Volume 91, Issue 3
May 1982, pages 207-348
pp 207-215 May 1982
A selected literature dealing with the relationship between vertebrate structures and functions has been reviewed. Published literature in this field generally relates to three approaches: evolutionary, ontogenetic and holistic. This paper explains the salient features of these approaches and how their findings can be verified experimentally. Evolutionary approach can only make use of theoretical explanation, whereas, in both ontogenetic and holistic approaches experimentation is possible.
pp 217-223 May 1982
Oxygen consumption, carbon dioxide production and NH3-N excretion increased with increase in random (spontaneous) activity inTilapia mossambica in air-saturated water in tests at 30 and 35° C. The random activity change did not affect the RQ which remained near unity at adequate ambient oxygen. But, the AQ decreased with increase in activity at both 30 and 35° C, suggesting that increased protein utilization in quieter fish when adequate ambient oxygen is available. The routine and standard metabolic rates at 35° C are slightly higher than at 30° C, but, in general, the overall metabolic rates and quotients are significantly in close proximity, suggesting that the temperature range (30–35° C) does not seem to cause a marked metabolic difference inTilapia mossambica.
pp 225-234 May 1982
Microanatomical studies on the 7th abdominal ganglion of the scorpion were carried out by histological methods. The ganglion revealed a total of approximately 2000 nuclei, most of them belonging to medium-sized cells. The connective and peripheral nerves revealed fibres of varying number in each, with fibres of 3 μm contributing largely to the total content. The fibres included the axons of motor, sensory and interneurons.
pp 235-241 May 1982
Freshwater fishTilapia mossambica (Peters) were exposed to sublethal alkaline water (pH 9·0) and the branchial protein metabolism was studied on acute exposure and acclimation. Branchial tissue had elevated structural and soluble protein fractions on acclimation which was correlated towards the gill hypertrophy. Proteolytic activity of the tissue was elevated on both acute exposure and acclimation. A/O ratio which forms a measure of ammonia formed per unit O2 consumption was lesser on acclimation and hence mobilization of tissue free ammonia towards glutamine formation was suggested. The metabolic modulations have been correlated towards the positive survival value of the fish in alkaline waters.
pp 243-247 May 1982
Correlated studies on the influence of temperature in the frequency of inversions in theD. ananassae population of Golabandha shows that temperature fluctuation has a positive bearing on 2LA inversion while negatively so with respect to 3LA and 3RA inversions.
pp 249-257 May 1982
The present paper deals with the life and fecundity tables for the cerambycid borer,Olenecamptus bilobus (Fabricius). Under a given set of conditions and food supply, the population of this species increased with an infinitesimal and a finite rate. The population increased by 20·41 times between two successive generations and 86·42 days were taken to complete one generation. The adults constituted only 1·29% to the population of the stable age, while eggs, larvae, pupae and dormant adults contributed to the extent of 24·95, 68·22, 4·38 and 1·16% respectively.
pp 259-265 May 1982
Behavioural responses of the Indian gerbil,Tatera indica, to conspecific sebum odour of the male ventral marking scent gland were studied in a glass cage and a plus maze. Male and female gerbils were attracted towards the strange male sebum odour though its magnitude was low in females possessing the ventral marking gland, still lower in the females in which the marking gland was absent. The diversity in preferential behaviour of femaleTatera indica is discussed in relation to the role of ventral marking behaviour in chemical communication among rodents. Correlating the results of the experiments with our field observations, it appears that the function of scent marking inT. indica is more of a ‘familiarisation’ nature to label the habitat for its own use in orientation or to signal ‘home’ to the marking animal.
pp 267-273 May 1982
The effect of temperature and humidity onAcrida exaltata Walk. has been studied to have two aspects in relation to (i) its effect on hopper development and (ii) its effects on the fertility-fecundity. The rate of development was affected by the moisture present in the environment. No development took place at 0%, 10% and 20% RH. Most desirable range of humidity was between 50–70% RH. Development took place at 20°, 30°, 35° and 40° C in 92·8, 74·8, 71·8 and 66·6 days in males and 101·0, 86·4, 85·6 and 75·2 days in females. Percentage of hoppers reaching the adult stage, longevity of adults, average number of copulation and average number of eggpods per female was influenced by the temperature.
pp 275-282 May 1982
Coeuritrema sutlejensis Mehrotra, 1973 andC. sheilae arc described in detail and their validity is discussed. A key to the species ofCoeuritrema is provided and a few of the diagnostic features of the genus are emended.C. lyssimus Mehra, 1933 is recorded from a new locality and some variations from the original description are mentioned.
pp 283-295 May 1982
The embryonic development of the cyst nematode,Heterodera oryzicola and its emergence from egg misses was completed within 8 to 9 days. The emerged second stage juveniles were attracted to roots of rice within 24 hr and penetrated the roots within 24 hr. After penetration, the endoparasitic juveniles developed into males within 14 days and white females within 20 days. Orientation of females was equal towards hypocotyl (42%) and root tip (48%) while a few (10%) matured vertically in thin secondary roots or small rootlets. The sex-ratio between males and females was about 1:4. The virgin females secreted a strong male attractant and the males migrated towards the females in response to this stimulus and mated with the females. The eggs were laid in gelatinous matrix secreted by the females within 22 days and the females turned into brown cysts by 24 days. A singleH. oryzicola female laid on an average 198 eggs in an egg mass and retained 120 eggs within the body of the brown cyst. None of the females was left unmated and all of them laid a single egg mass each within 30 days. One life cycle was completed in 30 days and 12 generations occurred in a year.
pp 297-303 May 1982
Based on the collections of benthic ostracodes during January-December 1977 from two selected marginal water bodies, namely Bimili backwater and Balacheruvu tidal stream on the east coast of India, the quantitative variations in the ostracode fauna have been studied in relation to the sedimentological characteristics like sand, silt and clay and organic matter content.
pp 305-315 May 1982
Neurosecretory cells occur in groups, medially, dorsally, dorsolaterally, laterally and midventrally, in the protocerebrum and tritocerebrum of adultPoekilocerus pictus. Mid-brain is devoid of such cells. On the basis of staining reactions the NS cells have been differentiated into A and B types. The median group consists of about 50–55 A and 30 B cells lying on either side of the midline in the parsintercerebralis. The other parts of the protocerebrum and tritocerebrum are filled with only B cells. Scant NSM is found in the NS cells of freshly moulted adult. Synthetic activity increases with age and after about 5 or 6 days the cells contain deep staining secretory vesicles.
Treatment of 1–6 day oldP. pictus with DDT for different periods showed that short incubation of 24 hr triggers the synthetic activity of NS cells, but prolonged incubation of 72 hr leads to a total depletion of NSM and to disruptive changes, like undulation of cell wall, cell shrinkage and ultimate cellular disruption.
pp 317-322 May 1982
Non-aggressive social behaviour rhythms ofBandicota bengalensis were studied in the laboratory. The species exhibited 95% rhythmicity for social behaviour but the rhythms were uni- or bimodal and were influenced by the number and sex of interacting conspecifics. Peaks occurred at 0900 and 1800 hr. Males were more socially active than females.
pp 323-328 May 1982
Bioassay studies reveal the toxicity levels of pesticides utilised in the area to the larvivorous fishesAplocheilus lineatus andMacropodus cupanus. The resistance of both fishes decreases with increase in period of exposure to the pesticides. Comparing the major groups of synthetic organic pesticides, the chlorinated hydrocarbons, here exemplified by DDT, are more toxic to the fishes than ekalux and malathion, the organophosphates experimented with. The carbamate sevin is the least toxic. Nevertheless, all the pesticides are ‘toxic’ to ‘very toxic’ as defined by the Joint ICMO/FAO/UNESCO/WHO group of experts, having an acute lethal threshold of below 1 to 100 mg/l.M. cupanus is the more resistant of the two fishes, probably on account of its obligate air-breathing nature, and thus its tendency to absorb less toxicant across the gills. Contrasting the susceptibility of mosquito larvae and the fishes studied to the pesticides investigated, the closeness of the LC50 values obtained inA. lineatus to that recorded in certain species of mosquito larvae indicates that whileM. cupanus could be employed in conjunction with pesticides for anti-larval work,A. lineatus should not be so utilised.
pp 329-335 May 1982
Non-specific esterases were studied in the epididymis of the bat,C. sphinx sphinx by employing α-naphthyl acetate and 5-bromoindoxyl acetate as substrates and eserine sulphate (10−4 M) as an enzyme inhibitor. The enzyme activity in epididymal cells was diffused cytoplasmic and granular in nature. The granular activity was eserine resistant. Holocrine cells were also observed in the epididymis of this bat. Seasonal variations in epididymal esterases are described.
pp 337-348 May 1982
Pupae ofSpodoptera litura were treated topically with a juvenoid, 6, 7-epoxy-3-ethyl-1 (p-ethyl phenoxy)-7 methylnonane. The effects comprised death, production of pupal-adult intermediates of varying grades and adultoids. The production of pupal-adult intermediates was studied in relation to age of the pupa at the time of treatment and the dose of the compound administered. It was found that up to the age of 20 hr the degree of morphogenetic response was directly correlated with the dose of the compound administered and inversely with age, but after this age, an increase in the quantity of the hormone, beyond the effective dose did not further augment the effect.