Annotated records of scombroid eggs and larvae distribution in northeastern Mediterranean waters

The distribution of eggs and larvae of scombroid fish in northeastern Greek waters were studied during the summer of three consecutive years(1992-1994) to determine spawning, time of spawning peaks, and the possible preferred spawning grounds. Among eggs only those of Xiphias gladius were successfully identified. Larvae of Thunnus alalunga, Euthynnus alleteratus, X. gladius and Auxis rochei were recorded, the latter species being encountered more frequently than the rest. Most scombroid larvae were collected in the Sporades Islands’ basin and their abundance, particularly that of A. rochei, was relatively increased at the end of the summer, possibly suggesting increased spawning activities during that period

Summer distribution of fish larvae in northern Aegean Sea

Larval fish and hydrographic data were collected in Kavala Gulf (northern Aegean Sea) across a fine scale grid of 17 stations in two surveys, carried out in the beginning of July 2002 and 2003. Despite the different taxonomic resolution and excluding the unidentified larvae, 22 taxa were caught in 2002 and 27 in 2003. Seventeen taxa were present in both years' collections. A total of 833 larvae were collected during the two samplings. The adults of several larvae caught, although sometimes at very low concentrations, are species with high commercial value or represent a major proportion of the captured production of the northern Aegean Sea. The larvae of European anchovy (Engraulis encrasicolus) were most abundant in both years followed by the brown comber (Serranus hepatus), the gobies (Gobius sp.) and, only for 2003, round sardinella (Sardinella aurita). Maximum anchovy larval densities reached 4145/10 m(2) and 13852/10 m(2) in the 2002 and 2003 surveys, respectively. The spatial extent Of anchovy larvae was also high as they were collected at 12 stations in 2002 and at 15 in 2003. Besides water circulation, the spatial distribution of fish larvae was largely influenced by temperature, salinity and dissolved oxygen

Tub gurnard Chelidonichthys lucerna

A trial was conducted to evaluate the growth performance and survival of Chelidonichthys lucerna. A total of 13 352 180-days old juveniles (5.5 ± 2 g; 5 ± 1 cm) were reared at two different densities (A-EXP = 68 fish m−3; B-FFA = 15 fish m−3) in eight tanks (four tanks per group) for 360 days. The welfare status and meat quality of fish were evaluated for the A-EXP and B-FFA groups in comparison with wild-caught fishery gurnard (C-WID). The survival rate was high for both A-EXP (79%) and B-FFA (93.5%). B-FFA fish had the highest specific growth rate (1.16 vs. 1.07; P < 0.05), and were heavier than A-EXP fish (321 ± 40 g vs .239 ± 44 g; P < 0.01). Rearing conditions did not affect blood metabolites, except for glucose concentrations, which were higher in C-WID (P < 0.05). The meat quality traits showed that reared groups were fatter (2.8–3.2%) than C-WID (0.94%); total n-3 fatty acids (19.02–19.26%) were lower in reared groups than C-WID (29.99%); and EPA + DHA were similar in all groups (15.1–16.61% vs. 27.99%). Despite the good growth and survival, the final mean weight was below that requested by the market (400–500 g). Future research efforts should focus on reducing the feed conversion rate (3:1)