Volume 88, Issue 5
October 1979, pages 311-383
pp 311-323 October 1979
One of the problems of breeding of endangered species in captivity is inbreeding. An exemplary illustration is the inbreeding in the white tigers of Rewa. Genealogies and other relevant information on white tigers were collected from four Zoological Parks to investigate whether matings between close relatives were responsible for the reduction in litter size and increase in early mortality which has been observed. Inbreeding coefficients were calculated for different types of mating. It was generally found that tigers failed to survive, if their inbreeding coefficient attained a level of 0·4687 or higher. Regression analysis reveals a tendency for the average litter size to decrease and the early mortality rate to increase with an increase in the value of the inbreeding coefficient.
pp 325-327 October 1979
Aquatic oligochaeteAllonais pectinata from an old well at Chittoor is reported as a new record for Andhra Pradesh.
pp 329-337 October 1979
Coelomocytes and haemocytes of 5 local species of earthworms were studied. The structure of different cells is the same in different species. The total and differential account of the haemocytes showed some species specificity.Perionyx excavatus, a species that can be adapted to a wide range of temperature, on acclimation to 8° C cold, did not show any significant change in the total count of cells, but did show some changes in the density of different stages of eleocytes.
pp 339-344 October 1979
The morphometric and meristic characters ofOsteobrama cotio (Ham.) have been studied and the results have been discussed. The change in the relative position of dorsal and pelvic fins at different size groups of this fish has been reported for the first time. Regression of predorsal and prepelvic lengths revealed the origin of dorsal fin in front of pelvic fins below 17·5 mm size groups, whereas in fishes with total length more than 17·5 mm dorsal fin was located behind the pelvic fins. The mathematical relationships of various parameters have been described. The ratios of different body parts with total length and those of head region with head length, have been replaced by percentage values. An attempt has been made to revise the description ofO. cotio (Ham.) for the purpose of identification.
pp 345-351 October 1979
An attempt is made to study the oxygen consumption, CO2 output and the nitrogen excretion of the freshwater mulletRhinomugil corsula. It is found that whereas the O2 consumption, the CO2 output and the respiratory quotient decreased with increase in the duration of exercise, the NH3-N and total-N excretion showed the opposite trend.
pp 353-362 October 1979
Yolk and copper utilisation during embryogenesis of the fresh-water prawnCaridina nilotica var.bengalensis (De Man) have been described. The egg number/brood increased with increase in length as well as volume (L8) of the mother animal. The water content increased from 61·3% (I stage) to 76·4% (III stage) as development proceeded. Fat appeared to be the major source of energy for embryonic metabolism. During development 28·4µg of dry substance were utilised for embryonic metabolism. The pattern of copper absorption followed the trend of salt absorption.
pp 363-365 October 1979
Acid phosphatase activity has been studied in hepatopancreas and foot tissues of the Indian apple snail,Pila globosa (Swainson), with reference to aestivation and starvation. The enzyme activity in the tissues of control snails is higher in hepatopancreas, than in foot. The activity of acid phosphatase increased in hepatopancreas and decreased in foot during starvation while it decreased in both the tissues during aestivation. The significance of these findings is discussed.
pp 367-375 October 1979
A mixed diet of cereals and pulses was used in cooked and uncooked forms for growth studies with young albino rats. The feeding responses and gain in weight were compared with a commercial rat food containing 24% protein. There were no significant differences in the growth patterns among the three diets. The growing rats consumed 8·5 to 9 g/100 g body weight per day which decreased after the tenth week. The feeding patterns of adult albino rats of both sexes were similar for both cooked and uncooked basal diets. The basal diet seems to be best suited for the albino rats. Since cooking did not enhance either palatability or the diet consumption, dry diets are suggested for rat feeding. Dry basal diet is also recommended to evaluate sub-acute and chronic toxicity of all pesticides particularly those which are thermolabile.
pp 377-383 October 1979
Geotactic responses of male freshwater field crab,Oziotelphusa senex senex have been studied with reference to salinity adaptation. The crabs exhibited a stereotyped walking behaviour. The pairsL2R3,L3R2,L4R1 andL1P4 comprising left and right walking legs were used for the movement in reciprocating fashion. The weight of the crab influenced the orientation angle significantly. Blinding of the eyes did not affect the orientation. Irrespective of the inclination angle, the salinity adaptation reduced the walking rates. All these results have been discussed in terms of the greater scope and potential for escape, available in salinity adapted individuals.