Volume 89, Issue 1
February 1980, pages 1-89
pp 1-8 February 1980
Changes of chemical composition of water due to growth kinetics ofAnabas testudineus and stocking of broods of different species of air-breathing teleosts were studied in two fish ponds at Kalyani Fish Farm over a period of one year. The results indicated significant differences in the mean values of temperature, bicarbonate alkalinity, hardness, specific conductivity, and phosphate content of water as well as organic carbon of the mud samples in the two ponds. The growth curve ofAnabas was not distinctly linked with the variations of pH, free CO2 and dissolved oxygen but was inversely related to the variations of specific conductivity, bicarbonate alkalinity and phosphate content of water. Also, there was a direct functional relationship between nitrite level and growth increment in individual fish.
pp 9-20 February 1980
Nesting material like paper is also shredded, or torn and chewed by the Indian gerbil,Tatera indica indica (Hardwicke). Shredded paper is used in lining the interior of nest-boxes; and in its absence, for making nests at corners of cage. An important component of nest-building activity, shrodding also acts with other behaviour patterns.
pp 21-24 February 1980
The rates of air breathing ofColisa fasciata were recorded at 5°; C interval over a temperature range of 20–40° C. The air breathing rate increased with the temperature. This was attributed to increase in the metabolic rate and the muscular activity (general restlessness), both of which make heavy demands of oxygen. Coupled with these, the decline of oxygen-holding capacity of the water at higher temperatures leave the fish with no option but to increase its dependence on the atmospheric oxygen and hence the rise in the air breathing rate. Increase in the temperature was also characterised by decrease in the time of asphyxiation when the fish was prevented from coming to the surface and gulping the air.
pp 25-28 February 1980
A new species of a septate gregarine,Sphaerocystis odontotermi n.sp. from the gut of the xylophagous termite,Odontotermis sp., is described.
pp 29-38 February 1980
The morphology of giant fibres in the last metasomatic ganglion of the scorpion,Heterometrus fulvipes, was studied by anatomical methods, making use of cobalt chloride back-filling of the 5th metasomatic segmental nerve. The pattern of activation of these giant fibres was examined by electrophysiological methods. The functional organisation of these giant fibres is supposed to bear significance with reference to the neural and muscular activity of the last metasomatic segment and the consequent movement of the stinger, and is thus of survival value to the animal.
pp 39-46 February 1980
The somatic karyotype ofDrosophila jambulina includes three pairs of V-shaped and one pair of rod-like chromosomes in the female, whereas one red is replaced by a J-shaped element in the male. The salivary chromosome complement comprises five long and one extremely short arms radiating out from a chromocentre. The photomap of salivary gland chromosomes has been prepared and the important identifiable landmarks described. From a sample of 130 wild females studied, 79 heterozygous paracentric inversions of 29 types and four deletions of three types have been detected, thus demonstrating that this species is highly polymorphic.
pp 47-52 February 1980
Natural variations existing in the levels of ammonia, urea, succinate dehydrogenase, glutamate dehydrogenase and arginase activities in the liver tissue of three species of genusRana were studied. The variations existing in the levels of these factors are discussed in the light of the habitat preferences exhibited by these three species.
pp 53-67 February 1980
Lactate dehydrogenase isozymes in three species of genusRana demonstrate species specific and tissue specific patterns in their electrophoretic mobility and band pattern. The activity levels of the enzyme, the levels of lactic acid and pyruvic acid and theKm (lactate) suggest that the enzyme in muscle is less efficient as lactate oxidase when compared to that of heart. Heat inactivation studies suggest that the enzyme has some adaptive significance to the habitat preferences of the species.
pp 69-73 February 1980
Heliothis armigera Hubner is a serious pest of sorghum earhead. Studies to determine the rate of multiplication of its population were conducted at 26 ± 1°C temperature and 75% relative humidity. Under a given set of conditions and food supply its population on sorghum earhead increased with an infinitesimal and finite rate. The population multiplied 285·06 times between two successive generations and one generation was completed within 46·71 days. The population on reaching the stable age-distribution comprised approximately 99% of immature stages.
pp 75-83 February 1980
The acute toxicity of five synthetic detergents to two freshwater teleostsChanna punctatus andSaccobranchus fossilis has been worked out. The LC50 values and slope function (S) for one nonionic and four anionic detergents were determined at 24, 48, 72 and 96 hr intervals by graphical interpolation and probit analysis. Side by side regression equations for all exposure time intervals and fiducial limits for LC50 at the 96 hr exposure were calculated. The relative potency of synthetic detergents was in the decreasing order from nonionic to anionic for both the fishes respectively. The relative susceptibility was highest for nonionic than anionic respectively forChanna punctatus in comparison toSaccobranchus fossilis.
pp 85-89 February 1980
Taxonomic account for threeDrosephila species is previded. Of these,D. mediobandes is new to science, whileD. obscuricornis andD. coei are recorded for the first time from India.