Abstract
Density of Penaeidae was assessed in habitats of Thalassia testudinum with different relative location (inshore zone and coastal lagoon) and sediment type (fine sand and coarse sand) during three weather seasons in the Yucatan peninsula, Mexico. A total of 26,847 penaeids were collected on a fortnightly basis from June 2001 to May 2002. A differential habitat use was observed in juveniles of three species of penaeids. Densities of Farfantepenaeus brasiliensis (mean size +/- SD: 8.3 +/- 3.8 mm CL, carapace length) and Farfantepenaeus notialis (5.5 +/- 2.2 mm CL) were highest in the coastal lagoon in T testudinum on fine sand, while density of Metapenaeopsis goodei (6.7 +/- 1.7 mm CL) was also highest in T testudinum on fine sand, but in the inshore zone. This spatial distribution pattern varied little during the three sampling seasons. A unimodal temporal distribution pattern was observed for juveniles of each species of penaeid, the abundance peaks of E brasiliensis and M. goodei overlap in the nortes season, while the abundance peak of E notialis was distinct, peaking in the rainy season. In contrast to juveniles, epibenthic Farfantepenaeus spp. postlarvae (3.2 +/- 0.5 mm CL) had a more uniform spatial distribution with a bimodal temporal distribution pattern, a highest abundance peak in the late rainy-early nortes seasons and other minor in the dry season. A redundancy analysis indicated that densities of penaeids were related primarily with water salinity, sediment grain size, and aboveground biomass and structural complexity of T testudinum, which are variables closely linked with the spatial arrangement of the habitats along the inshore zone and coastal lagoon. The use of different T testudinum habitats allows coexistence of sympatric penaeids in the nursery ground with minimal inter-specific interactions.
