• Volume 84, Issue 4

      October 1976,   pages  117-153

    • Laboratory studies on the development, survival and life tables ofCulex fatigans andAnopheles stephensi

      S Ravichandra Reddy

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      Observations on the duration of pre/post embryonic stages, survival and longevity of laboratory populations ofCulex fatigans andAnopheles stephensi were made in order to understand the factors controlling outbursts of these mosquito populations in original habitats. Regardless of the nature of culture medium and food,C. fatigans took a longer period (19 days) to complete the development of pre-embryonic stages thanA. stephensi (17 days). The highest survival rate ofC. fatigans was noticed in pupal stage (96%), while it was advanced to IV instar stage (95%) inA. stephensi. The survivorship curves ofC. fatigans andA. stephensi exhibited negatively skewed rectangles, indicating that the mortality is confined exclusively to aged individaals.

    • Micropyle formation in the ovule as an indicator of primitiveness in Angiosperms

      S Sundara Rajan

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      It has been shown by statistical methods that in Angiosperms significant correlation exists between micropyle formation by both the integuments and six other floral and vegetative characters which are admittedly primitive. A subjective assessment of the primitiveness of the feature in question (i.e., micropyle formation by both the integuments) supports the statistical findings.

    • Salinity effects on the food preference of the fresh water field crabOziotelphusa senex senex Fabricius 1798

      R V Krishnamoorthy K Srihari Hafeezur Rahaman

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      The fresh water field crabOziotelphusa senex senex was adapted to artificial sea water. The changes in its feeding behaviour on adaptation to salinity were recorded. Adaptation to higher salinity reduced the daily voluntary food intake and increased the scope for work and level of excitability. Under experimental conditions fresh water field crabs, regardless of their nutritional state, showed preference to marine fish muscle as food and sea water adapted crabs prefer fresh water fish muscle. The food consumption was reduced to a third in the sea water adapted crabs and the oxygen consumption was reduced by about half. Since minimal respiratory metabolism was available in the salinity adapted crabs, it was suggested that such animals have a lower calorific demand associated with low appetite. It was discussed that the behaviour of crabs exposed to higher salinity was not a non-genetic adaptation. Probably, the modifications of gustatory cues occur due to salinity stress.

    • Tubulimonoides gryllotalpae n.g., n.sp. (Mastigophora: Oxymonadida) from the cricket in India

      R Krishnamurthy Tayyaba Sultana

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      The morphology of a new flagellateTubulimonoides gryllotalpae n.g., n.sp. is described from the gut of the cricketGryllotalpa africana in Maharashtra, India. The organism has four flagella arising from two distinctly separated blepharoplasts as in the genusMonocercomonoides Travis, 1932 but the flagellar grouping is 3:1 instead of 2:2. The axostyle is distinctly tubular unlike in the latter genus where it is thread-like or filamentous. Body dimensions: 7·7–19·0×4·6−19·5µm (average: 11·7×9·3µm).

    • Observations on the morphology and life-history of a coccidianEimeria mecistophori n. sp. from the gut of a centipedeMecistocephalus punctifrons Newp.

      C C Narasimhamurti

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      The morphology and development of a coccidian,Eimeria mecistophori n.sp. from the gut of a centipede,Mecistocephalus punctifrons Newp. are described. The merozoites are elongated with alveolated cytoplasm containing a large number of refringent bodies, which are paraglycogen bodies. The microgametocytes are either rounded or oval measuring 26·0–28·0µm and produce a large number of comma-shaped biflagellate microgametes. The macrogametocytes are either round or oval measuring 30·0–32·0µm having larger cytoplasmic alveoli than the male and more reserve food material. The oocysts are perfectly spherical, double walled and without any polar thickenings. The oocysts sporulate in about 72–96 hr at room temperature. There are four sporocysts each containing two sporozoites.

    • A simple photorespiratory ratio for the delimitation of C4 from the C3 plants

      V S Rama Das G Rajendrudu

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      A simple technique for the determination of photorespiratory ratio was devised and was tested for its applicability in the screening for photosynthetic systems. The C4 plants gave a photorespiratory ratio around 0·11 while in the C3 plants the corresponding ratio was 0·41. The photorespiratory ratios were also well correlated with the characteristic differences in the leaf anatomy and interveinal distances between the C4 and C3 plants. By using the photorespiratory ratio, four species ofCymbopogon hitherto unreported are now shown to possess the C4 system.

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