Feeding habits of two skate species, Raja miraletus Linnaeus, 1758 and Dipturus oxyrinchus (Linnaeus, 1758) (Chondrichthyes, Rajidae), around the Gökçeada Island (Northern Aegean Sea)

Abstract

This study investigated the feeding habits of Raja miraletus Linnaeus, 1758 and Dipturus oxyrinchus (Linnaeus, 1758). For the purpose of this study, the specimens were obtained monthly from the commercial trawlers operating around the Gökçeada Island in the Northern Aegean Sea between February 2019 and February 2020. A total of 29 (24 female and 5 male) brown rays (Raja miraletus) and 36 (20 female and 16 male) longnosed skates (Dipturus oxyrinchus) were captured. The total lengths of the R. miraletus specimens ranged between 24.0 cm and 53.9 cm, while the D. oxyrinchus specimens measured between 17.1 cm and 85.0 cm. Total length-weight relationships of R. miraletus and D. oxyrinchus specimens, respectively; W=0.0002TL3.92 (R2=0.97) and W=0.0007TL3.43 (R2=0.97) were calculated. The analysis of the stomach content of the specimens showed that crustacea were the primary and the most important prey group for R. miraletus (IRI% = 67.09), followed by teleosts (IRI% = 1.00) and cephalopods (IRI% = 0.45). The D. oxyrinchus specimens were determined to primarily feed on crustacea (IRI% = 74.3), followed by teleosts (IRI% = 6.50) and nematoda (IRI% = 0.40).