Effect of water quality parameters on the distribution of Pleuromamma (Copepoda–Calanoida) species in the Indian Ocean: a statistical approach

• Published in: Environmental monitoring and assessment 2009-08, Vol.155 (1-4), p.373-392
• Main Authors: Jayalakshmy, K. V., Saraswathy, M., Nair, Maheswari
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; Atmospheric Protection/Air Quality Control/Air Pollution; Biological and medical sciences; Cluster Analysis; Copepoda; Copepoda - growth & development; Copepoda - physiology; Crustacea; Discriminant analysis; Dissolved oxygen; Diurnal variations; Earth and Environmental Science; Ecological conditions; Ecology; Ecotoxicology; Ecotoxicology, biological effects of pollution; Environment; Environmental Management; Environmental Monitoring; Factor analysis; Fundamental and applied biological sciences. Psychology; General aspects; Indian Ocean; Invertebrates; Latitude; Migratory species; Monitoring/Environmental Analysis; Nitrates; Pleuromamma; Pleuromamma abdominalis; Pleuromamma gracilis; Pleuromamma indica; Pleuromamma piseki; Pleuromamma xiphias; Population; Salinity; Seawater - analysis; Studies; Water quality; Xiphias
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-008-0441-0

The region between 10° N and 10° S latitude was known to be congenial for distribution of Pleuromamma species. Diel and ontogenetic migrations were observed for Pleuromamma xiphias . Multivariate analyses such as factor analysis on species’ abundance and predictive step-up multiple regression models of water quality parameters: temperature, salinity, dissolved oxygen and their first order interaction effects on Pleuromamma species’ abundance, were carried out in the regions, off 10° N, 10° N to 10° S, 10° S to 30° S, along the Somali Coast (38° S–40° S) and a fifth region along the western boundary of the above four regions. Relation between Pleuromamma species’ abundance and the water quality parameters showed a decreasing trend in the variability explained (VE) from region 1 (VE = 55.19%) to region 4 (VE = 31.15%) in the models, indicating that the influence of other ecological factors was of higher significance in the south than in the north, with a north south gradient. Indices of diversity (Shannon–Weaver) and evenness (Heips) were calculated and lognormal distributions fitted for these indices were found to be a good fit ( p