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The spadenose shark Scoliodon laticaudus Muller & Henle (1838), one of the smallest tropical Carcharhinid sharks is locally known as “balyar/ neer thate/chaate” in coastal area of Karnataka coast. The study deals with nature and composition of food items, feeding habits, intensity of feeding of S. laticaudus. Analysis of the gut content in both sexes showed that, fish remains and unidentified and semi-digested matter formed the major food items. Lesser sardines, anchovy, Saurida sp, Nemipturus sp., sardine, Priacanthus sp, Terapon sp, croackers, shrimps, Sepia sp, stomatopods, Loligo sp and molluscan remains also occurred in considerable quantity. The contribution of gut content shows approximately 3.6% lesser sardines, 5.08% Anchovies, 3.05% Saurida sp, 3.16% Nemipturus sp, 3.04% Sardine, 2.91% Priacanthus sp, 2.39% Terapon sp, 1.5% crockers, 28.49% fish remains, 4.47% Loligo sp, 2.25% shrimp, 1.39% Sepia sp, 3.23% molluscan remains, 1.80% stomatopods and unidentified and semi-digested matter 33.62% during the period 2015-16. The gut content consists of approximately 3.05% lesser sardines, 4.28 % Anchovies, 3.35 % Saurida sp, 2.51% Nemipturus sp., 5.43% Sardine, 3.45% Priacanthus sp., 2.65 % Terapon sp., 2.07 % croackers, 19.29% Fish remains, 3.19% Loligo sp., 2.95% shrimp, 2.54 % Sepia sp, 3.12 % molluscan remains, 1.27% stomatopods and 40.85% Unidentified and semi-digested matter during 2016- 17. [ABSTRACT FROM AUTHOR]

The present study deals with length-weight relationship of Scoliodon laticaudus from Dakshina Kannada and Udupi coast during September 2015 to May 2017. The regression co-efficient of female was found to be higher than male. From this observation it may be opnied that female gained more weight with increase in length compared to male. The corresponding equations for both the sexes were derived during September 2015 - May 2016 the corresponding equations were; W=0.00986 L2.7674 for male, W=0.0084 L2.8129 for female and pooled data was obtained at W=0.00914L2.7802. Likewise, during September 2016 to May 2017 the equations obtained for male W= 0.02138 L2.5826, for female W = 0.01972 L2.7249 and pooled value W= 0.02055 L2.6585. Analysis of the covariance indicated that there is no significant difference in the length-weight relationship between male and female. The data on seasonal variation in condition factor (Kn) of both male and female during both the years of study showed that the values were more or less similar in both the sexes, indicating almost identical metabolic activity in male and female which may be attributed to gonadal development and feeding intensity. [ABSTRACT FROM AUTHOR]

The length-weight relationship of Charybdis lucifera was estimated and corresponding equation was W=0.1112 L3.1716 for male and W=0.1248 L3.2785 for female. Analysis of covariance showed that there is no significant difference in length-weight relationship between the male and female. Hence, the pooled equation for both sexes was obtained at W = 0.118 L3.2144. The carapace width - weight and carapace length - weight relationship of C. lucifera showed that the weight of crab increased as 3.2144 power of the carapace width. The carapace length - weight relationship showed that the weight of crab increased as 2.7844 power of the carapace length. The fluctuation in the relative condition factor (Kn) value with respect to size indicated that condition of Charybdis lucifera more or less showed an increasing trend with increase in size of crab. The seasonal fluctuations in the relative condition factor of both the sexes could be attributed to the sexual cycle, food intake and environmental factors. [ABSTRACT FROM AUTHOR]