Age and growth of four-spotted megrim (Lepidorhombus boscii Risso, 1810) from Saros Bay (Northern Aegean Sea, Turkey)

Abstract

In this study, the growth parameters of the four-spotted megrim, (Lepidorhombus boscii Risso, 1810), were studied in Saros Bay, which had been closed to bottom trawl fishery since 2000. The sex ratio of females to males was 1:0.42. Length-weight relationships were W=0.0032L3.31 and W=0.0069L3.04 for females and males, respectively. Growth parameters of the populations were L∞=49.8 cm, k=0.09 year-1, t0=-2.15 year for females; L∞=39.1 cm, k=0.11 year-1, t0=-2.59 year for males. The growth performance index (Φ’) was found to be 2.35 and 2.23 for females and males, respectively.

Biology and fisheries of the spotted flounder (Citharus linguatula) caught by multiple gears with partial spatiotemporal overlaps

“…Larger female sizes have also been reported for other flatfish species (e.g. Lozán, 1992;Landa and Piñeiro, 2000;Gerritsen et al, 2010;Cengiz et al, 2013). According to Vassilopoulou and Papaconstantinou (1994) this difference is due to the fact that males are smaller at first maturity.…”

“…Ageing was carried out based on the interpretation of sagittal otolith macrostructure. We used the otoliths of the blind side, as in these the nucleus is more central compared to those of the ocular side making their macrostructure interpretation easier (Armsworthy and Campana, 2010;Cengiz et al, 2013Cengiz et al, , 2014. Otoliths were stored in glycerin.…”

Reproductive biology of the spotted flounder, Citharus linguatula (Actinopterygii: Pleuronectiformes: Citharidae), from Saros Bay (northern Aegean Sea, Turkey)

“…This phenomenon is a common feature in many pleuronectiforms (Lozán 1992, Landa and Pinerio 2000, Cengiz et al 2013). This could be attributed to differences in metabolism between females and males, such as differences in oxygen consumption (Pauly 1994a(Pauly , 1994b, differences in the level of surplus energy between reproduction and somatic growth (Rijnsdorp and Ibelings1989), and differential food ingestion (Lozán 1992).…”

“…The otoliths, placed in watch glass filled with the water, were read using a stereoscopic zoom microscope under reflected light against a black background. Opaque and transparent zones were counted; one opaque zone plus one transparent zone was assumed to be one year (Cengiz et al 2013).…”

Maximum Length Record of Common Two-banded Seabream (Diplodus vulgaris Geoffroy Saint-Hilaire, 1817) for Aegean Sea with Turkish Waters

“…The shelf extends at a water depth of 90-120 m. The length of the bay is about 61 km and the width at the opening to the Aegean Sea is about 36 km (Eronat and Sayın 2014;Cengiz et al 2019b). As Saroz Bay had been closed to bottom trawl fishing since 2000 (Cengiz et al 2011) and no industrial activity was prevalent in the area (Sarı and Çağatay 2001), the bay can be considered as a pristine environment (Cengiz et al 2013;2019c;2019d).…”