Penaeus semisulcatus: A potential species for commercial culture along Tamilnadu coast

Major portion of the marine export products By value wise, is being contributed by shrimps. Three fourth of exported shrimps is from sea and The rest from culture. Since the exploitation of Shrimps has already reached optimum level in Indian coastal waters, one alternative is to Increase shrimp entering shrimp culture for Quick and high returns. Farming technology for P.monodonand P.indicus has been considerably developed than that for the other species of Indiancoast. Prime species that are cultured successfullyat present in India are P.monodon . andP.indicus in the order of trade preference. But in Japanese market P.semisulcatus, a Striped shrimp is fetching higher price than P.indicus. Information on grow-out practices of P.semisulcatusis scanty. Experimental-scale cuRurehas been attempted in Kuwait, Israel, Bahrain,Taiwan, and Malaysia

Differential effects of cholesterol and 7-dehydrocholesterol on ligand binding of solubilized hippocampal serotonin<SUB>1A</SUB> receptors: implications in SLOS

The serotonin1A receptor is an important member of the G-protein coupled receptor family, and is involved in the generation and modulation of a variety of cognitive, behavioral, and developmental functions. Solubilization of the hippocampal serotonin1A receptor by 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS) is accompanied by loss of membrane cholesterol which results in a reduction in specific agonist binding activity. Replenishment of cholesterol to solubilized membranes restores the cholesterol content of the membrane and significantly enhances specific agonist binding activity. In order to test the stringency of the requirement of cholesterol in this process, we solubilized native hippocampal membranes followed by replenishment with 7-dehydrocholesterol (7-DHC). 7-DHC is an immediate biosynthetic precursor of cholesterol differing only in a double bond at the 7th position in its sterol ring. Our results show, for the first time, that replenishment of solubilized hippocampal membranes with 7-DHC does not restore ligand binding activity of the serotonin1A receptor, in spite of recovery of the overall membrane order. This observation shows that the requirement for restoration of ligand binding activity is more stringent than the requirement for the recovery of overall membrane order. These novel results have potential implications in understanding the interaction of membrane sterols with this important neuronal receptor under pathogenic conditions such as the Smith-Lemli-Opitz syndrome

Larval rearing of mud crab, Scylla tranquebarica (Fabricius, 1798) and feeding requirements of its zoea

Feeding experiments were conducted with zooplankton to find out the suitable food for zoea1 of the mud crab Scylla tranquebarica. Zoeae1 from seven berried females, three from wild and four from rematured specimens were the source material for the present study. The veliger larvae (50-55μm) of pearl oyster and two species (Pseudodiaptomus spp. and Labidocera spp.) of pelagic copepods (500-1000 μm) were tested as feed. However, the zoea1 accepted only the former. The feeding activity could be resolved into 5 stages. Significant role of the serrated caudal setae in prey abrasion into required size suitable to mandibles for mastication and the size preference of the items of diet in relation to the growth of the mandibles with the advancement of zoeal stage also have been discussed. In all the 7 feeding experiments that were conducted by providing rotifer, Brachionus rotundiformis (<100 μm), the zoea1 advanced to zoea3/zoea4 or the first crab stage. The present study is a significant development in narrating the feeding behaviour of zoea1

Observations on the growth of Penaeus semisulcatus in the nursery ponds

Hatchery produced postlarvae (PL 40) of green tiger prawn Penaeus semisulcatus were stocked in three earthen ponds at a rate of 40,0001ha in one (400 sq.m) and 50,00O/ha, in two ponds (800 sq. m) in November 1993 and reared for 110 days. During February-March water level and salinity in the ponds were raised by pumping water (25% salinity) from adjacent lagoon. Pond water was fertilised with urea and Ammonium phosphate at a rate of 50 kgha and 100 kgha respectively, 15 days before stocking. Shrimps were fed with commercial pellet feed. The survival was 51.9%, 15.0% and 65.8% in pond I, I1 and 111 respectively. The length and weight increment was 68.42 mm and 7.95 g in pond I; 65.78 mm and 8.25 g in pond 11; and 53.14 mm and 4.85 g in pond 111. Difference in growth between sexes was statistically significant in all three ponds on day 110. Growth in pond III was poor as compared to other two ponds due to prevalence of low salinity (~12%) for a period of 48 days

Tagging experiments on searanched Penaeus indicus in the Palk Bay, southeast coast of India

An attempt has been made to study the suitability of hatchery raised and farm grown Penaeus indicus for searanching, and to study the growth and movement of ranched population in the Palk Bay and the Gulf of Mannar. The eggs released by a spawner without eyestalk ablation were raised upto juveniles through rearing in the hatchery, nursery cement tanks and in earthern ponds. The hatching rate and subsequent survival rate from nauplius-1 to PL-1 was 92.3 and 53.0 % respectively. Survival from PL-1 to PL-21 was 49.5 %. The seeds thus raised were stocked in two coastal earthern ponds at a rate of 50,000/ha and fed with pellet diet daily at the rate of 5-10 % of biomass. After 111 days, retrieval was 41.45 % in pond I and 75 % in pond II. The growth was from 22.95 mm TL to. 111.7 mm TL/10.1 g wt. in pond I and 103.06 mm TIV 8.1 g wt. in pond II. These juvenile prawns were tagged with loop tags and released in the Palk Bay off Mandapam at 3 m depth. Recovery started from the subsequent day onwards in the trawl catches of Palk Bay and Gulf of Mannar and continued upto 28 days. Of the 3,430 prawns released, only 19 were recovered accounting for <1 % recapture. Distribution and movement of tagged prawns and the prospects of searanching of P. indicus have been discussed

Prawn fauna (Crustacea: Decapoda) of India - An annotated checklist of the Penaeoid, Sergestoid, Stenopodid and Caridean prawns

Twenty four species of Pandalid shrimps reported from the Indian waters, of which six genera (Chlorotocella, Chlorotocus, Chlorocurtis, Dorodotes, Heterocarpoides and Stylopandalus) are represented by single species each. The genera, Plesionika and Heterocarpus are represented by eleven and seven species respectively. Plesionika adensameri (Balss, 1914) a deep-sea shrimp hitherto unreported from Indian waters is recorded from west coast of India. Information on some biological aspects of few Pandalid shrimps from Indian waters is also reported in the present paper