No abstract

Background: Condition factor is an important factor to determine the general well being of any species. It is influenced by different factors like feeding, age of the fish, season, development of gonads etc. Reproductive development on other hand is a crucial factor in determining the condition of fish as gonad weight has certain impact on increasing the weight of fish as well as the condition of the fish. The experiment was thus to determine whether there is any synchronicity of reproductive development in the near threatened snakehead Channa bleheri with respect to its condition factor value.Methods: The condition of C. bleheri was closely monitored based on lenth-weight data round the year. The gonadal development of the species was determined calculating the Gonado-Somatic Ratio (GSR) as well as histological observation of the gonads.Result: It was found that the value of condition factor was directly proportional to the gonadal development which signifies the importance of gonad development in determining the fish condition. As there are many established factors that determine a fish condition, the inputs drawn out from the reproductive development can help to determine the condition of the fish.

Background: Macrognathus pancalus or barred spiny eel is a highly valued ornamental and food fish found in the Indian subcontinent. Due to the burgeoning population and their associated impacts, the population of the species is in rapid decline that necessitates time-bound intervention to conserve the species. The current investigation was undertaken to study the gonadosomatic index and gonad histology of Macrognathus pancalus collected from upper Assam, India.Methods: 500 samples of Macrognathus pancalus were collected from different water bodies such as wetlands, ponds, paddy fields, etc. from upper Assam, India during 2018-2019. Monthly samplings were carried out to evaluate the gonadosomatic index. The gonads were dissected out, measured and subsequently preserved for histological studies. Histological sections of preserved samples were prepared by employing accepted methodologies. The sections were then photographed using Leica DM 750 and gonadal staging was ascertained. Result: Gonadosomatic index studies revealed that it peaked in August in both males (3.45±0.18) and females (8.85±0.35), thereby indicating its spawning season. Minimum GSI values were observed during January in males (0.39±0.04) and in December in females (1.04±0.15) indicating the culmination of the breeding period and the advent of the preparatory phase. Macroscopic and microscopic examination unearthed five different phases of gonadal maturation. Gonadal staging through microscopic and macroscopic technique showed synchronicity with GSI values.

Feeding behaviour and rearing feasibility of a multipurpose wild goby fish, Glossogobius giuris in backyard ponds has been discussed. The fish shows inclination towards animal diet with wide range of food preferences at various trophic levels. Specimens collected from natural habitat and also from rearing pond indicate its preference towards small sized fishes. The fish is a voracious feeder and exhibit somewhat aggressive behaviour when kept in fasting mode for a period of 12 to 24 hour. Further, the fish prefers mostly in live food, be it small fish, earthworm or mosquito larvae but exhibit little interest towards homemade and commercial fish feed.