Volume 93, Issue 6
October 1984, pages 505-598
pp 505-510 October 1984
BothRhinocoris marginatus andCatamiarus brevipennis perform a sequential pattern of mating. The order of mating events is as follows—arousal—approach—preovulatory riding—embracing—extension of genitalia and connection achievement and postcopulatory acts such as grooming and ejection of spermatophore capsule by the female.
pp 511-516 October 1984
Heteropneustes fossilis were injected 0, 2·5, 5, 10, 20, 40, 60 or 80 mg 17α-methyltestosterone/kg fish. They were fedad libitum on choppedLepidocephalichthys thermalis and reared for 21 days. The steroid acts as an appetite stimulant and consequently both feeding and growth rates increased 2 to 3 times, when given the optimum dosage of 40mg/kg. It also doubles the growth efficiency. 17α-methy!testosterone is recognized as an appetite stimulant and an anabolic steroid.
pp 517-525 October 1984
Conspecific population density stress affects moult production and growth ofMacrobrachium lanchesteri (Palaemonidae) andCaridina weberi (Atyidae). In either species an intermediate density level of 4 and 8 individuals/151 of freshwater respectively, appears to be ideal for growth. While the effects of increased population densities on the physiological processes of food conversion of either species are comparable, intergeneric variations in the regulation of food intake and growth are evident.
pp 527-533 October 1984
sem studies of surface topography ofBucephalopsis karvei Bhalerao, 1937 shows tegumentary papillae, interlocking network of ridges and closely packed, distinct, separate knobs. Body poresviz, mouth with denticles, longitudinal and radiating muscles around the genital and excretory pore have been observed.
pp 535-542 October 1984
Specialized integumentary glands have been observed at certain specific body regions of the common house rat,Rattus rattus. Diverse zones such as eyelid, oral angle, prepuce and circum anal possess hypertrophied skin glands. The histophysiological aspects of these integumentary glands are reported. These specialized sebaceous glands have specific behavioural relevance.
pp 543-547 October 1984
Aspects of histology and histochemistry of injured tissues ofLycopersicon esculentum Mill due to feeding by the mirid,Cyrtopeltis tenuis Reut. based on increased activities of proteins, tannins, peroxidases, polyphenol oxidases and acid phosphatases are discussed.
pp 549-556 October 1984
Successive generations ofRhizopertha dominica were reared on sulpha drugs mixed diets, at varying sulpha drug concentrations. The symbionts from the above treated insects were adversely affected but the drugs failed to eliminate them totally. Heavy mortality as well as loss in multiplication potential of the symbionts occurred when concentrations were increased. There was comparatively higher mortality of symbionts in F2 and F3 generations as compared to F1 generation. The sulpha somids, sulphadiazine and sulphathiozole were more effective than sulphamethaxazole and pentidsulphas. These observations may be useful for eliminating the obligatory symbionts from the host for controlling it biologically.
pp 557-563 October 1984
Effect of phenol at different salinities on the phosphomonoesterases and adenosine triphosphatase activity in the liver, muscle and brain of cichlid fishSarotherodon mossambicus (Peters) is studied. Results indicate a general decrease in the activity of all the three enzymes assayed. The pattern of decrease shows a direct linear relationship with salinity and the toxicity is enhanced as salinity increases. The possible causes for the reduction in the activity of the enzymes are discussed.
pp 565-571 October 1984
Six different cell types were identified in the pituitary gland on the basis of their characteristic arrangement, distribution and staining properties. The lactotrops and thyrotrops were identified in the rostral pars distalis and the corticortrops in the interphase between the neurohypophysis and the rostral pars distalis. The somatotrops and the gonadotropic cells were distinguished in the proximal pars distalis and the melanotrops in the pars intermedia.
pp 573-584 October 1984
Ecology of the zooplankton of Kadinamkulam Backwater, a brackish water lake along the south-west coast of India, has been studied from February 1980-January 1981. Seasonal distribution of the zooplankton followed an uniform pattern throughout the backwater. Zooplankton in the Kadinamkulam Backwater is composed of foraminifers, coelenterates, nematodes, rotifers, chaetognaths, polychaetes, cladocerans, ostracods, amphipods, copepods, decapod larvae, insect larvae, bivalves, tunicates, and fish eggs and larvae. Among these, rotifers, copepods and copepod nauplii are the major components which form the bulk of the zooplankton (nearly 98 %). A distinct regional variation is discernible in the dominance of zooplankton components. Copepods constitute the dominant group near the barmouth and middle portion of the backwater, while rotifers are dominant in the upper reaches, where freshwater influx was relatively high. Factors influencing seasonal variation and distribution have also been discussed.
pp 585-589 October 1984
Brodifacoum, chlorophacinone and coumatetralyl treated pearl millet (Pennisetum typhoides) grains were tested in a desert scrub grassland to evaluate the comparative field efficacy of these three anticoagulant rodenticides. Baits were placed for 10 consecutive days in bait stations in 18 plots of one hectare each in a randomized block design. Per cent reduction in rodent population was calculated by pre and post-treatment active burrow counts, census baiting and live trapping. Results revealed that brodifacoum is significantly more effective than other two anticoagulants. However, analysis of variance revealed significant difference in the estimation of per cent reduction in the rodent population calculated by three methods, the possible reasons for which are also discussed.
pp 591-598 October 1984
A uniform log-normal pattern of frequency distribution of cestodes and nematodes in poikilothermic and homeothermic hosts from Garhwal Himalayan ecosystems by size and weight classes during infection period indicates subtle relationship to the range of variation in the earth’s environment. The frequency of occurrence of the rodent cestodes followed a definite, ordered, mathematical distribution. This conclusion presumably reflects that a number of random processes in the host-parasite interaction are superimposed and the environmental interplay has resulted in the log-normal distribution of parasite species inRattus rattus of high altitude in India.