Bibliography: Diseases, Parasites and Toxicology of Perna viridis,Crassostrea madrasensis and Villorita cyprinoids (Mollusca: Pelecypoda) of India

A proper understanding of the hazards associated with the fishery products on national basis has been the primary objective of the AP Cess Funded National Network Project on National Risk Assessment Programme for Fish and Fish Products for Domestic and International Markets. In this connection, the bibliography is prepared with the sole aim to compile all the available literature on this subject to produce a ready source of reference material for future investigators. In spite of the meticulous task and completeness, the authors express their regrets for any errors or omissions

Filtration in some tropical intertidal bivalves exposed to mercury and cadmium mixtures

Three species of intertidal filter feeding bivalves (Modiolus carvalhoi, Modiolus sp. and Donax spiculum) exposed to mercury and cadmium filtered significantly less volume of water under individual metal and metal mixture stress. Mercury and cadmium in mixtures interacted additively and more than additively (Synergism) in depressing the filtration rate of the bivalves

Hydrography of fishing grounds of Arabian sea off Mangalore

Hydrographical parameters, namely temperature, salinity, dissolved oxygen and density of the fishing grounds off Mangalore extending over an area of ca 850 km² have been studied during March 1976 - March 1977. Twelve stations along three transects up to 50 m isobaths were located for sampling. The vertical distribution of temperature show three distinct phases, namely, a period of conspicuous variation, a short intermediary phase and a period of thermal stability. The dissolved oxygen of the bottom waters was drastically low during September. Salinity fluctuations were not considerable between months and depths. Dense waters existed over the shelf region, especially along the bottom during september and to a certain extent in october also. The distribution patterns of temperature, dissolved oxygen and density clearly indicate the movement of cold, dense, oxygen-poor- bottom waters from greater depths to the upper reaches of the shelf during September

Preservation of Indian oil sardine (Sardinella longiceps) in iced and chilled seawater. Part 2 - Changes during storage with particular reference to salt penetration and lipid deterioration during CSW holding

Oil sardines in prime condition were chilled on board. Two lots were chilled in CSW (samples C & CI), one lot ice (sample I) and a fourth lot was left un-iced on deck (sample AI). Sample AI was iced after landing and sample CI was taken out of the chilled seawater and. iced. All the four samples were kept in a chilled room for storage studies. Sample C, chilled and stored in CSW, recorded a gradual gain in weight and an increase in salt content of the muscle. Presence of salt did not seem to cause any excessive protein denaturation. Salt extractability decreased at a gradual rate in all cases. Presence of salt seemed to wield no noticeable influence on lipid hydrolysis and subsequent peroxidation. Results of chemical and sensory evaluations highlight this. Holding sardines in CSW gave a product of excellent quality for the first four to five days of storage. Beyond the fifth day of storage quality deteriorated rapidly and there was no noticeable superiority for this sample (sample C) over the on board iced fish. This was evident in the sensory evaluation as well. However, a storage life of five days in a readily acceptable state is sufficient for the fish to be disposed in the market at a premium sale price over other landings of the same species

Mercury toxicity in two intertidal tropical marine molluscs

Lethal and sub-lethal effects of mercury have been studied in Perna viridis and Modiolus carvalhoi. For P. viridis LC30 is 1.0 p.p.m. at 48 h and 0.23 p.p.m. at 96 h. Recorded LC50 values for M. carvalhoi are 0.5 p.p.m. and 0.19 p.p.m. at 48 h and 96 h respectively. The results document that these two species, although inhabiting the same area in the tidal belt, exhibit clear differences in mercury resistance. It is further shown that the duration of exposure affects mortality rates. In sub-lethal concentration, between 0.01 and 0.10 p.p.m. decrease in pedal-gland activity is conspicuous in P. viridis. At concentrations much below LC50 values (at 96 h), although some animals are alive, pedal-gland activity is totally suspended, supporting the assumption that shell closure ability plays a minor role in byssus thread production. In M. carvalhoi total cessation of pedal gland activity occurred at 0.09 p.p.m. of mercury

Standing stock of three species of demersal fishes from southwest coast of India

Standing stock of three principal demersal fishes of the inshore waters off Mangalore was assessed. The assessment was based on fortnightly samplings conducted in an area extending over ca 850 km². The data gathered was computed employing Alverson's methods. The standing stock of Nemipterus japonicus, Saurida tumbil and Grammoplites scaber indicates that this area supports good quantities of these fishes and if properly exploited, will sustain a profitable demersal fishery

Effect of sublethal copper on growth efficiency of the shrimp Metapenaeus dobsoni (Miere)

In this investigation, an attempt is made to elucidate the effect of copper sublethal concentrations, on the energy conversion and growth efficiency of a commercially important Penaeid shrimp Metapenaeus dobsoni (Miere

Acute toxicity of cadmium to six intertidal invertebrates

Following a static bioassay techniques the acute toxicity of cadmium to six species of intertidal invertebrates was determined. The sensitivity of the animals to cadmium was of the following order: Emerita sp. (burrowing crustacean) Donax spiculum (burrowing bivalve) Perna viridis (sedentary bivalve) Sabellaria clandestinus (tube-dwelling polychaete) Modiolus carvalhoi and Modiolus sp. (sedentary bivalves). The above observation was based on the median lethal concentrations recorded for the different species, Emerita sp. 1.35 p.p.m., Donax spiculum 1.8 p.p.m., Perna viridis 2.5 p.p.m., Sabellaria clandestinus 2.8 p.p.m., Modiolus carvalhoi 5.6 p.p.m. and Modiolus sp. 9.6 p.p.m. The findings throw insight into the toxicity of cadmium to the common intertidal animals which are either suspension or detritus feeders

Metabolism in the baby clam Marcia opima

Oxygen consumption and ammonia excretion in different size groups of clam, Marcia opima collected from Tuticorin Bay in Tamil Nadu was studied. Oxygen: Nitrogen ratio was calculated by using atomic equivalents and ranged between 133 - 175 for small, 97 – 117.2 for medium and 63.5 – 75.8 for large clams on day one. After day 3, the range was 238.4 – 282.1, 160.9 – 189 and 100 - 137.5 respectively. During starvation, a decline in excretion rate has been observed, which can be proposed as an index of stress. The study supports interaction of oxygen consumption and nitrogen excretion, which can provide a better understanding of the oxidative and nitrogen metabolism in the clam

Preservation of Sardinella longiceps in iced and chilled seawater. Part 1 - Changes during storage with particular reference to bacterial load and nitrogenous compounds

Oil sardines in prime condition were subjected to onboard chilling. Two lots were chilled in CSW (samples C and CI), a third lot was chilled in crushed ice (sample I) and a fourth lot left not iced on deck (Sample AI). Upon landing sample AI was iced and sample CI was removed from the CSW and iced. All the four samples were kept in a chilled room for storage studies. The fish chilled and stored in CSW recorded the least, and the fish subjected to delayed icing, the highest values for all the indices of spoilage namely, free amino nitrogen, trimethylamine (TMA) and total volatile base nitrogen (TVBN). The total psychrophilic bacterial number also showed a similar trend. The organoleptic assessment of the cooked samples revealed C I, CI, AI to be the order of preference throughout the storage. This assessment was found to hold good for the rest of the parameters as well. The CSW held fishes were found to be distinctly superior to the iced ones for the first five days of storage. Such a marked prevalence in quality for five days would suffice for the fish to fetch a premium in the market over other landings of the same fish whether chilled or not chilled. Chilling on board in CSW and icing the same after landings, did not show encouraging results