Horizontal and Vertical Distribution of Penaeidean and Caridean Larvae and Micronektonic Shrimps in the Florida Keys

Horizontal and vertical distribution of penaeidean and caridean larvae and micronektonic shrimps were analyzed from 44 samples collected at 9 stations over the Pourtales Terrace off Looe Key National Marine Sanctuary, Florida, U.S.A. 28 May–2 June 1989. Two transects of stations extended across the shelf in depths from 40 to 262 m. A 1 m² MOCNESS with O.333-mm mesh, CTD, and XBTs were used for sampling plankton and mapping temperature and salinity profiles. Carideans were the most abundant natantian larvae, represented by 11 genera, mostly coastal shallow-water species. Penaeidean larvae were represented by five genera of the superfamily Penaeoidea and three genera of the Sergestoidea. Sergestes spp. larvae and Lucifer typus juveniles and adults showed diel vertical migration. Ontogenetic differences in depth were observed for Sergestes spp. Late stages of the penaeoids Solenocera sp., Penaeus duorarum, and Parapenaeus sp. larvae were abundant at Station 13 of the first Leg when the Pourtales Gyre was present. This cyclonic gyre apparently does not affect distribution of the coastal caridean species but may cause shoreward advection of penaeoid larvae.