Determination of the maturity stages of marine fishes

Determination of the maturity stages of marine fishe

Hydrographic features off northeast coast and Andaman - Nicobar Islands in relation to demersal finfish resources

Temperature varied from 17.6 to 28.5°C, salinity values from 32.12 to 35.21 x 10"" and dissolved oxygen from 0.8 to 4.41 ml/1. No identifiable relationship could be established between these three parameters and the total fish abundance, probably because the catch was made up of many species having different requirements. Higher abundance of trawl catches was from January to May when bottom water temperature was relatively low. The highest level of abundance of 2764 kg/hr in February 1989 was recorded when the parameters were 26°C, 33.6 x 10" and 2.71 ml/1; and the lowest level of 43.2 kg/hr in July 1988 was when the parameters were 25.3°C, 34.48 x 10'^ and 1.6 ml/1

Occurrence and growth of the commercially important red algae in fish culture pond at Mandapam

The red algae Gracilaria edulis, Hypnea valenliae, Acanthophora spicifera ard Sarconema irdica have been observed to occur arrl grow in a culture pard. Ove- a period of eight month s, the algae grew to lJ4 kg in the pard of 800 sq m. The hyd rological cordilions in the porn are compared to those in the sea containing natursl beds of these algae during the periro of observations. This occurrence ard growth may open up the ,,4. possibility of growing these algae in culture pards providing the requisite hyd rological ard nutrient corditions

Demersal finfish resources in certain areas of the EEZ of southwest and southeast coast of India

Bottom trawling data from the cruises of the FORV Sagar Sampada undertaken during 1989-91 in the middle and outer shelf waters of the southern EEZ, at 97 stations within a depth zone of 30 to 130 m, showed catch rates of 3 to 14000 kg/hr. The highest rate of 14 t/hr was recorded at lat. 1 l°N/75° 23.4' E, followed by 5.5t/hr at 8°54'N N/76° 19.6' E off the southwest coast, whereas the abundance was comparatively less off the southeast coast. The average catch rate per hour off the southwest was 724 kg and off the southeast it was 405 kg. The important demersal finfishes available were: threadfin breams (72%), major perches (5%), rays, carangids and goatfish (4% each) off the southwest; and carangids (29%), major perches (23%), rays (19%), threadfin breams (10%) and goatfish (5%) off the southeast. The depth belt of 41-80 m off both the coasts was found to be more productive than deeper regions. The results indicate that the potential yield from the depth zone of 50-100 m off the southwest coast is 2.6 x 10 tonne, which is much higher than the previous estimates of up to 1.5 x 10 tonne. The single largest group (80%) in this zone is threadfin breams, followed by bull's eye, lizard fishes and flatheads

Prawn, fish and molluscan seed resources along the Kerala and Tamilnadu coasts

The study detailed about the occurrence and quantitative abundance of prawn, fish and molluscan seed resources, their spatial, seasonal and diurnal variations, abundance in relation to lunar periodicities, influence of environmental features and pollution on them and areas suitable for brackishwater culture along the Kerala and Tamilnadu coasts

A bibliography of parasites and diseases of marine and freshwater fishes of India

With the increasing demand for fish as human food, aquaculture both in freshwater and salt water is rapidly developing over the world. In the developing countries, fishes are being raised as food. In many countries fish farming is a very important economic activity. The most recent branch, mariculture, has shown advances in raising fishes in brackish, estuarine and bay waters, in which marine, anadromous and catadromous fishes have successfully been grown and maintained

A new species of Peroderma Heller (Lernaeoceriformes: Copepoda) from sardines off the Porto Novo coast, India

Volume: 95Start Page: 473End Page: 47

Experimental Investigation on the Mechanical Properties of Hybrid Composites Made with Banyan and Peepal Fibers

Industries demand a material with better strength and light weight for various applications. Natural composites are fulfilling the needs of industries partially. The purpose of the present research is to develop a new composite material with light weight and better strength. In this research, hybrid composites were fabricated by conventional hand layup method using natural fibers such as banyan and peepal. Totally, four composites were manufactured namely banyan (Epoxy: banyan: 70 wt%: 30 wt %), peepal (Epoxy: peepal: 70 wt%: 30 wt %), BPB (Epoxy: banyan: peepal: 70 wt%: 20 wt%: 10 wt %) and PBP (Epoxy: banyan: peepal: 70 wt%: 10 wt%: 20 wt %). Density and porosity of the composites were determined and the results showed that BPB composite exhibited a least density. Further, all the composites displayed the maximum porosity percentage of 5. Moreover, the mechanical properties like tensile, flexural and impact strengths were tested. The hybrid composite BPB showed 2.7%, 4.9% and 13.5% increase in tensile, flexural and impact strength respectively, compared to PBP composite. Furthermore, water absorption study was conducted and the results revealed that BPB composite absorbed less amount of water (9%) at the immersion time of 12 hours. Hence, it is suggested from the present investigation that the BPB hybrid composite could be a suitable candidate for the industrial applications with better mechanical properties and light weight

Investigations on thermal properties, stress and deformation of Al/SiC metal matrix composite based on finite element method

AlSiC is a metal matrix composite which comprises of aluminium matrix with silicon carbide particles. It is characterized by high thermal conductivity (180-200 W/m K), and its thermal expansion are attuned to match other important materials that finds enormous demand in industrial sectors. Although its application is very common, the physics behind the Al-SiC formation, functionality and behaviors are intricate owing to the temperature gradient of hundreds of degrees, over the volume, occurring on a time scale of a few seconds, involving multiple phases. In this study, various physical, metallurgical and numerical aspects such as equation of continuum for thermal, stress and deformation using finite element (FE) matrix formulation, temperature dependent material properties, are analyzed. Modelling and simulation studies of Al/SiC composites are a preliminary attempt to view this research work from computational point of view