Pareurythoe Gustafson, 1930

Pareurythoe Gustafson View in CoL

Pareurythoe Gustafson, 1930: 309 View in CoL (species list), 319, 391–393 (diagn.); Hartman 1940: 203 (comp.);

1948: 45 ( type species: P. californica ( Johnson, 1897)) View in CoL ; Hartman, 1959: 137 ( type species: P. Gustafson, 1930); Fauchald 1977: 102 (diagn.); Hartmann-Schröder 1996: 28; Bleeker et al. 2023: 438 genera).

Type species

Pareurythoe japonica Gustafson View in CoL (by subsequent designation, Hartman 1959, 137).

Diagnosis

Tovar-Hernández et al. (2024). Amphinominae with body with parallel sides, usually abruptly anteriorly and posteriorly; caruncle narrow, without lateral lobes, sinuous, reaching chaetigers 1–4, longer than median antenna; branchiae dendritically branched present from chaetiger 2–3, extended body; parapodial cirri smooth.

Remarks

As indicated elsewhere ( Tovar-Hernández et al. 2024), Pareurythoe resembles Cryptonome Borda, Bienhold and Rouse by having chaetiger 1 dorsally incomplete, a small caruncle, and branchiae along body chaetigers. However, they differ mostly because in Pareurythoe the caruncle is longer than wide median antenna is shorter than the caruncle, whereas in Cryptonome the caruncle is cushion-shaped, median antenna is as long as, or longer than caruncle. There could be an ecological difference between species of these two genera, because the species of Pareurythoe thrive in sediments, sometimes in pockets in rocky shores, and those of Cryptonome are apparently restricted to living in decaying wood

Composition

Pareurythoe includes P. japonica Gustafson , the type species, and six others: P. borealis (Sars) from P. californica (Johnson) from California, P. chilensis (Kinberg) from Chile, P. paupera (Grube and Grube) from Chile; P. gracilis Gustafson apparently based upon specimens from the Marshall and Islands, which was not formally described, and P. pitipanaensis de Silva. Further , there is no type material P. borealis or P. japonica (see below), and neotypes are needed to clarify their status.

In contrast, P. parvecarunculata (Horst) from Malaysia was transferred to the genus by Imajima (2003 was regarded as belonging in Cryptonome by Borda et al. (2012), and confirmed by Tovar-Hernández (2024).