Three new species of fishes found in Western Ghats
Filament barbs are found in the rivers of peninsular India and Sri Lanka from where around nine species are currently known under the genus Dawkinsia.
They are popular among aquarium hobbyists around the world and are both wild-collected and captive-bred for the trade.
These were discovered after collaborative research by scientists from the Indian Institute of Science Education and Research (IISER) -Pune, the Bombay Natural History Society (BNHS) and the Kerala University of Fisheries and Ocean Studies (KUFOS).
This new research has signified the importance of employing integrated taxonomy in the identification of species as an integrative approach of evidence gathering using morphological and genetic analysis, and based on a fresh collection of Dawkinsia, a genus of cyprinid fish specimens from the Western Ghats, has resulted in the discovery of three new fish species.
In many fish species, particularly those from the superorder Ostariophysi, individuals contain club cells in their epidermal tissue. These cells contain a chemical substance, which when released by injury during predation events, leads to stereotyped anti-predatory behaviors in nearby fish. Recent evidence concerning the evolutionary origins of this system has suggested that club cells are associated with innate immunity, and may serve to protect fish from parasite infestations and injury.
David George Lonzarich, Megan Meller and Rebecca Frank made a research on variability in club cell investment in a North American Cyprinid fish species. In this study, they explored factors associated with variability in club cell investment from several populations of a North American cyprinid fish species (Creek Chub, Semotilus atromaculatus), with a primary goal to test the anti-parasite hypothesis in a natural setting.
Using a path model approach, they evaluated the relative effects of fish length, mucous cell densities, epidermis thickness and parasite burden on club cell investment. This model, which included all four independent variables, explained most of the variability in club cell densities for our fish (R2 = 0.80), and that fish length (acting either directly or indirectly on the other variables) explained most of this variability. Club cell densities were positively associated with parasite burden when examined in isolation of other factors, but in the path model, the association was not significant.
Although in this study, the model indicates that, at least in this species, most of the variability in club cell investment is associated with characteristics of individual fish, and not the conditions of the environments in which they occur.
Read the full paper at Probe-Fishery Science & Aquaculture: