Do habitat, month and environmental parameters affect shrimp assemblage in a shallow semi-enclosed tropical bay, Thailand?

Assemblages of shrimp in association with habitat, season, and environmental parameters were examined. The tested hypotheses was that habitat, season, and water parameters affect species diversity, density, and community structure of shrimps in the shallow semi-enclosed tropical bay, Thailand. Samples were collected monthly at five different habitats with different bottom characteristics and vegetation between February 2011 and January 2012 by an encircling seine net. Altogether, 32,523 shrimps from 14 species were collected. Acetes sp., Metapenaeus moyebi, and Metapenaeus lysianassa dominated the catch with 50.6%, 22.0%, and 17.6%%, respectively. Most of them were juveniles or adults of small sized-species. Both habitat and month had highly significant impacts on density of shrimps (P<0.005), but only monthly factor affected species richness (P<0.05). Cluster dendogram indicated further that the difference in community structure of shrimps was based mainly on seasonal impact. Canonical correspondence analysis (CCA) recorded different responses of shrimp assemblages to specific water quality parameters. Water temperature was the major factor structuring shrimp assemblage in the bay.