased within the last decade; however, knowledge about risks of NP to human health and ecosystems is still scarce. Common knowledge concerning NP effects on freshwater organisms is largely limited to standard short-term (?48 h) toxicity tests, which lack both NP fate characterization and an understanding of the mechanisms underlying toxicity. Employing slightly longer exposure times (72 to 96 h), we found that suspensions of nanosized (?100 nm initial mean diameter) titanium dioxide (nTiO(2)) led to toxicity in Daphnia magna at nominal concentrations of 3.8 (72-h EC(50)) and 0.73 mg/L (96-h EC(50)). However, nTiO(2) disappeared quickly from the ISO-medium water phase, resulting in toxicity levels as low as 0.24 mg/L (96-h EC(50)) based on measured concentrations. Moreover, we showed that nTiO(2) (?100 nm) is significantly more toxic than non-nanosized TiO(2) (?200 nm) prepared from the same stock suspension. Most importantly, we hypothesized a mechanistic chain of events for nTiO(2) toxicity in D. magna that involves the coating of the organism surface with nTiO(2) combined with a molting disruption. Neonate D. magna (?6 h) exposed to 2 mg/L nTiO(2) exhibited a "biological surface coating" that disappeared within 36 h, during which the first molting was successfully managed by 100% of the exposed organisms. Continued exposure up to 96 h led to a renewed formation of the surface coating and significantly reduced the molting rate to 10%, resulting in 90% mortality. Because coating of aquatic organisms by manmade NP might be ubiquitous in nature, this form of physical NP toxicity might result in widespread negative impacts on environmental health. PMID:21647422

Dabrunz, André; Duester, Lars; Prasse, Carsten; Seitz, Frank; Rosenfeldt, Ricki; Schilde, Carsten; Schaumann, Gabriele E; Schulz, Ralf

2011-01-01

361

Parasite communities of the Salzhaff (Northwest Mecklenburg, Baltic Sea) II. Guild communities, with special regard to snails, benthic crustaceans, and small-sized fish.  

PubMed

Metazoan parasites of guilds of benthic snails and crustaceans and of four fish families--Gobiidae, Gasterosteidae, Syngnathidae, and Zoarcidae--were investigated off the brackish Salzhaff area (Southwest Baltic) in the semienclosed Salzhaff and the near Rerik Riff in the free Baltic. Comparisons revealed greater similarities in parasite populations and communities within the fish guilds than between them. According to an evaluation of the core-/satellite-species concept using abundance values, the most important parasites of fish were some generalists, such as Cryptocotyle spp., Podocotyle atomon, and Diplostomum spathaceum, as well as some specialists, such as Acanthostomum balthicum, Thersitina gasterostei, and Aphalloides timmi. These specialists revealed high degrees of prevalence in their main hosts and lower degrees in one or two by-hosts. Additional importance is assigned to parasites that cause harm to their hosts due to their large size, e.g., Schistocephalus spp., or via massive infestation, e.g., several digenean metacercariae. Because specialists were more prominent in snails and fish from the Rerik Riff, the correlation of host numbers with prevalence resulted in only a slight increase instead of a more rapid rise in regression among crustaceans and fish from the entire Salzhaff, where the generalists were more prevalent. The selected host guilds demonstrated the entire life cycles of three digeneans (P. atomon, A. balthicum, A. timmi), one acanthocephalan (Echinorhynchus gadi), and one nematode (Hysterothylacium sp.). The prevalence increased in these cycles from host level to host level and attained relatively high values in all guilds. The parasite fauna of the Salzhaff area is influenced by eutrophication stress, which leads to a high level of productivity and, consequently, to great densities in primary consumers such as snails and crustaceans. These are attractive for several secondary consumers such as fish and birds, which is the reason for the existence of at least 24 autogenic and 20 allogenic parasite species at this locality. The slight surplus of the first category indicates a yet-balanced environment in the investigation area. PMID:10836510

Zander, C D; Reimer, L W; Barz, K; Dietel, G; Strohbach, U

2000-05-01

362

Genes involved in thoracic exoskeleton formation during the pupal-to-adult molt in a social insect model, Apis mellifera  

PubMed Central

Background The insect exoskeleton provides shape, waterproofing, and locomotion via attached somatic muscles. The exoskeleton is renewed during molting, a process regulated by ecdysteroid hormones. The holometabolous pupa transforms into an adult during the imaginal molt, when the epidermis synthe3sizes the definitive exoskeleton that then differentiates progressively. An important issue in insect development concerns how the exoskeletal regions are constructed to provide their morphological, physiological and mechanical functions. We used whole-genome oligonucleotide microarrays to screen for genes involved in exoskeletal formation in the honeybee thoracic dorsum. Our analysis included three sampling times during the pupal-to-adult molt, i.e., before, during and after the ecdysteroid-induced apolysis that triggers synthesis of the adult exoskeleton. Results Gene ontology annotation based on orthologous relationships with Drosophila melanogaster genes placed the honeybee differentially expressed genes (DEGs) into distinct categories of Biological Process and Molecular Function, depending on developmental time, revealing the functional elements required for adult exoskeleton formation. Of the 1,253 unique DEGs, 547 were upregulated in the thoracic dorsum after apolysis, suggesting induction by the ecdysteroid pulse. The upregulated gene set included 20 of the 47 cuticular protein (CP) genes that were previously identified in the honeybee genome, and three novel putative CP genes that do not belong to a known CP family. In situ hybridization showed that two of the novel genes were abundantly expressed in the epidermis during adult exoskeleton formation, strongly implicating them as genuine CP genes. Conserved sequence motifs identified the CP genes as members of the CPR, Tweedle, Apidermin, CPF, CPLCP1 and Analogous-to-Peritrophins families. Furthermore, 28 of the 36 muscle-related DEGs were upregulated during the de novo formation of striated fibers attached to the exoskeleton. A search for cis-regulatory motifs in the 5?-untranslated region of the DEGs revealed potential binding sites for known transcription factors. Construction of a regulatory network showed that various upregulated CP- and muscle-related genes (15 and 21 genes, respectively) share common elements, suggesting co-regulation during thoracic exoskeleton formation. Conclusions These findings help reveal molecular aspects of rigid thoracic exoskeleton formation during the ecdysteroid-coordinated pupal-to-adult molt in the honeybee. PMID:23981317

2013-01-01

363

The Y-organ secretory activity fluctuates in relation to seasons of molt and reproduction in the brachyuran crab, Metopograpsus messor (Grapsidae): Ultrastructural and immunohistochemical study.  

PubMed

This paper presents a first-time report on the localization, structure and seasonal secretory activity of the Y-organ of a grapsid brachyuran crab (Metopograpsus messor). Having exhibited discrete seasonality with reference to the programming of molt and reproduction, this brachyuran crab has offered us an excellent model to obtain a clear picture of the fluctuating secretory nature of the Yorgan, all the way through the reproductive (August-December) as well as the molt-reproduction active (January-May) and inactive (June-July) seasons. Ultrastructural studies revealed that the secretion of the Y-organ was at its peak in premolt crabs during molt-reproduction season (January-May). Interestingly, the Y-organs of the intermolt females that engaged in breeding activity showed higher levels of secretion than those of the molt-reproduction inactive season (June-July), implicating the gland's involvement in reproduction. Immunohistochemical studies using the antiserum raised against 2-succinyl conjugate of ecdysone have demonstrated the ecdysteroid nature of the secretion from the Y-organ, and results of the quantitative assay of ecdysteroids (through radioimmunoassay) revealed that the hormone titer fluctuates in consonance with the Y-organ's secretory activity during seasons of molt and reproduction. Pertinently, not only that the paper gives us a comprehensive understanding on the secretory activity of the Y-organ in a season-dependent fashion, it also allows us to have a better insight into the gland's function related to molting and reproduction (for the first time) in a grapsid brachyuran crab. PMID:24291010

Shyamal, Sharmishtha; Sudha, K; Gayathri, N; Anilkumar, G

2014-01-15

364

Guar meal diets as an alternative approach to inducing molt and improving Salmonella enteritidis resistance in late-phase laying hens.  

PubMed

Induced molting of laying hens is a practice used by commercial egg producers to increase the productive lifetime of their flock. However, the conventional method of inducing molt, which involves removal of feed, water, or both as well as a reduction in photoperiod to less than a natural day has drawn criticism due to animal welfare and food safety concerns. The objective of this study was to explore the efficacy of diets containing high levels of guar meal (GM) in inducing molt and reducing susceptibility to Salmonella Enteritidis colonization in late-phase laying hens. Late-phase (68 wk old) Lohmann laying hens were either full-fed standard laying hen diets (nonmolted control), induced to molt by feed withdrawal, or full-fed standard laying hen diets containing 20% GM with or without 250 units/kg of mannanase Hemicell supplementation. On the fourth day of treatment, all hens were orally challenged with SE (1.65 x 10(7) cfu). Hens were killed and evaluated for Salmonella colonization and differences in organ weights 5 d postinoculation. Salmonella Enteritidis present in crop, liver, ovary, and cecal contents were significantly reduced by feeding GM with enzyme supplementation compared with feed withdrawal hens. No significant differences were observed in reproductive tract weights of molted groups, although a difference in liver weight was detected. Results indicate that feeding diets containing 20% GM are as effective as complete feed withdrawal with respect to inducing molt with the added benefit of improved resistance to Salmonella Enteritidis colonization and translocation. PMID:18281581

Gutierrez, O; Zhang, C; Caldwell, D J; Carey, J B; Cartwright, A L; Bailey, C A

2008-03-01

365

Sampling Daphnia's expressed genes: preservation, expansion and invention of crustacean genes with reference to insect genomes  

PubMed Central

Background Functional and comparative studies of insect genomes have shed light on the complement of genes, which in part, account for shared morphologies, developmental programs and life-histories. Contrasting the gene inventories of insects to those of the nematodes provides insight into the genomic changes responsible for their diversification. However, nematodes have weak relationships to insects, as each belongs to separate animal phyla. A better outgroup to distinguish lineage specific novelties would include other members of Arthropoda. For example, crustaceans are close allies to the insects (together forming Pancrustacea) and their fascinating aquatic lifestyle provides an important comparison for understanding the genetic basis of adaptations to life on land versus life in water. Results This study reports on the first characterization of cDNA libraries and sequences for the model crustacean Daphnia pulex. We analyzed 1,546 ESTs of which 1,414 represent approximately 787 nuclear genes, by measuring their sequence similarities with insect and nematode proteomes. The provisional annotation of genes is supported by expression data from microarray studies described in companion papers. Loci expected to be shared between crustaceans and insects because of their mutual biological features are identified, including genes for reproduction, regulation and cellular processes. We identify genes that are likely derived within Pancrustacea or lost within the nematodes. Moreover, lineage specific gene family expansions are identified, which suggest certain biological demands associated with their ecological setting. In particular, up to seven distinct ferritin loci are found in Daphnia compared to three in most insects. Finally, a substantial fraction of the sampled gene transcripts shares no sequence similarity with those from other arthropods. Genes functioning during development and reproduction are comparatively well conserved between crustaceans and insects. By contrast, genes that were responsive to environmental conditions (metal stress) and not sex-biased included the greatest proportion of genes with no matches to insect proteomes. Conclusion This study along with associated microarray experiments are the initial steps in a coordinated effort by the Daphnia Genomics Consortium to build the necessary genomic platform needed to discover genes that account for the phenotypic diversity within the genus and to gain new insights into crustacean biology. This effort will soon include the first crustacean genome sequence. PMID:17612412

Colbourne, John K; Eads, Brian D; Shaw, Joseph; Bohuski, Elizabeth; Bauer, Darren J; Andrews, Justen

2007-01-01

366

A second proPO present in white shrimp Litopenaeus vannamei and expression of the proPOs during a Vibrio alginolyticus injection, molt stage, and oral sodium alginate ingestion.  

PubMed

Prophenoloxidase (proPO) is a melanin-synthesising enzyme that plays important roles in immune responses by crustaceans. Previously, we cloned and characterized proPO-I from white shrimp, Litopenaeus vannamei. In the present study, a novel prophenoloxidase-II (proPO-II) cDNA was also cloned from haemocytes of L. vannamei using oligonucleotide primers and reverse-transcriptase polymerase chain reaction (RT-PCR). Both 3'- and 5'-regions were isolated by the rapid amplification of complementary (c)DNA end (RACE) method. The 2504-bp cDNA contained an open reading frame (ORF) of 2073 bp, an 84-bp 5'-untranslated region, and a 347-bp 3'-untranslated region containing the poly A tail. The molecular mass of the deduced amino acid sequence (691 amino acids) was 78.8 kDa with an estimated pI of 6.07. It contains two putative tyrosinase copper-binding motifs and a conserved C-terminal region common to all known proPOs. Comparisons of the amino acid sequences showed that white shrimp proPO-II is more closely related to the proPO of other penaeids than to that of crayfish, lobsters, crab, or a freshwater prawn, and is the ancestor type of known penaeid proPOs. proPO-I and proPO-II messenger (m)RNAs of shrimp were located on different loci, and were constitutively expressed mainly in haemocytes. The transcriptional regulation of these two proPOs in shrimp at different molt stages, those administered dietary sodium alginate, and those challenged with Vibrio alginolyticus were surveyed. The results showed that the proPOs may be directly involved in the acute-phase immune defence, and proPO-II may contribute earlier to immune defence in shrimp injected with V. alginolyticus, and it may be regulated by ecdysone. However, a similar effect was found by stimulating proPO-I and proPO-II mRNA expression in shrimp fed a sodium alginate-containing diet. Results of this study provide a basis for developing a comprehensive understanding of expression/function relationships of individual proPOs in shrimp. PMID:18984057

Yeh, Maw-Sheng; Lai, Ching-Yi; Liu, Chun-Hung; Kuo, Ching-Ming; Cheng, Winton

2009-01-01

367

Crustaceans from bitumen clast in Carboniferous glacial diamictite extend fossil record of copepods.  

PubMed

Copepod crustaceans are extremely abundant but, because of their small size and fragility, they fossilize poorly. Their fossil record consists of one Cretaceous (c. 115?Ma) parasite and a few Miocene (c. 14?Ma) fossils. In this paper, we describe abundant crustacean fragments, including copepods, from a single bitumen clast in a glacial diamictite of late Carboniferous age (c. 303?Ma) from eastern Oman. Geochemistry identifies the source of the bitumen as an oilfield some 100-300?km to the southwest, which is consistent with an ice flow direction from glacial striae. The bitumen likely originated as an oil seep into a subglacial lake. This find extends the fossil record of copepods by some 188?Ma, and of free-living forms by 289?Ma. The copepods include evidence of the extant family Canthocamptidae, believed to have colonized fresh water in Pangaea during Carboniferous times. PMID:20975721

Selden, Paul A; Huys, Rony; Stephenson, Michael H; Heward, Alan P; Taylor, Paul N

2010-01-01

368

Increase of crustacean sensitivity to purified hepatotoxic cyanobacterial extracts by manipulation of experimental conditions.  

PubMed

Toxic cyanobacterial blooms are one of the most common consequences of water eutrophication. Microbiotests with crustaceans are not expensive and are easy to prepare for screening tests. They can be applied in the determination of bioactivity and interaction between toxic substances in water, including hepatotoxins. The principal aim of this study was to modify the standard conditions in the Thamnotoxkit F trade mark and Artoxkit M in order to increase crustacean sensitivity to purified cyanobacterial extracts containing microcystins. The results reported show that exposure time, higher temperature, and presence of DMSO can increase the sensitivity of microbiotests to microcystins. The best sensitivity with the Artemia salina test was achieved after a 48-h exposure at 25 degrees C. The tests using a 24-h exposure at 27 degrees C were the most sensitive for Thamnocephalus platyurus. The test without preincubation with DMSO provided the best correlation of microcystin concentration and LC(50) for Thamnocephalus platyurus and is recommended. PMID:15269916

Drobniewska, Agata; Tarczy?ska, Ma?gorzata; Mankiewicz, Joanna; Jurczak, Tomasz; Zalewski, Maciej

2004-08-01

369

Effects of temperature and salinity on the development of the amphipod crustacean Eogammarus sinensis  

NASA Astrophysics Data System (ADS)

The amphipod crustacean Eogammarus sinensis has useful features that make it suitable for use in the aquaculture of fish and large decapod crustaceans. In this study, we investigated the effects of temperature and salinity on the development, fecundity, survival, and growth rate of E. sinensis. The results show that temperature significantly affected E. sinensis development, but salinity. As temperature increased, the duration of E. sinensis embryonic development decreased. Fecundity was affected significantly by temperature and the combination of temperature and salinity, but by salinity alone. In addition, high temperatures accelerated E. sinensis juvenile growth rates, whereas high salinity reduced it. Therefore, our data suggest that E. sinensis tolerates a wide range of salinities and that temperature has more significant effects than salinity on the embryonic development, fecundity, and growth of E. sinensis. Our results shall be useful for mass production of this species for use in aquaculture.

Xue, Suyan; Fang, Jianguang; Zhang, Jihong; Jiang, Zengjie; Mao, Yuze; Zhao, Fazhen

2013-09-01

370

Selfing in a malacostracan crustacean: why a tanaidacean but not decapods  

NASA Astrophysics Data System (ADS)

The crustacean class Malacostraca, with over 22,000 species, includes commercially important members, such as crabs, shrimps, and lobsters. A few simultaneous hermaphrodites are known in this group, but self-fertilization was unknown. Here we show, through microscopy and breeding experiments, that the simultaneously hermaphroditic malacostracan Apseudes sp. (order Tanaidacea) can self-fertilize; individuals reared in isolation become hermaphroditic via a male-like phase and produce eggs that develop into fertile adults. Although selfing occurs in crustaceans like the Branchiopoda, in which simultaneous hermaphrodites have the sex ducts united, in decapods the separation of gonadal ducts and gonopores, specialized mating organs, and complex mating behavior appear to have constrained the evolution of selfing. In contrast, in most tanaidaceans, sperm is released externally by a male and reaches the eggs in the female brood pouch, where fertilization occurs. This mode of fertilization permitted Apseudes sp. to achieve selfing without large modifications in morphology or behavior.

Kakui, Keiichi; Hiruta, Chizue

2013-09-01

371

Scale Dependence of the Mechanical Properties and Microstructure of Crustaceans Thin Films as Biomimetic Materials  

NASA Astrophysics Data System (ADS)

The exoskeletons of crustacean species in the form of thin films have been investigated by several researchers to better understand the role played by the exoskeletal structure in affecting the functioning of species such as shrimps, crabs, and lobsters. These species exhibit similar designs in their exoskeleton microstructure, such as a Bouligand pattern (twisted plywood structure), layers of different thickness across cross section, change in mineral content through the layers, etc. Different parts of crustaceans exhibit a significant variation in mechanical properties based on the variation in the above-mentioned parameters. This change in mechanical properties has been analyzed by using imaging techniques such as scanning electron microscopy and energy-dispersive x-ray spectroscopy, and by using mechanical characterization techniques such as nanoindentation and atomic force microscopy. In this article, the design principles of these biological composites are discussed based on two shrimp species: Rimicaris exoculata and Pandalus platyceros.

Verma, Devendra; Qu, Tao; Tomar, Vikas

2015-03-01

372

Selective extraction of astaxanthin from crustaceans by use of supercritical carbon dioxide.  

PubMed

An on-line supercritical fluid extraction (SFE) system coupled to a continuous flow manifold including a UV detector was used as a screening system to extract astaxanthin from crayfish, which was found to be the major carotenoid present in the samples. This compound constitutes the principal additive used to dye salmon flesh. The flow manifold was used to confirm the presence of astaxanthin in the crustacean samples. Also, an HPLC/UV-vis method was used to ascertain that this compound was the major carotenoid extracted under the optimum SFE conditions employed. The influence of SFE operating variables such as pressure, temperature, equilibration time, extraction time, trap temperature, and volume of CO(2) modifier was examined in order to maximize the efficiency of analyte extraction. The use of supercritical CO(2) enables the expeditious, selective, quantitative extraction of astaxanthin from crustaceans. PMID:18969665

López, M; Arce, L; Garrido, J; Ríos, A; Valcárcel, M

2004-10-20

373

Molecular cloning of the crustacean DD4 cDNA encoding a Ca(2+)-binding protein.  

PubMed

A cDNA, named DD4, was identified in the prawn Penaeus japonicus in a search for genes that were expressed during calcification of the crustacean exoskeleton. DD4 transcripts were detected in the epidermal cells underlying the exoskeleton specifically during the postmolt stage, when the calcification takes place. In the DD4 cDNA an open reading frame of 542 amino acids was found. The deduced protein was acidic and proline-rich, and exhibited similarity to the Drosophila Ca(2+)-binding protein calphotin in the amino acid sequence and composition. The DD4 cDNA was expressed in Escherichia coli to characterize Ca(2+)-binding of the encoded protein, and Ca(2+) was found to bind to a central segment of 186 amino acids. The DD4 protein is suggested to play a role in the calcification of the crustacean exoskeleton. PMID:11006119

Endo, H; Persson, P; Watanabe, T

2000-09-16

374

Changes in abundance and spatial distribution of geese molting near Teshekpuk Lake, Alaska: Interspecific competition or ecological change?  

USGS Publications Warehouse

Goose populations molting in the Teshekpuk Lake Special Area of the National Petroleum Reserve-Alaska have changed in size and distribution over the past 30 years. Black brant (Branta bernicla nigricans) are relatively stable in numbers but are shifting from large, inland lakes to salt marshes. Concurrently, populations of greater white-fronted geese (Anser albifrons frontalis) have increased seven fold. Populations of Canada geese (Branta canadensis and/or B. hutchinsii) are stable with little indication of distributional shifts. The lesser snow goose (Anser caerulescens caerulescens) population is proportionally small, but increasing rapidly. Coastline erosion of the Beaufort Sea has altered tundra habitats by allowing saltwater intrusion, which has resulted in shifts in composition of forage plant species. We propose two alternative hypotheses for the observed shift in black brant distribution. Ecological change may have altered optimal foraging habitats for molting birds, or alternatively, interspecific competition between black brant and greater white-fronted geese may be excluding black brant from preferred habitats. Regardless of the causative mechanism, the observed shifts in species distributions are an important consideration for future resource planning. ?? 2007 Springer-Verlag.

Flint, P.L.; Mallek, E.J.; King, R.J.; Schmutz, J.A.; Bollinger, K.S.; Derksen, D.V.

2008-01-01

375

Megabenthic decapod crustacean assemblages on the Galician continental shelf and upper slope (north-west Spain)  

Microsoft Academic Search

The structure of megabenthic decapod crustacean assemblages on the Galician (north-west Spain) continental shelf (100 to\\u000a 200 depth) and upper slope (200 to 500 m) was analyzed based on surveys carried out in autumn and spring, from 1980 to 1987.\\u000a Forty species belonging to 19 families were caught. The portunid crab Polybius henslowii, a species with pelagic phases, was the

A. C. Fariña; J. Freire; E. González-Gurriarán

1997-01-01

376

Reef-associated crustacean fauna: biodiversity estimates using semi-quantitative sampling and DNA barcoding  

Microsoft Academic Search

The cryptofauna associated with coral reefs accounts for a major part of the biodiversity in these ecosystems but has been\\u000a largely overlooked in biodiversity estimates because the organisms are hard to collect and identify. We combine a semi-quantitative\\u000a sampling design and a DNA barcoding approach to provide metrics for the diversity of reef-associated crustacean. Twenty-two\\u000a similar-sized dead heads of Pocillopora

L. Plaisance; N. Knowlton; G. Paulay; C. Meyer

2009-01-01

377

The CHH-superfamily of multifunctional peptide hormones controlling crustacean metabolism, osmoregulation, moulting, and reproduction.  

PubMed

Apart from providing an up-to-date review of the literature, considerable emphasis was placed in this article on the historical development of the field of "crustacean eyestalk hormones". A role of the neurosecretory eyestalk structures of crustaceans in endocrine regulation was recognized about 80 years ago, but it took another half a century until the first peptide hormones were identified. Following the identification of crustacean hyperglycaemic hormone (CHH) and moult-inhibiting hormone (MIH), a large number of homologous peptides have been identified to this date. They comprise a family of multifunctional peptides which can be divided, according to sequences and precursor structure, into two subfamilies, type-I and -II. Recent results on peptide sequences, structure of genes and precursors are described here. The best studied biological activities include metabolic control, moulting, gonad maturation, ionic and osmotic regulation and methyl farnesoate synthesis in mandibular glands. Accordingly, the names CHH, MIH, and GIH/VIH (gonad/vitellogenesis-inhibiting hormone), MOIH (mandibular organ-inhibiting hormone) were coined. The identification of ITP (ion transport peptide) in insects showed, for the first time, that CHH-family peptides are not restricted to crustaceans, and data mining has recently inferred their occurrence in other ecdysozoan clades as well. The long-held tenet of exclusive association with the eyestalk X-organ-sinus gland tract has been challenged by the finding of several extra nervous system sites of expression of CHH-family peptides. Concerning mode of action and the question of target tissues, second messenger mechanisms are discussed, as well as binding sites and receptors. Future challenges are highlighted. PMID:22146796

Webster, Simon George; Keller, Rainer; Dircksen, Heinrich

2012-01-15

378

Acute Toxicity Responses of Two Crustaceans, Americamysis bahia and Daphnia magna, to Endocrine Disrupters  

Microsoft Academic Search

The acute toxicity of endocrine disrupters in two crustaceans, Americamysis bahia (A. bahia) and Daph- nia magna (D. magna), was investigated and the toxi- cological responses compared. Bisphenol A had the lowest toxicity to D. magna, the 48 hr median lethal concentrations (LC50) values was 12.8 mg\\/l. However, the toxic sensitivity of A. bahia to bisphenol A was ap- proximately

Masashi Hirano; Hiroshi Ishibashi; Naomi Matsumura; Yukiko Nagao; Naoko Watanabe; Akiko Watanabe; Norio Onikura; Katsuyuki Kishi; Koji Arizono

2004-01-01

379

Partial sequence of the mitochondrial genome of the crustacean Daphnia pulex  

Microsoft Academic Search

A 4062-nucleotide (nt) fragment of the mitochondrial genome of the crustacean Daphnia pulex was sequenced and found to contain the complete genes for eight tRNAs and five proteins (ATP6, ATP8, COII, COIII, ND3) and\\u000a the partial sequence of COI. In combination with data described previously, approximately 50% of the D. pulex mitochondrial genome has been sequenced. The gene order in

Teresa J. Crease; Thomas J. Little

1997-01-01

380

Oxygen consumption of midwater fishes and crustaceans from the eastern Gulf of Mexico  

Microsoft Academic Search

Oxygen consumption was measured as a function of temperature, oxygen partial-pressure (PO2)and species depth of occurrence for twenty-three species of midwater fishes and crustaceans collected from the eastern Gulf of Mexico from June 1981 to July 1985. Q10s (7° to 20°C) of 3.90 and 3.24 were recorded for myctophid and non-myctophid fish groups, respectively, while values of 2.22, 2.19, 2.19

J. Donnelly; J. J. Torres

1988-01-01

381

The time course and frequency content of hydrodynamic events caused by moving fish, frogs, and crustaceans  

Microsoft Academic Search

In the present study the time course and spectral-amplitude distribution of hydrodynamic flow fields caused by moving fish, frogs, and crustaceans were investigated with the aid of laser-Doppler-anemometry. In the vicinity of a hovering fish sinusoidal water movements can be recorded whose velocity spectra peak below 10 Hz (Fig. 2). Single strokes during startle responses or during steady swimming of

H. Bleckmann; T. Breithaupt; R. Blickhan; J. Tautz

1991-01-01

382

Metal toxicity, uptake and bioaccumulation in aquatic invertebrates--modelling zinc in crustaceans.  

PubMed

We use published data on the different patterns of the bioaccumulation of zinc by three crustaceans, the caridean decapod Palaemon elegans, the amphipod Orchestia gammarellus and the barnacle Amphibalanus amphitrite, to construct comparative biodynamic models of the bioaccumulation of zinc into metabolically available and detoxified components of accumulated zinc in each crustacean under both field and laboratory toxicity test conditions. We then link these bioaccumulation models to the onset of toxic effects on exposure of the crustaceans to high dissolved zinc bioavailabilities, using the tenets that toxicity effects are related to the total uptake rate of the toxic metal, and that toxicity is not usually dependent on the total accumulated metal concentration but always on the concentration of accumulated metal that is metabolically available. We dismiss the general concept that there is a critical accumulated body concentration of a metal in an invertebrate at which toxicity ensues, except under specific circumstances involving a rare lack of storage detoxification of accumulated metal. We thus propose a theoretical framework that can be extended to other metals and other aquatic invertebrates (indeed other animals) to explain the variation in the relationship between bioaccumulated body concentrations and toxicity, and subsequently to predict this relationship in many other species for which we have bioaccumulation modelling data. PMID:21872557

Rainbow, P S; Luoma, S N

2011-10-01

383

Hiding opaque eyes in transparent organisms: a potential role for larval eyeshine in stomatopod crustaceans.  

PubMed

Opaque screening pigments are a fundamental requisite for preserving resolution in image-forming eyes. Possession of any type of image-forming eye in a transparent, pelagic animal will thus undermine the ability of that animal to be invisible in the water column. Transparent, pelagic animals must therefore deal with the trade-off between the ability to see and the ability of other animals to see them. Stomatopod larvae, like many transparent crustaceans, possess specialized optics in their compound eyes that minimize the volume of the opaque retina. Though the volumes of these retinas are reduced, their opacity remains conspicuous to an observer. The light reflected from structures overlying the retinas of stomatopod crustacean larval eyes, referred to here as eyeshine, is hypothesized to further reduce the visibility of opaque retinas. Blue or green wavelengths of light are most strongly reflected in stomatopod larval eyeshine, suggesting a putative spectral matching to the light environment against which the larval eyes are viewed. We tested the efficacy of stomatopod crustacean larval eyeshine as an ocular camouflaging mechanism by photographing larvae in their natural light environment and analysing the contrast of eyes with the background light. To test for spectral matching between stomatopod larval eyeshine and the background light environment, we characterized the spectrum of eyeshine and calculated its performance using radiometric measurements collected at the time of each photographic series. These results are the first to demonstrate an operative mirror camouflage matched in both spectrum and radiance to the pelagic background light environment. PMID:25232197

Feller, K D; Cronin, T W

2014-09-15

384

Toxicity of two types of silver nanoparticles to aquatic crustaceans Daphnia magna and Thamnocephalus platyurus.  

PubMed

Although silver nanoparticles (NPs) are increasingly used in various consumer products and produced in industrial scale, information on harmful effects of nanosilver to environmentally relevant organisms is still scarce. This paper studies the adverse effects of silver NPs to two aquatic crustaceans, Daphnia magna and Thamnocephalus platyurus. For that, silver NPs were synthesized where Ag is covalently attached to poly(vinylpyrrolidone) (PVP). In parallel, the toxicity of collargol (protein-coated nanosilver) and AgNO? was analyzed. Both types of silver NPs were highly toxic to both crustaceans: the EC50 values in artificial freshwater were 15-17 ppb for D. magna and 20-27 ppb for T. platyurus. The natural water (five different waters with dissolved organic carbon from 5 to 35 mg C/L were studied) mitigated the toxic effect of studied silver compounds up to 8-fold compared with artificial freshwater. The toxicity of silver NPs in all test media was up to 10-fold lower than that of soluble silver salt, AgNO?. The pattern of the toxic response of both crustacean species to the silver compounds was almost similar in artificial freshwater and in natural waters. The chronic 21-day toxicity of silver NPs to D. magna in natural water was at the part-per-billion level, and adult mortality was more sensitive toxicity test endpoint than the reproduction (the number of offspring per adult). PMID:23143296

Blinova, Irina; Niskanen, Jukka; Kajankari, Paula; Kanarbik, Liina; Käkinen, Aleksandr; Tenhu, Heikki; Penttinen, Olli-Pekka; Kahru, Anne

2013-05-01

385

Adult neurogenesis: Examples from the decapod crustaceans and comparisons with mammals  

PubMed Central

Defining evolutionary origins is a means of understanding an organism’s position within the integrated web of living beings, and to not only to trace characteristics back in time, but also to project forward in an attempt to reveal relationships with more recently evolved forms. Both the vertebrates and arthropods possess condensed nervous systems, but this is dorsal in the vertbrates and ventral in the arthropods. Also, whereas the nervous system in the vertebrates develops from a neural tube in the embryo, that of the arthropods comes from an ectodermal plate. Despite these apparently fundamental differences, it is now generally accepted that life-long neurogenesis, the generation of functionally integrated neurons from progenitor cells, is a common feature of the adult brains of a variety of organisms, ranging from insects and crustaceans to birds and mammals. Among decapod crustaceans, there is evidence for adult neurogenesis in basal species of the Dendrobranchiata, as well as in more recent terrestrial, marine and fresh-water species. The widespread nature of this phenomenon in decapod species may relate to the importance of the adult-born neurons, although their functional contribution is not yet known. The many similarities between the systems generating neurons in the adult brains of decapod crustaceans and mammals, reviewed in this paper, suggest that adult neurogenesis is governed by common ancestral mechanisms that have been retained in a phylogenetically broad group of species. PMID:21396485

Sandeman, David C.; Bazin, Francois; Beltz, Barbara S.

2011-01-01

386

Patterns of use and distribution of king eiders and black scoters during the annual cycle in northeastern Bristol Bay, Alaska  

Microsoft Academic Search

Northeastern Bristol Bay, Alaska, which includes three large estuaries, is used by multiple sea duck species during the annual\\u000a cycle. Limited aerial surveys indicate that this area supports tens of thousands of king eiders and black scoters during spring\\u000a migration and the autumn molt. Existing satellite telemetry data were used to assess the temporal patterns of habitat use\\u000a and spatial

J. L. Schamber; P. L. Flint; A. N. Powell

2010-01-01

387

Effects of zinc on Salmonella in the layer house environments and laying hens, and the ability of zinc to induce molt in laying hens  

E-print Network

as to style and content by: Steven C. Ricke Sarah G. Birkhold (Co-Chair of Committee) (Co-Chair of Committee) Leon F. Kubena... Dr. Steven C. Ricke There is increasing interest in developing methods to detect and identify Salmonella, to eliminate or reduce the risk of contamination of shell eggs, and to retain the economic advantages of induced molting without...

Park, Shinyoung

2005-02-17

388

Etoposide-induced apoptosis in lymphoblastoid leukaemic MOLT-4 cells: evidence that chromatin condensation, loss of phosphatidylserine asymmetry and apoptotic body formation can occur independently.  

PubMed

Apoptosis is characterised by a series of typical morphological features, such as nuclear and cellular convolution, chromatin condensation and the final disintegration of the cell into membrane-bound apoptotic bodies, which are phagocytosed, by neighbouring cells. Relocation of phosphatidylserine residues from the inner leaflet of the cellular membrane to being exposed on the cell surface is a necessary event for the phagocytic elimination of apoptotic cell debris. Using the MOLT-4 lymphoblastoid leukaemic cell line we investigated whether the formation of apoptotic bodies and loss of phosphatidylserine asymmetry were causally related. We have previously demonstrated that classical apoptotic morphology, including production of apoptotic bodies, was only possible in etoposide-treated MOLT-4 cells when administered in the presence of non-cytotoxic doses (200 microM) of aurin tricarboxylic acid (ATA). Electron microscopic analysis, followed by the quantitation of the ultrastructural morphological features of apoptotic MOLT-4 cells, demonstrated that the etoposide and ATA co-treatment, which caused the cellular fragmentation into apoptotic bodies, was closely associated with extensive chromatin condensation in individual cells. In this model however, the addition of ATA to frank cytotoxic doses of etoposide (50 microM), which we confirmed lead to formation of apoptotic bodies, caused no further increase in externalisation of phosphatidylserine moieties as determined by staining with fluorescence labelled annexin V. Consequently, in MOLT-4 cells undergoing etoposide-induced apoptosis, the mole-cular mechanisms leading to loss of phosphatidylserine asymmetry and the formation of apoptotic bodies are not causally related. PMID:11773706

Ramirez, C D; Catchpoole, D R

2002-02-01

389

Larval ecology and synchronous reproduction of two crustacean species : Semibalanus balanoides in New England, USA and Gecarcinus quadratus in Veraguas, Panama  

E-print Network

The environmental cues for synchronous reproduction were investigated for two highly abundant, ecologically important crustacean species: the temperate acorn barnacle, Semibalanus balanoides, and the tropical terrestrial ...

Gyory, Joanna

2011-01-01

390

De novo assembly and characterization of a maternal and developmental transcriptome for the emerging model crustacean Parhyale hawaiensis  

PubMed Central

Background Arthropods are the most diverse animal phylum, but their genomic resources are relatively few. While the genome of the branchiopod Daphnia pulex is now available, no other large-scale crustacean genomic resources are available for comparison. In particular, genomic resources are lacking for the most tractable laboratory model of crustacean development, the amphipod Parhyale hawaiensis. Insight into shared and divergent characters of crustacean genomes will facilitate interpretation of future developmental, biomedical, and ecological research using crustacean models. Results To generate a transcriptome enriched for maternally provided and zygotically transcribed developmental genes, we created cDNA from ovaries and embryos of P. hawaiensis. Using 454 pyrosequencing, we sequenced over 1.1 billion bases of this cDNA, and assembled them de novo to create, to our knowledge, the second largest crustacean genomic resource to date. We found an unusually high proportion of C2H2 zinc finger-containing transcripts, as has also been reported for the genome of the pea aphid Acyrthosiphon pisum. Consistent with previous reports, we detected trans-spliced transcripts, but found that they did not noticeably impact transcriptome assembly. Our assembly products yielded 19,067 unique BLAST hits against nr (E-value cutoff e-10). These included over 400 predicted transcripts with significant similarity to D. pulex sequences but not to sequences of any other animal. Annotation of several hundred genes revealed P. hawaiensis homologues of genes involved in development, gametogenesis, and a majority of the members of six major conserved metazoan signaling pathways. Conclusions The amphipod P. hawaiensis has higher transcript complexity than known insect transcriptomes, and trans-splicing does not appear to be a major contributor to this complexity. We discuss the importance of a reliable comparative genomic framework within which to consider findings from new crustacean models such as D. pulex and P. hawaiensis, as well as the need for development of further substantial crustacean genomic resources. PMID:22118449

2011-01-01

391

Abundance of ringed seals (Pusa hispida) in the fjords of Spitsbergen, Svalbard, during the peak molting period  

USGS Publications Warehouse

Ringed seal (Pusa hispida) abundance in Spitsbergen, Svalbard, was estimated during the peak molting period via aerial, digital photographic surveys. A total of 9,145 images, covering 41.7%?100% of the total fast-ice cover (1,496 km2) of 18 different fjords and bays, were inspected for the presence of ringed seals. A total of 1,708 seals were counted, and when accounting for ice areas that were not covered by images, a total of 3,254 (95% CI: 3,071?3,449) ringed seals were estimated to be hauled out during the surveys. Extensive behavioral data from radio-tagged ringed seals (collected in a companion study) from one of the highest density fjords during the molting period were used to create a model that predicts the proportion of seals hauled out on any given date, time of day, and under various meteorological conditions. Applying this model to the count data from each fjord, we estimated that a total of 7,585 (95% CI: 6,332-9,085) ringed seals were present in the surveyed area during the peak molting period. Data on interannual variability in ringed seal abundance suggested higher numbers of seals in Van Keulenfjorden in 2002 compared to 2003, while other fjords with very stable ice cover showed no statistical differences. Poor ice conditions in general in 2002 probably resulted in seals from a wide area coming to Van Keulenfjorden (a large fjord with stable ice in 2002). The total estimated number of ringed seals present in the study area at the time of the survey must be regarded as a population index, or at least a minimum estimate for the area, because it does not account for individuals leaving and arriving, which might account for a considerable number of animals. The same situation is likely the case for many other studies reporting aerial census data for ringed seals. To achieve accurate estimates of population sizes from aerial surveys, more extensive knowledge of ringed seal behavior will be required.

Krafft, B.A.; Kovacs, K.M.; Andersen, M.; Aars, J.; Lydersen, C.; Ergon, T.; Haug, T.

2006-01-01

392

The effect of mushroom and pokeweed extract on salmonella, egg production, and weight loss in molting hens.  

PubMed

An experiment was conducted to evaluate the effects of mushroom and pokeweed extract alone or in combination with alfalfa meal on Salmonella spp. population, egg production, and weight loss in laying hens during a 10-d molting period. The trial used 54 active laying hens approximately 77 wk of age that were naturally infected with Salmonella spp. The layers were subjected to 1 of 9 treatment groups, replicated 3 times with 2 hens per replicate cage. The treatment conditions were as follows: 1) full-fed + H(2)0 (FFW), 2) full-fed + mushroom (FFM), 3) full-fed + pokeweed (FFP), 4) nonfed + H(2)0 (NFW), 5) nonfed + mushroom (NFM), 6) nonfed + pokeweed (NFP), 7) full-fed alfalfa meal + H(2)0 (FFAW), 8) full-fed alfalfa meal + mushroom (FFAM), and 9) full-fed alfalfa meal + poke-weed (FFAP). The results showed that the base-10 logarithm values of Salmonella from the ceca significantly increased (P molting hens and induce a comparable molt with feed withdrawal. PMID:19038799

Willis, W L; Goktepe, I; Isikhuemhen, O S; Reed, M; King, K; Murray, C

2008-12-01

393

Survivorship in micro fungi and crustacean resting stages during ultraviolet (UV) and vacuum land testing of EXPOSE unit  

NASA Astrophysics Data System (ADS)

Dormancy protects animals and plants in harsh environmental conditions within a special resting phases of life cycle lasting from months up to hundred years. This phenomenon is perspective for space researches on interplanetary quarantine within space missions. Direct experiments in open space supported in principle the fact of survivorship of bacteria and fungi spores in open space during long time experiments (Novikova et al. 2007). The rate of survivorship in long-term mission was low but enough to conclude that biological invasion to Mars is a real danger. The possibility for resting stages to survive under UV treatment in vacuum without some protection was not clear. To test it dormant stages (spores) of primitive fungi Aspergillus versicolor, Aspergillus sydowii, Penicillium expansum, and Penicillium aurantiogriseum derived from ISS environment were used in the land EXPOSE imitation of outside space station UV and vacuum conditions. Survivorship in resting eggs of some crustaceans with dried (cladoceran Daphnia magna, fair-shrimp Streptocephalus torvicornis and ostracode Eucypris ornate from hemi desert Caspian area) and wet diapause state (copepod Mixodiaptomus tatricus from the Tatra mountains, altitude 1510 m) was tested also. The total UV dose of 9,1x10 to the 4th KJ/m2 during this imitation was accomplished with a SOL 2000 sun simulator lamp. The final vacuum value achieved during EST was 10 to the minus 6 Pa. Temperature during the experiment fluctuated in the range 19-25 o C. Micro fungi showed a high level of survivorship in samples treated with UV samples varied from 95 till 100 Supported by RFBR grant 07-04-00006.

Alekseev, Victor; Alekseev, Victor; Novikova, Nataliya; Sychev, Vladimir; Levinskikh, Margarita; Deshevaya, Elena; Brancelj, Anton; Malyavin, Stanislav

394

Role of gonadal and adrenal steroids and thyroid hormones in the regulation of molting in domestic goose.  

PubMed

Plasma levels of testosterone (T), 17-?-estradiol (E2), progesterone (P4), dehydroepiandrosterone (DHEA), corticosterone (B), thyroxine (T4) and triiodothyronine (T3) were monitored during postnuptial and the prenuptial molt in domestic goose (Anser anser domesticus) in both sexes. 1. At the beginning of postnuptial molt (when the old, worn dawny-, and cover feathers' loss starts) in ganders, the levels of T, E2, P4 decrease while DHEA and B significantly increase. The elevated levels of T4 and low T3 concentrations characteristic of the last phase of the reproduction, remain unchanged. In layers, similar changes were observed, however, B decreases. 2. In the early phase of outgrowth of wing and cover feathers, plasma levels of T, E2 and P4 are low. Elevated B, DHEA and T4 concentrations decrease in ganders, while in layers DHEA increases and B and T4 levels remain unchanged. T3 increases in both sexes. 3. The subsequent intensive outgrowth period of wing- and cover feathers both in ganders and in layers is characterized by very low levels of T, E2, DHEA and T4, but P4 increased, and T3 concentration remain high. 4. At the end of postnuptial molt - when the outgrowth of dawny, cover-, and wing feathers stops - very low T, E2, P4, DHEA and T4 levels and and high T3 plasma levels were found in both sexes. Fast increase of plasma B was detected in ganders, while in geese, B concentration remain high. 5. During prenuptial molting (outgrowth of contour and tail feathers) low E2, P4 and T4, increasing T and DHEA, but very high T3 and B plasma concentration were measured in ganders. In layers, very low T, E2, P4, DHEA and T4 levels, and very high B and T3 levels were found. 6. At the beginning of the fall-winter sexual repose (postmolting stage) T, E2, P4, DHEA and T4 levels increase, T3 and B declines in both sexes. 7. In the subsequent phase of fall-winter period (preparatory stage) there is a further increase in T, P4 and T4, a fast increase of B and a decrease of E2, DHEA and T3 in ganders. In layers, T, P4 and DHEA decrease, B increases and the T4 and T3 do not change. 8. At the beginning of reproduction high T level, unchanged DHEA, slightly declined P4, and decreased E2, T4, T3 and a strong decline of B concentrations occur in ganders. In layers, T is further increased, E2 and P4 shows high levels, and, at the same time DHEA and T3 remain unchanged, while B and T4 decrease. PMID:21388915

Péczely, P; Bogenfürst, F; Kulcsár, Margit; Polgár, Bea

2011-03-01

395

Temporal and spatial habitat preferences and biotic interactions between mosquito larvae and antagonistic crustaceans in the field.  

PubMed

Investigations on natural antagonists of mosquito larvae found that micro-crustaceans (e.g., Cladocera) control mosquito populations under experimental conditions. However, their relevance for mosquito control under field situations remains widely unclear because important information about habitat preferences and time of occurrence of crustaceans and mosquito larvae are still missing. In order to fill this knowledge gap, a field study was undertaken in different wetland areas of Saxony, Germany, in different habitats (i.e., grassland, forest, and reed-covered wetlands). We found negative interactions between larvae of Ae. vexans and predatory Cyclopoida (Crustacean: Copepoda), which both were dominant during the first two weeks of hydroperiod, at ponds located at grassland habitats. Larvae of Cx. pipiens were spatially associated with competing Cladocera, but they colonized ponds more rapidly. Populations of Cladocera established from the third week of hydroperiod and prevented Cx. pipiens colonization thereafter. Ostracoda were highly abundant during the whole hydroperiod, but their presence was restricted to habitats of reed-covered wetland at one geographical area. Mosquito larvae hardly occurred at those ponds. In general, we found that ponds at the reed-covered wetlands provided better conditions for the initial development of crustaceans and hence, mosquito larval colonization was strongly inhibited. Grassland habitat, in contrast, favored early development of mosquito larvae. This study showed that micro-crustaceans are relevant for mosquito management but their impact on mosquito larvae varies between species and depends on environmental conditions. PMID:24820562

Kroeger, Iris; Liess, Matthias; Duquesne, Sabine

2014-06-01

396

Expanding the Crustacean Neuropeptidome using a Multi-Faceted Mass Spectrometric Approach  

PubMed Central

Jonah crab Cancer borealis is an excellent model organism long served for many areas of physiology, including the study of endocrinology and neurobiology. Characterizing the neuropeptides present in its nervous system provides the first critical step toward understanding the physiological roles of these complex molecules. Multiple mass spectral techniques were used to comprehensively characterize the neuropeptidome in C. borealis, including matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI FTMS), MALDI time of flight (TOF)/TOF MS and nanoflow liquid chromatography coupled to electrospray ionization quadrupole time of flight tandem mass spectrometry (nanoLC ESI Q TOF MS/MS). In order to enhance the detection signals and expand the dynamic range, direct tissue analysis, tissue extraction, capillary electrophoresis (CE) and off-line HPLC separation have also been employed. In total, 142 peptides were identified, including 85 previously known C. borealis peptides, 22 peptides characterized previously from other decapods, but new to this species, and 35 new peptides de novo sequenced for the first time in this study. Seventeen neuropeptide families were revealed including RFamide, allatostatin (A and B type), RYamide, orcokinin, orcomyotropin, proctolin, crustacean cardioactive peptide (CCAP), crustacean hyperglycemic hormone precursor-related peptide (CPRP), crustacean hyperglycemic hormone (CHH), corazonin, pigment-dispersing hormone (PDH), tachykinin, pyrokinin, SIFamide, red pigment concentrating hormone (RPCH) and HISGLYRamide. Collectively, our results greatly increase the number and expand the coverage of known C. borealis neuropeptides, and thus provide a stronger framework for future studies on the physiological roles played by these molecules in this important model organism. PMID:19222238

Ma, Mingming; Wang, Junhua; Chen, Ruibing; Li, Lingjun

2009-01-01

397

High-definition De Novo Sequencing of Crustacean Hyperglycemic Hormone (CHH)-family Neuropeptides*  

PubMed Central

A complete understanding of the biological functions of large signaling peptides (>4 kDa) requires comprehensive characterization of their amino acid sequences and post-translational modifications, which presents significant analytical challenges. In the past decade, there has been great success with mass spectrometry-based de novo sequencing of small neuropeptides. However, these approaches are less applicable to larger neuropeptides because of the inefficient fragmentation of peptides larger than 4 kDa and their lower endogenous abundance. The conventional proteomics approach focuses on large-scale determination of protein identities via database searching, lacking the ability for in-depth elucidation of individual amino acid residues. Here, we present a multifaceted MS approach for identification and characterization of large crustacean hyperglycemic hormone (CHH)-family neuropeptides, a class of peptide hormones that play central roles in the regulation of many important physiological processes of crustaceans. Six crustacean CHH-family neuropeptides (8–9.5 kDa), including two novel peptides with extensive disulfide linkages and PTMs, were fully sequenced without reference to genomic databases. High-definition de novo sequencing was achieved by a combination of bottom-up, off-line top-down, and on-line top-down tandem MS methods. Statistical evaluation indicated that these methods provided complementary information for sequence interpretation and increased the local identification confidence of each amino acid. Further investigations by MALDI imaging MS mapped the spatial distribution and colocalization patterns of various CHH-family neuropeptides in the neuroendocrine organs, revealing that two CHH-subfamilies are involved in distinct signaling pathways. PMID:23028060

Jia, Chenxi; Hui, Limei; Cao, Weifeng; Lietz, Christopher B.; Jiang, Xiaoyue; Chen, Ruibing; Catherman, Adam D.; Thomas, Paul M.; Ge, Ying; Kelleher, Neil L.; Li, Lingjun

2012-01-01

398

Embryotoxicity of the alkylphenol degradation product 4-nonylphenol to the crustacean Daphnia magna.  

PubMed Central

Laboratory studies have suggested that some alkylphenols and pesticides elicit developmental toxicity to crustaceans. The purpose of the present study was to evaluate the possibility that the alkylphenol degradation product 4-nonylphenol is embryotoxic to the crustacean Daphnia magna through its known ability to interfere with the metabolic elimination of testosterone. Direct exposure of maternal daphnids to testosterone caused developmental abnormalities in neonates that consisted of partial arrest of early embryonic development and abnormalities in shell spine and first antennae development. Exposure of maternal daphnids to concentrations of 4-nonylphenol also produced developmental abnormalities though the profile of abnormalities was distinct from that observed throughout the testosterone concentration-response curve. Thus, 4-nonylphenol is a developmental toxicant in daphnids, but its toxicity is not consistent with that elicited by elevated testosterone accumulation. Further experiments demonstrated that testosterone was directly toxic to developing embryos, and the maternal organism can serve as the vector for this toxicity. In contrast, neither direct embryo exposure nor early maternal exposure to 4-nonylphenol elicited embryotoxicity consistent with that observed during continuous maternal and gestational exposure. Thus, 4-nonylphenol is not directly embryotoxic at these exposure levels, but rather toxicity is mediated by maternal influences during gestation. The threshold concentration for the occurrence of developmental abnormalities ( approximately 44 microg/L) indicates that typical environmental concentrations of 4-nonylphenol pose no imminent hazard with respect to developmental toxicity. However, these effects do occur at sufficiently low levels to warrant evaluation of the relative susceptibility of other crustacean species to this previously uncharacterized mode of toxicity. PMID:11133392

LeBlanc, G A; Mu, X; Rider, C V

2000-01-01

399

N-glycan moieties of the crustacean egg yolk protein and their glycosylation sites.  

PubMed

Vitellogenin (Vg) is the precursor of the egg yolk glycoprotein of crustaceans. In the prawn Macrobrachium rosenbergii, Vg is synthesized in the hepatopancreas, secreted to the hemolymph, and taken up by means of receptor-mediated endocytosis into the oocytes. The importance of glycosylation of Vg lies in its putative role in the folding, processing and transport of this protein to the egg yolk and in the fact that the N-glycan moieties could provide a source of carbohydrate during embryogenesis. The present study describes, for the first time, the structure of the glycan moieties and their sites of attachment to the Vg of M. rosenbergii. Bioinformatics analysis revealed seven putative N-glycosylation sites in M. rosenbergii Vg; two of these glycosylation sites are conserved throughout the Vgs of decapod crustaceans from the Pleocyemata suborder (N 159 and N 660). The glycosylation of six putative sites of M. rosenbergii Vg (N 151, N 159, N ,168 N ,614 N 660 and N 2300) was confirmed; three of the confirmed glycosylation sites are localized around the N-terminally conserved N-glycosylation site N 159. From a theoretical three-dimensional structure, these three N-glycosylated sites N 151, N 159, and N 168 were localized on the surface of the Vg consensus sequence. In addition, an uncommon high mannose N-linked oligosaccharide structure with a glucose cap (Glc1Man9GlcNAc2) was characterized in the secreted Vg. These findings thus make a significant contribution to the structural elucidating of the crustacean Vg glycan moieties, which may shed light on their role in protein folding and transport and in recognition between Vg and its target organ, the oocyte. PMID:19921429

Roth, Ziv; Parnes, Shmuel; Wiel, Simy; Sagi, Amir; Zmora, Nili; Chung, J Sook; Khalaila, Isam

2010-01-01

400

Detrimental effect of CO2-driven seawater acidification on a crustacean brine shrimp, Artemia sinica.  

PubMed

The effects of the decline in ocean pH, termed as ocean acidification due to the elevated carbon dioxide in the atmosphere, on calcifying organisms such as marine crustacean are unclear. To understand the possible effects of ocean acidification on the physiological responses of a marine model crustacean brine shrimp, Artemia sinica, three groups of the cysts or animals were raised at different pH levels (8.2 as control; 7.8 and 7.6 as acidification stress according to the predictions for the end of this century and next century accordingly) for 24 h or two weeks, respectively, followed by examination of their hatching success, morphological appearance such as deformity and microstructure of animal body, growth (i.e. body length), survival rate, expression of selected genes (involved in development, immunity and cellular activity etc), and biological activity of several key enzymes (participated in antioxidant responses and physiological reactions etc). Our results clearly demonstrated that the cysts hatching rate, growth at late stage of acidification stress, and animal survival rate of brine shrimp were all reduced due to lower pH level (7.6 & 7.8) on comparison to the control group (pH 8.2), but no obvious change in deformity or microstructure of brine shrimp was present under these acidification stress by microscopy observation and section analysis. In addition, the animals subjected to a lower pH level of seawater underwent changes on their gene expressions, including Spätzle, MyD88, Notch, Gram-negative bacteria binding protein, prophenoloxidase, Apoptosis inhibitor 5, Trachealess, Caveolin-1 and Cyclin K. Meanwhile, several key enzyme activities, including superoxide dismutase, catalase, peroxidase, alkaline phosphatase and acid phosphatase, were also affected by acidified seawater stress. Taken together, our findings supports the idea that CO2-driven seawater acidification indeed has a detrimental effect, in case of hatching success, growth and survival, on a model crustacean brine shrimp, which will increase the risk of juvenile brine shrimp and possibly also other crustaceans, as important live feeds for aquaculture being introduced in the ecosystem especially the marine food webs. PMID:25555807

Zheng, Chao-Qun; Jeswin, Joseph; Shen, Kai-Li; Lablche, Meghan; Wang, Ke-Jian; Liu, Hai-Peng

2015-03-01

401

Amplification of the thymidylate synthase gene in an N 10 -propargyl-5,8-dideazafolic-acid-resistant human leukemia, MOLT3 cell line developed in pteroylglutamic acid, but not in leucovorin  

Microsoft Academic Search

The types of folates used during the development of resistance to methotrexate have been suggested to play an important role in the mechanisms of established resistance. In this study, effects of reduced and oxidized folates on the development of resistance to a thymidylate synthase (TS) inhibitor,N10-propargyl-5,8-dideazafolic acid (CB3717), were examined in the human leukemia cell line MOLT-3. MOLT-3 cells were

Hayato Miyachi; Yuzuru Takemura; Hiroyuki Kobayashi; Yasuhiko Ando

1996-01-01

402

Rock Cycle: Cycling  

NSDL National Science Digital Library

This Science Object is the third of four Science Objects in the Rocks SciPack. It explores the variables that contribute to rock transformation and the continuous processes of rock formation that constitute the rock cycle. The rock cycle provides an example of the transfer of energy and mass in the Earth system. Earth is a closed system containing essentially a fixed amount of each element. Movement of matter is driven by the Earth's internal and external sources of energy, and is often accompanied by changes in the physical and chemical properties of the matter. Minerals are made, dissolved, and remade--on the Earth's surface, in the oceans, and in the hot, high-pressure layers beneath the crust. The total amount of material stays the same as its forms change. Learning Outcomes:? Recognize the formation and transformation processes as part of a continuing cycle.? Identify that while the form and location of different rocks change over time, the amount of material and the distribution among the elements remains constant.? Explain the different processes or paths that each type of rock may take in the rock cycle.

National Science Teachers Association (NSTA)

2006-11-01

403

Functional analysis of a mutated analogue of the crustacean hyperglycaemic hormone from the crayfish Pontastacus leptodactylus.  

PubMed

The crustacean hyperglycaemic hormone (CHH), a pleiotropic neuropeptide, belongs to a family of structurally related peptides, having six cysteine residues in conserved positions forming three disulphide bridges, and regulating several physiological processes in crustaceans and insects. Structure-activity studies have shown that amidation of the C-terminus is important to confer biological activity to CHH. In this study we investigated the function of the d-Phe(3) of the N-terminal motif of Pontastacus leptodactylus CHH by a mutational analysis. The d-Phe in position 3 was substituted by a d-Ala and the functionality of the mutated analogue (Glp-d-A-CHH) was tested by in vivo biological assays. The mutated analogue resulted far less active than its wild-type counterparts, either in d- (Glp-d-CHH) or l- (Glp-l-CHH) configuration. These results suggest that Phe(3) is essential for the biological activity of P. leptodactylus CHH, demonstrating that also the N-terminus is involved in the binding with the receptor, and identifying in the Phe(3) a hot spot for the peptide-receptor binding. J. Exp. Zool. 323A: 121-127, 2015. © 2015 Wiley Periodicals, Inc. PMID:25678476

Mosco, Alessandro; Zlatev, Ventsislav; Guarnaccia, Corrado; Giulianini, Piero G

2015-02-01

404

Parasite transfer from crustacean to fish hosts in the Lübeck Bight, SW Baltic Sea  

NASA Astrophysics Data System (ADS)

Four helminth parasites out of 19 species found in the Lübeck Bight, Baltic Sea, were chosen for investigations on the transfer from invertebrate to small-sized fish hosts: larvae of the tapeworms Schistocephalus sp. and Bothriocephalus sp. (Cestoda) living in planktonic copepods as primary hosts; Podocotyle atomon (Digenea) and Hysterothylacium sp. (Nematoda) were found in benthic crustaceans, especially Gammarus spp. These hosts were the prey of 3 gobiid fishes, Gobiusculus flavescens (feeding mainly on plankton), Pomatoschistus minutus (preferring benthos), and P. pictus (feeding more on plankton than benthos). Because the fishes selected smaller sizes of crustaceans, they ingested all stages of the copepods but only the smaller-sized groups of gammarids which were often less infested by parasites. In order to evaluate the probability for a fish to be parasitized by a helminth, an infestation potential index (IP) was calculated. Podocotyle atomon and Hysterothylacium sp. revealed an IP which was far lower in gobies than expected when the prevalences of the previous hosts were taken into consideration. The IP of tapeworm larvae was mainly influenced by the feeding pressure of the gobiid predators, which might change with developmental stage and season. It is concluded that parasite transfer to the next host decreases when sizes of prey and predator differ only moderately. This mechanism can reduce the numbers of parasites transferred to less suitable or wrong hosts.

Zander, C. D.; Groenewold, S.; Strohbach, U.

1994-03-01

405

Crustacean dopamine receptors: localization and G protein coupling in the stomatogastric ganglion  

PubMed Central

Neuromodulators, such as dopamine (DA), control motor activity in many systems. To begin to understand how DA modulates motor behaviors, we study a well-defined model: the crustacean stomatogastric nervous system (STNS). The spiny lobster STNS receives both neuromodulatory and neurohormonal dopaminergic input, and extensive background information exists on the cellular and network effects of DA. However, there is a void of information concerning the mechanisms of DA signal transduction in this system. In this study, we show that Gs, Gi, and Gq are activated in response to DA in STNS membrane preparations from five crustacean species representing distant clades in the order Decapoda. Three evolutionarily conserved DA receptors mediate this response in spiny lobsters: D1?Pan, D1?Pan and D1?Pan. G protein coupling for these receptors can vary with the cell type. In the native membrane, the D1?Pan receptor couples with Gs and Gq, the D1?Pan receptor couples with Gs, and the D2?Pan receptor couples with Gi. All three receptors are localized exclusively to the synaptic neuropil and most likely generate global biochemical signals that alter ion channels in distant compartments, as well as local signals. PMID:17986222

Clark, Merry C.; Khan, Reesha; Baro, Deborah J.

2014-01-01

406

Nuclear DNA content variation associated with muscle fiber hypertrophic growth in decapod crustaceans.  

PubMed

We tested the hypothesis that hypertrophic muscle growth in decapod crustaceans is associated with increases in both the number of nuclei per fiber and nuclear DNA content. The DNA-localizing fluorochrome DAPI (4',6-diamidino-2-phenylindole) and chicken erythrocyte standards were used with static microspectrophotometry and image analysis to estimate nuclear DNA content in hemocytes and muscle fibers from eight decapod crustacean species: Farfantepenaeus aztecus, Palaemonetes pugio, Panulirus argus, Homarus americanus, Procambarus clarkii, Cambarus bartonii, Callinectes sapidus, and Menippe mercenaria. Mean diploid (2C) values in hemocytes ranged from 3.6 to 11.7 pg. Hemocyte 2C estimates were used to extrapolate ploidy level in the multinucleated skeletal muscle tissue of juvenile and adult animals. Across all species, mean muscle fiber diameters from adult animals were significantly larger than those in juveniles, and nuclear domains were greater in larger fibers. The number of nuclei per fiber increased with increasing fiber size, as hypothesized. Maximum nuclear DNA content per species in muscle ranged from 4C to 32C, consistent with endopolyploidy. Two patterns of body- and fiber-size-dependent shifts in ploidy were observed: four species had a significantly higher ploidy in the larger fibers of adults, while three species exhibited a significantly lower ploidy in adults than in juveniles. Thus, across species, there was no systematic relationship between nuclear domain size and nuclear DNA content. PMID:20237594

Jimenez, Ana Gabriela; Kinsey, Stephen T; Dillaman, Richard M; Kapraun, Donald F

2010-03-01

407

Health management during handling and live transport of crustaceans: a review.  

PubMed

Best practice approaches used in the live transport of commercial crustacean species groups are reviewed and the physiological responses to handling practices are described. Codes of practice aimed at providing technological guidelines in handling and transportation of live prawns, lobsters, crabs and freshwater crayfish are examined. While some handling and transport practices are common across species groups, for example purging and chilling, recommended practices vary with species group. The influence of stress responses on health and survival during live transport is discussed and research investigations on the effect of stressors, in particular air exposure, handling and physical disturbances and temperature fluctuations on physiological processes are reviewed for the six species groups, crabs, freshwater crayfish, clawed and spiny lobsters, freshwater prawns and marine prawns. Investigations on the assessment of immune responses to live transport stressors using haemograms, clotting times, phenoloxidase activity, phagocytic activity, bacteremia and antibacterial activity and haemolymph protein concentration are described. A combination of physiological parameters is desirable in the assessment of stress response or health status in crustacean species transported live to seafood markets. PMID:21215361

Fotedar, S; Evans, L

2011-01-01

408

From cooperation to combat: adverse effect of thermal stress in a symbiotic coral-crustacean community.  

PubMed

Although mutualisms are ubiquitous in nature, our understanding of the potential impacts of climate change on these important ecological interactions is deficient. Here, we report on a thermal stress-related shift from cooperation to antagonism between members of a mutualistic coral-dwelling community. Increased mortality of coral-defending crustacean symbionts Trapezia cymodoce (coral crab) and Alpheus lottini (snapping shrimp) was observed in response to experimentally elevated temperatures and reduced coral-host (Pocillopora damicornis) condition. However, strong differential numerical effects occurred among crustaceans as a function of species and sex, with shrimp (75%), and female crabs (55%), exhibiting the fastest and greatest declines in numbers. These declines were due to forceful eviction from the coral-host by male crabs. Furthermore, surviving female crabs were impacted by a dramatic decline (85%) in egg production, which could have deleterious consequences for population sustainability. Our results suggest that elevated temperature switches the fundamental nature of this interaction from cooperation to competition, leading to asymmetrical effects on species and/or sexes. Our study illustrates the importance of evaluating not only individual responses to climate change, but also potentially fragile interactions within and among susceptible species. PMID:24343842

Stella, J S; Munday, P L; Walker, S P W; Pratchett, M S; Jones, G P

2014-04-01

409

The Decapod Crustacean Circulatory System: A Case That Is neither Open nor Closed  

NASA Astrophysics Data System (ADS)

Historically, the decapod crustacean circulatory system has been classed as open. However, recent work on the blue crab, Callinectes sapidus, suggests the circulatory system may be more complex than previously described. Corrosion casting techniques were refined and used to map the circulatory system of a variety of crab species (order: Decapoda; family: Cancridae) to determine if the complexity observed in the blue crab was present in other species. Seven arteries arose from the single chambered heart. The anterior aorta, the paired anterolateral arteries, and the paired hepatic arteries exited from the anterior aspect of the heart. The small-diameter posterior aorta exited posteriorly from the heart. Exiting from the ventral surface of the heart, the sternal artery branched to supply the legs and mouthparts of the crab. These arteries were more complex than previously described, with arterioles perfusing all areas of the body. The arterioles split into fine capillary-like vessels. Most of these capillaries were blind ending. However, in several areas (antennal gland, supraesophageal ganglion) complete capillary beds were present. After passing through the capillary-like vessels, blood drained into a series of sinuses. However, rather than being arbitrary spaces as previously described, scanning electron micrographs showed the sinuses to be distinct units. Most of the sinuses formed a series of flattened membrane-bound lacunae. This complexity may qualify the decapod crustacean circulatory system as one that is "partially closed" rather than open.

McGaw, Iain J.

2005-02-01

410

Comparative toxicity of pyrethroid insecticides to two estuarine crustacean species, Americamysis bahia and Palaemonetes pugio.  

PubMed

Pyrethroid insecticides are widely used on agricultural crops, as well as for nurseries, golf courses, urban structural and landscaping sites, residential home and garden pest control, and mosquito abatement. Evaluation of sensitive marine and estuarine species is essential for the development of toxicity testing and risk-assessment protocols. Two estuarine crustacean species, Americamysis bahia (mysids) and Palaemonetes pugio (grass shrimp), were tested with the commonly used pyrethroid compounds, lambda-cyhalothrin, permethrin, cypermethrin, deltamethrin, and phenothrin. Sensitivities of adult and larval grass shrimp and 7-day-old mysids were compared using standard 96-h LC50 bioassay protocols. Adult and larval grass shrimp were more sensitive than the mysids to all the pyrethroids tested. Larval grass shrimp were approximately 18-fold more sensitive to lambda-cyhalothrin than the mysids. Larval grass shrimp were similar in sensitivity to adult grass shrimp for cypermethrin, deltamethrin, and phenothrin, but larvae were approximately twice as sensitive to lambda-cyhalothrin and permethrin as adult shrimp. Acute toxicity to estuarine crustaceans occurred at low nanogram per liter concentrations of some pyrethroids, illustrating the need for careful regulation of the use of pyrethroid compounds in the coastal zone. PMID:23364944

DeLorenzo, Marie E; Key, Peter B; Chung, Katy W; Sapozhnikova, Yelena; Fulton, Michael H

2014-10-01

411

Genetic Evidence Confirms Polygamous Mating System in a Crustacean Parasite with Multiple Hosts  

PubMed Central

Mating systems are diverse in animals, notably in crustaceans, but can be inferred from a limited set of parameters. Baeza and Thiel (2007) proposed a model predicting mating systems of symbiotic crustaceans with three host characteristics and the risk of predation. These authors proposed five mating systems, ranging from monogamy to polygynandry (where multiple mating occurs for both genders). Using microsatellite loci, we tested the putatively mating system of the ectoparasite crab Dissodactylus primitivus. We determined the mating frequencies of males and females, parentage assignment (COLONY & GERUD software) as well as the contents of female spermathecae. Our results are globally consistent with the model of Baeza and Thiel and showed, together with previous aquarium experiments, that this ectoparasite evolved a polygamous mating system where males and females move between hosts for mate search. Parentage analyses revealed that polyandry is frequent and concerns more than 60% of clutches, with clutches being fertilized by up to 6 different fathers. Polygyny is supported by the detection of eight males having sired two different broods. We also detected a significant paternity skew in 92% of the multipaternal broods. Moreover, this skew is probably higher than the estimation from the brood because additional alleles were detected in most of spermathecae. This high skew could be explained by several factors as sperm competition or cryptic female choice. Our genetic data, combined with previous anatomic analyses, provide consistent arguments to suggest sperm precedence in D. primitivus. PMID:24609105

Jossart, Quentin; Wattier, Rémi A.; Kastally, Chedly; Aron, Serge; David, Bruno; De Ridder, Chantal; Rigaud, Thierry

2014-01-01

412

Interactions of methyl farnesoate and related compounds with a crustacean retinoid X receptor.  

PubMed

While a functional role for the sesquiterpenoid hormone methyl farnesoate in arthropods has been recognized for decades, the identification of a receptor that mediates the action of this hormone remains equivocal. Luciferase reporter assays were used in the present study to evaluate the ability of methyl farnesoate and other putative ligands to activate gene transcription associated with the retinoid X receptor (RXR) and RXR:EcR heterodimeric complexes from the crustacean (Daphnia magna). The daphnid RXR constructs, transfected into HepG2 cells along with the reporter construct, significantly activated luciferase gene expression in response to tributyltin indicating that the crustacean RXR is indeed ligand activated. However, RXR was not activated by methyl farnesoate or other putative RXR ligands. Cells co-transfected with the daphnid RXR and EcR produced luciferase in response to ecdysteroids and this activation was significantly enhanced when cells were also provided either methyl farnesoate or other putative RXR ligands. This synergy among RXR and EcR ligands was not dependent upon the co-activator SRC-1 and did not correlate to a physiological response of daphnids to juvenoid hormones (male sex determination). Results indicate that methyl farnesoate, along with compounds that are functionally similar to methyl farnesoate synergize with ecdysteroids to activate the RXR:EcR receptor complex. However, this effect appears to be unrelated to the ability of these compounds to stimulate male sex determination. PMID:19486925

Wang, Ying H; LeBlanc, Gerald A

2009-10-15

413

The coordination of the sequential appearance of MHR4 and dopa decarboxylase during the decline of the ecdysteroid titer at the end of the molt  

Microsoft Academic Search

During the last larval molt in Manduca sexta, in response to an increasing, then decreasing ecdysteroid titer, a number of transcription factors such as E75B, MHR3, MHR4, and ?FTZ-F1 appear and disappear in the abdominal epidermis leading to dopa decarboxylase (DDC) expression. Messenger RNAs for both the 20E-induced transcription factors, MHR3 and E75B, are maximal near the peak of the

Kiyoshi Hiruma; Lynn M. Riddiford

2007-01-01

414

crustaceans drawer  

NSDL National Science Digital Library

Holothurians are animals, related to other echinoderms by their 5-way pseudosymmetry and body composed of calcitic plates. They are not widely known to most people, and when they are, they are called "sea cucumbers."

2001-03-21

415

SPATIO-TEMPORAL FLUCTUATIONS IN THE DISTRIBUTION AND ABUNDANCE OF DEMERSAL FISH AND EPIBENTHIC CRUSTACEANS IN YAQUINA BAY, OREGON  

EPA Science Inventory

A total of over 32,000 demersal fish and epibenthic crustaceans belonging to 62 species were caught in 42 biweekly trawls from 10 stations in Yaquina Bay, Oregon, during 1967 and 1968. English sole, Parophrys vetulus, was the most abundant species. eventeen species (13 fishes and...

416

INFLUENCE OF SALINITY ON HABITAT UTILIZATION OF OYSTER REEFS BY RESIDENT FISHES AND DECAPOD CRUSTACEANS IN THE CALOOSAHATCHEE ESTUARY, FLORIDA.  

EPA Science Inventory

A spatiotemporal comparison of habitat suitability of oyster reefs for fishes and decapod crustaceans was conducted for the lower Caloosahatchee Estuary, Florida. Lift nets (1-m2) containing 5 liters (volume displacement) of oyster clusters were deployed monthly at three sites al...

417

Checklist of crustaceans (Decapoda and Stomatopoda), collected during the Victor Hensen Costa Rica expedition (1993/1994).  

PubMed

A checklist of the marine crustaceans (Decapoda and Stomatopoda) from the Pacific coast of Costa Rica collected by trawling during the RV Victor Hensen Cruise (1993-1994) is presented. A total of 117 species were identified, 10 stomatopods and 107 decapods. PMID:9393647

Vargas, R; Jesse, S; Castro, M

1996-12-01

418

Are Cirripedia hopeful monsters? Cytogenetic approach and evidence for a Hox gene cluster in the cirripede crustacean Sacculina carcini  

Microsoft Academic Search

The “hopeful monster” has haunted evolutionary thinking since Richard Goldschmidt coined the phrase in 1933. The phrase is directly related to genetic mechanisms in development and evolution. Cirripedes are peculiar crustaceans in that they all lack abdomens as adults. In a previous study aimed at describing the repertoire of Hox genes of the Cirripedia, we failed to isolate the abdominal-A

Élodie Géant; Emmanuèle Mouchel-Vielh; Jean-Pierre Coutanceau; Catherine Ozouf-Costaz; Jean S. Deutsch

2006-01-01

419

Immunocytochemical localization of CCAP, a novel crustacean cardioactive peptide, in the nervous system of the shore crab, Carcinus maenas L  

Microsoft Academic Search

Polyclonal antibodies were raised in rabbits against synthetic crustacean cardioactive peptide (CCAP) conjugated to bovine thyroglobulin, and were used to map CCAP-immunoreactive structures in the central nervous system of Carcinus maenas. As expected, the neurohemal pericardial organs (PO) displayed abundant immunoreactivity in nerve fibers and terminals. In addition, immunoreactive neurons were demonstrated in other parts of the nervous system. At

Heinrich Dircksen; Rainer Keller

1988-01-01

420

Comparative strategies of heavy metal accumulation by crustaceans: zinc, copper and cadmium in a decapod, an amphipod and a barnacle  

Microsoft Academic Search

This study investigates the comparative strategies of accumulation under standardised laboratory conditions of the essential metals zinc and copper, and the non-essential metal cadmium by three crustaceans of different taxa; vizPalaemon elegans Rathke (Malacostraca: Eucarida: Decapoda),Echinogammarus pirloti (Sexton & Spooner) (Malacostraca: Peracarida: Amphipoda) and the barnacleElminius modestus Darwin (Cirripedia: Thoracica).

P. S. Rainbow; S. L. White

1989-01-01

421

JOURNAL OF CRUSTACEAN BIOLOGY, 16(1): 111-141, 1996 BIOCHEMICAL SYSTEMATICS AND EVOLUTION OF THE  

E-print Network

, however, might provide insight into the evolutionary history and past dispersal patterns of these crayfish established themselves west of the Mississippi River where they eventually diverged from the stocks found common fresh- water crustaceans that inhabit very diverse niches that include small streams, large riv

Fetzner Jr., James W.

422

Future prospects for prophylactic immune stimulation in crustacean aquaculture - the need for improved metadata to address immune system complexity.  

PubMed

Future expansion of the crustacean aquaculture industry will be required to ensure global food security. However, this expansion must ensure: (a) that natural resources (including habitat use and fish meal) are sustainably exploited, (b) that the socio-economic development of producing nations is safeguarded, and (c) that the challenge presented by crustacean diseases is adequately met. Conventionally, the problem of disease in crustacean aquaculture has been addressed through prophylactic administration of stimulants, additives or probiotics. However, these approaches have been questioned both experimentally and philosophically. In this review, we argue that real progress in the field of crustacean immune stimulants has now slowed, with only incremental advances now being made. We further contend that an overt focus on the immune effector response has been misguided. In light of the wealth of new data reporting immune system complexity, a more refined approach is necessary - one that must consider the important role played by pattern recognition proteins. In support of this more refined approach, there is now a much greater requirement for the reporting of essential metadata. We propose a broad series of recommendations regarding the 'Minimum Information required to support a Stimulant Assessment experiment' (MISA guidelines) to foster new progression within the field. PMID:24796867

Hauton, Chris; Hudspith, Meggie; Gunton, Laetitia

2015-02-01

423

Changes in the crustacean communities of Lakes Michigan, Huron, and Erie following the invasion of the predatory cladoceran Bythotrephes longimanus  

Microsoft Academic Search

The crustacean zooplankton communities in Lakes Michigan and Huron and the central and eastern basins of Lake Erie have shown substantial, persistent changes since the invasion of the predatory cladoceran Bythotrephes in the mid-1980s. A number of cladoceran species have declined dramatically since the invasion, including Eubosmina coregoni, Holopedium gibberum, Daphnia retrocurva, Daphnia pulicaria, and Leptodora kindti, and overall species

Richard P. Barbiero; Marc L. Tuchman

2004-01-01

424

Water Cycle  

NSDL National Science Digital Library

4th Grade Science - Water Cycle Water Cycle two day interactive lesson plan. DAY 1: Welcome to the Water Cycle! Today we are going to be exploring and finding out more about the wonderful Water Cycle! For starters we are going to start with a movie, click the following link and watch the video and ...

Mrs. Staley

2009-11-09

425

Carbon Cycles  

NSDL National Science Digital Library

Students are introduced to the concept of energy cycles by learning about the carbon cycle. They learn how carbon atoms travel through the geological (ancient) carbon cycle and the biological/physical carbon cycle. They consider how human activities disturb the carbon cycle by emitting carbon dioxide into the atmosphere. They discuss how engineers and scientists are working to reduce carbon dioxide emissions. Lastly, students consider how they can help the world through simple energy conservation measures.

2014-09-18

426

LTR-Retrotransposons in R. exoculata and Other Crustaceans: The Outstanding Success of GalEa-Like Copia Elements  

PubMed Central

Transposable elements are major constituents of eukaryote genomes and have a great impact on genome structure and stability. They can contribute to the genetic diversity and evolution of organisms. Knowledge of their distribution among several genomes is an essential condition to study their dynamics and to better understand their role in species evolution. LTR-retrotransposons have been reported in many diverse eukaryote species, describing a ubiquitous distribution. Given their abundance, diversity and their extended ranges in C-values, environment and life styles, crustaceans are a great taxon to investigate the genomic component of adaptation and its possible relationships with TEs. However, crustaceans have been greatly underrepresented in transposable element studies. Using both degenerate PCR and in silico approaches, we have identified 35 Copia and 46 Gypsy families in 15 and 18 crustacean species, respectively. In particular, we characterized several full-length elements from the shrimp Rimicaris exoculata that is listed as a model organism from hydrothermal vents. Phylogenic analyses show that Copia and Gypsy retrotransposons likely present two opposite dynamics within crustaceans. The Gypsy elements appear relatively frequent and diverse whereas Copia are much more homogeneous, as 29 of them belong to the single GalEa clade, and species- or lineage-dependent. Our results also support the hypothesis of the Copia retrotransposon scarcity in metazoans compared to Gypsy elements. In such a context, the GalEa-like elements present an outstanding wide distribution among eukaryotes, from fishes to red algae, and can be even highly predominant within a large taxon, such as Malacostraca. Their distribution among crustaceans suggests a dynamics that follows a “domino days spreading” branching process in which successive amplifications may interact positively. PMID:23469217

Esnault, Caroline; Graça, Paula; Higuet, Dominique; Bonnivard, Eric

2013-01-01

427

High sequence variability among hemocyte-specific Kazal-type proteinase inhibitors in decapod crustaceans.  

PubMed

Crustacean hemocytes were found to produce a large number of transcripts coding for Kazal-type proteinase inhibitors (KPIs). A detailed study performed with the crayfish Pacifastacus leniusculus and the shrimp Penaeus monodon revealed the presence of at least 26 and 20 different Kazal domains from the hemocyte KPIs, respectively. Comparisons with KPIs from other taxa indicate that the sequences of these domains evolve rapidly. A few conserved positions, e.g. six invariant cysteines were present in all domain sequences whereas the position of P1 amino acid, a determinant for substrate specificity, varied highly. A study with a single crayfish animal suggested that even at the individual level considerable sequence variability among hemocyte KPIs produced exist. Expression analysis of four crayfish KPI transcripts in hematopoietic tissue cells and different hemocyte types suggest that some of these KPIs are likely to be involved in hematopoiesis or hemocyte release as they were produced in particular hemocyte types or maturation stages only. PMID:19715720

Cerenius, Lage; Liu, Haipeng; Zhang, Yanjiao; Rimphanitchayakit, Vichien; Tassanakajon, Anchalee; Gunnar Andersson, M; Söderhäll, Kenneth; Söderhäll, Irene

2010-01-01

428

Visualization of ecdysteroid activity using a reporter gene in the crustacean, Daphnia.  

PubMed

Ecdysone is a hormone known to play a pivotal role in crustaceans and insects. In order to evaluate the ecdysone activities in the environment and within the organism, we have developed a biomonitoring Daphnia strain by introducing a reporter gene. In this study, the ecdysone response element was inserted in the upstream region of a reporter gene, and the DNA construct was injected into Daphnia eggs. The expression of the reporter gene was detected during the early embryonic development stage. In addition, when the eggs expressing the reporter gene were exposed to ecdysone, there was enhanced expression of the reporter gene at detectable levels, while the presence of an antagonist led to its downregulation. These results suggested that this system could be potentially developed for monitoring ecdysone activities in media. PMID:24296240

Asada, Miki; Kato, Yasuhiko; Matsuura, Tomoaki; Watanabe, Hajime

2014-02-01

429

Life histories and abundance of crustacean zooplankton in the outlet of Lake Superior, 1971-72  

USGS Publications Warehouse

In sampling throughout a year, at about 3-wk intervals, of the crustacean zooplankton discharged from Lake Superior through the St. Marys River, 30 species were collected, including three not previously recorded for the lake: the copepod Cyclops strenuus, and the cladocerans Alona costata and Alonella acutirostris. Five copepods, Cyclops bicuspidatus thomasi, Diaptomus ashlandi, D. sicilis, Limnocalanus macrurus, and Senecella calanoides were present in the plankton throughout the year while three other copepods, Diaptomus minutus, Epischura lacustris, and Mesocyclops edax, along with all cladocerans, were present only during summer and fall. Five species of copepods, Diaptomus sicilis, D. minutus, Limnocalanus macrurus, Senecella calanoides, and Epischura lacustris produced a single generation annually; three other copepods and all cladocerans produced two or more generations. All species breed 1-3 mo later in Lake Superior than in lakes Michigan and Erie.

Selgeby, James H.

1975-01-01

430

Foreseeing fates: a commentary on Manton (1928) ‘On the embryology of a mysid crustacean, Hemimysis lamornae’  

PubMed Central

Sidnie Manton became best known for her work on arthropod locomotion, and for proposing radical views on the evolution of arthropods that were accepted for a generation. However, her early training was as an embryologist, and the work that she carried out at the beginning of her career still stands as one of the major twentieth century contributions to the study of crustacean embryology. Here, I review her first major paper, largely completed while she was a graduate student, describing embryonic development in Hemimysis lamornae, a small shrimp-like animal found in the seas around the UK. The clarity of her writing and the quality of her figures set a standard that laid the basis for subsequent work, and although not all of her conclusions have stood the test of time, they remain a standard reference for work today. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750244

Akam, Michael

2015-01-01

431

Determination of bioactivity of chemical fractions of liquid wastes using freshwater and saltwater algae and crustaceans  

SciTech Connect

Complex wastes from industrial and municipal outfalls were fractionated chemically and tested for toxicity with freshwater and saltwater algae and crustaceans. The organic fraction of each waste was subfractionated into acid-, base-, and neutral-extractable portions, and the inorganic fraction was subfractionated into its anion and cation components. All wastes affected growth of the algae Skeletonema costatum (saltwater) and Monoraphidium capricornutum (freshwater) or survival of Mysidopsis bahia (saltwater) and Daphnia magna (freshwater). Usually, bioactivity was limited to one or two subfractions. In some cases, algal growth was stimulated by a fraction or subfraction, whereas stimulation was not detected in whole waste. It is suggested that fractionation must be done in order to estimate the full potential impact of complex wastes on aquatic systems. The method can also be used to identify toxic factors before application of cost-effective control technology.

Walsh, G.E. (US Environmental Protection Agency, Gulf Breeze, FL); Garnas, R.L.

1983-03-01

432

Putative Pacemakers in the Eyestalk and Brain of the Crayfish Procambarus clarkii Show Circadian Oscillations in Levels of mRNA for Crustacean Hyperglycemic Hormone  

PubMed Central

Crustacean hyperglycemic hormone (CHH) synthesizing cells in the optic lobe, one of the pacemakers of the circadian system, have been shown to be present in crayfish. However, the presence of CHH in the central brain, another putative pacemaker of the multi-oscillatory circadian system, of this decapod and its circadian transcription in the optic lobe and brain have yet to be explored. Therefore, using qualitative and quantitative PCR, we isolated and cloned a CHH mRNA fragment from two putative pacemakers of the multi-oscillatory circadian system of Procambarus clarkii, the optic lobe and the central brain. This CHH transcript synchronized to daily light-dark cycles and oscillated under dark, constant conditions demonstrating statistically significant daily and circadian rhythms in both structures. Furthermore, to investigate the presence of the peptide in the central brain of this decapod, we used immunohistochemical methods. Confocal microscopy revealed the presence of CHH-IR in fibers and cells of the protocerebral and tritocerebal clusters and neuropiles, particularly in some neurons located in clusters 6, 14, 15 and 17. The presence of CHH positive neurons in structures of P. clarkii where clock proteins have been reported suggests a relationship between the circadian clockwork and CHH. This work provides new insights into the circadian regulation of CHH, a pleiotropic hormone that regulates many physiological processes such as glucose metabolism and osmoregulatory responses to stress. PMID:24391849

Nelson-Mora, Janikua; Prieto-Sagredo, Julio; Loredo-Ranjel, Rosaura; Fanjul-Moles, María Luisa

2013-01-01

433

Mapping of neuropeptides in the crustacean stomatogastric nervous system by imaging mass spectrometry  

PubMed Central

Considerable effort has been devoted to characterizing the crustacean stomatogastric nervous system (STNS) with great emphasis on comprehensive analysis and mapping distribution of its diverse neuropeptide complement. Previously, immunohistochemistry (IHC) has been applied to this endeavor yet with identification accuracy and throughput compromised. Therefore, molecular imaging methods are pursued to unequivocally determine the identity and location of the neuropeptides at a high spatial resolution. In this work, we developed a novel multi-faceted mass spectrometric strategy combining profiling and imaging techniques to characterize and map neuropeptides from the blue crab Callinectes sapidus STNS at the network level. In total, 55 neuropeptides from 10 families were identified from the major ganglia in the C. sapidus STNS for the first time, including the stomatogastric ganglion (STG), the paired commissural ganglia (CoG), the esophageal ganglion (OG), and the connecting nerve stomatogastric nerve (stn) using matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) and the MS/MS capability of this technique. In addition, the locations of multiple neuropeptides were documented at a spatial resolution of 25 ?m in the STG and upstream nerve using MALDI-TOF/TOF and high-mass-resolution and high-mass-accuracy MALDI-Fourier transform ion cyclotron resonance (FT-ICR) instrument. Furthermore, distributions of neuropeptides in the whole C. sapidus STNS were examined by imaging mass spectrometry (IMS). Different isoforms from the same family were simultaneously and unambiguously mapped, facilitating the functional exploration of neuropeptides present in the crustacean STNS and exemplifying the revolutionary role of this novel platform in neuronal network studies. PMID:23192703

Ye, Hui; Hui, Limei; Kellersberger, Katherine; Li, Lingjun

2012-01-01

434

Astakine 2--the dark knight linking melatonin to circadian regulation in crustaceans.  

PubMed

Daily, circadian rhythms influence essentially all living organisms and affect many physiological processes from sleep and nutrition to immunity. This ability to respond to environmental daily rhythms has been conserved along evolution, and it is found among species from bacteria to mammals. The hematopoietic process of the crayfish Pacifastacus leniusculus is under circadian control and is tightly regulated by astakines, a new family of cytokines sharing a prokineticin (PROK) domain. The expression of AST1 and AST2 are light-dependent, and this suggests an evolutionarily conserved function for PROK domain proteins in mediating circadian rhythms. Vertebrate PROKs are transmitters of circadian rhythms of the suprachiasmatic nucleus (SCN) in the brain of mammals, but the mechanism by which they function is unknown. Here we demonstrate that high AST2 expression is induced by melatonin in the brain. We identify RACK1 as a binding protein of AST2 and further provide evidence that a complex between AST2 and RACK1 functions as a negative-feedback regulator of the circadian clock. By DNA mobility shift assay, we showed that the AST2-RACK1 complex will interfere with the binding between BMAL1 and CLK and inhibit the E-box binding activity of the complex BMAL1-CLK. Finally, we demonstrate by gene knockdown that AST2 is necessary for melatonin-induced inhibition of the complex formation between BMAL1 and CLK during the dark period. In summary, we provide evidence that melatonin regulates AST2 expression and thereby affects the core clock of the crustacean brain. This process may be very important in all animals that have AST2 molecules, i.e. spiders, ticks, crustaceans, scorpions, several insect groups such as Hymenoptera, Hemiptera, and Blattodea, but not Diptera and Coleoptera. Our findings further reveal an ancient evolutionary role for the prokineticin superfamily protein that links melatonin to direct regulation of the core clock gene feedback loops. PMID:23555281

Watthanasurorot, Apiruck; Saelee, Netnapa; Phongdara, Amornrat; Roytrakul, Sittiruk; Jiravanichpaisal, Pikul; Söderhäll, Kenneth; Söderhäll, Irene

2013-03-01

435

Astakine 2—the Dark Knight Linking Melatonin to Circadian Regulation in Crustaceans  

PubMed Central

Daily, circadian rhythms influence essentially all living organisms and affect many physiological processes from sleep and nutrition to immunity. This ability to respond to environmental daily rhythms has been conserved along evolution, and it is found among species from bacteria to mammals. The hematopoietic process of the crayfish Pacifastacus leniusculus is under circadian control and is tightly regulated by astakines, a new family of cytokines sharing a prokineticin (PROK) domain. The expression of AST1 and AST2 are light-dependent, and this suggests an evolutionarily conserved function for PROK domain proteins in mediating circadian rhythms. Vertebrate PROKs are transmitters of circadian rhythms of the suprachiasmatic nucleus (SCN) in the brain of mammals, but the mechanism by which they function is unknown. Here we demonstrate that high AST2 expression is induced by melatonin in the brain. We identify RACK1 as a binding protein of AST2 and further provide evidence that a complex between AST2 and RACK1 functions as a negative-feedback regulator of the circadian clock. By DNA mobility shift assay, we showed that the AST2-RACK1 complex will interfere with the binding between BMAL1 and CLK and inhibit the E-box binding activity of the complex BMAL1-CLK. Finally, we demonstrate by gene knockdown that AST2 is necessary for melatonin-induced inhibition of the complex formation between BMAL1 and CLK during the dark period. In summary, we provide evidence that melatonin regulates AST2 expression and thereby affects the core clock of the crustacean brain. This process may be very important in all animals that have AST2 molecules, i.e. spiders, ticks, crustaceans, scorpions, several insect groups such as Hymenoptera, Hemiptera, and Blattodea, but not Diptera and Coleoptera. Our findings further reveal an ancient evolutionary role for the prokineticin superfamily protein that links melatonin to direct regulation of the core clock gene feedback loops. PMID:23555281

Watthanasurorot, Apiruck; Saelee, Netnapa; Phongdara, Amornrat; Roytrakul, Sittiruk; Jiravanichpaisal, Pikul; Söderhäll, Kenneth; Söderhäll, Irene

2013-01-01

436

Mapping of Neuropeptides in the Crustacean Stomatogastric Nervous System by Imaging Mass Spectrometry  

NASA Astrophysics Data System (ADS)

Considerable effort has been devoted to characterizing the crustacean stomatogastric nervous system (STNS) with great emphasis on comprehensive analysis and mapping distribution of its diverse neuropeptide complement. Previously, immunohistochemistry (IHC) has been applied to this endeavor, yet with identification accuracy and throughput compromised. Therefore, molecular imaging methods are pursued to unequivocally determine the identity and location of the neuropeptides at a high spatial resolution. In this work, we developed a novel, multi-faceted mass spectrometric strategy combining profiling and imaging techniques to characterize and map neuropeptides from the blue crab Callinectes sapidus STNS at the network level. In total, 55 neuropeptides from 10 families were identified from the major ganglia in the C. sapidus STNS for the first time, including the stomatogastric ganglion (STG), the paired commissural ganglia (CoG), the esophageal ganglion (OG), and the connecting nerve stomatogastric nerve ( stn) using matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) and the MS/MS capability of this technique. In addition, the locations of multiple neuropeptides were documented at a spatial resolution of 25 ?m in the STG and upstream nerve using MALDI-TOF/TOF and high-mass-resolution and high-mass-accuracy MALDI-Fourier transform ion cyclotron resonance (FT-ICR) instrument. Furthermore, distributions of neuropeptides in the whole C. sapidus STNS were examined by imaging mass spectrometry (IMS). Different isoforms from the same family were simultaneously and unambiguously mapped, facilitating the functional exploration of neuropeptides present in the crustacean STNS and exemplifying the revolutionary role of this novel platform in neuronal network studies.

Ye, Hui; Hui, Limei; Kellersberger, Katherine; Li, Lingjun

2013-01-01

437

The Global Diversity of Parasitic Isopods Associated with Crustacean Hosts (Isopoda: Bopyroidea and Cryptoniscoidea)  

PubMed Central

Parasitic isopods of Bopyroidea and Cryptoniscoidea (commonly referred to as epicarideans) are unique in using crustaceans as both intermediate and definitive hosts. In total, 795 epicarideans are known, representing ?7.7% of described isopods. The rate of description of parasitic species has not matched that of free-living isopods and this disparity will likely continue due to the more cryptic nature of these parasites. Distribution patterns of epicarideans are influenced by a combination of their definitive (both benthic and pelagic species) and intermediate (pelagic copepod) host distributions, although host specificity is poorly known for most species. Among epicarideans, nearly all species in Bopyroidea are ectoparasitic on decapod hosts. Bopyrids are the most diverse taxon (605 species), with their highest diversity in the North West Pacific (139 species), East Asian Sea (120 species), and Central Indian Ocean (44 species). The diversity patterns of Cryptoniscoidea (99 species, endoparasites of a diverse assemblage of crustacean hosts) are distinct from bopyrids, with the greatest diversity of cryptoniscoids in the North East Atlantic (18 species) followed by the Antarctic, Mediterranean, and Arctic regions (13, 12, and 8 species, respectively). Dajidae (54 species, ectoparasites of shrimp, mysids, and euphausids) exhibits highest diversity in the Antarctic (7 species) with 14 species in the Arctic and North East Atlantic regions combined. Entoniscidae (37 species, endoparasites within anomuran, brachyuran and shrimp hosts) show highest diversity in the North West Pacific (10 species) and North East Atlantic (8 species). Most epicarideans are known from relatively shallow waters, although some bopyrids are known from depths below 4000 m. Lack of parasitic groups in certain geographic areas is likely a sampling artifact and we predict that the Central Indian Ocean and East Asian Sea (in particular, the Indo-Malay-Philippines Archipelago) hold a wealth of undescribed species, reflecting our knowledge of host diversity patterns. PMID:22558143

Williams, Jason D.; Boyko, Christopher B.

2012-01-01

438

Ciliate Epibionts Associated with Crustacean Zooplankton in German Lakes: Distribution, Motility, and Bacterivory  

PubMed Central

Ciliate epibionts associated with crustacean zooplankton are widespread in aquatic systems, but their ecological roles are little known. We studied the occurrence of ciliate epibionts on crustacean zooplankton in nine German lakes with different limnological features during the summer of 2011. We also measured the detachment and re-attachment rates of the ciliates, changes in their motility, and the feeding rates of attached vs. detached ciliate epibionts. Epibionts were found in all lakes sampled except an acidic lake with large humic inputs. Epibiont prevalence was as high as 80.96% on the cladoceran Daphnia cucullata, 67.17% on the cladoceran Diaphanosoma brachyurum, and 46.67% on the calanoid copepod Eudiaptomus gracilis. Both cladoceran groups typically had less than 10 epibionts per individual, while the epibiont load on E. gracilis ranged from 1 to >30 epibionts per individual. After the death of the zooplankton host, the peritrich ciliate epibiont Epistylis sp. detached in an exponential fashion with a half-life of 5?min, and 98% detached within 30?min, leaving behind the stalks used for attachment. Immediately after detachment, the ciliates were immotile, but 62% became motile within 60?min. When a new host was present, only 27% reattached after 120?min. The average measured ingestion rate and clearance rate of Epistylis were 11,745 bacteria ciliate?1?h?1 and 24.33??l ciliate?1?h?1, respectively. Despite their high feeding rates, relatively low epibiont abundances were observed in the field, which suggests either diversion of energy to stalk formation, high metabolic loss by the epibionts, or high mortality among the epibiont populations. PMID:22783247

Bickel, Samantha L.; Tang, Kam W.; Grossart, Hans-Peter

2012-01-01

439

Subsurface crustacean communities as proxy for groundwater-surface water interactions in the Henares and Tajuña Rivers floodplains, central Spain  

NASA Astrophysics Data System (ADS)

In the last decades, the linkage between surface water - groundwater via the hyporheic zone and the alluvial floodplains become more and more acknowledged. Hydrological exchanges between the stream and hyporheic zone ensure the transport of matter and energy and provide support for biogeochemical processes occurring in-stream bed sediments. Furthermore, the hyporheic zone is directly linked to permeable alluvial aquifers of which exchanges in both directions ensure the withstanding of a mixt biotic community's that may originate either from the surface benthic habitats or from the shallow aquifer. Data on the subsurface crustacean assemblages are used to infer the surface-groundwater interaction in two-groundwater fed-streams in central Spain. The survey was conducted on 20 hyporheic sites (20-40 cm depth) and 28 shallow or deep boreholes. Multivariate statistics were applied to test for differences in crustacean communities resulting from changes in water chemistry between the upstream and downstream parts of the alluvial aquifer, and between the hyporheic zone and the alluvial aquifer. Our aims were to: 1) test whether groundwater discharges in-stream bed sediments are reflected in changes in the crustacean assemblage's structure; and 2) establish whether the surface water influence decreases with increasing groundwater depth and distance from the river. We further aimed to test whether the diversity-stability ecotonal paradigm associated with the distinct level of disturbances and stability at the interface surface-groundwater and the aquifer is reflected in groundwater crustacean community structure. We start from the assumption that groundwater ecosystems undergo significant changes in space and time, and that classical groundwater stability hypothesis ought to be changed to concepts operative for surface ecosystems: disturbance and resilience. The streams are characterised by distinct gradients of surface-groundwater exchanges at spatial scale, with major interactions at the rivers headwaters compare to the lower part of the alluvial a