Comparative account of growth rate of body parts with total length in adult Puntius sarana (Ham.)

The present study on growth rate of different body parts in relation to total length, in the male and female Puntius sarana (Ham.) did not show any significant heterogeneity except in snout length (p.01). The growth rate of snout length was found to be higher in females (b=0.0377) than in males (b=0.0266). Since the growth rate of most of the body parts was found to be homogeneous in both the sexes, the common regression co-efficient "b" was calculated on pooled data to represent the growth rate of different body parts against total length, the linearity of regression lines indicated isometric growth.

Studies on fecundity of Puntius sarana (Ham.) in relation to total length, total weight and ovary weight

A total of 43 mature female of Puntius sarana (Ham.) ranging from 204 mm to 320 mm in length and 102 to 482 g in weight were used for present studies. The relationship between fecundity with respect to total length (TL), total weight (TW) and ovary weight (OW) was found to be linear. The coefficient of co-relation 'r' of the above relationships was found to be 0.5947, 0.5761 and 0.9837 respectively. All these values are highly significant (P=0.01) indicating a close relationship between these parameters. However, as indicated by value of 'r' (0.9837), the fecundity is more closely related to ovary weight and hence the ovary weight may be a better index of fecundity than the total length or weight.

Determination of length-weight relationship in Sepia pharaonis and test for sex specific variation

The parameters a and b of the length-weight relationship of Sepia pharaonis of the form of W=a.L was determined. Sex separated size fequency data collected from Karachi fish Harbour was analysed the length-weight equations, separable by male, female and sex combined. The apparent difference in paired values of exponents b1, b2 for any combination i.e. male versus female and male, female versus sex combined was tested for their significant difference. No significant difference was observed for any combination, this indicated no sex specific variation in length-weigh relationship of Sepia pharaonis.

Length-weight relationship and relative condition factor in Daysciaena albida (Cuv.) and Gerres filamentosus (Cuv.)

The length-weight relationship of Daysciaena albida and Gerres filamentosus were calculated separately for indeterminants, mature males and mature females. The logarithmic regression equation obtained for D. albida - males: log w = -1.5055 + 2.8618 log l; females: log w = -0.9260 + 2.4089 log l; indeterminants: log w = -l.7188 + 3.0616 log l. The regression co-efficients between males and females, males and in determinants and female and in determinants showed significant differences. In G. filamentosus the relationship can be expressed as males: log w = -1.3224 + 2.8740 log 1; females: log w = -1.2874 + 2.8381 log l; indeterminants: log w = -0.8167 + 2.2558 log l. The difference in regression co-efficients between male and female are insignificant at 5% level whereas significant differences were observed between males and indeterminants and females and indeterminants. The relative condition factor (Kn) was calculated for the above two species. In D. albida the reasons for the fluctuations of Kn values can be attributed to both spawning cycle as well as feeding intensity whereas in G. filamentosus it synchronies mainly with spawning cycle.

Length-weight relationship of two palaemonid prawns, Macrobrachium idella and M. scabriculum: a comparative study

Length-weight relationships of two commercially important freshwater prawns, Macrobrachium idella and M. scabriculum, have been worked out separately for the two sexes of the two species. 't' test showed that growth departs significantly from the isometric growth in the case of both sexes of M. idella and in the female of M. scabriculum. Therefore, the cubic formula W = CL^3 may be applied only in the case of males of M. scabriculum. In all the other cases W = CL^n may be followed.

Allometric study of skeleton weight, body weight and length relationship of Euryglossa orientalis (Bl. & Schn.) (Family: Soleidae) from Karachi coast

Present study deals with the family Soleidae (common sole) Euryglossa orientalis (Bl. & Schn.) of the order Pleuronectiformis from Karachi coast. Separate equation (regression line) for describing the length weight relationships for male and female combined are justified. Allometric studies were made on skeleton weight relative to the length and the weight of the fish. The regression equation 'a' and 'b' values of standard length/skeleton weight and body weight/skeleton weight are statistically significant.