Rheocricotopus (Rheocricotopus) unidentatus Saether et Schnell

Namayandeh, Armin, Bilyj, Bohdan, Beresford, David V., Somers, Keith M. & Dillon, Peter J., 2012, 3324, Zootaxa 3324, pp. 1-65 : 46-47

Rheocricotopus (Rheocricotopus) unidentatus Saether et Schnell

Figs 37A–D

Diagnosis. Head without tubercles; Labrum and premandible as in Fig. 37A; SI seta bifid; premandible with single apical tooth, no apparent brush; antenna ( Fig. 37B) AR 1.5; mandible ( Fig. 37C) with long apical tooth, slightly shorter than combined length of 3 inner teeth; mentum ( Fig. 37D) with large median tooth, having a pointed apex, about 4x the width of 1 st lateral, accessory tooth present, or appears as lateral notch or completely worn off, 5 lateral teeth; VM plates (see Fig. 37D) elongate, tapering to a rounded base, beard with about 25 setae; procercus with lateral tooth and 5 apical setae; anal tubules cylindrical 0.5x as long as posterior parapods with several claws each having sharply angled tooth.

Notes. The median mental tooth can exhibit various degrees of wear patterns affecting the expression of the accessory tooth. The beard in our specimens is not as dense as described by Saether and Schnell (1988: 72) with a range of 28–40 setae.

Ecology and habitat. In study streams they were less common than Rh. eminellobus but occurred in the same habitats. They never occurred in the same streams as Rh. tuberculatus . Larvae of this species are shredders found in high numbers in the bottom leaf litter.

Sampling sites. Killarney and Algonquin Provincial Parks.

Nearctic distribution. First record for Canada: Ontario . USA: Ohio and North Carolina .