Volume 93, Issue 7
December 1984, pages 599-702
pp 599-615 December 1984
Aspects of food utilisation, growth and egg production were studied inCyrtophora cicatrosa as a function of food abundance and ration. Restriction of ration resulted increased mortality, extension of nymphal period and prolongation of interoviposition period. Rates of feeding and conversion showed decreasing trend with reduced ration levels.C. Cicatrosa exhibited the following aspects of egg production: (a) larger the egg sac, higher the number of eggs present, (b) at optimum rearing conditions, such asad libitum ration at 27°C, the female produced large egg sacs and oviposited as many times as possible (c) age definitely affected the size of the egg sac, older the female, smaller the egg sac produced, (d) increased food consumption resulted in high egg production and (e) dry weight of the egg tends to be more or less constant.
pp 617-621 December 1984
The rates of aquatic and aerial oxygen consumption of an intertidal tropical gastropodMorula granulate increases with increasing temperature. The temperature at which the breakdown occurred in their oxygen consumption was observed to be different, 45°C for aquatic and 42°C for aerial respiration. However, the aquatic rates of oxygen consumption were higher than the aerial rates at all temperatures studied. The aquatic and aerial Q10 values showed almost the same trend, higher at lower temperatures and vice versa. The results were discussed in relation to the habitat of the animal.
pp 623-628 December 1984
The origin and course of hypothalamic neurosecretory tracts is demonstrated byin situ staining procedure. Both Pars parvocellularis and Pars magnocellularis, components of nucleus preopticus, contribute to the formation of the right and left main neurosecretory tract. Anteriorly the tract is loosely assembled and formed of 3 subsidiary tracts which later join at the level of horizontal commissure to form a thick consolidated single tract. From the main tract several bundles of axons are given towards the mid-ventral region at the point of curvature to form ventromedian tracts. The ventromedial and the main tract of each side jointly enter the pituitary, anterio-dorsally.
pp 629-637 December 1984
Ethanolic extract of the defatted roots ofB. chitria was chromatographed when a compound-I (C21H25O5N) characterised as dihydropalmitinium hydroxide was isolated. Chronic administration of DPH for 20 days reduces the weights of ovary, uterus and vagina in normal cycling gerbils. Atresia of the large follicles and vacuolization of follicular cells was conspicuous. The luteal cells and endometrial glands were shrunken. Vaginal smear showed prolonged diestrous cycle reflecting suppression of estrogenic activity. Simultaneous administration of oestradiol dipropionate and DPH to spayed gerbils failed to maintain the growth of uterus and vagina. DPH treatment to intact/spayed/pregnant gerbils inhibited protein synthesis and decreased the sialic acid and glycogen contents of the genital tract. Serum protein was low whereas serum sialic acid, cholesterol, phospholipids, triglycerides and NEFA did not change. Antioestrogenic activity of the compound is discussed. Abortifacient action of DPH is of great significance in fertility regulation using plant products.
pp 639-654 December 1984
Four new species of mesozoansviz Dicyema ganapatii n.sp. from the renal appendages ofSepia elliptica Hoyle,Dicyema madrasensis n.sp. andDicyema octopusi n.sp. from the renal appendages of Octopus sp., andDicyema nouveli n.sp. from the renal appendages ofLoligo duvauceli d’ Orbigny are described. All the hosts were collected from different localities on the east coast of India.
pp 655-662 December 1984
The fine structure of the sebaceous gland acini which form the bulk of the flank gland in the Indian musk shrew was studied. The secretion of the gland appeared to be mainly lipoid in nature, seen as numerous intracellular lipid droplets showing varying degrees of osmophilia from light to intense dark. The mitochondria contained one to several electron dense inclusions which were discharged from disrupted mitochondria and were seen floating in the cytoplasm and also in the ducts of the gland complex. It is suggested that these inclusions which presumably contain high concentrations of waxes synthesized within the mitochondria, form the major components of the holocrine secretion discharged from the flank gland of the shrew.
pp 663-669 December 1984
This communication records eight ectoparasites of the gills and skin from edible freshwater fishes of Haryana. Since all eight parasites collected differ from those described earlier in the literature, they are briefly redescribed and arranged systematically.
pp 671-674 December 1984
Seasonal fluctuations along with certain physico-chemical parameters were recorded for two hillstreams, the Alaknanda (snow-fed) and the Nayar (spring-fed). In the former, the water temperature range of 9–14°C is considered optimum for the growth of diatoms, compared to 12–21°C in the Nayar. In both hillstreams diatoms achieved their maxima during January, when the water temperature is the lowest. Sudden influx of rain water carrying enormous silt during monsoon is responsible for the decline in density. The water temperature and current, especially the latter is thus a detrimental factor. The interesting feature of the study is, the relatively higher percentage of diatoms in the Nayar than in the Alaknanda, obviously to be attributed to the warm waters in the former.
pp 675-689 December 1984
The above ground and underground grassland ecosystem showed qualitative and quantitative variations in flora and fauna, being less in number on the above ground part and maximum in the underground part. In the experimental area of grassland, microarthropod population was maximum (59·04%) followed by the populations of grasshoppers (31·49%) and Collembola (9·47%). The fungi population and other soil microarthropods showed a direct correlation with the soil moisture. Maximum grasshoppers were recorded when the vegetative growth of grasses was maximum. Activities of collembola and fungi in “humification” and “mineralization” in the grassland ecosystem are schematically illustrated.
pp 691-695 December 1984
Phenoxy herbicides 2,4-D, its sodium and ethyl amine salts and ethyl esters, commonly used in aquatic weed eradication programmes, were tested by acute and static bioassay investigations on a cyprinid fishLebistes (Poecilia) reticulatus under laboratory conditions. The toxicities of these different formulations are compared and reported in relative toxicity ratings. ‘Safe application rate’ and ‘safe application factor’ equations were also calculated. Median lethal concentrations at various time intervals are also reported along with respective fiducial limits and regression equations. Comparative regressions are drawn for three time intervals, 24, 48 and 96 hr.
pp 697-702 December 1984
The primary production of lake Lakhotia in the semiarid region of Rajasthan, India is reported. The results are compared with other tropical and temperate water bodies. Primary production revealed positive relationship between water temperature and chlorophyli-a. High production was observed when temperatures ranged from 27–33° C.