Seasonal length-weight relationships and condition factors of Pachypterus atherinoides (Bloch, 1794) in two habitats

Abstract

The present study aims to analyse the relationship among length, weight, condition factor (K), and relativecondition factor (Kn) of Pachypterusatherinoides (Bloch, 1794) with emphasis on seasonal variation of growthpatterns, productivity, stocks, and conservation in two contrasting ecosystems pond, and river in the PaschimMedinipur and Jhargram districts of West Bengal, India. The result reveals that the species showed allometricgrowth patterns in all seasons and did not strictly abide by the intended cube law. The regression parameter(b) values ranged from 1.98 to 3.13; the condition factor varied between 0.34 to 0.78; a relative conditionfactor ranged from 0.51 to 1.17 for P. atherinoides, in the study area. The average values of regression parameter(b), condition factor (K), and the relative condition factor (Kn) were highest during the post-monsoonseason. The regression coefficient (r2) values depict a strong relationship between the length and weight inboth habitats and all seasons. The Pearson’s correlation indicates some positive and negative significantcorrelations among season, length, weight, condition factor, and relative condition factor in the study area (P<0.01 and P<0.05). The Post Hoc test represents a significant (P<0.05) seasonal relationship betweenlength, weight, condition factor, and relative condition factor. However, there is no significant habitatbasedrelationship between the same parameters. Therefore, the present findings will help fishery managersto develop effective methods for the sustainable management of P. atherinoides in their habitats.