Tub gurnardChelidonichthys lucernaL.: a new fish species suitable for farming? First answers evaluating the growth of juveniles reared at different stocking densities, welfare and fillet quality

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).