Volume 91, Issue 2
March 1982, pages 99-206
pp 99-112 March 1982
The present transmission electron microscopic study of the spermatheca of a common Indian grasshopper,Gesonula punctifrons, has highlighted the presence of the glandular secretory cells (SGC) and ductule cell (DC) in the spermathecal epithelium and additionally the occurrence of muscle cells, tracheoles and haemocytes. Both the former cell types are secretory in nature and probably their discharges in the lumen of the cuticle-lined spermathecal duct or ductule vary in their chemical nature. The ultrastructural evidence gives ample support to a concept of a lysosomal control of the secretory materials prior to their liberation in the lumen. The characteristic features of the plasma membranes of the secretory cells clearly suggest their involvement in the transepithelial transport of ions and smaller molecules across the basement membrane. A neuronal supply to the spermathecal wall is yet to be demonstrated to explain the filling in and out of the male gametes by this organ.
pp 113-120 March 1982
The histology of the adrenals of the mongooseHerpestes edwardsii edwardsii has been studied. Three layers in the cortex, namely zona giomerulosa, zona fasciculata and zona reticularis and central medulla surrounded by the cortex have been observed.
Employing histochemical techniques it was revealed that the cortex is rich in glycoproteins, lipids and protein bound Amino groups. It has moderate amounts of proteins containing sulphydril and disulphide radicals and tyrosine. Tryptophan has not been detected.
Negligible amounts of mucopolysaccharides were detected in the medulla. Aspects dealing with the occurrence of carbohydrates, proteins and lipids in various regions of the cortex are discussed.
pp 121-133 March 1982
Male and femaleT. mossambica were x-rayed with 100 r and the meta-phase chromosome aberrations in their gill epithelia were studied at 13 different intervals against suitable control. The chromosomes of males appeared more radiosensitive than those of females. Among the diploid complement of 44 chromosomes, the individual type aberrations were non-random in both sexes. The longest pair of chromosomes, taken as the marker pair, was found very highly radio-sensitive, while the remaining 21 pairs as non-markers were somewhat resistant to x-radiation when the observed and the expected numbers were subjected to statistical analysis. The break in the marker chromosome was also non-randomly distributed as the distal half had a significantly large number of breaks.
pp 135-141 March 1982
The present study deals with the preliminaryin vivo screening of suramin and levamisole in rai-Setaria cervi system with special reference to the histochemical changes in the adult worms caused by the drugs. Levamisole proved to be highly effective as a micro- and macro- filaricidal agent. It also appears to be interfering with the normal activity of alkaline phosphatase and glycogen of the adult worms with no apparent effect on its protein content. The drug also causes irreversible paralysis in adult worms. Suramin, though an active pharmacological agent, proved to be completely ineffective on microfilariae as well as on adult worms ofSetaria cervi. Consequently, no notable alterations in the histochemistry of the parasite following suramin treatment were observed.
pp 143-152 March 1982
The survival and growth ofChanda (= Ambassis) gymnocephalus (Lac.) fry (8·8 ± 0·2mm) collected from Murukumpuzha Lake (9·34‰) for a ninety day period in different salinity grades were studied. A faster rate of growth is exhibited by the fish in the highest salinity grades (22·41 and 28·51‰), even though during the first month, growth and health was apparently better in the lower salinity grades (4·11, 10·21 and 16·31‰). Assimilation efficiency also showed a similar gross picture. Thus inC. gymnocephalus, an euryhaline species, the fry show preferred salinity gradients for optimum growth within the fluctuating salinity regime at a stable temperature (26 ± 2° C) and hence may make salinity bound emigrations with growth.
pp 153-158 March 1982
The amounts of cations Ca, P, Na, K, Cu and Zn inRaillietina tetragona (Cestoda) and in liver, intestinal tissues and blood serum of its host (Gallus gallus dotmsticus) were determined using spectrophotometry, titrimetry, flame photometry and atomic absorption spectrophotometry. Quantitative variations were observed in the distribution of these minerals in the immature, mature and gravid regions of the worm, on dry weight basis. There was a gradual decrease in Ca content of worm along the antero-posterior axis. The Na content, on the other hand showed a reverse trend with the greatest amount in the gravid proglottids. The immature region contained the highest levels of P, K and Cu. The worms showed significantly higher levels of Ca, P, Cu and Zn than the liver and intestinal tissues on dry weight basis.R. tetragona, like host liver and intestinal tissues (but unlike blood serum), had quantitative excess of K over Na and other cations.
pp 159-163 March 1982
The present paper reports the haemoglobin pattern by paper electrophoresis of seven rodent and one insectivore commensal species collected from Bombay-Pune region. Almost all the samples possess 1/1 type of haemoglobin which is slower in mobility than that of the normal human type. While the genusBandicota possesses polymorphic haemoglobin types, it is quite surprising thatSuncus murinus has the haemoglobin of anodic mobility as against itsSoricidae counterpart’s,Sorex’s, haemoglobin showing cathodic mobility.
pp 165-176 March 1982
Three species of egg parasites, viz.,Anagrus sp.,A. optabilis (Mymaridae) andOligosita sp. (Trichogrammatidae), and a nymphal/adult parasiteGonatopus sp. of rice planthoppers were studied for their biology and control potential. Larger number of adult mymarids emerged from host eggs between 8·30 a.m. and 12·30 p.m. of the day whereas trichogrammatid adults emerged between 12·30 p.m. to 4·30 p.m. All the three species parasitised both brown planthopper (BPH) and white backed planthopper (WBPH) but, in general, failed to parasitise rice leaf-hoppers.
Developmental duration from oviposit ion to adult emergence noted for these parasites indicated that males of mymarids, in general, developed faster (10–11 days) than females (12–13 days) at 20–32° C prevailing during October, whereasOligosita females developed more slowly (14–15 days). However, bothA. optabilis andOligosita developed three days faster at 30–38° C prevailing during April, Fecundity in terms of number of eggs parasitised per female varied from 12·3 to 20·3. Under greenhouse conditions, release of 1 and 5 pairs of mymarid parasites for 10 days reduced the nymphal hatch of BPH by 60 and 85%, respectively. Nymphal/adult parasiteGonatopus sp. completed its life cycle in 19·5 to 31 days on both BPH and WBPH. While the 4th and 5th instar nymphs of BPH were parasitised more frequently, green leafhopper nymphs were not parasitised. Besides being endoparasitic, the adult females also predated on and killed as many as 5·2 nymphs a day.
pp 177-187 March 1982
Natural enemy complex of the planthoppers,Dichoptera hyalinata F.,Eurybrachys tomentosa F., andRicania fertestrata F. includes two nymphal ectoparasites (Dryirtus spp.), two egg parasites (Proleurocents fulgoridis F. andTetrastichus sp.), an internal larval mermithid parasite, and a predator (Phidippus sp.). Biological aspects ofDryinus spp. andP. fulgoridis are discussed.
pp 189-197 March 1982
The phenomenon of transabdominal migration of ova is fairly common in all three fresh water turtles,Lissemys punctata punctata (70%),Kachuga tectum tectum (4%) andK. smithi (73%), studied for the present work. Individuals ofLissemys punetata punctata, Kachuga smithi, showed higher frequency of ovular migration in smaller individuals. It is suggested that a better weight balance is possibly achieved by ovular migration in these aquatic reptiles.
pp 199-206 March 1982
A 16 km stretch of the lower Vasishta Godavari estuary (lat. 16° 18′ N long. 81° 42′ E) was surveyed during October 1976–January 1978 to study the polychaete-sediment relationship. Mean high mid- and low water marks at six permanent stations were sampled for studying polychaete distribution as well as sediment characteristics. Sand fraction dominated stations I and II and the silt-clay per cent increased higher up the estuary. Organic matter in the estuary ranged from 0·1 to 4·2% and the amount is generally linked with the silt-clay fraction of the sediment. Depending upon their tolerance to the sediment composition polychaete species colonised different tidal levels. Carnivores were restricted to sandy substrata. For the detritus feeders, the influencing factor appears to be organic matter than the sediment composition.