Applied Zoology

Copepods are the most abundant metazoans in marine ecosystems. They can be regarded as a keystone component of biogeochemical cycles and functioning of pelagic food webs. Their dynamic changes may affect the biomass of many fish stocks. Therefore, it’s critical to assess their distribution in this changing climate. The aim of this study was to assess the copepods distribution patterns in relation to environmental factors in the most productive upwelling ecosystem in the world: Canary Current Ecosystem (CCLME) between Cape Blanc (21°N) and Cape Bojador (26°N). Overall, we counted 19 mesozooplankton groups. Copepods constituted the highest fraction in all sampled layers during both investigated seasons (autumn and summer) since they represented at least 65% of the total mesozooplankton community. A cluster analysis allowed the definition of five main species assemblages during each season. The total copepods abundances projected on T/S, T/DO and T/chl-a diagrams showed no clear pattern in densities variation. However, when dominant species were individually projected on T/chl-a diagrams showed different distribution patterns according to their thermic and diet preferences. Multiple Analysis Factorial analysis performed between dominant species densities and major environmental factors revealed a clear positive correlation between most of species and chl-a concentration during both seasons; most of these species were phytophagous. Our finding shows that temperature and chl-a concentration seem to be the most important environmental factors and thus strongly influence the distribution of the copepod population in the CCLME. To further investigate the relationship between copepods and environmental factors we suggest adding upwelling index, which may be responsible for the major changes found in copepod distribution.

The first instar larvae of Tribolium castaneum were treated with sub-lethal concentrations (LC20 and LC40) of Lufenuron through the culture medium for 2days, 4days, 8days and 16days to investigate total soluble protein content in the larval tissues during development. It was found that for all concentrations tested, there was a significant reduction in total soluble protein content of the treated larvae as compared to that of control. At LC20 and LC40, there was a progressive decrease in the total soluble protein as a function of increase in age of the larvae. Thus sub-lethal concentrations of Lufenuron alter the total soluble protein content of Tribolium castaneum larvae during development there by resulting in developmental abnormalities as observed earlier by Salokhe et al.,(2010).

Polycystic ovarian syndrome (PCOS) is a common reproductive disorder which leads to infertility in association with several disorders like oligomenorrhea, obesity, type II diabetes mellitus and cardiovascular disorder. It is characterized by an increased level of androgen production and disordered gonadotropin secretion, which results in chronic anovulation. In fact, it is the leading cause of anovulatory infertility. It mostly affects the women of reproductive age. In this review, there is a detailed description about the clinical manifestations, diagnosis, etiologies and treatments.

Weight-Length relationships (WLRs) and Relative condition factors (Kn) were estimated for 9 freshwater fish species namely Brycinus leuciscus (Günther, 1867), Hydrocynus forskali (Cuvier, 1819 ), Odaxothrissa mento (Regan, 1917), Labeo coubie (Rüppell, 1832), Labeo parvus (Boulenger, 1902), Labeo senegalensis (Valenciennes, 1842), Distichodus engycephalus (Günther, 1864), Parailia pellucida (Boulenger, 1901)and Schilbe mystus(Linnaeus, 1758)from the lower reaches of the White Volta. Samples were collected from the catches of the artisanal fishermen from October 2011 to March 2012. Using W=aTLb, the weight-length relationships of the species were calculated. Relative condition factors of the species were obtained using the formula: Wo/Wc. The WLRs of all the 9 fish species were highly significant (P<0.001). The determination coefficients (r2) ranged between 0.5764 for Parailia pellucida to 0.9784 for Hydrocynus forskali. The slopes(bvalues) of the WLR regression models of the nine (9) species ranged from 2.0045 to 3.1614 with 95% confidence interval of b for all the nine fish species within 1.386 to 3.352. In terms of growth pattern, 4 out of the 9 species exhibited isometric growth (b=3). Three (3) were observed to have negative allometric growth (b<3) and 2 fish species had positive allometric growth (b>3) patterns. Mean relative condition factors of the species ranged from 1. 00 to 1.09. A T-test of the observed weight (Wo) versus the calculated (Wc) on all the nine (9) species produced no significant difference (P>0.05) between the observed weight and the calculated weight. The models are thus good proxies for approximating the weights of the species.Even though, not all the species exhibited isometric growth, the general wellbeing of the fish specieswas suitable during the study period as inferred from relative condition factors (Kn). This is a contribution of information to support researchers in future and fishery managers for reliable growth estimation and health status of freshwater fishes.

The stages of gonad maturity, reproductive aspect, length-weight relationship, and condition factor of labeo senegalensis from the White Volta at Yapei, Northern Region of Ghana were investigated during the dry season of 2013. One hundred and fifty (150) specimens caught by gill nets were examined. Out of the 150 specimen, Eighty- nine were females and sixty- one were males. The sex ratio of males to females was thus 1:1.5. Eleven (11) out of the eighty –nine (89) females of thelabeo senegalensis were found to contain gonads. The stages of gonad maturity ranged from stage I (Immature stage) to stage IV (Maturity stage). The total eggs found in the eleven female labeo senegalensis was 2,385 with a mean value of 217 eggs per gravid female. The gonado- somatic index (GSI) ranged from 1.29 to 3.28 with a mean and standard deviation of 2.0 and ± 0.57 respectively. The total length of labeo senegalensis ranged from 9.5 cm- 24.6 cm with a mean and standard deviation of 16.0 cm and ± 2.86 cm respectively. The standard length ranged from 6.2 cm - 20.7 cm with a mean and standard deviation of 13.0 cm and ± 2.27 cm respectively. The body weight of labeo senegalensis ranged from 20 grams - 212 grams with a mean and standard deviation of 121.34 grams and ± 93.89 grams respectively. The LWR of species was highly significant (P<0.001) with determination coefficients (r2) of 0.907. The fitted length –weight relationship of the labeo senegalensis was W = 0.180 x TL 2.66. The slope b of labeo senegalensis length- weight power regression (both male and females) which was 2.6 indicated a negative allometric growth pattern (b<3) of the species. The Condition factor (K) ranged from0.93 to 2.90 and with a mean and a standard deviation of 1.926 and ± 0.61 respectively. The general wellbeing of the labeo senegalensiswas suitable during the study period.

Lipids play a nutritional physiological role by providing an efficient source of energy and essential fatty acids. As the freshwater bivalves are the filter feeder the role of Mantle is very efficient. A seasonal change in endogenous and exogenous factors in freshwater bivalves requires more energy and is control by various ganglion such as cerebral, visceral and pedal, The lipid content in control group mussels was significantly maximym 5.9313+0.04 mg/100mg during post- monsoon and minimum during the winter season. In cerebralectomizes group the content was significantly higher in unilaterally cerebralectomized mussel during the post- monsoon as compared to control, hence the present investigation was undertaken to study the impact of cerebral ganglia on lipid content in mantle of freshwater mussel Lamellidens Corrianus, during different season.

Excessive use of pesticides resulted in serious ecological and environmental problems as well as health hazards. Histopathological changes are mostly confined to organs directly involved in their metabolism and detoxification. In Molluscs, hepatopancreas is the main site of action, degradation and detoxification of pesticide, hence hepatopancreas is chosen as test organs. Ascorbic acid is main dietary antioxidant. For different physiological acts vitamins are essential, although required in trace amount. Therefore, the present study was conducted to evaluate the effectiveness of L-ascorbic acid in Methomyl -induced toxicity in an experimental model, the fresh water bivalve, Lamellidens marginallis. The animals were exposed to acute dose (35 PPM LC 50/2 value of 96 h) of Methomyl, Methomyl in same dose along with 50 mg/L of L- ascorbic acid and Methomyl in same dose along with100mg/L of L-ascorbic acid for 96 hours. Control animals were maintained in normal water. Due to Methomyl intoxication damage to the hepatopancreas was extensive resulting epithelial hyperplasia, necrotic changes in basement membrane and intertubular connective tissue at 24 hours of exposure. The severity of damage progressed with longer exposure, after 96 hours of exposure to Methomyl, swelling, rupture and flattening of epithelial cells along with displacement of nuclei and widening of tubular lumen were noted. Exposure to Methomyl in combination with 50 mg/l of L-ascorbic acid showed considerable reduction in nature of damage, while with 100 mg/l of L-ascorbic acid showed almost normal histological structure of hepatopancreas.

The river Cauvery is one of the major perennial river in the peninsular India, which originates at Talakaveri of Brahmagiri Hills of Western Ghat in Coorg District, Karnataka and flows eastwards through Tamil Nadu state and enter into Bay of Bengal. It runs a distance of about 1170 km with many tributaries and distributaries. Which carries a large amount of nutrient and probably promotes species richness both racially and individually. The Grand Anaicut and Lower Anaicut are the main distributaries of Cauvery deltaic regions of Thanjavur, Thiruvarur, Cuddalore and Nagapattinam districts. In view of large volume of nutrients and water availability. The productivity of water is significant and therefore the prawns are diverse. In the present study 12 species of prawns which are commercially and ecologically important have been identified. They are Macrobrachium malcolmsonii, M. aemulum, M. nobilii, M. australe, M. rude, M. lamarrei, M. scabriculum, M. indicum, M. dolichodactylus, Caridina nilotica, C. gracilipes and C. gracilirostris. The present study significant to the presence of commercially important and ecologically important populations available in the Grand Anaicut and Lower Anaicut regions of river Cauvery. The prawns of the river Cauvery are documented.

This study was conducted to estimate relationships between body lengths from several biometrical traits viz. Total length relationship between Standard length, Head length, Interorbital space, Length of the snout, Depth at the origin of dorsal fin and Orbit diameter of Macrones vittatus (Bloch, 1794). Samples of 419 individuals (ranging between 86-175 mm) were studied in the present investigation. The linear regression equation and coefficient correlation for Total length and Standard length is 0.785, r=0.99, Total length and Head length is 0.166, r=0.949, Total length and Interorbital space is 0.182, r=0.995, Total length and Length of the snout is 0.083, r=0.938, Total length and Depth at the origin of the dorsal fin is 0.260, r=0.991 and Total length and Orbit diameter is 0.033, r=0.924.

Solvent extracts of xerophytic plant, Opuntia dillenii Haw were screened for larvicidal, ovicidal and repellent properties against the dengue vector Ae. aegypti L. Five different extracts viz., hexane, petroleum ether, ethyl acetate, carbon tetrachloride and distilled water were tested for larvicidal, ovicidal activity in five different concentrations ranging from 62.5, 125, 250, 500 and 1000 ppm. Among the five solvent extracts of O. dillenii, petroleum ether extract showed the highest larvicidal activity at 1000 ppm against the fourth instar larvae of Ae. aegypti. The LC50 and LC90 values of O. dillenii petroleum ether extract were recorded as 323.76 and 829.76 ppm against Ae. aegypti larvae respectively. High ovicidal activity of 64% was recorded at 1000ppm concentration of petroleum ether extract. The petroleum ether extract was also found to be the most effective protectant against the adult female mosquitoes of Ae. aegypti. The mean protection time recorded in petroleum ether extract was up to 107 min at 5 mg/cm2 dosage against Ae. aegypti adults. The potential of petroleum ether extract of O. dillenii could be used in dengue vector control.