Applied Zoology

The present study is to investigate the effect of selective Synthetic feed like Zeepromin and Fishmin having some additive components for enhancing on certain metabolic profiles and yield parameters of the cultivable fish species like Catla catla, Labeo rohita, Cirrhinus mrigala. The fishes selected for the study are considered into two groups viz. control group and experimental group .The control group of fishes are fed with control feed i.e. Groundnut cake, rice bran. The experimental group of fishes shall further be divided into two groups, Zeepromin and Fishmin which are commercially available, have been selected for the study. The first group of experimental fish was fed with control feed mixed with Zeepromin . The second groups of experimental fish are being fed with control feed mixed with fishmin. Hence the feed i.e., control feed+ Zeepromin and Fishmin supplied to the two groups of experimental fishes shall be called as synthetic feed. Elevation of rate of fecundity and rate of fertilization was observed when fed with Zeepromin and Fishmin fed fish species. Zeepromin and Fishmin treatment enhanced the fertilization rate and all the changes were found to be statistically significant over their corresponding control values.

Silkworm silk is among the most widely used natural fibers for textile and biomedical applications due to its extraordinary mechanical properties and superior biocompatibility. There is a growing interest to introduce more new functionalities into silk while maintaining its advantageous intrinsic properties. Various methods with their merits are assessed to produce functional silk, specifically those with colour and luminescence. There is a highlight on intrinsically coloured and luminescent silk produced directly from silkworms for a wide range of applications and a discussion on the suitable molecular properties for being incorporated effectively into silk while it is being produced in the silk gland. This paper elicits an in vivo uptake of neutral red, a weak cationic azine dye by Bombyx mori, which results the production of vibrantly coloured cocoons. It is a green process without any chemical pollution, which offers the development of an insect system to produce coloured silk. It has significant potential applications in sericulture research. The colour change observed in haemolymph and silk gland is evident for the efficacy of the selected dye to incorporate into the silkworm body. The results of larval and cocoon traits shows that there is no significant difference between the control and dye added diet fed groups. The findings suggest that neutral red is a promising candidate dye for the production of environmental friendly colour silk production, which eliminates the generation of dye waste.

Invasive Salmonella Typhimurium infection is in a flux in resource poor settings in Kenya. However, sequence analysis of the strains in the study areas have not been determined. This study aimed to determine the distribution and genetic diversity of S.Typhimurium. Single locus sequence typing (SLST) based on fliC gene indicated S.Typhimurium isolates exhibited geographic restriction in addition to intraspecies diversity. The dominant strain isolated belonged to S.Typhimurium strain UK-1 lineage in both study areas. Data on genetic diversity is vital in monitoring the disease in the study areas.

In the present investigation an attempt was made to test the antibacterial activity in the coelomic fluid of the epigeic species of earthworm, Eudrilus eugeniae and the anecic species of earthworm, Polypheretima elongata. The Eudrilus eugeniae was collected from Selvam Vermicomposting farm, Udumalpet, Tamil Nadu, India. Likewise, the Polypheretima elongata was also collected from the soil of National college campus, Tiruchirappalli, Tamil Nadu, India. Both worms were identified by following standard taxonomical key characters. After identification, both worms were cultured under favorable laboratory condition for 30 days providing the food material consisting of 50% predeomposed organic waste and 50% predecomposed cow dung in separate cement tanks. At the end of 30 days a pool of 20 healthy worms was selected from both cultures for the extraction of coelomic fluid. Later on, the fluid was extracted by electric shock method employing 9 volt electrode. The extracted coelomic fluid (100%) was used to test the antibacterial activity against two gram positive bacteria namely Staphylococcus aureus and Pseudomonas aeruginosa and one gram negative bacterium namely E.coli. Among the selected bacterial strains, the coelomic fluid of Eudrlus eugeniae and Polypheretima elongata showed the maximum inhibition zones 7.01 ± 0.28mm and 2.43 ± 0.38 mm against Staphylococcus aureus respectively when compared to inhibition zones 2.35 ± 0.31 mm and 2.28 ± 0.29 mm; 2.66 ± 0.31 mm and 1.35 ± 0.17 mm produced by Eudrilus eugeniae and Polypheretima elongata against Pseudomonas aeruginosa and E.coli respectively. Besides that the coelomic fluid of Eudrilus eugeniae exhibited more inhibition activity than the zone (3.70 ± 0.13mm) produced by the positive control (standard antibiotic, penicillin) against Staphylococcus aureus. But at the same time there is no remarkable difference between the inhibition zone of the coelomic fluid of Polypheretima elongata and the positive control experiment against all the bacterial strains tested. However, the control experiment showed more inhibition zone (3.97 ± 0.24 mm) than the inhibition zone produced by the coelomic fluid of Polypheretima elongata against Pseudomonas aeruginosa. As for the present study the bacterium Staphylococcus aureus activity is highly inhibited by the coelomic fluid of both species of earthworms than the other bacterial strains tested even though there is remarkable difference in the size of zone of inhibition. The data were statistically analyzed at 5.0% level employing ANOVA.

Surveillance was carried out in the xerophytic climatic condition of Kalakkad forest area (8°41’ N 77°19’E) to study the arousal and foraging behaviour of the Linshcosteus karupus (Galvao et. al.) during different dusk timing in two successive years. The photoperiod, temperature and humidity recorded at the time of investigation were 12 ± 2 hrs, 22°C – 26°C and 76% – 82% respectively. Triatomine bugs are most important vector of trypanosomiasis or Chaga’s disease, a protozoan infection of man and other mammals caused by Trypanosoma cruzi (Chagas). These bugs are nocturnal and prefer to feed and mate after the sunset. Therefore our study was conducted precisely after dusk. In our study maximum number of L. karupus were noticed late after sunset i.e. between 8- 9 pm in two years, May 2013 and May 2014. The wind formation timing was a key factor in the arousal and foraging behaviour of this bug. Similarly when the wind velocity reached to the upper day’s limit i.e. ? 6 but > 3 Km/hr again maximum individuals were collected. The total of thirteen bugs was collected when the wind was at high velocity, among them eight adults and five fifth nymphal instars. Among adults greater numbers was of males which provide a very clear idea about the attraction of adults males to females and to their hosts through the olfactory sense by wind. Observation was also made about the response of these bugs to the air temperature, as the temperature declined the number of bugs seemed aroused in an increased number. At the temperature below 22°C at kalakkad hills forest, the total collected individuals of L. karupus were eleven; this number was more than twice the bugs reported at temperature above 24°C. In the delayed condition of wind formation, the bugs suddenly started to appear when wind picked speed and the number of individuals reached to maximum limit all at once. It was presuming that insects are waiting for the wind to blow and it may be the conditional respond of its feeding behaviour. In our surveillance studies all attempted were done to understand the natural arousal and behaviour of these haematophagous bugs in its natural habitat.

In recent years, the use of pesticides in agriculture has been increasing steadily. The pesticides which are liberated into the aquatic environment have a deleterious effect on fish and subsequently to man. Pyrethroids insecticides, including lambda-cyhalothrin (trade name Karate) are widely used for the control of insect pests all over the world to increase the production of food grain and other agricultural products. It may also be used in public health applications to control insects such as cockroaches, mosquitoes, ticks and flies may act as a disease vector. However, with the steadily increasing use of lambda-cyhalothrin, there is an urgent need to identify their possible effects on living organisms. Majority of the studies concerning effects of pesticide have been confined to the acute toxicity tests with the death of fish as an end point. Acute toxicity tests aimed at estimating the effect of toxicants on organisms in a short period of time. The static bioassay procedure was used to study the toxicity of lambda-cyhalothrin on Etroplus suratensis. The experimental fish E.suratensis were exposed to different concentrations of lambda-cyhalothrin. Ten healthy fishes were introduced into each concentration and the mortality was observed after 24, 48, 72, 96 and 120 hrs of exposure. The 96 hrs LC50 value of lambda-cyhalothrin to E.suratensis was 0.107 ppm respectively. The results showed that, the mortality rate of E.suratensis increased with the increase in the concentration of lambda-cyhalothrin, but, this phenomenon was not observed in control. Based on the result, lambda-cyhalothrin is highly toxic to Etroplus suratensis, therefore its use near fish farms or in areas close to aquatic bodies should not be encouraged.

The District Cooch Behar endeavours a number of freshwater bodies both of lentic and lotic types having zooplankton communities. A total of sixteen taxa of zooplankton were recorded from the Panishala Beel (one lentic system) encompassing three rotifera, five copepoda, one ostracoda and seven cladocera. On the other hand, a total of thirteen taxa of zooplankton were recorded from the River Ghargharia (one lotic system) that includes five copepoda, one ostracoda, one rotifera and six cladocera. Both the water bodies contains four zooplankton groups and show same kind of group diversity in respect of their zooplankton group. Both the water bodies were dominated by Cyclops sp. most probably due to organic pollution and abundant nutrients.

Efficacies of the chloroform and aqueous extracts of the leaf, stem and root of three indigenous plants viz. Calotropis procera, Polygonum hydropiper and Thevetia neriifolia against the larval mortality and reproductive potential of two urban mosquitoes Culex quinquefasciatus Say and Aedes aegypti L. are reported here. Results show that the chloroform extracts of C. procera leaf (LC50 = 167.48 ppm), P. hydropiper stem (LC50 = 341.79 ppm) and T. neriifolia leaf (LC50 = 209.45 ppm) had excellent larvicidal effect on Cx. quinquefasciatus. The aqueous extracts of C. procera stem (LC50 = 207.18 ppm), P. hydropiper stem (LC50 = 634.92 ppm) and T. neriifolia leaf (LC50 = 453.34 ppm), however, had relatively milder larvicidal effect on the mosquitoes under study. Both the extracts significantly reduced percentage of egg-hatch and adult emergence per raft, lengthened immature duration and increased immature mortality in all the treatment groups. The chloroform extracts had a significantly negative effect on the number of eggs per raft, but both chloroform and aqueous extracts failed to induce any appreciable effect on the female ratio. Compared to the aqueous extracts, chloroform extracts are much more efficient against Cx. quinquefasciatus productivity. Results on Ae. aegypti indicated that the leaf extracts of C. procera (LC50 =696.14 ppm), the stem extract of P. hydropiper (LC50 =1164.36 ppm), and the leaf extract of T. neriifolia (LC50 =872.91 ppm) had significant larvicidal effects compared to the respective controls. In general, the extracts significantly reduced egg-laying, decreased egg-hatch, lengthened immature duration, and increased immature mortality culminating in reduced adult emergence. A comparison of the larvicidal efficacy of the extracts against the two mosquito species reveals that Cx. quinquefasciatus is more sensitive to the plant extracts than Ae. aegypti. However, further research is solicited to evaluate the impact, persistence and effectiveness of these extracts against the vector mosquitoes under indoor and field conditions.

The study was conducted on the morphological aspects such as shell shape and shell dimensions of freshwater snails Bellamya dissimilis and Lymnaea acuminata. The shell of B. dissimilis is globular in shape with broad ovate mouth and 4-5 whirls that are dextrally rotated. Shell length and shell width ranges from 2.3-3.9cm and 3.2-5.9cm respectively. Snail B. dissimilis gives birth to a large number (120-130) of fully developed young ones measures up to 0.2-0.5cm in length. The shell of L. acuminata is tapering conical with 3-5 whorls that end in dextral opening of shell. Shell length and shell width ranges from 1.2-2.7cm and 1.9-3.5cm respectively. The snail is hermaphrodite and breeds almost throughout the year, this snail contains the egg clutches and each egg clutch contains 170-180 eggs.

Ranges of two vital environmental factors like temperature and relative humidity (RH) were utilized to assess their impacts on the life-history parameters such as immature development (hrs), adult emergence (%) and sex-ratio (male: female) in the mulberry silkworm Bombyx mori L. under laboratory conditions. Disease-free layings (DFLs) from M2P2 variety of the silkworm were reared in a digitalized environmental growth chamber (EGC) at 25°-38° C and corresponding 60-95% RH to record the incubation, larval and pupal developmental periods (in hrs), and subsequent adult emergence and sex-ratio. Results revealed that the rise in temperature and RH significantly (P<0.001) shortened the immature developmental periods in the experimental insects, but the adult emergence and sex-ratio were not affected (P>0.05), even though the number of males outnumbered the females. Negative coefficient of correlation (r) values existed between the environmental factors and all the life-history parameters of B. mori, suggesting further that elevated temperature and RH had adverse impacts on the reproductive biology of this commercially important species. Relevance of the present findings to the climate change issues on the silkworm productivity has been discussed.