Systematic studies conducted on the Sillago fish species of Kollam district of Kerala. Meristic, metric and other morphometric characters of these fishes were studied and taxonomically analyzed

Observations on the sex ratio and fecundity of Sillago sihama have been made in this report. By the help of these observations we can say that the female to male ratio was found to be 1: 1.3 i.e. males are comparatively more abundant in small size groups. Mean fecundity was found to be 58781, the minimum and maximum being 5483 and 63244 from the fish measuring 180 – 189 mm T.L to 270 – 279 mm T.L respectively. Right lobe was found to be more fecund than the left one. The results will help to increase our knowledge of reproduction biology of Sillago sihama which can be utilize in aquaculture management and breeding programmes.

Biometry, length-weight relationships (LWRs) and length-length relationships (LLRs) of Sillaginopsis panijus (Hamilton, 1822) were investigated in the Indian coast of north-western Bay of Bengal. Altogether 622 specimens were collected between August 2018 and September 2019 from landings by trawls (30-35 mm mesh size), gillnets (15-55 mm mesh size) and shore seines (7-15 mm bag mesh size). The total length and weight of the specimens ranged from 7.8-40.3 cm and 2.9-506 g, respectively. The LWR established was W=0.0048 L3.059 for males, W=0.0032 L3.185 for females and W=0.0047 L3.0645 for indeterminates, indicating positive allometric growth pattern. All the LWRs were highly significant (p<0.001, r2≥0.977). The highest coefficient of correlation (r) was observed for total length against fork length (0.999) and lowest for head length against eye diameter (0.951). The fin formula was expressed as D1 X, D2 I + 24-28, P 17-22, V I + 5, A II + 25-27, GR 2-3/6-9. The study provides the ...

Length weight relationship and Size distribution are presented for 522 specimens of Sillago sihama (Forrskal, 1775) (Family: Sillaginidae) collected fortnightly from commercial landings at Korangi Creek (Ibrahim Hydari) and Karachi Fish Harbor during the period from September 2003 to January 2005. Length weight relationship of males and females computed separately and also pooled. The logarithmic weight and length relationship showed a straight line pattern. A high percentage of length frequency found during the spawning months. Length frequency was most prominent between size ranges from 160-169 mm T.L.

Sillago sihama has been found as carnivore fish on the basis of contents analysis from stomachs. Sillago sihama is a crustacean, teleosts, mollusks, echinoderms and polychaetes feeder. Stomach contents were consisted of echinoderms Amphipholis squamata, Ophioplocus imbricatus, mollusks, bivalves Cardium sp., Tellina sp., Anadora sp., gastropod shells, crustaceans Pagurus digenus (hermit crab) Acetes sp., Carideans, polychaetes Lumbrineris sp., polynoid worm (scale worms) Eunicid worms, Gozia zeder, rotifer Hydratina sp., Echiuroid worm, monaxone spicules, gills, appendages, chela, parts of carapace, eyes and flash of crabs and prawns, telson of prawns, scales and eggs of fish, parts of bivalves and gastropod shells, parts of sea urchin shells, partially digested earth worms and polychaete worms, nematodes, broken arms of star fishes, fecal material, mucous and sand. Overall 4.21% stomachs were found to be gorged, 8.23% full, 14.55% ¾ full, 17.24% ½ full, 24.52 % ¼ full, 26.43 % barely full and 4.78 % were empty it was noticed that feeding activity slows down during the spawning months. Overall this fish changes its food habit with the change in season.

Due to difficulty in recognition, many true species have been covered under the synonyms of wide-spread species. To justify the identification of a widely distributed species, Sillago sihama from the Bay of Bengal, Bangladesh, an integrated approach including morphology and DNA barcoding was used. Two unrecognized species of Sillago, i.e., Sillagomuktijoddhai sp. nov. and S. mengjialensis sp. nov., were identified from the coastal area of Bangladesh. S. muktijoddhai sp. nov. has marked differences in the body color, anal fin color, number of gill rakers, snout length, and swimbladder. S. mengjialensis sp. nov. has notable differences in the anal fin color, snout length, and swimbladder and is distinguished from S. muktijoddhai sp. nov. by the body color and swimbladder. The morphological characters of 14 documented Sillago species with two posterior extensions of the swimbladder were referenced and distinguished to accredit the two new species. Genetic analyses of partial mitochondr...

Sillago sihama have a prolonged breeding season from June to December, with spawning activity peaked during the period of September to November. Length at first maturity stage was found to vary between 155-164 mm (total length) in both sexes. Although overall sex ratio indicated predominance of female, Chi-square test ( x 2 ) showed no significant difference throughout the year. Fecundity varied from 11,376 to 103,695 per fish, is significantly correlated with total length (r = 0.85, ρ < 0.01), body weight (r = 0.88, ρ < 0.01) and ovary weight (r = 0.87, ρ < 0.01).