Spawning strategies and transport of early stages of the two Cape hake species, Merluccius paradoxus and M. capensis, in the southern Benguela upwelling system
B Grote
EK Stenevik
Werner Ekau
HM Verheye
MR Lipiński
W Hagen
Abstract
Seasonal and short-term variability of environmental parameters influence the spawning strategies of fish species. In this study, the spawning strategies and the transport of early stages of the two Cape hake species off South Africa were investigated. Distribution of eggs and larvae of Merluccius paradoxus and M. capensis was analysed in order to derive more detailed and species-specific information on spawning season, spawning location, and transport of early stages. Samples were collected during three pilot surveys between January and October 2007 and during an extensive survey in September/October 2008 in the southern Benguela upwelling system off South Africa. Eggs and larvae of M. paradoxus were found in greater numbers than those of M. capensis during all surveys. Highest abundances were found from September to October, indicating one spawning peak for M. paradoxus during late austral winter to spring. The western Agulhas Bank was identified as the primary spawning ground, and smaller spawning events occurred on the West Coast. Larvae of both species were mainly distributed in subsurface waters between 25 and 100 m. More than 50% of all larvae caught had a total length between 3 and 4 mm and size increased significantly with decreasing latitude. Merluccius capensis were found closer inshore than M. paradoxus, indicating that early stages of the two species followed separate drift routes. We assume that this distribution pattern most likely evolved from differences in spawning location and phenology. The spawning strategies of M. paradoxus and M. capensis are well adapted to a time-frame of optimal transport conditions favourable for larval survival in the highly variable environment of the southern Benguela upwelling system, but the peak spawning of the two species is separated in time and space.
Grote B., Stenevik E., Ekau W., Verheye H., Lipiński M. and Hagen W. (2012) Spawning strategies and transport of early stages of the two Cape hake species, Merluccius paradoxus and M. capensis, in the southern Benguela upwelling system. African Journal of Marine Science 34(2): 195-204. 10.2989/1814232X.2012.675040
@article{Grote2012,
Title = {Spawning strategies and transport of early stages of the two Cape hake species, Merluccius paradoxus and M. capensis, in the southern Benguela upwelling system},
Author = {Grote, B and Stenevik, EK and Ekau, Werner and Verheye, HM and Lipiński, MR and Hagen, W},
Editor = {},
Journal = {African Journal of Marine Science},
Year = {2012},
Pages = {195-204},
Volume = {34},
Doi = {10.2989/1814232X.2012.675040},
Abstract = {Seasonal and short-term variability of environmental parameters influence the spawning strategies of fish species. In this study, the spawning strategies and the transport of early stages of the two Cape hake species off South Africa were investigated. Distribution of eggs and larvae of Merluccius paradoxus and M. capensis was analysed in order to derive more detailed and species-specific information on spawning season, spawning location, and transport of early stages. Samples were collected during three pilot surveys between January and October 2007 and during an extensive survey in September/October 2008 in the southern Benguela upwelling system off South Africa. Eggs and larvae of M. paradoxus were found in greater numbers than those of M. capensis during all surveys. Highest abundances were found from September to October, indicating one spawning peak for M. paradoxus during late austral winter to spring. The western Agulhas Bank was identified as the primary spawning ground, and smaller spawning events occurred on the West Coast. Larvae of both species were mainly distributed in subsurface waters between 25 and 100 m. More than 50% of all larvae caught had a total length between 3 and 4 mm and size increased significantly with decreasing latitude. Merluccius capensis were found closer inshore than M. paradoxus, indicating that early stages of the two species followed separate drift routes. We assume that this distribution pattern most likely evolved from differences in spawning location and phenology. The spawning strategies of M. paradoxus and M. capensis are well adapted to a time-frame of optimal transport conditions favourable for larval survival in the highly variable environment of the southern Benguela upwelling system, but the peak spawning of the two species is separated in time and space.},
}
TY - JOUR
AU - Grote, B
AU - Stenevik, EK
AU - Ekau, Werner
AU - Verheye, HM
AU - Lipiński, MR
AU - Hagen, W
TI - Spawning strategies and transport of early stages of the two Cape hake species, Merluccius paradoxus and M. capensis, in the southern Benguela upwelling system
T2 - African Journal of Marine Science
PY - 2012
SP - 195-204
VL - 34
DO - 10.2989/1814232X.2012.675040
AB - Seasonal and short-term variability of environmental parameters influence the spawning strategies of fish species. In this study, the spawning strategies and the transport of early stages of the two Cape hake species off South Africa were investigated. Distribution of eggs and larvae of Merluccius paradoxus and M. capensis was analysed in order to derive more detailed and species-specific information on spawning season, spawning location, and transport of early stages. Samples were collected during three pilot surveys between January and October 2007 and during an extensive survey in September/October 2008 in the southern Benguela upwelling system off South Africa. Eggs and larvae of M. paradoxus were found in greater numbers than those of M. capensis during all surveys. Highest abundances were found from September to October, indicating one spawning peak for M. paradoxus during late austral winter to spring. The western Agulhas Bank was identified as the primary spawning ground, and smaller spawning events occurred on the West Coast. Larvae of both species were mainly distributed in subsurface waters between 25 and 100 m. More than 50% of all larvae caught had a total length between 3 and 4 mm and size increased significantly with decreasing latitude. Merluccius capensis were found closer inshore than M. paradoxus, indicating that early stages of the two species followed separate drift routes. We assume that this distribution pattern most likely evolved from differences in spawning location and phenology. The spawning strategies of M. paradoxus and M. capensis are well adapted to a time-frame of optimal transport conditions favourable for larval survival in the highly variable environment of the southern Benguela upwelling system, but the peak spawning of the two species is separated in time and space.
ER -
