Occurrence of larvae of spanish mackerels, genus Scomberomorus (Teleostei : Scombridae), in shelf waters of the Great Barrier Reef

Abstract

Presence of larvae of Scomberomorus species in plankton samples collected over a 3-year period from the coastal and Great Barrier Reef lagoon region off Townsville was seasonal, occurring over the spring-summer period. S. semifasciatus and S. queenslandicus larvae occurred from October to February, whereas S. commerson larvae occurred over a more limited period, from November to January. S. semifasciatus larvae were restricted to the coastal bays and the inner margin of the lagoon. S. queenslandicus larvae occurred in the coastal bays but extended over the lagoonal region as well. S. commerson larvae occurred only in the lagoon. This inshore-offshore separation is considered to be related to distribution of spawning adults and longshore currents in the lagoon. Absence of S. commerson larvae from inshore stations suggests that juveniles reach their coastal-estuarine habitat through directed movement at the juvenile stage rather than through passive transport of eggs and larvae.