Tidal exchange of two decapod larvae Palaemon pacificus ( Caridea) and Upogebia africana ( Thalassinidae) between the Swartkops River estuary and adjacent coastal waters.

Abstract

Zoea 1 of U. africana are flushed out of the estuary into Algoa Bay on the nocturnal ebb-tide with very few returning on the subsequent flood-tide. Most P. pacificus larval movement occurred at peak velocities as they utilize the tidal currents in dispersion and recruitment. Some P. pacificus zoea 6 are washed out again on ebb-tides, but lateral movement to the banks during slack-tide appears to be a mechanism to prevent this occurring. P. pacificus adult movement in the mouth region was better correlated with nocturnal activity than with tidal movements.-from Author