Observations on the food and feeding habits of the Ttorpedo trevally Megalaspis cordyla (Linnaeus) from Vizhinjam bay

A study of the food and feeding habits of Megalaspis cordyla based on an examination of 1692 specimens revealed that it is a pelagic carnivorous feeder, subsisting mainly on Stolephorus spp.; Leiogiiathus spp., Gazza &p., Carangoides spp., fish juveniles, fish larvae, alima larvae of Squilla spp., Acetes spp., amphipods, Squilla spp., Lucifer spp., megalopa larvae of crab, prawn juveniles, copepods, euphausids, pteropods, Sepia spp., and Nereis spp. were the other food items recorded. The intensity of feeding decreased with advancement of maturity. Feeding was observed to be comparatively higher during night than by day

Seed production technology for edible marine molluscs

One of the major constraints in the mariculture industry is the shortage of seed supply for the farming activities. This fact is applicable to molluscan farming also, because availablity of seed in the wild is severely restricted to few patches and to certain seasons in the natural beds which cannot meet the demand. The'refore need was felt to cllilance the seed supply e'ther by increasing effort for seed collection from the natural beds by identifying areas of abundance or production of seed by hatchery techniques

Potentialities of Muttukadu mariculture farm for green mussel culture

Experimental trials were conducted for the culture of green mussel (Perna viridis) at Muttukadu Mariculture Farm of CMFRI located near Madras using Pole culture and Bag culture methods.Studies based on the growth and production potential revealed that the location is highly suitable for green mussel mariculture

Coleroon estuary, Tamil Nadu - A potential area for edible oyster and green mussel culture

A potential area for edible oyster and green mussel cultur

Involvement of binding lipoproteins in the absorption and transport of α-tocopherol in the rat

1. Specific lipoproteins binding α-tocopherol but not its known metabolites have been isolated and identified from cytosol of rat intestinal mucosa and from serum. 2. A timestudy of the appearance of the orally administered α-[3H]tocopherol with these lipoproteins indicates that very-low-density lipoprotein of serum acts as a carrier of the vitamin. 3. The involvement of the mucosal lipoprotein in the absorption of the vitamin from the intestine has been inferred from observations on the amounts of α-tocopherol in serum of orotic acid-fed rats where release of lipoproteins from the liver to serum is completely inhibited. A considerable decrease in the association of α-tocopherol with serum very-low-density lipoprotein under this condition is interpreted to mean that serum lipoproteins are limiting factors for the transport of the vitamin across the intestine and that this is possibly effected by exchange of α-tocopherol between serum very-low-density lipoprotein and mucosal lipoprotein

On the occurrence of the black clam, Villorita cyprinoides (Gray)in Pulicat Lake

The black clam villorita cyprinodes belonging to the family corbiculidae is widely distributed in the estuaries of west coast of india

Distribution of seed clams of Meretrix casta (Chemnitz) in Vellar estuary

A survey conducted in Vellar estuary during April and May 1978 on the abundance of the seed of Meretrix casta (Chemnitz) indicated that the densest population occurred in the mid-portion of the estuary. The population was from scarce to absent near river mouth and moderate in the upper reaches. From The environmental characteristics associated with such distribution, it is evident that M. casta prefers a Salinity range of 30 - 32 %„, a depth of so -100 cm and a sandy muddy substratu

Length-weight relationship in Decapterus dayi Wakiya

Length-weight (relationship in Decapterus dayi was worked- out. Comparison of <the regression coefficient b of fish foefomgaittg to different stages of maturity among males and females sthowdd that variations were not significant in the former and sigmficarat only ait S% level in the 'tetter. There was also no difference between males and females but both of them differed significantly from those of iindtetetrminaites. Therefore, a common equation for the males and females (log w = -4.7669 + 2.9886 log 1) and a separate one for imdetermimates (log w = -5.2628 + 3.1691 log 1) were proposed

Feeding biology of the Scad Decapterus dayi Wakiya

Decapterus dayih a pelagic carnivore, feeding on small fishes, fish eggs and larvae, planktonic crustaceans polychaetes and molluscs. Food preference was observed towards Stolephorus spp., Leiognathus spp., Sardinella spp., larval fishes, Acetes spp., Penaeus spp., alima larvae, coipepods and Cresis sp. Small fishes prey mostly upon crustaceans while larger ones are piscivorous. Fishes formed major portion of the diet during different months and times of the day. Feeding was observed to be active in pre and post-monsoon months while it was poor during monsoon. Neither stages of maturity nor time of the day had much influence on feeding. Based on the food preference and feeding behaviour of D. dayi introduction of light fishing in the exploitation of the scad is suggested

Observations on the fishery and biology of Megalaspis cordyla (Linnaeus) at Vizhinjam

The fishery for Megalaspis cordyla (locally called Vangoda) formed on an average 6.63% of the total marine fish landings at Vizhinjam. An increasing trend in the fishery was noticed from 1969 to 1973. Hooks and lines and drift nets contributed to about 95.8% of the catch. Post-monsoon period was the best season for the landings of M. cordyla. Maturity studies indicated that the fish spawned only once a year and the spawning psriod was of prolonged nature, from December to July with intensive spawning during monsoon season. Spawning takes place beyond 5Km fishing belt of Vizhinjam and the probable time of spawning being during night. Both the females and males mature at the minimum size of 250 mm and the size at first maturity being 270 mm. Females were generally found more in the catches. The fish grows to 250 mm in the first year and to 290 mm in second year, 320 mm in the third year and to 330 mm by 40 months. The fishery was composed of 0-year and one-year old fishes, both of them accounting to 90% of the catches, and generally the former being the dominant