The enchytraeid assemblage (Annelida: Clitellata: Enchytraeidae) of a Sandhill prairie site in Nebraska, USA

Abstract

Hitherto the enchytraeid fauna of North American prairie and other types of grassland remains unknown. In March 2011 soil samples were taken in a Sandhill prairie habitat used as rangeland, close to Grand Island, Nebraska. Enchytraeids were extracted by the wet funnel method and identified alive. The total enchytraeid density was 3400 ± 800 individuals/m² (± SE); 70 % of the individuals were present in the upper 3 cm of soil (sampling depth: 12 cm). The assemblage consisted of at least six species, the identity of four could be ascertained. Bryodrilus librus (Nielsen & Christensen, 1959) was predominant, followed by Fridericia bulboides Nielsen & Christensen, 1959. For B. librus this is the southern-most reported locality within its known range. Also present was Enchytraeus dichaetus Schmelz & Collado, 2010, the occurrence of which in North America had been published once before from Canada without any details on its locality. The rather poor assemblage might be the result of a harsh climate and drought-sensitive sandy soil.