Indian Council of Agricultural Research
CENTRAL MARINE FISHERIES RESEARCH INSTITUTE
CENTRAL MARINE FISHERIES RESEARCH INSTITUTE
The taxonomic characteristics of the little-known flathead species Cociella crocodilus (Family: Platycephalidae) are described in this study. A total of 30 morphometric and 16 meristic characters were measured and counted. A detailed description of the species is provided, together with morphological characters, photographs and a comparison with other related species found along India’s southwest coast.
The present study represents the first information on direct age determination based on band counts in the mesocardiac ossicle (gastric mill) and eyestalk, in Aristeus alcocki, Penaeus monodon, Penaeus indicus, Panulirus homarus, and Portunus sanguinolentus from India. The determination of growth bands is important in understanding the accurate age of a specimen for the effective management strategies for stock sustainability of the natural resource. Longitudinal sections of the eyestalk and meso-cardiac ossicle of the gastric mill were observed for growth band counts in all species except for P. homarus, where the growth bands were recorded only in the ossicle. Growth bands count five in females and four in males of A. alcocki, respectively. In the case of inshore prawns, two growth bands were observed in P. monodon and one growth band in P. indicus, five growth bands in P. homarus, and three in P. sanguinolentus.
The effect of temperature, salinity and body-size on depuration of naturally accumulated heavy metals in clams, mussels and oysters harvested from Ashtamudi and Vembanad estuaries of Kerala, India were investigated using a static depuration system. Before depuration, the concentrations of heavy metals such as Ni, Co, Fe, Mn, Cu, Pb and Zn were analysed and it was found that the Fe, Zn, Cu and Pb contents in all the three bivalve molluscs were above the prescribed limit which poses a significant health risk to bivalve consumers. To protect consumer food safety, depuration experiments were conducted at varying temperatures, salinities and body-sizes. The clams, mussels and oysters depurated under the room temperature depuration system (RTDS) showed a better reduction of heavy metals compared with low-temperature depuration system (LTDS). ANOVA showed clams and mussels depurated at RTDS significantly (p?<?0.05) reduced the heavy metals than LTDS. However, there was no significant (p?>?0.05) difference in oysters between RTDS and LTDS.
Age, growth and maturation in the mesopelagic squid Abralia andamanica (Cephalopoda: Enoploteuthidae) were studied in 140 individuals of 15-60 mm dorsal mantle length (DML) captured from open waters in the southeast Arabian Sea. The length-weight relationship was estimated as W=0.278 DML1.884 (R2 =0.93). Age estimates based on statolith increment counts ranged from 79 to 177 days, suggesting a short (<200-day) lifespan. Growth in length was best described by a linear function for males and a power function for females. Growth in weight was best described by a power function for both sexes. Growth rates of the DML ranged from 0.16 to 0.30 (mean=0.24) mm/day in males and from 0.23 to 0.43 (mean=0.33) mm/ day in females. The hatching season extended from June to August (monsoon season).
The deep sea squid Asperoteuthis acanthoderma (family: Chiroteuthidae) is reported here for the first time from the Arabian Sea of the India. A single specimen was collected while conducting a trial fishing with 49.5m Cosmos mid water trawl onboard FORV Sagar Sampada between latitude 11o 47.767’N and longitude 73o 39.065’E at a depth range of 350 to 400 m during the month of October 2013. The morphometric measurements of the specimen are described and are compared with the same species reported from the North Atlantic Ocean. The female specimen measured 788 mm in standard length, 22.50 mm in mantle length, 89.26 mm fin length and weighed 85.38 gm.
Food and feeding habits of eight species of female elasmobranchs in gestation stages were studied. The low feeding intensity and smaller mean volume of food per fish (in ml) attributed with their gestating activities and cease feeding in the nursery region as protecting measures for young ones. The prey items occurred in guts content of these species were analyzed by index of relative importance (IRI). Carcharhinus macloti and Rhizoprionodon acutus (100 %) were piscivorous which feed exclusively on teleosts found above the bottom. Rhizoprionodon oligolinx (96.5 %) and Scoliodon laticaudus (50.3 %), were generalized predators, feeding throughout the water column and occasionally at bottom chiefly on teleost and small quantities of crustaceans and molluscs. Amphotistius imbricate (86.06 %), Rhinobatos annandalei (68.9 %) and Rhynchobatus djiddensis (61.58 %) were carnivores, feeding mainly on free-living crustaceans and supplemented by teleost at the sea bottom.
