Observations on the durability of fifteen species of CCA treated timber in the Cochin harbour

Observations on the durability of fifteen species of common Indian timber treated with CCA at two absorption levels, for eight years are presented. CCA treatment has improved the durability of this timber to a great extent. T. grandis, D. indicus and X. xylocarpa give maximum durability on treatment with CCA. Less durable A. kurzi, T. nudiflora and P. longifolia when treated with CCA showed results comparable to the best species.

Observations on the ingression and distribution of larval prawns in the Nethravati-Gurupur estuary, Mangalore

The spatial and temporal distributions of larval prawns of penaeids and non-penaeids in the estuarine waters of Mangalore were studied. Larvae appear to be passively brought in by the incoming flood tides to the estuary, enjoy a wider distribution throughout the estuarine complex with abundance towards the mouth. The distribution of larval prawns was more in Nethravati than in the Gurupur stretch. The influence of temperature, hydrogen-ion-concentration, salinity and dissolved oxygen on the distribution of larvae in the estuaries is discussed. Inference on spawning seasons of commercially important prawns in the neighbouring waters has been arrived at based on their larval abundance.

Observations on the fish and prawn seed resources of the Gulf of Kutch and their utilization in aquaculture

The characteristics of the fish and prawn seed resources of the Gulf of Kutch are described. Results of experiments conducted in a primary low saline reservoir of a solar salt works to study their utility for aquaculture are reported. The prospective role of aquaculture in augmenting fish production along the coast is also discussed.

Observations on the artificial fertilization of eggs and larval rearing of the grey mullet, Mugil cephalus L.

The results are presented of attempts to artificially fertilize Mugil cephalus eggs in the Philippines. Embryonic development is outlined and rearing of the larvae described. Mass mortality occurred during week 3 of rearing.

Some observations on the growth and cyst production characteristics of the brine shrimp Artemia sp. (Gujarat strain) in pond culture and its potential for import substitution

Experimental culture of the brine shrimp Artemia sp. (Gujarat strain) and production of cyst is discussed. The qualitative and quantitative aspects of the cyst and its economic potential for import substitution are highlighted.

Observations on the taxonomy and biology of Lates (Cuvier 1828) in Lake Albert

Both in terms of commercial landings and biological importance, the Nile Perch is one of the most prominent fish in Lake Albert. It can bear considerable further exploitation, is the source of stockings elsewhere, and it is, therefore, important to know whether more than one species is being dealt with, and, if so, what differences there are in the ecology of the different species.

Observations on the influences of codend mesh size on bottom trawl catches in Lake Victoria, with emphasis on the Haplochromis population

Codends of four different mesh size" were compared during exploratory bottom trawling on Lake Victoria. Small mesh sizes (19 and 38 mm) generally caught greater quantities of fish than large mesh sizes (64 and 76 mm) with haplochromis species responsible for the difference. The differences in catch rates were most pronounced where dense concentration of small haplochromis were found. This was generally in shallow water since the average size of haplochromis tends to increase with depth. Catch rates for species other than haplochromis were fairly similar for the codends tested, although there were indications of lower catches in small mesh coderlds fished through dense haplochromis concentrations. For haplochromis fished with 64 and 38 mm eodends, the estimated 50% retention lengths were 13.6 and 8.0 cm, respectively. The predicted value for the 19 mm codend was 4.5 cm.