Habitat utilization by postlarval and juvenile penaeid shrimps in Mobile Bay, Alabama

Densities of juvenile and postlarval Farfantepenaeus aztecus, F. duorarum, and Litopenaeus setiferus were compared in vegetated fringing marsh and adj acent nonvegetated areas over a range of environmental conditions in Mobile Bay, Alabama. Densities of all three species were significantly greater in vegetated than nonvegetated areas, with 82% of all penaeids found in veget ated areas. Among vegetated sites, significantly lower densities were found in oligohaline areas;, whereas mesohaline areas had the highest densities. Significant positive correlations were found between density and salinity for F. aztecus and F. duorarum but not for L. setiferus. Emergent vegetatio n is important habitat for F. aztecus and F: duorarum as reported from othe r locations, and our data support a similar conclusion for L. setiferus. Sh oreline emergent marsh vegetation is particularly important in Mobile Bay a s it represents the only extensive vegetated habitat readily available to F . aztecus, F. duorarum, and L. setiferus.