Composition and diversity of shrimps in the Protected Ma'an Archipelago area

Abstract:

Understanding shrimps community structure in regional scales is vital in the study of its ecological roles to predators, especially when studied area are happened to be idea feeding and spawning grounds for commercial fishes. Based on samples collected by shrimp trawls from summer(July) and autumn(October) in 2013 to winter(march) and spring(may) in 2014 in the protected Ma'an Archipelago area, we analyzed the seasonal variations in species composition, dominance, resource density and species diversity and richness of shrimps, and discussed the contribution of dominant species to the total resource density. In all, 20 species of shrimp were collected, which belonged to 9 families under 16 genera. From summer to spring, the number of shrimp species turned out to be 12, 16, 13 and 14. Palaemon gravie, Parapenaeopsis tenella and Oratosquilla oratoria were dominant species in all year, which were the main species influencing the variation in shrimp resource density. The biomass and abundance of shrimp were greatest in summer(206.7kg/km² and 117.4×103 ind/km²), while the least in autumn (46.9kg/km² and 28.7×10³ ind/km²). The Margalef richness index(D) of shrimp was 1.12-1.55, the Shannon-Wiener diversity index(H') was 0.84-1.55, and the Pielou evenness index(J') was 0.41-0.76. Diversity indinces tend to be highest in autumn, and then was in winter and summer, but lowest in spring. One-way ANOVA declared that diversity indinces had notable difference between seasons (P<0.05).