Aulodrilus pigueti Kowalewski 1914

Aulodrilus pigueti Kowalewski, 1914

Records. Štĕpánek Pond, Pozďatín, 49°13'22"N / 16°02'25"E, lgt. JS, det. KP (2007); the single specimen collected during this study was immature.

Characteristics of sites. Aulodrilus pigueti was found at a single locality, the Štĕpánek fishpond in the Czech-Moravian Highland Mountains (Českomoravská vrchovina), which is situated in the middle part of the Czech Republic. This fishpond is a small shallow pond (2.2 ha) exploited by intensive fish farming. The management of the fish stock composed of Cyprinus carpio Linnaeus and Tinca tinca Linnaeus involved supplementary feeding and application of manure, which caused nutrient enrichment. Macrophytes, mostly Glyceria maxima (Hartman) and Typha latifolia Linnaeus, covered only 5% of the littoral zone.

Ecology. Aulodrilus pigueti burrows in sediments where it forms tubes from detritus (Timm & Veldhijzen van Zanten 2002). Finogenova and Arkhipova (1994), Schloesser et al. (1995) and Šporka (1996b) reported that A. pigueti inhabits various freshwater environments, such as lakes, rivers, and marshes. It prefers water quality from oligo- to alpha-mesosaprobic and substrate pelal (Šporka 2003), and tolerates a lower amount of dissolved oxygen and acidification (Orciari & Hummon 1975; report EPA/600/3-90/073). The sample from which this single specimen of A. pigueti was identified was dominated by Dero digitata (Müller, 1774), more species in the genus Limnodrilus, and other Tubificinae.

Morphology. Aulodrilus pigueti can be distinguished from all other taxa by distal dilatations of bifid crotchets with shorter upper teeth (typical for the genus Aulodrilus). Dorsal crotchets beginning from VI–IX are replaced by oar-shaped pectinate chaetae with a rounded or sometimes slightly bifid tip. It is possible to distinguish it from congeners and all other Tubificinae by the presence of oar-shaped chaetae in dorsal bundles in its middle segments.

Distribution. Aulodrilus pigueti is a cosmopolitan species, often found in tropical countries (Timm & Veldhijzen van Zanten 2002; Arslan & Sahin 2003). The nearest record to the Czech Republic is from backwaters of the Morava River in Slovakia (Šporka 1996b); it has also been recorded from the neighbouring countries of Germany and Poland (Timm & Giani 2004). While A. pigueti is widely distributed in many other European countries it has not been reported from Austria, Hungary, Romania, Belgium, the UK, Denmark, Latvia, Switzerland, and Slovenia (Timm & Giani 2004).