Length-weight relationships and condition factors of Mystus vittatus (Hamilton, 1822) in natural and culture habitat

The Asian catfish Mystus vittatus is very popular food and ornamental fish in India. Length- weight relationships and condition factors of this fish are crucial component in fishery managements. The objective of this study is to investigate the relationships between the length, weight, condition factor (K), relative condition factor (Kn) and modified condition factor of Mystus vittatus (Hamilton, 1822). The study is particularly focus on analysing the sex wise variations in growth patterns, productivity, stocks, and conservation in two different habitats, natural habitat and biofloc system. The findings show that the species did not strictly follow the predicted cube law and showed allometric growth patterns in both habitats. The "b" value varies from 2.72 to 3.12, the condition factor (K) ranges from 0.587-1.50, modified condition factor ranges 0.54-2.26 and relative condition factor (Kn) ranges from 0.71-1.65. Natural habitats had the highest mean values for the regression parameter (b), condition factor (K), and relative condition factor (Kn). For male, female, and combined sexes in two different habitats, the R2 values show a statistically significant relationship between weight and length. The correlation analysis indicates some positive and negative significant relationships among sex, length, weight, condition factor, and relative condition factor. Therefore, there is significant relationship between condition factor, relative condition factor length, weight in two different habitats and it varies between male and female within same habitat. Thus, this finding will help to fishery managers for long term strategy development of Mystus vittatus in both natural as well as biofloc system.