Age, Growth, and Mortality of the Redcoat Sargocentron rubrum (Forsskal, 1775), in Iskenderun Bay, Northeastern Mediterranean

Abstract

This study was carried out to determine the age, growth, mortality rate, and exploitation rate of Redcoat, Sargocentron rubrum from Iskenderun Bay, Northeastern Mediterranean. A total of 331 individuals were examined by sampling monthly from September 2017 to August 2018 in the years. The examined samples were 143 (43.20%) females and 188 (55.13%) males. S. rubrum specimens ranged from 10.0 to 21.5 cm, TL with an average of 16.07 +/- 0.12 cm and from 17.40 to 196.016.86 g, TW with an average of 85.04 +/- 2.05 g. The age ranged from 1 to 4 years for females and males and the 3 age group was dominant in the population. The minimum length was found as 10.00 cm for 1 age group while the maximum length was found as 21.50 cm for 4 age group. The mean length at the end of each year of life for all individuals of S. rubrum was calculated 11.78, 14.52, 16.39, and 19.07 cm for 1(st), 2(nd), 3(rd), and 4(th), years of life respectively. The length-weight relationships were computed for female, male and combined sexes respectively as; W= 0.0129xL(3.1453), R-2= 0.968, W= 0.0118xL(3.1742), R-2= 0.966 and W= 0.0124xL(3.1576), R-2= 0.967. von Bertalanffy growth parameters were estimated as L-infinity= 35.64 cm, K= 0.110 year(-1), t(0)= -1.015 years for females, L-infinity= 35.36 cm, K= 0.112 year-(1), t(0)= -1.065 years for males, and as L-infinity= 35.53 cm, K= 0.113 year(-1), t(0)= -1.112 years for combined sexes. The growth performance index (o') was found to be 2.149 for combined sexes and the obtained growth performance index for this study was compared with those reported by different authors. Fulton's condition (CF) factor values were determined 1.933 for females and 1.923 for males of S. rubrum. The total mortality rate (Z) of the S. rubrum individuals was 1.38, the natural mortality rate (M) was 0.99, and the fishing mortality rate (F) was determined to be 0.39. The exploitation ratio (E) was calculated as 0.28, and this result revealed that the S. rubrum population was not over-exploited. The comprehensive biological characteristics of this species for the first time have been examined in the Northeastern Mediterranean, Turkey. Thus, this study will provide an important contribution to the science and fisheries management applications for this species.