This study is aiming to investigate the distribution of epibenthic shrimp communities in relation to the environmental factors of their habitats in the coastal sandy bottom of southwestern Taiwan. Shrimp samples were collected from April 2002 to July 2003, with a beam trawl operated at seven stations along the coasts. Simultaneously, water temperature, salinity, dissolved oxygen were measured and sediments were collected. Particle size and organic matter of the sediments were then analyzed in the laboratory. The results of PCA analyses on these environmental factors revealed that the observations could be segregated into two groups along the PC1, representing rainy season with high temperature, low salinity and dry season with low temperature, high salinity, respectively. The observations with coarse particle (>0.125 mm), representing samples from north sites, were found to distribute in the upper part of the PC2; while those with fine particle (<0.125 mm), representing samples from south sites, distributed in the lower part. In total, 15,591 individuals of shrimp were collected, including 20 genus, 39 species. Metapenaeopsis palmensis (88.2%), Trachysalambria curvirostris (3.6%), M. barbata (3.5%) and Parapenaeopsis cornuta (1.4%) were the four dominant species.
Significant differences in the spatial distribution were due to the different composition of the dominant species. Although M. palmensis was the most abundant species in most stations, its percentage abundance was the lowest at Fangliao and Jiading, where the dominant species were T. curvirostris for the former and M. barbata and P. cornuta for the latter. Species preferences for various combinations of environmental variables are responsible for shifts in the structure and overall abundance of assemblages and dictated some patterns. Higher abundances of T. curvirostris, Trachypenaeus granulosus, and Solenocera koelbeli were associated with the appearance of high temperature, low salinity and very fine sand, representing the environmental features of Fangliao and Linbian during the rainy season. Stenopus hispidus, Metapenaeus moyebi, Metapenaeus ensis and M. palmensis were abundant coinciding with low temperature, high salinity and high silt and clay that reflecting the dry season of Linyuan and Linbian waters. Metapenaeopsis dalei and M. barbata appeared in large numbers at habitats with high temperature, low salinity and coarse sand, which mainly occurred in Zouying to Jhongjhou during the rainy season. Moreover, Scyllarus rugosus and Parapenaeopsis cornuta seemed to prefer coarse sandy bottom mainly distributed from Jiading to Linyuan.
Temporal fluctuations were associated with the population dynamic of the dominant species. The abundance was reduced while the M. palmensis migrated to open sea in late summer and early autumn. As the juveniles of M. palmensis and M. barbata back to the inshore waters, the abundance were increased and reached the peak in spring. Because of the limited distribution, T. curvirostris and P. cornuta were not influence the overall temporal fluctuations but the local fluctuations.
Overall, temporal fluctuations act more at a specific level even structural one, and may be linked to some particular stages of the benthic shrimp life cycle, but do not significantly influence the spatial organization.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0713106-165442 |
| Date | 13 July 2006 |
| Creators | Chen, Hsu-sen |
| Contributors | Ming-shiou Jeng, Mao-sen Su, Tin-yam Chan, Meng-hsien Chen, Chiee-young Chen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0713106-165442 |
| Rights | campus_withheld, Copyright information available at source archive |
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