Estimates of growth, mortality, recruitment pattern and MSY of important resources from the Maharashtra coast

Based on the data collected from the year 1987-1991 the growth, mortality and recruitment pattern of eighteen species of fish, two species of cephalopods and four species of penaeid prawns have been presented in the present communication. The total mortality coefficient, (Z) varied from lowest of 1.20 for O. cuvieri to a highest of 10.78 for P. stylifera. The natural mortality coefficient, (M) varied from 0.52 for T. thalassinus to 3.44 for S. crassicornis. The average annual yield of eighteen species of fish, four species of prawns and two species of cephalopods are 65.083, 38.404 and 11.373 tons as against the MSY of 83.023, 72.460 and 10.475 tons respectively. The MSY estimated for the total fish stock is 1.77.753 tons whereas the present yield is 1.14.859 tons. This indicates that higher yield can be obtained by increasing the effort.

The modelling of soil plasticity

The modeling of the soil plasticity was discussed and it was shown that the grain breakage is an important factor of the plastic soil behaviour. A reduction of internal coefficient of friction was observed when stress-level was increased. The yield paths of all stress path tests determined by curve fitting were presented.

Seasonal growth of five commercially important fishes at Sofala Bank, Mozambique

An analysis of growth of scad and mackerels on Sofala Bank, Mozambique, was performed using data collected from commercial vessels during the year 1986-87, using the "Compleat Elefan" software package. Updated estimates of growth parameters of Decapterus russelli, D. macrosoma (Carangidae), and Rastrelliger kanagurta (Scombridae) were obtained which take seasonal growth oscillations into account. Preliminary growth parameter estimates are also presented for Selar crumenophthalmus (Carangidae) and Saurida undosquamis (Synodontidae).

Relationship between total length and mouth gap of some commercially important carp fry

The estimated regression equation for total length and mouth gape computed were Log TL = Log 0.23 + 0.663 log MG (vertically) (r = 0.960) and Log TL = Log 0.08 + 0.686 log MG (horizontally) (r = 0.949). In case of rohu average total length from 11350 mm to 23775 mm and mouth gape 805 um to 1225 um (vertically) and 700 um to 1110 um (horizontally) between the first day of mouth opening up to 15 days. The regression equation for total length and mouth gap were Log TL = Log 0.20 + 0.660 log MG (vertically) (r = 0.935) and Log TL = Log 0.02 + 0698 log MG (horizontally) ( r = 0.907). In case of silver carp average total length from 12800 ,urn to 33555 um and mouth gape 690 um to 1210 um (vertically) and 615 um to 1115 um (horizontally) between the first day of mouth opening up to 15 days. The regression equation for total length and mouth gape were Log TL = Log 0.36 + 0.596 log MG (vertically) (r = 0.936) and Log TL = Log 0.26 + 0.607 log MG (horizontally) (r = 0.891). The relationship between total length and mouth gape (vertically and horizontally) of the studied fry were found to be linear and highly significant.

Heavy metals in certain commercially important finfish off Mahim in Mumbai coastal waters

The coastal water of the metropolitan city of Mumbai has deteriorated due to the indiscriminate discharge of untreated sewage and industrial waste in huge quantities. Mahim creek is one such locality surrounded by a large number of industrial units discharging heavy metals. The accumulation of the heavy metals Cu, Cd, Zn and Pb in finfishes (Coilia dussumeri, Lepturacanthus savala, Harpodon nehereus and Johnieops elongates) from this locality along with that in the sediment was studied. The rate of accumulation of Cu was high compared to Cd, Zn and Pb. A gradual increase in the bioaccumulation of heavy metals was noticed in fishes with increase in average body weight and length, perhaps due to biomagnification. A declining trend in concentration of heavy metals horizontally from inshore to offshore was observed in these fishes.

RNAi, DRD1, and histone methylation actively target developmentally important Non-CG DNA methylation in Arabidopsis

Cytosine DNA methylation protects eukaryotic genomes by silencing transposons and harmful DNAs, but also regulates gene expression during normal development. Loss of CG methylation in the Arabidopsis thaliana met1 and ddm1 mutants causes varied and stochastic developmental defects that are often inherited independently of the original met1 or ddm1 mutation. Loss of non-CG methylation in plants with combined mutations in the DRM and CMT3 genes also causes a suite of developmental defects. We show here that the pleiotropic developmental defects of drm1 drm2 cmt3 triple mutant plants are fully recessive, and unlike phenotypes caused by met1 and ddm1, are not inherited independently of the drm and cmt3 mutations. Developmental phenotypes are also reversed when drm1 drm2 cmt3 plants are transformed with DRM2 or CMT3, implying that non-CG DNA methylation is efficiently re-established by sequence-specific signals. We provide evidence that these signals include RNA silencing though the 24-nucleotide short interfering RNA (siRNA) pathway as well as histone H3K9 methylation, both of which converge on the putative chromatin-remodeling protein DRD1. These signals act in at least three partially intersecting pathways that control the locus-specific patterning of non-CG methylation by the DRM2 and CMT3 methyltransferases. Our results suggest that non-CG DNA methylation that is inherited via a network of persistent targeting signals has been co-opted to regulate developmentally important genes. © 2006 Chan et al.

Methionine content of some of the important species of Indian fishes

A very little work is reported on the methionine content of Indian fishes. This work was therefore undertaken to determine the methionine content of some of the important varieties of Indian fishes.

Productivity and seasonal abundance of commercially important fishes of Gobindsagar Reservoir

Fishing experiments with gill nets were carried out at different centres of Gobindsagar reservoir through the years 1964-70. The seasonal abundance of main species of fishes and their zone of distribution were studied. Labeo diplostoma, Labeo bata, Barbus tor and Mystus seenghala are the main fish species of the reservoir. The abundance of the above species were observed to be the highest towards the Lunkhar arm of the reservoir.