Some Biological Characteristics of the Daysciaena albida (Cuvier 1830), on Largest Brackish Water Lagoon of India

Abstract

An attempt to study length-weight relationship (LWR), condition factor and reproductive aspects of Daysciaena albida was done in Chilika lagoon over one year. The fish specimens for the biological study were collected from landing centers of central and northern sector during pre-monsoon, monsoon and post-monsoon seasons. The LWR from total length and body weight were computed both by sex and seasons. The equations found from the relationships were y=0.010x 2.992 for male, y=0.010x 2.998 for female and y=0.010x 2.996 as unsexed specimens. The highest condition factor (K)value was recorded during monsoon (1.42±0.08) followed by post-monsoon (1.4±0.09) and the lowest (0.92±0.11) during pre-monsoon seasons. The mean condition factor was registered as 1.06±0.09 in all the seasons of unsexed specimens. Among sex, males registered slightly higher K value than females. For reproductive study, maturation stages, gonad somatic index (GSI) and gastro somatic index (GaSI) were analyzed seasonally. Considering maturation stages highest maturation stages (stages 4 to 7) obtained during pre-monsoon season (in both sexes) which are considered as matured conditions for fish. The highest GSI was registered during pre-monsoon followed by postmonsoon and the lowest was during monsoon season among both the sexes. The GaSI value was lowest during pre-monsoon among males and gradually increased during monsoon and postmonsoon. But in case of female, lowest value was during monsoon and again increased afterwards and was highest in pre-monsoon.

Preferred food items of Juvenile hilsa (Tenualosa ilisha) of the Meghna river estuary in Moju Chowdhury Hat, Lakshmipur

“…De et al (2013) [5] in West Bengal showed different result and mentioned that copepods were the major items in the guts of hilsa from 10 g to 30 g, followed by diatoms which also supported the present study result. The percentage frequency of the existence of sand particles (5-15%) was discovered in the present study result which was also reported by Karna et al (2014) [11] .…”

“…Plankton were identified to the genus level following the determination keys of Yamaji's (1984) [19] and Sahu et al (2013) [16] . The frequency of occurrence method (Hynes, 1950; Hyslop, 1980) [6] [10] , volumetric analysis method (Hynes, 1950) [6] and index of relative importance (Pinkas, 1971) [12] were used to estimate the gut contents quantitatively.…”

“…In frequency of occurrence, the number of stomachs containing a specific type of food, expressed as a percentage of the total number of non-empty stomachs examined. It is the total number of food items present in the gut, as determined by the formula (Hynes, 1950;Hyslop, 1980) [6,10] .…”

Seasonal Variation in the Epibenthic Feeding Habits of Hilsa Shad (Tenualosa ilisha) in the Upper Meghna River Estuary, Bangladesh

“…The frequencies (%F) of sand particles we observed to be decreased with increased fish sizes, suggesting feeding by young hilsa in the nearshore, in epibenthic habitats. The presence of sand particles in hilsa guts, however, was also reported by [31]. Hora and Nair (1940) [32] reported sand grains in hilsa guts from the West Bengal waters, India, and they suggested that hilsa fish feed at the bottom, but no other studies considered the presence of sand in hilsa guts as indicators of feeding habitat in Bangladeshi riverine areas.…”