Search results for "Freshwater Fish"
showing 5 items of 45 documents
Carotenoid-based colour of acanthocephalan cystacanths plays no role in host manipulation.
2009
Manipulation by parasites is a catchy concept that has been applied to a large range of phenotypic alterations brought about by parasites in their hosts. It has, for instance, been suggested that the carotenoid-based colour of acanthocephalan cystacanths is adaptive through increasing the conspicuousness of infected intermediate hosts and, hence, their vulnerability to appropriate final hosts such as fish predators. We revisited the evidence in favour of adaptive coloration of acanthocephalan parasites in relation to increased trophic transmission using the crustacean amphipodGammarus pulexand two species of acanthocephalans,Pomphorhynchus laevisandPolymorphus minutus. Both species show car…
Gut Microbiome Analysis In Adult Tropical Gars (Atractosteus tropicus)
2019
AbstractTropical gar (Atractosteus tropicus), is freshwater and estuarine fish that has inhabited the Earth since the Mesozoic era, undergoing limited physiological variation ever since. This omnivorous fish is endemic to southern Mexico and part of Central America. Besides its recognized cultural and scientific relevance, the species has seen remarkable growth in its economic impact due to pisciculture. Previous studies have highlighted the role of microbial communities in fish, particularly those in the gut microbiome, in maintaining their host homeostasis or disease. In this study, we present the first report of the whole taxonomic composition of microbial communities in gut contents of …
On the infracommunity structure of adult cestodes in freshwater fishes.
1990
The distribution–co-occurrence and exchange of adult cestode species in two fish communities (the Bothnian Bay and Lake Yli-Kitka both in Finland) was studied. Coexistence of two or more mature cestode species in the same fish host population was zero for all fish species studied (33) except pike in the Bothnian Bay and whitefish in the lake. It was found that 60% of the fish species studied in the Bothnian Bay and 80% of the fish species studied from Lake Yli-Kitka harboured only 1 mature cestode species. Exchange of adult cestode species between the different fish species in these two fish communities was found to be as rare as coexistence. The infra-community structure of adult cestodes …
The Role of Aquatic Refuge Habitats for Fish, and Threats in the Context of Climate Change and Human Impact, during Seasonal Hydrological Drought in …
2021
In spite of the obvious climate changes effects on the Carpathian Basin hydrographic nets fish fauna, studies on their potential refuge habitats in drought periods are scarce. Multiannual (2016–2021) research of fish in some streams located in the Saxon Villages area during hydrological drought periods identified, mapped, and revealed the refuge aquatic habitats presence, management needs, and importance for fish diversity and abundance for small rivers. The impact of increasing global temperature and other human activities induced hydrologic net and habitats alteration, decreased the refuge habitats needed by freshwater fish, diminished the fish abundance, and influenced the spatial and te…
Induction of Hsp70 by the Herbicide Oxyfluorfen (Goal) in the Egyptian Nile Fish, Oreochromis niloticus
1999
This paper deals with the expression of the biomarker hsp70 in the liver and kidney of the freshwater fish Oreochromis niloticus following exposure to the herbicide oxyfluorfen (Goal). Fishes were exposed to three concentrations, the 96-h LC50 (3 mg/L), the 96-h (1/2)LC50 (1.5 mg/L), and the 96-h (1/4)LC50 (0.75 mg/L) of oxyfluorfen for 6, 15, and 24 days, respectively, and samples were taken at three different time periods for each concentration. The livers responded to the herbicide by an induction of the expression of both the constitutive (hsp75; Mr 75 kDa) and the inducible (hsp73; Mr 73 kDa) hsp70 proteins. In kidney, the herbicide induced a time-dependent increase in the expression o…