The Length-Weight Characteristics of Five Elasmobranch Species (Pisces: Chondrichthyes) from Izmir Bay (Aegean Sea Coast of Turkey): Spring 2018

Abstract

In this study, a total of 364 samples were collected and 349 of them belonged to, 349 specimens of Dasyatis pastinaca, 6 of Gymnura altavela, 5 of Torpedo marmorato, 2 of Aetomylaeus bovinus and Mustelus mustelus, were obtained by-catch in trammel nets off the Izmir Bay (Aegean sea coast of Turkey) during period of spring in 2018. Males of D. pastinaca ranged from 28–62 cm and females from 31.5-94 cm total length. The analysis of the angular coefficient (b) demonstrated that growth (in weight) in relation to length was isometric in males and females of D. pastinaca. Morphologic measurements of a total of 60 individuals to represent all individuals of the population, t test in independent groups to determine differences in males and females and all other morphometric measurements were statistically tested by multiple regression analysis (stepwise method). Therefore, difference between mean values obtained according to sexes was not found different. However, A linear correlation between weight- pelvic length for females and weight- preanal length for males according to multiple regression analysis in male and female individuals. Isometric and positive allometric growths were calculated for species of Torpedo marmorata and Gymnura altavela, respectively.

Keywords

• length-weight relationship
• elasmobranch
• chondrichthyes
• morphometrics
• skates
• aegean sea