Resumen de Length-Girth Relations of Five Sparid Fishes off Gökçeada Island, Northern Aegean Sea, Turkey
This study was carried out in order to explore the relations between opercular girth (Gope), maximum girth (Gmax) and total length (TL) for five sparid fishes [Pagellus acarne Risso, 1827, Pagellus bogaraveo Brünnich, 1768, Pagellus erythrinus Linnaeus, 1758, Sarpa salpa Linnaeus, 1758, and Spondyliosoma cantharus Linnaeus, 1758] in family sparidae.
The samples were obtained during January 2014 to December 2016 with the aid of commercial fishermen off Gökçeada Island (Northern Aegean Sea, Turkey). The linear regression of opercular girth and maximum girth with the total length were calculated for each species. Gope and Gmax were found to increase linearly with total length for all sparids. The mean±standard error (and range) of total length were 16.5±0.24 (15.0–23.8) cm, 15.0±0.15 (14.0–17.7) cm, 18.1±0.38 (15.0–21.5) cm, 28.1±0.51 (20.3–32.0) cm and 24.9±0.79 (19.7–31.7) cm for Pagellus acarne, Pagellus bogaraveo, Pagellus erythrinus, Sarpa salpa and Spondyliosoma cantharus, respectively. However, the opercular girth-length relations were calculated as Gope = 0.6190TL–1.0964 (r²=0.95), Gope = 0.9499TL–4.8657 (r²=0.85), Gope = 0.8453TL–3.7876 (r²=0.89), Gope = 0.4286TL+3.0323 (r²=0.87), Gope = 0.8329TL–1.5604 (r²=0.96), whereas the maximum girth-length relations were determined as Gmax = 0.6643TL–0.9501 (r²=0.93), Gmax = 1.0017TL–4.6680 (r²=0.90), Gmax = 0.8714TL– 2.9893 (r²=0.88), Gmax = 0.4463TL+5.2661 (r²=0.80), Gmax = 0.8088TL+1.3091 (r²=0.91) for Pagellus acarne, Pagellus bogaraveo, Pagellus erythrinus, Sarpa salpa and Spondyliosoma cantharus, respectively. The present research comprises the first findings about length-girth relations (LGRs) of Spondyliosoma cantharus for the northern Aegean Sea, whereas, no LGRs estimates of Sarpa salpa have beforehand been reported worldwide. Because these findings are important for the selectivity of fishing gear so as to prevent the capture of younger and/or undersized individuals, it will contribute to the development of ecosystem-based fisheries management
