Volume 91, Issue 6
November 1982, pages 493-637
pp 493-499 November 1982
829Tor tor (Ham.) were examined for food habits, parasites and length-weight relationships. Parabolic equations describing the body length-body weight relationships wereW=0·0009298l2.0553;W=0·-0013146L1.9769, andW=0·0010884L1.9501 for females, males and pooled fishes respectively. The regression coefficients of the <15·0 cm, 15·1–20·0 cm and >20·1 cm length classes and sexes were found to be significantly different from One another and from 3. The regression coefficients of the fishes of larger size classes were higher than those of the fishes of <15·0 cm size classes.
pp 501-505 November 1982
Liver and muscle total proteins declined inSarotherodon mossambicus subjected to sublethal concentrations of ddt, malathion and mercury. The results indicate their role in maintenance of energy supply irrespective of the nature of the toxicant. The qualitative variations in serum protein pattern also support the quantitative changes in tissues.
pp 507-513 November 1982
Results of the experiments conducted to. estimate the maximum single food intake, satiation time and daily ration in the predator,Chanda thomassi using different size groups of teleostean prey (guppies) and in six non-lethal salinities are presented. The results suggest that satiation amount and satiation time vary considerably with the size of the fish prey. It is seen that the appetite of the fish is lost on consuming relatively fewer number of larger fish prey, while the predator could accommodate a much larger number of smaller prey fish of greater gross size. Also the satiation amount decreases when the prey is available in bulk than when given at regular intervals. The computed daily ration of the predator shows high values when compared with available data on other tropical predators. The over all results project the destructive potential of this predatory species coupled with its shoaling habits.
pp 515-521 November 1982
Three unknownTetracotyle metacercariae, collected from piscine host, have been described.Tetracotyle pandei n.sp.,Tetracotyle srivastavai n.sp. AndTetracotyle ramalingi n.sp. were collected from the visceral organs and musculature ofChanna punctatus (Bl.). They are characterised by the shape and position of pseudosuckers, shape of hold fast organ and hold fast gland, number and postion of genital rudiment and pattern of reserve excretory system.
pp 523-532 November 1982
Toxicity and the effect of sub-lethal concentrations of endosulfan on a fresh water fishBarbus stigma had been studied. Endosulfan proved to be lethal toB. stigma at a concentration of 0·01 ppm and above. The LC50 was 0·0043 ppm and the sub-lethal concentration was 0·003 ppm and below. At sub-lethal concentrations the fish exhibited erratic swimming activity and at lethal concentrations it lost the sense of balance. The rate of feeding was reduced by 5·94% to 9·02% and assimilation by 6·44 to 9·60% in different sub-lethal concentrations. Growth (weight) retarded from 11·6mg/day in the control fish to. 7·3, 6·0 and 5·1 mg/day in the endosulfan treated fishes. Respiratory rate of the pesticide treated fish also dropped by 10 to 16·6%. Due to. the over all effect of the toxicity, the fish,B. stigma comparatively showed a poor nutritive value by displaying a drop of nearly 35% in the organic constituents.
pp 533-538 November 1982
Barbiturates inhibit thelh surge and release of gonadotrophins (lh and fsh) and prolactin from the pituitary in rats and hamsters. In the present study administration of phenobarbital (7-5mg) or barbital sodium (20 mg) twice a day from day 8–11 interrupts the pregnancy in rats with little or no foetal survival. The ovaries and the uterus of these rats resemble those of non-pregnant rats when autopsied on day 20 of pregnancy. These results suggest that the failure of maintenance of pregnancy by barbiturate treatment may be due to the inhibition of luteotrophic hormones from the pituitary during the crucial period of pregnancy, resulting in the insufficient secretion and release of ovarian progesterone and also estrogen.
pp 539-552 November 1982
Ropalidia marginata, the most common Indian social wasp, belongs to a crucial stage of social evolution showing no obvious morphological caste differentiation but a behavioural caste differentiation and a dominance hierarchy that appears to influence division of labour. The nests consist of a single open comb that can sometimes have up to 500 cells and 10 pedicels. Nests are initiated and abandoned all round the year. Initiation is by 1–20 foundresses, 1–4 being the most common number. There is a great deal of variation in brood developmental times both within and between nests. Male progeny disappear from the nest soon after emergence while daughters stay on at the parent nest for a mean period of about a month. Small nests have a single egg layer while large nests have two or more females with well developed ovaries that presumably lay eggs. Most nests are short-lived, small nests being highly susceptible to failure. Large nests are less susceptible to failure but the emergence of multiple egg layers reduces the average relatedness of workers to the brood which presumably is the cause for large scale emigrations from these nests. An interaction of ecological and soical factors therefore appears to determine the growth of a nest.
pp 553-562 November 1982
The SpongillidCorvospongilla lapidosa (Annandale 1908) (Porifera: Spongillidae) is reported for the first time from the Manjira reservoir in Andhra Pradesh. Its sausage shaped spicules have adaptive value to thrive in low silica environments. The species is tolerant to high turbidity. High calcium and bicarbonate may be unfavourable and the sponge ha? not been found either on molluscan shells or on aquatic vegetation. It can thrive in waters more than 4 m deep. The range and mean values of twenty-seven physico-chemical parameters of the habitat ofC. lapidosa are given as the base data for the species ecology.
pp 563-568 November 1982
The small mouse-tailed bat,Rhinopoma hardwickei, collected from various districts of Rajasthan, is primarily an insectivorous species. Orthoptera, Dictyoptera, Lepidoptera, Hymenoptera, Coleoptera and Diptera are preferred in all main four seasons in varying amounts, while Isoptera are consumed in all but the winter season. Occurrence of ground dwelling insects, caterpillars, spiders and water beetles in the stomachs of bats have been discussed in the light of behavioural adaptations of this species. Presence of fur of same bat species in stomachs coincides with its breeding season. Presence of various polyphagous insect pest species of crops in feeding menu of bats shows that this species plays an important role in biological management of harmful insects.
pp 569-576 November 1982
This study is the first to detail the annual reproductive cycle of any echiuran. Here the annual reproductive cycle ofAchaetohonellia maculata Fisher is described. Oocytes first appear in the coelomic fluid in late spring or early-summer. During fall and winter, gametes production and differentiation continue. Differentiation of gametes lasts four to six months. Spawning occurs in spring. Since the niaks are the permanent residents in the gone duct of the female, the fertilization is internal in Boneliidae. Temperature of the sea water probably is the most important exogenous factor controlling the reproductive cycle. Individuals reach sexual maturity when they are one year old.
pp 577-585 November 1982
Administration of 4-methyl (6,7-b-tetrahydrobenzofurano) coumarin, 20 mg/kg/altemate day, for a period of 40 days caused degenerative changes in the testes of male rabbits. Inhibition of spermatogenesis was achieved at primary spermatocyte stage level. Total protein, sialic acid and glycogen contents of the testes, epididymis and seminal vesicle were significantly reduced while the testicular cholesterol was elevated in the 4-methyl coumarin treated animals. Serum cholesterol, phospholipid, triglyceride, nefa, were elevated. Antispermatogenic activity of 4-methyl coumarin is discussed.
pp 587-597 November 1982
Histochemical techniques for lipids were employed to study the steroid synthesizing cellular sites in the ovary of teleost fish (Cyprinus carpio L.). The cellular sites of steroid biosynthesis appear to be the ovulating corpora lutea, interstitial cells, and special thecal cells of developing follicle. They possess the cytc-logical and histochemical features of well-established steroid gland cells. The functional significance of histochemical changes in the granulosa cells of post-ovulatory follicles in the teleost ovary has been discussed in the light of recent researches on corresponding cells in the ovaries of other vertebrates. The corpora atretica are merely the large yolky eggs in the process of their degeneration and resorption.
pp 599-607 November 1982
The development of the neurosecretory cells in eyestalk is studied in zoea, juvenile and adult stages of theMacrobrachium kistnensis. In zoea, the ganglionic mass of the eyestalk compreses of three parts viz. medulla externa, medulla interna and medulla terminalis. The future sensory pore x-organ is characterized by onion bodies near medulla terminalis and a vacuole closely applied to the outer surface of the eyestalk. The monopolar giant neuron is observed in zoea. In juvenile prawn, in addition to zoeal features the sinus gland makes its appearance. At this stage, neurosecretory cells are discernible in the medulla externa and terminalis. In adults, the eyestalk presents well developed lamina ganglionaris, medulla externa ganglionic x-organ (m.e.g.x.), medulla interna ganglionic x-organ (mi.g.x.) and medulla terminalis ganglionic x-organ (m.t.g.x.).
pp 609-621 November 1982
The development of the tracheal supply to the larval wing pad ofOncopeltus fasciatus is described. The formation of lacunae is also described and it is shown that their development precedes the growth of the associated tracheal supply. Tracheae from anterior and posterior ends of the wing pad enter the lacunae in second instar. The pattern of adult wing tracheation is well established in the third instar. Where the Sub-costa, Radius and Medius arise from Costo-radial trunk, the Cubitus, the first and the second anal tracheae arise from the Cubito-anal trunk. Both groups are connected by a basal transverse connection.
pp 623-629 November 1982
In this paper, the seasonal fluctuations in adrenal glands and its relationship with their body weights, reproduction activity and population density of soft-furred field rat,Rattus meltada pallidior in the Indian desert has been discussed. Results of the present study revealed that the left adrenal gland in both the sexes of rodents was found to be significantly heavier (P<0·01) than the right one. The paired adrenal of female rats was significantly heavier (F<0·001) than those of males. The seasonal variations in adrenal weights of pregnant females were found to be significantly heavier (P<0·01) than those of nonparous females. The adrenal weights of male, pregnant and non-pregnant female rats were found to be significantly correlated with their body weights. Results of this study further revealed that changes in adrenal weights inRattus m. pallidior are functions of body weights which are regulated by the availability of food and its nutritional level.
pp 631-637 November 1982
Drosophila koraputae, D. neomedleri andD. puriensis all belonging to the subgenusScaptodrosophila are described as new species. Their taxonomic relationships, based on the morphology and male genital structures, are established.