Fish are the most numerous group of vertebrates in the world. This article is aimed to present the volumetric study of air-bladder in a local fish- Bata, scientifically known as Labeo bata (Hamilton, 1822). The study was performed by anatomical dissection of184 fishes of Bata species with further macroscopic examination of air-bladders. The research showed that in investigated species this organ has significant differences and is composed of two chambers. The present study assesses air-bladder dynamics in natural occurring populations with the aim to examine volumetric relationship between air-bladder and body of the individuals. It is clear that the buoyancy provided by the air-bladder. Air-bladder volume is a mean 9.4% of fishbody volume. Evidence is given to indicate that this is quite large when compared with data ‘5% of fish volume for marine fish, and 7% for freshwater fish.
The population growth of Cybister confusus, an aquatic insect in a pond was studied with emphasis on water temperature. Population of the Cybister confusus was examined in relation to temperature. This measure accounts for time and the minimum temperature necessary for insect growth and reproduction to enhance population size. Result showed highest population density at about 17.6 °C temperature. Studies demonstrated that the population of insects is directly proportional to change in seasonal temperature cycle.
In the present work an attempt has been made to study the effect of few hormones and pharmacological drugs on changes in proximate composition in whole body in a fresh water air breathing murrel, Channa marulius (Ham.). The water, protein, lipid and carbohydrate + ash content of the fish body (50.0±1.5g) of control group of fishes were 74.79±0.19, 16.02±0.32, 3.21±0.11 and 5.98±0.43% respectively. The treatment of Hydrocortisome and Durabolin brought decrease in water content but increase in protein and lipid content as compared to control. While the treatment of L-thyroxine brought an increase in water content but decrease in protein and lipid content. The details have been discussed in this fish.
Studies on seasonal variations in proximate composition have been made in a teleostean air breathing fish, Channa marulius(Ham.) in relation to ambient water temperature. Minimum values of percent water, protein, lipid, carbohydrate content and calorific values (K.cal/g) were recorded in the months of November, March, August, June and February respectively while maximum values of above noted parameters were recorded respectively in the months of July/August, June, December, May and June. The statistical relationships between ambient water temperature Vs. proximate composition fractions 0 0 were established by two separate regression lines one between 18.5 to 29.0 C and another between 29.0 C 0 to 33.4 C. The details have been discussed in this paper.
Aquatic macroinvertebrates, which play a significant role in the food chain of an ecosystem, are used in freshwater quality assessment to identify the environmental stress resulting from a variety of anthropogenic disturbances. Samples survey of macroinvertebrate communities were conducted from April 2016 to March 2017 in ox-bow wetland (Kawar lake) of Begusarai district (Bihar). Altogether 74 species (7 species of Annelida, 56 species of Arthropods and 11 species of Mollusca) of macroinvertebrates were recorded from the studied sites during the investigation. In present paper we analyse the qualitative and quantitative abundance of macroinvertebrates (annelids, insects and molluscs) of Kawar lake ecosystem.
The physico-chemical parameters of Kosi river near Koparia, Saharsa, Bihar have been studied monthly during July 2014 to June 2015 from two sites. The results revealed that there was significant seasonal variation in some physico-chemical parameters and most of the parameters are in the normal range indicating better quality water resources