Oxydromus okudai Uchida, 2019

Hiro, Uchida, omi, Lopéz, Eduardo & Sato, Masanori, 2019, New Hesionidae (Annelida) from Japan: Unavailable Names Introduced by Uchida (2004) Revisited, with Reestablishment of their Availability, Species Diversity 24, pp. 69-95 : 79-83

Oxydromus okudai Uchida , sp. nov.

[Japanese name: Moguri-otohime] ( Fig. 9 )

Podarke pugettensis (non Johnson 1901): Okuda 1936: 413, fig. 4.

Ophiodromus angustifrons (non Grube 1878): Uchida and Ui 1991: 89.

Ophiodromus sp. oku.: Uchida and Ui 1992: 79, 86; Uchida and Ui 1993: 84; Uchida and Ui 1994: 31, 32; Uchida and Ui 1998: 34.

Ophiodromus okudai Uchida, 2004: 55–58 , fig. 11 (unavailable specific name, without explicit fixation of namebearing types).

Oxydromus okudai (specific name unavailable): Villalobos- Guerrero and Harris 2012: 24 (referred in check list); Rizzo and Salazar-Vallejo 2014: 281 (in key).

Type material. Holotype: (NSMT-Pol H-608), “Huis Ten Bosch”, Ohmura Bay , Sasebo-shi, Nagasaki Prefecture (33°05′03″N, 129°47′24″E), Ekman-Birge grab, 3.4 m depth, coll. H. Uchida, 15 April 1991. Seven paratypes: one (NSMT-Pol P-712), Nagasaki Holland Village , Ohmura Bay , Nagasaki Prefecture (32°59′42″N, 129°45′30″E), Ekman- Birge grab, 4.4 m depth, coll. H. Uchida, 24 October 1991; one (NSMT-Pol P-713), “Huis Ten Bosch”, Ohmura Bay , Sasebo-shi , Nagasaki Prefecture (33°05′03″N, 129°47′24″E), 5.7 m depth, coll. H. Uchida, 23 April 1992; one (NSMT-Pol P-714), Nagasaki Holland Village , Ohmura Bay , Nagasaki Prefecture (32°59′42″N, 129°45′30″E), Ekman-Birge grab, 7.0 m depth, coll. H. Uchida, 24 May 1993; one (NSMT-Pol P-715), Nagasaki Holland Village , Ohmura Bay , Nagasaki Prefecture (32°59′42″N, 129°45′30″E), Ekman-Birge grab, 6.7 m depth, coll. H. Uchida, 27 October 1993; one (NSMT- Pol P-716), Nagasaki Holland Village , Ohmura Bay , Nagasaki Prefecture (32°59′42″N, 129°45′30″E), Ekman-Birge grab, 5.6 m depth, coll. H. Uchida, 26 April 1994; one (NSMT-Pol P-717), Nagasaki Holland Village , Ohmura Bay , Nagasaki Prefecture (32°59′42″N, 129°45′30″E), Ekman-Birge grab, 7.8 m depth, coll. H. Uchida, 26 April 1994; one (NSMT-Pol P-718), Nagasaki Holland Village , Ohmura Bay , Nagasaki Prefecture (32°59′42″N, 129°45′30″E), Ekman-Birge grab, 7.2 m depth, coll. H. Uchida, 22 April 1998.

Diagnosis. Holotype 10.5 mm long for 30 chaetigers, body pale brown dorsally, with conspicuous white bands on segments 2, 8, 12, 17, 27, 31, 35, 39, 43, 47, 51, 53 and 57 ( Fig. 9A ). Lateral antennae nearly as long as prostomium; median antenna fusiform, 1/3 as long as lateral ones; palps as long as lateral antennae, palpostyles twice as long as palpophores; two pairs of dark red, circular eyes, anterior ones larger ( Fig. 9A ). Parapodia biramous ( Fig. 9B–E ). Notopodia bearing discrete cirrophore with sub-distal constriction and thinner distal region ( Fig. 9B–E ); with 1–3 forked notochaetae ( Fig. 9G ). Neuropodia bearing prechaetal lobe with long triangular projection ( Fig. 9B–E ), with about 23 supraacicular and 25 sub-acicular compound chaetae with bifid tips ( Fig. 9H–L ).

Etymology. The species is named in honor of the pioneering Japanese polychaetologist Prof. Shiro Okuda, who first reported this species (as Podarke pugettensis Johnson, 1901 ) from Japan dwelling on apodous holothurian burrows and described their characteristic color pattern.

Remarks. The detailed description and drawings of the type materials were presented in Uchida (2004). Oxydromus okudai sp. nov. possesses white bands on dorsum, similarly to O. spinapandens and O. fauveli sp. nov. (see above). However, O. spinapandens bears a distinct wide white area on dorsum that extends to segment 11, and it is absent from O. okudai sp. nov. and O. fauveli sp. nov. The last two species clearly differ in the shape of the shafts of compound neurochaetae, which are bifid in O. okudai sp. nov. and pointed in O. fauveli sp. nov. Both taxa are similar in the arrangement of white bands in anterior segments (up to segment 21 = chaetiger 18), but differ from each other in the arrangement as follows: white bands occur in segments 27 and 31 in O. okudai sp. nov., whereas they occur in segments 25, 29 and 33 in O. fauveli sp. nov.

Oxydromus parapallidus Uchida , sp. nov. [New Japanese name: Kushimoto-haya-otohime] ( Figs 4F , 10 , 11 )

Ophiodromus parapallidus Uchida, 2004: 58–62 , figs 12, 13, pl. 1, fig. 6 (unavailable specific name, without explicit fixation of name-bearing types).

Oxydromus okudai (specific name unavailable): Villalobos- Guerrero and Harris 2012: 24 (referred in check list); Rizzo and Salazar-Vallejo 2014: 280 (in key).

Type material. Holotype: (NSMT-Pol H-719), Izumo, Kushimoto, Wakayama Prefecture (33°26′50″N, 135°47′56″E), lobster gillnet, coll. M. Suzuki, 18 October 1976. Thirty four paratypes: one (NSMT-Pol P-720), Sabiura , Kushimoto , Wakayama Prefecture (33°28′51″N, 135°44′45″E), 1 July 1973; one (NSMT-Pol P-721), same locality, SCUBA diving, 10 m depth, coll. K. Nomura, 4 July 1984; three (NSMT-Pol P-722), same locality, SCUBA diving, 5 m depth, coll. K. Nomura, 19 September 1992; one (NSMT-Pol P-723), Aquarium tank in Kushimoto Marine Park, Sabiura, Kushimoto, Wakayama Prefecture (33°28′50″N, 135°44′43″E), coll. H. Misaki, 2 December 1980; one (NSMT-Pol P-724), same locality, coll. H. Uchida, 1 March 1982; one (NSMT-Pol P-725), same locality, coll. K. Nomura, 18 April 1985; one (NSMT-Pol P-726), same locality, coll. H. Uchida 15 May 1992; two (NSMT-Pol P-727), Izumo, Kushimoto, Wakayama Prefecture (33°26′50″N, 135°47′56″E), lobster gillnet, coll. M. Suzuki, 18 October 1976; one (NSMT-Pol P-728), same locality, coll. H. Misaki, 14 December 1976; one (NSMT-Pol P-729), same locality, coll. H. Misaki, 15 December 1976; one (NSMT-Pol P-730), Arita, Kushimoto, Wakayama Prefecture (33°28′41″N, 135°44′2″E), lobster gillnet, coll. H. Misaki, 30 November 1976; four (NSMT-Pol P-731), same locality, coll. H. Misaki and M. Suzuki, 1 December 1976; four (NSMT-Pol P-732), same locality, 30 m depth, coll. K. Ikazaki, 7 February 1979; one (NSMT-Pol P-733), same locality, coll. M. Suzuki, 23 February 1980; two (NSMT-Pol P-734), around Kushimoto, Wakayama Prefecture, lobster gillnet, coll. H. Misaki, 17 December 1976; one (NSMT-Pol P-735), same locality, coll. K. Nomura, 22 March 1985; one (NSMT-Pol P-736), Myogashima Islet, Ohshima, Kushimoto, Wakayama Prefecture (33°27′45″N, 135°47′39″E), SCUBA diving, 20 m, coll. M. Suzuki, K. Ikazaki and Sh. Ui, 16 July 1980; two (NSMT- Pol P-737), same locality, 25 m depth, coll. K. Nomura, 17 April 1992; one (NSMT-Pol P-738), Fukuro, Kushimoto, Wakayama Prefecture (33°28′33″N, 135°46′30″E), intertidal zone, 20 March 1983; one (NSMT-Pol P-739), Shionomisaki, Kushimoto, Wakayama Prefecture (33°26′29″N, 135°44′58″E), lobster gillnet, coll. H. Misaki, 7 February 1979; two (NSMT-Pol P-740), same locality, 40 m depth, coll. H. Ikazaki, 7 February 1979; one (NSMT-Pol P-741), Shobadani, Shionomisaki, Kushimoto, Wakayama Prefecture (33°28′30″N, 135°46′13″E), lobster gillnet, coll. K. Nomura, 21 October 1989; one (NSMT-Pol P-742), same locality, coll. K. Nomura, 15 January 1992; two (NSMT- Pol P-743), same locality, coll. K. Nomura, 31 March 1992; two (NSMT-Pol P-744), Tsuga, Koza, Wakayama Prefecture (33°30′57″N, 135°50′51″E), lobster gillnet, coll. H. Misaki, 20 April 1990; one (NSMT-Pol P-745), Hasama-ura, Minami-ise-cho, Gokasho Bay , Mie Prefecture (34°19′5″N, 136°39′37″E), 16 August 1979; one (NSMT-Pol P-746), Miwazaki, Shingu, Wakayama Prefecture (33°41′19″N, 135°59′33″E), coll. H. Uchida, 25 October 1984; two (NSMT-Pol P-747), Minabe, Wakayama Prefecture (33°44′41″N, 135°19′18″E), lobster gillnet, coll. F. Iwase, 28 December 1991; two (NSMT-Pol P-748), same locality, coll. F. Iwase, 11 January 1992; four (NSMT-Pol P-749), same locality, coll. F. Iwase, 4 February 1992; one (NSMT-Pol P-750), off Nakamagawa River , Iriomote-jima Island , Okinawa Prefecture (24°16′21″N, 123°53′34″E), SCUBA diving, 3 m depth, coll. K. Nomura, 5 June 1984; four (NSMT-Pol P-751), Nakamoto, Kuroshima Island , Okinawa Prefecture (24°13′57″N, 123°59′41″E), SCUBA diving, 3 m depth, in moat within reef, coll. K. Nomura, 15 June 1984; one (NSMT-Pol P-752), same locality, 2 m depth in moat within reef, 13 June 1991; one (NSMT-Pol P-753), off Iko, Kuroshima Island , Okinawa Prefecture (24°15′2″N, 124°0′57″E), SCUBA diving, 2 m depth, coll. K. Nomura, 29 August 1986; one (NSMT-Pol P-754), off Nishinohama Beach, Kuroshima Island , Okinawa Prefecture (24°15′19″N, 123°59′31″E), SCUBA diving, 15 m depth, coll. K. Nomura, 12 September 1986; one (NSMT-Pol P-755), Fuki, Kuroshima, Okinawa Prefecture (24°14′23″N, 123°59′25″E), in moat within reef, 21 June 1991; one (NSMT-Pol P-756), Akajima Island , Okinawa Prefecture (26°11′26″N, 127°17′10″E), SCUBA diving, 5 m depth in harbor, coll. K. Nomura, 5 July 1992.

Other material examined. Records of 184 other specimens collected from 10 localities were given in Uchida (2004).

Diagnosis. Holotype incomplete, 5 mm long for 35 chaetigers, body dorsally brown, with three thin pale brown bands on each segment, prostomium uniformly brown or with paler area around posterior eyes ( Fig. 4F ). Lateral antennae slightly longer than prostomium; median antenna fusiform and short; palps as long as lateral antennae, palpostyles twice as long as palpophores; two pairs of dark red, circular eyes, anterior ones larger ( Fig. 10A ). Parapodia biramous ( Figs 10C, D , 11A ). Notopodia bearing cylindrical, distinctly long cirrophore with conspicuous constriction at 1/3 of total length ( Fig. 11B ); 1–4 forked notochaetae, with short sub-apical spine and long serrated shaft ( Fig. 11D ). Neuropodial lobe with a wide, triangular postchaetal lobe ( Fig. 10C, D ) and two thick aciculae ( Fig. 11C ); neurochaetae typical of the genus ( Fig. 11E–I ). Pygidiun with a pair of long, slender anal cirri ( Fig. 10B )

Etymology. The specific name refers to the close resemblance with the Mediterranean species O. pallidus .

Remarks. The detailed description and drawings of the type materials were presented in Uchida (2004). Oxydromus parapallidus sp. nov. is characterized by notopodial cirrophores of medium length with a rather proximal constriction, and the cirrostyle diameter not reduced beyond constriction. As implied by the name, this new species is very similar to O. pallidus , described from the western Mediterranean and common in Western Europe ( Claparède 1864; Parapar et al. 2004), but this species lacks any remarkable constriction on notopodial cirrophores, and never bears more than three forked chaetae on notopodial bundles. Oxydromus parapallidus sp. nov. is also similar to O. brevipodus sp. nov. (see above), but the latter possesses stout parapodia and rounded and short post-chaetal lobes, and to O. agilis ( Ehlers 1864) , from the Mediterranean Sea ( Ehlers 1864), but this species bears only one non-forked chaeta on each parapodium. Finally, the new species is similar to Oxydromus lanai Rizzo and Salazar-Vallejo, 2014 , from southern Brazil, but the latter never bears more than one forked chaetae on notopodial bundles and presents solid dorsal pigmentation ( Rizzo and Salazar-Vallejo 2014), lacking the characteristic pale bands of O. parapallidus sp. nov.

Genus Heteropodarke Hartmann-Schröder, 1962a Heteropodarke kiiensis Uchida , sp. nov. [New Japanese name: Suna-ba-otohime] ( Fig. 12 )

Heteropodarke kiiensis Uchida, 2004: 66–68 , fig. 15 (unavailable specific name, without explicit fixation of namebearing types).

Material examined. Holotype: (NSMT-Pol H-757), Nachi-Katsuura, Nachi Bay, Kii Peninsula , Wakayama Prefecture (33°38′18″N, 135°56′35″E), SCUBA diving, 9.4 m depth, sandy bottom, 27 September 1988.

Diagnosis. Holotype 6 mm long for 42 chaetigers, body colorless. Median antenna subulate, as long as prostomium; lateral antennae similar, but slightly longer; palps similar in shape and length to lateral antennae, without articulation ( Fig. 12A, B ). Outer margin of proboscis surrounded by 10 triangular papillae ( Fig. 12C, D ). Parapodia sub-biramous ( Fig. 12E–G ). Notopodia with cylindrical cirrophore ( Fig. 12E–G ); cirrostyles articulated ( Fig. 12F, G ), alternating long and short; notochaetae absent. Anterior neuropodial lobes cylindrical ( Fig. 12E, F ); posterior ones long and stout ( Fig. 12G ); single spiniger compound chaetae present in supra-acicular position ( Fig. 12K ); modified falciger chaetae present along chaetigers 6–32, with very short, conical blades ( Fig. 12H, I ); those in remaining chaetigers with longer blades with expanded tips ( Fig. 12J ).

Etymology. Named after the Kii Peninsula, Nachi Bay, the type locality of the new species that is located near the southernmost coast of the peninsula.

Remarks. The detailed description of the holotype was presented in Uchida (2004). Within the genus Heteropodarke , the new species is most similar to H. heteromorpha Hartmann-Schröder, 1962 , from Peru ( Hartmann-Schröder 1962a), but differs from it in the following aspects: (1) the stout modified neurochaetae occurring along chaetigers 6 to chaetiger 32, in contrast to occurring from chaetigers 4–6 and continuing up to chaetiger 16 in H. heteromorpha ; (2) the modified neurochaetae with conical tips, in contrast to those with markedly bifid tips in H. heteromorpha ; (3) the non-modified neuropodial compound chaeteae (falcigers) with rounded tips, in contrast to those with sharply pointed tips in H. heteromorpha ; and (4) the presence of a single spiniger in each parapodium of all the segments, in contrast to the absence of this kind of chaeta in H. heteromorpha .

Figures

Fig. 9. Oxydromus okudai sp. nov., holotype (NSMT-Pol H-608). A, dorsal view of the anterior body, with proboscis everted (white areas shown as black dotted ones). B, posterior view of right parapodium 17 with a short notocirrus (neurocirrus artificially twisted inward).C, anterior view of right parapodium 26 with a long notocirrus. D, posterior view of the same parapodium. E, posterior view of right parapodium 6, with a notocirrus lost. F, posterior view of notopodium of right parapodium 15. G, notochaeta. H, short type of sub-acicular compound falciger. I, long type of sub-acicular falciger. J, enlarged image of the apical end of the same falciger. K, short type of sub-acicular falciger in inferior portion. L, tip of shaft of long type of sub-acicular falciger. Scale bars: 1mm for A; 0.5mm for B, C; 0.2mm for D, E; 0.1mm for F, I; 0.02mm for G; 0.05mm for H, J–L.

Fig. 4. Photographs of live specimens of four species of Oxydromus. A, B, O. bunbuku sp. nov.: A, holotype (NSMT-Pol H-693); B, paratype (NSMT-Pol P-695) associated with the spatangoid urchin Brissus latecarinatus. C, D, O. constrictus sp. nov.: C, holotype (NSMT-Pol H-698); D, nontype (UAM Pol-1-12-6-1-A) crawling among spines of the host sea urchin (photograph by Dr. Daisuke Uyeno). E, O. fauveli sp. nov., paratype (NSMT-Pol P-707). F, O. parapallidus sp. nov., paratype (NSMT-Pol P-737).

Fig. 10. Oxydromus parapallidus sp. nov., paratype (NSMT-Pol P-725). A, dorsal view of the anterior body. B, dorsal view of the posterior body. C, anterior view of right parapodium 19 with a short notocirrus. D, posterior view of the same parapodium. Scale bars: 1mm for A, B; 0.2mm for C, D.

Fig. 11. Oxydromus parapallidus sp. nov., paratype (NSMT-Pol P-725). A, posterior view of right parapodium 22 with a long notocirrus. B, anterior view of the notopodium of the same parapodium. C, posterior view of the neuropodium of the same parapodium (only proximal parts of superiormost and inferiormost supra- and sub-acicular chaetae are shown). D, notochaeta. E, superior supra-acicular neuropodial falciger. F, superior sub-acicular falciger. G, middle sub- acicular falciger. H, inferiormost sub-acicular falciger. I, tip of shaft of compound falciger. Scale bars: 0.5mm for A; 0.1mm for B; 0.2mm for C; 0.02mm for D; 0.05mm for E–I.

Fig. 12. Heteropodarke kiiensis sp. nov., holotype (NSMT-Pol H-757). A, dorsal view of the anterior body. B, Enlarged dorsal view of the anterior end. C, ventral view of the anterior end with everted proboscis. D, lateral view of a papilla of proboscis. E, anterior view of left parapodium 27. F, posterior view of the same parapodium. G, posterior view of right parapodium 38 with neuropodial acicula and inferiormost chaetae broken. H, neurochaeta of median position in left parapodium 27. I, inferiormost neurochaeta in the same parapodium. J, neurochaeta in right parapodium 38. K, spiniger in the same parapodium. Scale bar: 0.5mm for A; 0.2mm for B, C, F; 0.1mm for D, E, G; 0.05mm for H, I; 0.02mm for J, K.