A study on some population parameters of spot-tail mantis shrimp (Squilla mantis L.; Crustacea: Stomatopoda) in Edremit Bay (Northern Aegean Sea)

Abstract

This study was carried out for the determination of the biological characteristics of mantis shrimp (Squilla mantis, L.) in Edremit Bay. For this purpose, a total of 627 mantis shrimp were caught by the vessel Salih Reis from Edremit Bay between September 2014 and April 2015. The age and sex composition, total length, carapace length, and weight distributions, age-length, length-weight relationships, gonadosomatic index (GSI), von Bertalanffy growth parameters, mortality rates, and exploitation ratio (E) of the spottail mantis shrimp populations were presented. The total length values of the investigated individuals were found to be 9.0 - 20.8 cm, the carapace length values were between 2.0 - 5.4 cm, and their weights were between 6.5 - 78.0 g. It was determined that 35.5% of the population was made up of males and 64.5% were females, and the sex ratio was D: E = 1.81: 1. The age distribution of individuals was found to be between 1 and 4 years of age, and 4 years of age was dominant in the population. The total length - weight relationship was calculated as W = 0.0106TL2.9469, the total length - carapace length relationship CL = 0.3735TL0.8555 and the carapace length - weight relationship was calculated as W = 0.7507CL2.8418. von Bertalanffy Growth Equation was calculated as L∞ = 21.64*[1-e - 0.18*(t+1.03)] for all spot-tail mantis shrimp. Total mortality rate (Z), natural mortality rate (M), fishing mortality (F), and Exploitation rate (E) were calculated as 0.67, 0.47, 0.20, 0.30, respectively. Exploitation rate showed that spot-tail mantis shrimp stock in Edremit Bay was not caught enough. It was found that spawning occurred from winter to spring.