mystus gulio is a euryhaline fish, occurring mostly in freshwater; it has also been found to thrive in backwaters of low salinity. it is a popular food fish due to its good taste and recently it has also been reported to be exported as indigenous ornamental fish from india. number of workers earlier has studied morphology, age, growth pattern, food and feeding habit and reproductive biology of ...

An experiment was undertaken to develop a suitable seed production technique for Sperata aor in captivity. Naturally produced fry of aor was reared at different densities in nine nursery ponds 0.012 ha in size with an average depth of 0.8 m each. Three stocking densities tested, each of which was triplicated. Fry of aor stocked at 100,000/ha was designated as treatment-1 (T1), 150,000/ha as tre...

An experiment was undertaken to develop a suitable seed production technique for Sperata aor in captivity. Naturally produced fry of aor was reared at different densities in nine nursery ponds 0.012 ha in size with an average depth of 0.8 m each. Three stocking densities tested, each of which was triplicated. Fry of aor stocked at 100,000/ha was designated as treatment-1 (T1), 150,000/ha as tre...

We define the notion of whiskered categories and groupoids, showing that whiskered groupoids have a commutator theory. So also do whiskered R-categories, thus answering questions of what might be ‘commutative versions’ of these theories. We relate these ideas to the theory of Leibniz algebras, but the commutator theory here does not satisfy the Leibniz identity. We also discuss potential applic...

Proliferative gill disease (PGD) in channel catfish Ictalurus punctatus is caused by the myxozoan parasite Henneguya ictaluri. There is no effective treatment for PGD, and mortalities can exceed 50% in severe outbreaks. One approach to controlling losses would be to utilize a less susceptible ictalurid species in pond culture; alternatively, one could identify the traits that convey resistance ...

Whiskered Auklets Aethia pygmaea are relatively rare alcids, currently distributed on select islands within the Aleutian, Commander, and Kurile island chains of the North Pacific to which they are endemic (Fig. 1; Byrd & Williams 1993, Gaston & Jones 1998). Whiskered Auklets forage in tiderips, swirls, and tidal pumps or fronts on zooplankton that is concentrated near islands and offshore reefs...