Life history trait variation of Greenland lumpfish (Cyclopterus lumpus) along a 1600 km latitudinal gradient

Lumpfish (Cyclopterus lumpus) is a highly commercial semi-pelagic fish found throughout the North Atlantic. In West Greenland, lumpfish are distributed along a 1600 km continuous north–south gradient, and is an ideal candidate for studying the effects of latitude and environment on key life history traits (LHT).

We describe the spatial variation in length-weight relationships, size-at-age and age-at-maturity in pre-spawning adult males and females in six areas from south (60.7°N, area 1) to north (72.8°N, area 6) and estimate the reproductive output of females as a product of fecundity and individual egg energy content.

All the studied LHT varied significantly among areas. The average age of both sexes was approximately three years in the areas 1–3 and gradually increased to approximately four years in area 6. Fecundity and individual egg energy content increased from area 2 to area 5 and then decreased in area 6. Consequently, the relative reproductive output (kJ gonad/kg fish) ranged from 1.21 ± 0.38 in area 6 to 2.53 ± 0.84 in area 5.

These spatial differences are hypothetically explained by variations in secondary production and temperature.