Toxic effects of dietary seaweeds Sargassum bovianum, Caulera faridii and Gracilaria corticata on blood parameters of albino rats

The present communication deals with the feeding trials of brown (Sargassum bovianum), green (Caulerpa faridii) and red (Gracilaria corticola) seaweeds in albino rats for a period of thirty days in order to investigate their digestibility and acceptability as supplementary food for animals. The parameters used were: changes in blood hemoglobin, ESR, MCHC, PCV and plasma vitamin levels. The result revealed that all the three species of seaweeds had acceptability up to 5% level, as no ill effect was noted during the experiment. But at 10% and 20% levels, marked changes were observed in blood parameters with diarrhea, vomiting and convulsions indicating possibilities of either tissue and muscular dystrophy, gastrointestinal tract necrosis or functional disorder of central nervous system. A heavy mortality was noted due to excessive water loss through diarrhea and vomiting. However, no mortality was observed after 22nd day at both 10% and 20% levels with subsided clinical signs. The results suggest that these three seaweed species could be used safely as a supplementary food, in native form, in animals at low concentrations.

A preliminary account and review of the simple methods for determining the operational parameters of fishing gear, underwater, with notes on its application

An account and review of the simple methods for determining the operational parameters of fishing gear, underwater, such a tilt of otter boards (outwards or inwards, forwards or afterwards), vertical height of net, its horizontal spread, angle of divergence at bosom, spread between wing tips, angle of inclination of danlenos, butterfly, slope of legs and sweep-line has been given. The relationship of distance between the otter boards spread and the vertical height of net has been obtained as generally linear. The possibilities of regulating the vertical height of net (dependent variate) and spread of otter boards (independent variate) for increasing the fishing efficiency has been discussed. The angle of attack of oval shaped otter boards used during the operations still remain undetermined, however, it has been explained how the best angle of attack for increasing the efficiency of gear can be obtained by regulating the ratio of depth to warp for a given net. The inadequacy of the mere indices of catch per hour of trawling in comparing the relative efficiency of trawls in gear research studies has been indicated. The importance of estimating the operational parameters and its application to commercial fisheries depending upon the distribution pattern of fish and in gear research has been discussed. The efficiency of the jelly bottle method has been compared statistically with the observations made on the trawl gear underwater with instruments.

Effects of different types of drying on the nutritive value of proteins in the fishmeals

A comparative study on the effect of different types of drying on the nutritive value of the proteins in the different fishmeals of known history was made. From the observations, it is clear that the mode of drying has got little or no effect on the nutritive value of the meal as revealed by the chemical indices of available lysine and pepsin digestibility, provided enough precautions were taken to avoid scorching during drying process. Sun dried meals are in no way inferior to the meals prepared by hot-air, steam or vacuum drying.

An accelerated method of hot air drying of fish

The effects of temperature and relative humidity on the rate of drying of split open fish and salted fish in a tunnel dryer have been studied at a constant air velocity. By a judicious combination of these two, the rate of drying could be considerably accelerated, 10 to 12 hours only being required for drying to moisture levels below 30% in the case of mackerel, lactarius, otolithes and kilimeen (Nemipterus japonicus)

Environmental parameters and incidence of white spot disease in Penaeus monodon (Fab.) farming

An investigation was carried out to monitor management practices and to find out whether there is any relationship with occurrence of deadly white spot disease and environmental parameters. Three semi-intensive and a improved traditional shrimp farms were selected in which mass mortality of shrimp (Penaeus monodon) by white spot disease occurred previously. The farms were situated at two different geographical locations. Two ponds from each farm at random were selected for the study. Out of eight investigated ponds, 6 ponds in three farms were affected by the disease during investigation period. The non-affected ponds had relatively lower stocking density, lightly different management practice and were located at different geographical area. There was no significant variation in water quality parameters among the affected and non-affected ponds. No significant variations were recorded in pond preparation, source of Post Larvae (PL), water and feed management among the affected and non-affected ponds. The observation indicated that pond micro-organisms in a farm may not the only cause of the disease but some external factors also might be responsible for the outbreak of this disease.

Toxicity of copper sulphate on some haematological parameters of a freshwater teleost Cyprinus carpio var. communis

Haematological changes in a freshwater teleost, Cyprinus carpio var. communis, exposed to acute and sublethal toxicity of copper sulphate were studied. During the acute treatment, erythrocyte and leucocyte count, and haemoglobin content increased, whereas during the sublethal treatment, erythrocyte count and haemoglobin content decreased and leucocyte count increased.

Growth parameters of Lepturacanthus savala (Cuvier, 1829) from Mumbai waters

Lepturacanthus savala (Cuvier, 1829) constitutes a minor fishery contributing 23.3% to the total ribbonfish catch in Maharashtra. Based on the length data obtained from shrimp trawlers and the traditionally operated bag nets, age and growth of the species have been investigated from Mumbai waters. Growth was studied by various computer-based methods incorporated in FiSAT Programme. The growth parameters L∞ and K (on annual basis) by Gulland-Holt plot were 683.3 mm and 0.87, respectively. As the seasonal temperature variations in coastal waters of Mumbai are not pronounced, the seasonally oscillating growth patterns by ELEFAN and Appledoorn's method were not considered. Following the von Bertalanffy growth model, the fish attains 399.8, 567.2 and 637.4 mm at the end of 1, 2 and 3 years, respectively, and the lifespan of the fish is about 3.3 years.

Temperature dependences of oscillation parameters in ferroelectric liquid crystals

Oscillation processes have been revealed in the course of reversible polarization study in ferroelectric liquid crystals. The oscillation frequency of polarization vector has been found to be from 1 to 30 kHz. The oscillation parameters were studied as functions of temperature. Temperature dependences of the oscillation amplitude and damping decrement have been measured.

A revision of growth parameters of some commercially exploited fishes from Mozambique

Data on age and growth of the following species were reviewed and von Bertalanffy's growth curves were fitted: Hilsa kelee, Decapterus russellii, D. macrosoma, Rastrelliger kanagurta, Pellona ditchela, Thryssa vitrirostris and Leiognathus equulus. For the five first species, microstructures in the otoliths were used for ageing. For most species growth curves based on size-frequency distributions are also presented. The reliability of the data presented is discussed.

A procedure for automatically estimating model parameters in optical motion capture

Model-based optical motion capture systems require knowledge of the position of the markers relative to the underlying skeleton, the lengths of the skeleton's limbs, and which limb each marker is attached to. These model parameters are typically assumed and entered into the system manually, although techniques exist for calculating some of them, such as the position of the markers relative to the skeleton's joints. We present a fully automatic procedure for determining these model parameters. It tracks the 2D positions of the markers on the cameras' image planes and determines which markers lie on each limb before calculating the position of the underlying skeleton. The only assumption is that the skeleton consists of rigid limbs connected with ball joints. The proposed system is demonstrated on a number of real data examples and is shown to calculate good estimates of the model parameters in each. © 2004 Elsevier B.V. All rights reserved.

Water quality parameters of coastal shrimp farms from southwest and southeast regions of Bangladesh

The impacts of shrimp farming on water quality and effluent loading of shrimp farms in southwest (Khulna) and southeast (Cox's Bazar) regions of Bangladesh was investigated during March-August and August-October season, respectively. Water salinity fluctuated from 3.0 to 15.0 ppt in the southwest, whereas it was between 2.5 to 20.0 ppt. in southeast region. Total ammonia nitrogen as recorded in most farms of Cox's Bazar region was higher (0. 1160.438 mg/L) than the recommended level of shrimp farming. Mean values of total ammonia nitrogen and total nitrogen at the outlet of shrimp farms were higher than those of inlet in both regions. Mean values of phosphate phosphorus and total phosphorus at outlet were lower than inlet except in harvest time of Penaeus monodon. Total suspended solids were deposited on the bottom of shrimp farms in both regions, which resulted in higher concentration in inlets than outlets in both regions.

Observation on some of the environmental parameters of selected shrimp farms in Khulna, Bangladesh

In recent years, the ecological degradation, loss of technological sustenance and other multidimensional consequences caused by shrimp farming have made the experts and authorities bound to rethink about the development of the industry. The present study describes the water and sediment quality, and culture and management techniques in five selected shrimp farms at Paikgacha, Khulna throughout a production cycle from March to September 1997. The water quality parameters were found to be more or less suitable throughout the cycle. The concentration of the limiting major nutrients such as nitrogen and phosphorus and minor nutrients such as calcium and magnesium were satisfactorily high, concentrations of the organic matter content were also high. Remarkable negative correlation of shrimp production with secchi depth was observed among the farms. Production per cycle ranged between 273 kg/ha and as low as 63 kg/ha.