Colonization of a man-made gravel bar by Oligochaeta

摘要: Quantitative substrate samples were collected at a newly constructed gravel bar habitat in the Tombigbee River, Mississippi, to characterize oligochaete (naididae and tubificidae) species richness community composition. A total of 28 naidid tubificid worms indentified during three-year study; Nais pardalis, Dero nivea, D. obtusa, Pristina aequiseta (naididae), Branchiura sowerbyi (Tubificidae) dominant. In June, 1985, three months after construction, 30 yielded seven taxa oligochaetes; densities (± standard deviation) 12.9 29.7) 10.1m-2 (±39.6), respectively. October, 20 identified, 387.9 300.5 22.9m-2 (±50.7), Tubificid highest spring, except first year, showed their fall all years. Dominance changed from pardalis nivea year last year. The naididae, which typically inhabit gravel, exhibited more uniform colonization patterns than did tubificidae. Comparatively low characterized high last. Because this is relatively isolated similar substrates, since oligochaetes disperse only via drift or crawling, processes have been slow.