A review of three species of Hesperonoe (Annelida: Polynoidae) in Asia, with descriptions of two new species and a new record of Hesperonoe hwanghaiensis from Korea

Two new species of Parahesione (Annelida: Hesionidae) associated with ghost shrimps (Crustacea: Decapoda) and their phylogenetic relationships

“…Again, this contrasts with the free-living species of Amphiduropsis - Amphiduros clade, suggesting this trait was newly acquired in Parahesione . A bright red color was also reported for Hesperonoe (Polynoidae), which also live in association with mud shrimps ( Sato et al, 2001 ; Hong, Lee & Sato, 2017 ), while some crustacean-associated mollusks have red blood cells that are considered as an adaptation to thrive in the burrow hypoxic conditions ( Goto et al, 2018 ). Therefore, we agree with Martin & Britayev (2018) , who suggested that red bodies (likely associated to the presence of dissolved pigment) in Hesperonoe may be an adaptation to live in the burrows’ hypoxic environment.…”

Synonymy of the Scale Worm <i>Hesperonoe urechis</i> with <i>Arctonoella sinagawaensis</i> (Annelida: Polynoidae), Newly Recorded from the Seto Inland Sea, Western Japan, with Remarks on Symbiosis with the Spoon Worm <i>Urechis unicinctus</i> (Annelida: Thalassematidae)

“…Arctonoella resembles Hesperonoe in having two types of notochaetae and neurochaetae, with their close relationship being also phylogenetically supported. Hesperonoe is a wellknown commensal scale-worm genera Britayev 1998, 2018), including eight species distributed along the coasts of the North Pacific and adjacent seas, with five living commensally with decapod crustaceans (Upogebia Leach, 1814 or Neotrypaea Manning and Felder, 1991) and two with echiuroids (Anker et al 2005;Hong et al 2017).…”

“…The Asian species of Upogebia may harbor three other symbiotic Hesperonoe scale worms, H. hwanghaiensis Uschakov and Wu, 1959;H. coreensis Hong, Lee, andSato, 2017, andH. japonensis (Hong et al 2017; Marin and Antokhina 2020), which have never been observed sharing the burrows with A. sinagawaensis.…”

“…The American Upogebia and Neotrypaea harbor two other symbiotic scale worms, Hesperonoe sp. and H. complanata (Johnson, 1901), respectively (Hong et al 2017). According to the currently known information, A. sinagawaensis and H. adventor seem to be more species-specifically associated to species of Urechis, likely showing parallel speciation in the North Pacific coasts.…”

“…Arctonoella resembles Hesperonoe in having two types of chaetae both on notopodia and neuropodia (except H. andriashevi Averincev, 1990, which has only one type of neurochaetae), but differs in having 16 instead 15 pairs of elytra (13 in H. andriashevi) (Hong et al 2017). Arctonoella also differs from most species of Hesperonoe [except H. adventor (Skogsberg in Fisher and MacGinitie, 1928), see below] in the variable presence of cephalic peaks, which are consistently present in Hesperonoe, and in the bifurcated tips Arctonoella sinagawaensis (Izuka, 1912) [Japanese name: Shinagawa-urokomushi] (Figs 1-6; Table 1) Description.…”