Comparison of juvenile spotted wolffish, Anarhichas minor, growth in shallow raceways and circular tanks.

摘要

We compared growth properties of juvenile spotted wolffish with initial mean weight (+or-SE) 105.9 (+or-3.1) g reared in shallow raceways and conventional circular tanks in a 202-d-long growth trial at ambient temperature (approximately 4.0 C). From Day 41 onward, the fish in the shallow raceways was significantly larger, and final mean weights were 356.3 (+or-18.2) and 318.2 (+or-15.6), in the shallow raceways and the circular tanks, respectively. Overall, growth rates were 14% higher (0.62%/d) in the shallow raceway group compared to the circular tanks (0.52%/d). Feed conversion efficiency differed and was 17% higher in the shallow raceways (1.01) compared to the circular tanks (0.84). Correlation between adjacent growth rates was more profound in the circular tanks (mean Spearmans rank, rSp=0.38) than in the shallow raceways (mean rSp=0.15). This could indicate a stronger social hierarchy in conventional tanks leading to suppressed growth, which is in line with the growth data presented in this study. The findings of the present study may have important consequences for optimization of commercial production of spotted wolffish and could be applicable to other bottom-dwelling species..