Volume 89, Issue 4
July 1980, pages 311-406
pp 311-331 July 1980
The use of metals for human benefit started more than 6000 years ago. Their harmful effects were noted much later, with the growing consciousness about environmental hazards. The different industrial processes and other adjuncts of industrial revolution have added considerably to the quantities of such metal occurring under natural conditions. An appreciable proportion enters into the formation of aerosols, known to be toxic to living systems. Assessment of the hazards posed by metal effluents and their mode of action are therefore gaining considerable importance as a part of environment protection.
pp 333-345 July 1980
Ontogenetic manifestations of four isozymes namely, acid phosphatase, alkaline phosphatase, α-esterase and β-esterase have been analysed in two closely related species—D. nasuta nasuta andD. sulfurigaster neonasuta. By adopting polyacrylamide gel electrophoretic technique 15 different developmental stages have been assayed. Electrophoretically homologous and distinct enzyme phenotypes for each enzyme system have been recognised in the two species under study. The implications of these findings are discussed.
pp 347-349 July 1980
Field experiments were conducted in paired plots to assess the losses due toDactynotus sonchi Linn. in the yield of safflower in two successive winters 1977–78 and 1978–79. The percentage losses in the number of capitula per plant and in seed yield have been calculated and discussed. Excepting the secondary branches per plant, all the yield contributing characters and the seed yield showed significant differences in treated and untreated plots.
pp 351-357 July 1980
Intra- and interspecific bisexual encounters betweenBandicota bengalensis, Rattus rattus, Tatera indica and domesticated strain ofRattus norvegicus were staged for 10 min every day for seven days. The amicable, aggressive, submissive/avoidance and residual behaviour counts were recorded for each partner of the different species combinations and compared. The different species pair combinations were classified as amicable, aggressive and neutral, depending on the ratios of aggressive and amicable behaviour counts. These results are discussed with reference to inter-species relationships, resident-intruder status, body weight-dominance correlation, ‘bully effect’ of albino rats and sex differences in agonistic behaviour.
pp 359-370 July 1980
The effect of administering different quantities of a JHA topically and orally to the last instar larva ofSpodoptera litura of different ages has been studied. With both modes of treatment the effects comprised prolongation of the life of the instar followed frequently by death; imperfect ecdysis adversely affecting survival; production of non-viable larval-pupal intermediates, and occurrence of extra larval moults. Topical treatment is more effective but ecdysial failure and production of 1-p intermediates are more frequent with oral administration. A single supernumerary larval moult may be caused by administering a large quantity of JHA to 1 day old larva. Supernumerary instars are non-viable. Contrary to expectation, 1-p intermediates produced by early treatment show more pupal characters whereas middle-aged larvae show more larval characters. Prolongation of larval life caused by small quantities of JHA is the largest single effect which results into larval mortality.
pp 371-376 July 1980
Two trypanosomes,Trypanosoma channai n. sp. fromChanna punctata (Bloch) andTrypanosoma qadrii n. sp. fromClarias batrachus Bleeker are described.Trypanosoma channai n. sp. is a pleomorphic from having slender, medium and stumpy forms and measures 38·4–62·0µm (including free flagellum). The body length/width ratio of the slender, medium and stumpy forms ranges 14·5–17·3, 7·5–12·0 and 3·5–5·6 respectively. Kinetoplast subterminal; vacuoles absent in the slender forms and present in the other two forms.T. qadrii n. sp. is monomorphic measuring 30·4–48·2µm in length including free flagellum and 1·6–3·2µm in width. Both the ends are pointed; granules absent; kinetoplast subterminal.
pp 377-380 July 1980
The frogs belonging to the speciesRana hexadactyla (Lesson) were subjected to localised muscular exercise and training. The muscular exercise induced decreased proteolysis and elevated soluble and structural protein fractions of the brain. The amino acid oxidations were inhibited resulting into elevated amino acid content. The training programme seems to develop improved ammonia detoxificatory mechanism in the brain. The possible correlation between the training programme and structural organisation of the brain was suggested.
pp 381-385 July 1980
Changes in the level of total proteins and protease activity in brain, muscle and liver tissues of normal and x-irradiated frogs were determined. Low doses of radiation produced an increment in protein level while high doses produced decrement. However, protease activity at all doses exhibited an elevatory trend. Exposure of frogs to lethal doses resulted in increased protease activity and decreased protein content during post-irradiation periods. The results are discussed on the basis of protein destruction and lysosomal damage.
pp 387-402 July 1980
The predatory behaviour of three reduviids, the millipede-feedingHaematorrhophus nigroviolaceus (Reuter) (Ectrichodiinae), the insectivorousPirates affinis Serville (Piratinae) and the haematophagousTriatoma rubrofasciata (De Geer) (Triatominae), both under natural and laboratory conditions, is discussed. Visual stimuli elicited by the moving prey appear important for the initiation of feeding response. The olfactory stimuli from the defensive secretions of the prey appear to enhance the response and help in the continuation of feeding. In the haematophagousTriatoma rubrofasciata, while feeding responses are elicited only by the temperature gradient around their vertebrate hosts, the visual and olfactory senses play only a minor role. On the basis of observations on feeding behaviour, appropriate predatory behaviour models for the three reduviid species have been constructed.
pp 403-406 July 1980
Preliminary observations were made on the effect of copper intoxicated food on the growth (biomass) ofChanna gachua (Ham.). Ingestion of copper contaminatedLebistes reticulatus (Peter) as food byChanna gachua for 30 days had reflected in reduction of biomass with no histopathological changes in the gills or intestine.