Sexual maturity cycle and spawning of Greenland halibut Reinhardtius hippoglossoides in the Davis Strait
Abstract:Female sexual maturation cycle and the main spawning time of Greenland halibut Reinhardtius hippoglossoides in the Davis Strait were studied through regularly collected samples during 1 year starting in spring 2003. Samples were collected from the southern slope of the Davis Strait Ridge between Canada and Greenland in the depth range 1000–1500 m. Female sexual maturation was described using different approaches: gonado-somatic index, visual macroscopic maturity stage index, histological microscopic maturity index and oocyte diameter measurements. A significant increase in the gonado-somatic index was seen from September onwards until February with a maximum estimated value of 18%. The proportion of mature fish increased from December until March. At the same time, the proportion of females with a low gonado-somatic index also increased from February, indicating that spawning had occurred and females were recovering. Oocyte diameter distribution revealed a leading cohort development during autumn through to December to February. A coupling between sexual maturity and fish condition was seen for females in maturing condition indicating a steady build up of stored energy in the liver from June to November.
Document Type: Regular Paper
Affiliations: 1: DTU Aqua/National Institute of Aquatic Resources, Technical University of Denmark, Department of Marine Fisheries, Charlottenlund Slot, DK-2920 Charlottenlund, Denmark 2: Møreforsking AS Marin, P.O. Box 5075, Larsgården, N-6021 Ålesund, Norway 3: Greenland Inst. of Natural Resources, P.O. Box 570, DK-3900 Nuuk, Greenland
Publication date: July 1, 2010