Modelling the variation in larval dispersal of estuarine and coastal ghost shrimp: Upogebia congeners in the Gulf of Cadiz

Abstract

Upogebia pusilla and U. deltaura are 2 common ghost shrimp species occurring in estuaries and over the shelves of European coasts, respectively. The adults have a great impact on benthic habitats and communities, as they depend on sandy and muddy substrates to construct long burrows that provide shelter and appropriate conditions for reproduction and feeding. Their planktonic larval phase lasts around 3 wk and consists of 4 zoeal stages and a decapodid that must settle in the benthos before recruiting to adult populations. In situ data were obtained from CTD casts and plankton hauls during an oceanographic survey that took place along the southern Portuguese coast in August 2010. All zoeal stages and decapodids of both species were found distributed over the shelf not exceeding 30 km from the coastline. A modelling approach was used to explain the differences in dispersal of these Upogebia congeners inhabiting different habitats of the same geographic area and exposed to similar oceanographic conditions. Their vertical distribution, oceanic circulation and the points of larval release were considered. A different dispersal strategy, influenced by natal origin and vertical behaviour, was evident for each species. The presence of decapodid stages close to substrates suitable for settlement where adult populations occur, especially for U. deltaura, suggests a good probability of successful settlement. Dispersal patterns observed for the 2 species and the agreement between field observations and model simulations indicate that these species are good models for other coastal invertebrates that reproduce in summer and have short larval development. © 2013 Inter-Research.