First records of Parergodrilus heideri (Annelida: 'Polychaeta') from North America

摘要

Parergodrilus heideri Reisinger, 1925 is one of two species of the family Parergodrilidae (together with the marine litoral, interstitial species Stygocapitella subterranea Knollner, 1934) and one of only two truly soil-dwelling "polychaetes" (the other being Hrabeiella periglandulata Pizl and Chalupsky, 1984) that are predominantly known from terrestrial habitats (Reisinger 1925, 1960; Rombke and Jans 1991; Chalupsky 1992; Graefe 1993; Rota 1997, 1998; Purschke 1999; Rota et al. 2001; Beylich and Graefe 2007; Martinez-Ansemil and Parapar 2009; Rota et al. 2010). Due to its small body size (adults up to 1 mm) and sensitivity to dessication, the species has usually been found by researchers using some type of wet extraction for soil mesofauna, such as enchytraeids and free-living flatworms ("turbellarians"). However, due to its similar chaetae, Parergodrilus heideri can be easily mistaken for a freshly hatched enchytraeid, even by enchytraeid specialists without experience with this species.