The present study describes the annual condition as well the length-weight (LWR) and length-length relationships (LLR) of the Asian striped catfish, Mystus vittatus (Bloch, 1794) (Siluriformes: Bagridae), an important fishery in the Mathabhanga River (SW Bangladesh). A total of 2438 specimens (3.60-9.60 cm standard length) used in this study was caught with traditional fishing gear from January to December 2004. Overall, the allometric coefficient b of the LWR was close to the isometric value (b ¼ 3.058), although it suggested negative allometric growth for males (b ¼ 2.959) whilst positive allometric growth for females (b ¼ 3.134). The results further indicated that the LLRs were highly correlated (r 2 > 0.989, P < 0.001). The monthly gonadosomatic index showed that the reproductive period of M. vittatus began in April, and ended in August when the highest values of the Fulton's condition factor (K) indicated their recovery. These results will be useful for fishery managers to impose adequate regulations for sustainable fishery management not only in the Mathabhanga River of Bangladesh but also in neighbouring countries.

The diet of zebrafish Danio rerio in Bangladesh consisted primarily of zooplankton and insects. Zebrafish was an annual species, with the main period of reproduction commencing just before the onset of the monsoon season. Growth rates varied with age and season, with the period of most rapid growth in early life during the monsoon months.

The effects of introduction of common carp, Cyprinus carpio (L,), in poiycuiture with major Indian carps and silver carp were studied in fertilized and fed earthen ponds in Mymensingh. Bangladesh. Bottom-dwelling common carp were found to exert an influence on the quality and quantity of planktonic food organisms. The presence of common carp significantly increased (P < 0.05) the growth of other carps including the bottom-feeder mrigal, Cirrhinus mrigala (Hamilton). A significantly higher fish yield (P<0.05) was observed in the fish ponds containing common carp when the combined yields of all species in three treatments were compared. 619

The present study describes the length-weight (LWR) and length-length (LLR) relationships for eight important small indigenous fish species (SIS) from the Mathabhanga River, southwestern Bangladesh, namely Amblypharyngodon mola