Descriptions of larval, prejuvenile, and juvenile finescale menhaden (Brevoortia gunteri) (family Clupeidae), and comparisons to gulf menhaden (B. patronus)

Larval and juvenile development of finescale menhaden (Brevoortia gunteri) is described for the first time by using wild-caught individuals from Nueces Bay, Texas, and is compared with larval and juvenile development of co-occurring gulf menhaden (B. patronus). Meristics, morphometrics, and pigmentation patterns were examined as development proceeded. An illustrated series of finescale menhaden is presented to show changes that occurred during development. For finescale menhaden, transformation to the juvenile stage was completed by 17−19 mm standard length (SL). By contrast, transformation to the juvenile stage for gulf menhaden was not complete until 23−25 mm SL. Characteristics useful for separating larval and juvenile finescale menhaden from gulf menhaden included 1) the presence or absence of pigment at the base of the insertion of the pelvic fins; 2) the standard length at which medial predorsal pigment occurs; 3) differences in the number of dorsal fin ray elements; and, 4) the number of vertebrae.

Seasonal growth of King George whiting (Sillaginodes punctata) estimated from length-at-age samples of the legal-size harvest

Samples of 11,000 King George whiting (Sillaginodes punctata) from the South Australian commercial and recreational catch, supplemented by research samples, were aged from otoliths. Samples were analyzed from three coastal regions and by sex. Most sampling was undertaken at fish processing plants, from which only fish longer than the legal minimum length were obtained. A left-truncated normal distribution of lengths at monthly age was therefore employed as model likelihood. Mean length-at-monthly-age was described by a generalized von Bertalanffy formula with sinusoidal seasonality. Likelihood standard deviation was modeled to vary allometrically with mean length. A range of related formulas (with 6 to 8 parameters) for seasonal mean length at age were compared. In addition to likelihood ratio tests of relative fit, model selection criteria were a minimum occurrence of high uncertainties (>20% SE), of high correlations (>0.9, >0.95, and >0.99) and of parameter estimates at their biological limits, and we sought a model with a minimum number of parameters. A generalized von Bertalanffy formula with t0 fixed at 0 was chosen. The truncated likelihood alleviated the overestimation bias of mean length at age that would otherwise accrue from catch samples being restricted to legal sizes.

Sex ratios of Metapenaeus kutchensis George, George and Rao, 1963 and Parapenaeopsis sculptilis (Heller, 1862) in the Gulf of Kachchh, Western India

Sex ratio data of two species of penaeid prawns Metapenaues kutchensis George, George and Rao, 1963 and Parapenaeopsis sculptilis (Heller, 1862), occurring in the Gulf of Kachchh, were statistically analysed. A preponderance of females was observed in both the species and the ratio of male to female for both years combined for M. kutchensis and P. sculptilis was found to be 1:15 and 1:2.7, respectively. Chi-square analysis revealed significant difference in the sex ratio of the two species.