perifretum, Cottus Freyhof [J.], Kottelat [M.] & Nolte [A.] 2005:144, Figs. 18-20 [Ichthyological Exploration of Freshwaters v. 16 (no. 2); ref. 28259] Stream Zwaanebeek, 51°14'44N, 4°34'58'E, Province Flandern, Belgium. Holotype: ZMB 33588. Paratypes: FSJF 1383 (15). Plus non-type material. Previously misspelled perifrenatum. •Valid as Cottus perifretum Freyhof, Kottelat & Nolte 2005 -- (Kottelat & Freyhof 2007:513 [ref. 29996], Sideleva 2009:210 [ref. 30173], Goto et al. 2014:[11] [ref. 33456], Sideleva et al. 2015:33 [ref. 35276], Sideleva et al. 2018:9 [ref. 36393], Bravničar et al. 2021: [2] 429 [ref. 38624]). Current status: Valid as Cottus perifretum Freyhof, Kottelat & Nolte 2005. Cottidae. Distribution: Northern Europe. Habitat: freshwater.