Sample records for yellowfish labeobarbus kimberleyensis
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NASA Astrophysics Data System (ADS)
Retief, N.-R.; Avenant-Oldewage, A.; du Preez, H. H.
Infection of fish by the Asian tapeworm can damage intestines and cause abnormal growth. Eighty largemouth yellowfish Labeobarbus kimberleyensis were collected in the Vaal Dam (26°52.249‧S, 28°10.249‧E) with the aid of gill nets during a study between April 2005 and February 2006. The fish were killed and the weight and length determined. Thereafter the intestines were removed, the length determined and the intestines opened to expose the tapeworms. The distance between the beginning of the intestine and the attachment position of the first tapeworm was measured, and thereafter all the worms were collected. The prevalence, abundance and mean intensity was calculated for all the surveys. Seasonality and intensity of tapeworms were compared to the intestine and total lengths of the fish. All the tapeworms were identified as the Asian Tapeworm Bothriocephalus acheilognathi Yamaguti, 1934. The position of the first tapeworm was located between 10% and 20% from the anterior end of the intestine in close proximity to the bile opening. A total of 100% prevalence was recorded for all the surveys and the highest mean intensity of 231.1 was recorded during the autumn survey. The lowest mean intensity of 73.7 was recorded during the summer survey. Although the infection rates were very high, the fish condition was good and apparently the fecundity of the fish was not negatively affected as young fish fry was collected during the summer survey. Parasite numbers are higher and differ from a study conducted in 2000 and this is attributed to water temperature and water quality. No correlation was observed between parasite intensity and total length of each fish. This indicates that intensity is not dependant on host size and that infection is not the result of a buildt of over years.
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Gilbert, Beric M; Avenant-Oldewage, Annemariè
2016-07-28
Monogenea is a diverse group of ectoparasites showing great potential as sentinel organisms for monitoring environmental health. Exposure to metals negatively affects infrapopulations of monogeneans and exposure to aluminium has been found to negatively impact the survival of gyrodactylids. Samples of infected host fish, the smallmouth yellowfish Labeobarbus aeneus (Cyprinidae), were collected from the Vaal Dam, South Africa and transported back to the laboratory in dark 160 l containers. Eggs of the monogenean Paradiplozoon ichthyoxanthon infecting L. aeneus were collected and exposed to varying concentrations of aluminium along with a control group in static tanks. The eggs were checked every 24 h and hatching commenced 13-14 days after exposure. Water samples were taken from exposure tanks and acidified for analysis of Al levels with inductively-coupled plasma mass spectrometry. Hatching of eggs was variable between exposures, and in 30 μg Al/l and 60 μg Al/l was found to occur before eggs in control beakers, whereas, exposure to 120 μg Al/l delayed hatching and reduced hatchability. Survival of hatched oncomiracidia was concentration dependent and negatively correlated with aluminium concentrations. Lowest survival was recorded for 60 μg Al/l and 120 μg Al/l where all larvae died shortly after or during hatching. Normal development of embryos of P. ichthyoxanthon within eggs exposed to all doses of aluminium indicates that the egg shell is moderately impermeable to metals and inhibits movement of aluminium across the shell and interacting with developing embryos. Higher larval mortality rate in 120 μg/l exposure can be related to aluminium crossing the egg shell in the late stages and causing death of unhatched yet fully developed embryos, possibly due to changes in the permeability of the egg shell as embryos neared developmental completion. Accelerated death of oncomiracidia after hatching indicates sensitivity toward high concentrations of aluminium.
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Ahrens, Lutz; Gashaw, Habiba; Sjöholm, Margareta; Gebrehiwot, Solomon Gebreyohannis; Getahun, Abebe; Derbe, Ermias; Bishop, Kevin; Åkerblom, Staffan
2016-12-01
Lake Tana is Ethiopia's largest lake and there are plans to increase the harvest of fish from the lake. The objective of this study was to assess the levels of poly- and perfluoroalkyl substances (PFASs) in different compartments of the lake (water, sediment, and fish muscle tissue), and its implications for human exposure. The results showed higher PFAS concentrations in piscivorous fish species (Labeobarbus megastoma and Labeobarbus gorguari) than non-piscivorous species (Labeobarbus intermedius, Oreochromis niloticus and Clarias gariepinus) and also spatial distribution similarities. The ∑PFAS concentrations ranged from 0.073 to 5.6 ng L -1 (on average, 2.9 ng L -1 ) in surface water, 0.22-0.55 ng g -1 dry weight (dw) (on average, 0.30 ng g -1 dw) in surface sediment, and non-detected to 5.8 ng g -1 wet weight (ww) (on average, 1.2 ng g -1 ww) in all fish species. The relative risk (RR) indicates that the consumption of fish contaminated with perfluorooctane sulfonate (PFOS) will likely not cause any harmful effects for the Ethiopian fish eating population. However, mixture toxicity of the sum of PFASs, individual fish consumption patterns and increasing fish consumption are important factors to consider in future risk assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Aplin, K. P.; Rhind, S. G.; Ten Have, J.; Chesser, R. Terry
2015-01-01
The Australian Brush-tailed Phascogale (Phascogale tapoatafa sensu lato) has a broad but highly fragmented distribution around the periphery of the Australian continent and all populations are under significant ongoing threat to survival. A new appraisal of morphological and molecular diversity within the group reveals that the population in the ‘Top End’ of the Northern Territory is specifically distinct from all others, including those in the Kimberley region of Western Australia to the west and on Cape York of Queensland to the east. The name P. pirata Thomas, 1904 is available for the ‘Top End’ taxon. Three geographically disjunct populations are distinguished at subspecies level within P. tapoatafa on a suite of external and cranio-dental features; these are found in southeast Australia from South Australia to mid-coastal Queensland (nominotypical tapoatafa), southwest Western Australia (wambenger subsp. nov.), and the Kimberley region of Western Australia (kimberleyensis subsp. nov.). A potential fourth subspecies occurs on Cape York but remains too poorly represented in collections for adequate characterization. Molecular divergence estimates based on partial sequences of the mitochondrial cytochrome b gene indicate that the range disjunction across southern Australia probably dates from the Late Pliocene, with the multiple disjunctions across northern Australia being more recent though almost certainly exceeding 400,000 years. An argument is made for the continued use of the subspecies rank in Australian mammalogy, despite a general lack of consistency in its current application.
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Taxonomic revision of the genus Carasobarbus Karaman, 1971 (Actinopterygii, Cyprinidae)
Borkenhagen, Kai; Krupp, Friedhelm
2013-01-01
Abstract Representatives of the fish genus Carasobarbus Karaman, 1971 (Actinopterygii: Cyprinidae) from the Middle East and North Africa were previously placed in 14 different genus-group taxa (Barbellion, Barbus, Barynotus, Capoeta, Carasobarbus, Cyclocheilichthys, Kosswigobarbus, Labeobarbus, Luciobarbus, Pseudotor, Puntius, Systomus, Tor and Varicorhinus). The generic assignment of several species changed frequently, necessitating a re-evaluation of their taxonomic status. In this study, the genus Carasobarbus is revised based on comparative morphological examinations of about 1300 preserved specimens from collections of several museums and freshly collected material. The species Carasobarbus apoensis, Carasobarbus canis, Carasobarbus chantrei, Carasobarbus exulatus, Carasobarbus fritschii, Carasobarbus harterti, Carasobarbus kosswigi, Carasobarbus luteus and Carasobarbus sublimus form a monophyletic group that shares the following combination of characters: medium-sized barbels with a smooth last unbranched dorsal-fin ray, nine or 10 branched dorsal-fin rays and six branched anal fin-rays; scales large, shield-shaped, with many parallel radii; the lateral line containing 25 to 39 scales; the pharyngeal teeth hooked, 2.3.5-5.3.2 or 2.3.4-4.3.2; one or two pairs of barbels. The species are described in detail, their taxonomic status is re-evaluated and an identification key is provided. A lectotype of Systomus luteus Heckel, 1843 is designated. Carasobarbus Karaman, 1971, Kosswigobarbus Karaman, 1971, and Pseudotor Karaman, 1971 are subjective synonyms, and acting as First Reviser we gave precedence to the name Carasobarbus. PMID:24146585