Zooplankton biodiversity in a large region of the Argentine Sea: key crustacean species and their trophic role for main fisheries resources

VIÑAS, M. D.; SANTOS, B. A.; CEPEDA, G. C.; DIMAURO, R; MARRARI, M.; MORIONDO, P; PADOVANI, L; RAMÍREZ, F; TEMPERONI, B

Conferencia; World Marine Biodiversity Conference; 2011

Zooplankton biodiversity of the Argentinean shelf has been examined in several studies since the 80’s. Common finding were summarized and related with hydrographic and productivefeatures, between a large shelf portion (34º - 47ºS). Key crustacean species were identified and their trophic relationships with main fisheries resources were considered. Four faunistic areas (FA) were observed: estuarine, coastal, middle shelf and shelf break, generally bounded by particular hydrographic structures, such as fronts. In the estuarine FA, the copepod Acartia tonsa and the mysid Neomysis americana provide food for larvae and juveniles of most coastal fishes. North of 40ºS, in the coastal FA,  cladocerans and small copepods Oithona nana, Paracalanus spp. and Ctenocalanus vanus are major food items for Engraulis anchoita larvae and adults, while the calanid Calanoides carinatus and the hyperiid Themisto gaudichaudii are preferred prey of chub mackerel (Scomber japonicus). Further south (42º-47ºS), in the coastal and middle shelf FAs, the latter crustaceans and the euphausiid Euphausia lucens are main food for hake (Merluccius hubbsi) larvae and juveniles and shrimp (Pleoticus muelleri). South of 45ºS, in coastal and shelf FAs, T. gaudichaudii is also the dominant prey of squid (Illex argentinus) and demersal fishes.