Initial feeding by Antarctic fish larvae during winter at South Georgia

North A.W., Ward P.

Date de parution: décembre 1989
Volume: 13
Number: 4
Pagination: 357-364
Editeur: Société Française d'Ichtyologie
doi: https://doi.org/10.26028/cybium/1989-134-007
Résumé

Initial feeding is described for larvae of four fish species from a fjord at the sub-Antarctic island of South Georgia during winter (May to August 1980). The data are limited because few fish larvae were caught in winter by the shorebased sampling methods available. Pagothenia hansoni (11-30 mm standard length), fed on calanoid copepods including adult Drepanopus forcipatus. Harpagifer georgianus (6.5-11 mm SL) and Parachaenichthys georgianus (11-17 mm SL) fed on a range of copepod taxa and stages. Pseudochaenichthys georgianus (14-177 mm SL) was exclusively piscivorous. Species which begin feeding during winter are larger by summer than species which hatch later in the year and therefore have larger trophic scope during the summer peak of zooplankton biomass and abundance. There is annual succession of larval fish species in the plankton which spreads predation on copepods throughout the year, thereby increasing the stability of the food-web, and the number of species of fish larvae that the copepods can support. The timing of the early life history of the fish larvae in relation to that of their prey species may affect the amount of food available to them.

Mots-clés: Feeding - Hapagifer georgianus - Larvae - Notothenioidae - Pagothenia hansoni - Parachaenichthys georgianus - Pseudochaenichthys georgianus - PSW - South Georgia
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