Cherax quadricarinatus: Identifying potentially invasive species in Lake Laut Tawar through their bio-population aspects

Abstract

Cherax quadricarinatus is an introduced species that is deliberately stocked in Lake Laut Tawar, Takengon, Indonesia. This study aims to analyze bio-population aspect of this species, including length frequency distribution, length-weight relationship, condition factors, and biology reproductive. A total of 361 individual was sampled bi-weekly from October to December 2021 in Lake Laut Tawar, Central Aceh, Indonesia. The carapace length of the crayfish ranged from 26.5 to 69.9 mm CL, with the length class mode being 41.69 mm CL. The growth pattern of freshwater crayfish is negative allometric (b<3) as described as an equation W = 0.0002CL29522 (R2 = 0.907). The sex ratio of C. quadricarinatus between male and female was in balance ratio (1:1) (Chi-square test result). The length of maturity (L 50) in male was 49.49 mm CL, while in female was 47.41 mm CL. The highest gonad somatic index (GSI) was in December at 1.02, while the lowest was in November at 0.79. Fecundity of female ranged from 267 to 970 eggs.