Length based growth estimation of sea cucumbers (Holothuria verrucosa and Holothuria pardalis) (Holothuroidea:Echinodermata) collected from coastal areas of Karachi, Pakistan (northern Arabian sea)

Abstract

To estimate the growth parameters, the non-seasonal von Bertalanffy and Hoenig seasonal von Bertalanffy models were fitted to the length frequency data of Holothuria pardalis and H. verucosa obtained from coastal areas of Karachi during January and December 2018. The Hoenig seasonal von Bertalanffy growth parameters were estimated as L∞ = 18.0 cm total length (TL), K = 1. 00 year-1 for H. pardalis and as L∞ = 18.0 cm TL, K = 0.86 year-1 for H. verrucosa. H. verrucosa individuals reached 68.9% of their maximum total length at the one year old class. For H. pardalis it was calculated as 54.2%. The seasonal oscillation in growth rate for H. pardalis (C = 0.90) was larger than it was for H. verrucosa (C = 0.18). The slowest period of growth corresponded to June in H. verrucosa and February in H. pardalis may be the result of the extended both reproduction and poor nutrition periods due to high rainfall regime. The relatively high growth rate (K) of these species may have important implications for their survival, mainly in environments where conditions cause biological stress and oceanic disturbances but may also increase its potential as a candidate for aquaculture.