Iphione fimbriata de Quatrefages, 1866

Salazar-Vallejo, Sergio I., Piotrowski, Christina N. & Paulay, Gustav, 2024, Revision of Iphione Kinberg, 1856 (Annelida, Aphroditiformia, Iphionidae), Zootaxa 5548 (1), pp. 1-84 : 27-34

Iphione fimbriata de Quatrefages, 1866 reinstated

Figs 7–9 , 36

Iphione fimbriata de Quatrefages, 1866: 271–272 ; Haswell 1882b; 277 (after de Quatrefages 1866); Solís-Weiss et al. 2004: S14.

Iphione fustis Hoagland, 1920: 605 , Pl. 46, Figs 4–8 ; Hartman 1938: 107; Suárez-Morales & Salazar-Vallejo 2022:502–503, Fig. 4 (parasites).

Iphione muricata : Monro 1924: 46 (partim); Pettibone 1986: 9–16, Figs 1 , 2 (partim, non (Savigny in Lamarck, 1818)).

Holotype. Northeastern Australia, Torres Strait . Holotype of I. fimbriata de Quatrefages, 1866 ( MNHN POLY TYPE 325), 1 Jan. 1841, Hombron & Jacquinot, coll.

Other type material examined. Philippine Islands. Paratype of I. fustis Hoagland, 1920 ( USNM 18968 ), USFCS Albatross, Sta. 5401, off Tanguingui Island Light, North of Cebu, fine sand, 54 m, 16 Mar. 1909 (bent ventrally, partially dried out, five elytra previously removed (kept in container); body 22 mm long, 10 mm wide, 28 chaetigers) . Paratype of I. fustis Hoagland, 1920 ( USNM 18969 ), USFCS Albatross, Sta. 5202, off East coast of Leyte Island , Caguayan Point , 14 m, 13 Apr. 1908 (used for redescription) .

Additional material

Australia. Seven specimens ( AM 2612 ), Low Isles , Queensland, Feb. 1929, Whitley & Boardman, coll. (no further data; soft, probably ethanol-fixed, 4 bent ventrally, smallest one broken; elytra brownish with an oblique longitudinal black band in a few specimens only, with abundant sediment particles; macrotubercles in 3–5 rows (size-dependent), progressively smaller posteriorly; cirrigerous segments with basal tubercle of dorsal cirrophore projected (barely visible in softer specimens; body 19–23 mm long, 8–13 mm wide, 29 chaetigers) . Two specimens ( AM 2814 ), East Point, near Darwin NT, 22 Jun. 1929, A.A. Livingstone, coll. (one markedly bent, not measured; elytra with abundant sediment particles; macrotubercles in 3–4(5) rows, decreasing in size posteriorly; basal tubercle of dorsal cirrophore distinct, not projected over cirrophore base; body 28.5 mm long, 14 mm wide, 29 chaetigers) . Two specimens ( AM 5720 ), Brampton Island , Queensland, Jan. 1949, Zoology Department, University of Sydney, coll. (no further data; bent ventrally; elytra brownish with an oblique longitudinal black band; macrotubercles in 4–5 rows; basal tubercle of dorsal cirrophore projected; body 20–26 mm long, 15.5–17.0 mm wide, 29 chaetigers) . Two specimens ( MAGNT W270 ), Oxley Island , NT, coral rubble, reef edge, low tidal, 20 Oct. 1982, R. Hanley, coll. (bent ventrally, one too bent to be measured; right elytra 7 removed for observation; elytra with oblique longitudinal blackish band, 3–5 rows of macrotubercles, progressively smaller posteriorly; cirrigerous segments with basal tubercle of dorsal cirrophores projected; body 30 mm long, 14 mm wide, 29 chaetigers) .

Australia. Two specimens ( MAGNT W6780 ), Scorpion Island , WA, Sta. RH 91-55, fringing shore reef, low subtidal, 14 Aug. 1991, J.R. Hanley, coll. (bent ventrally; elytra with oblique longitudinal black band, and darker posterior margins; macrotubercles in 3–4 rows, progressively smaller posteriorly; ventral cirri base blackish; body 20–32 mm long, 12–15 mm wide, 29 chaetigers) . One specimen ( NMH 1925.1.28.17), H.M.S. Alert, Port Denison (no further data; bent ventrally, some parapodia and elytra previously removed (lost); elytra brownish, with a wide oblique longitudinal darker band, macrotubercles in 4 rows; neurochaetae unidentate, slightly falcate; body 28 mm long, 17 mm wide, 29 chaetigers) . Three specimens ( NHM 1925.1.28.18–20), H.M.S. Alert, Claremont and Bird Islands (no further data; one markedly bent, elytra brownish, each with 3–4 rows of macrotubercles; basal tubercle of dorsal cirrophore projected; body 12–25 mm long, 11.5–13.0 mm wide, 29 chaetigers) . Three specimens ( NHM 1925.1.28.21–23), H.M.S. Alert, Torres Strait Islands, Thursday Island , sand, 7–13 m (no further data; smallest one damaged, some elytra previously removed; elytra yellowish to brownish, oblique longitudinal darker band visible; each elytron with 3–4 rows of macrotubercles (2–3 in smallest specimen) progressively smaller towards posterior margin; basal tubercle of dorsal cirrophores projected; neurochaetae unidentate, slightly falcate; body 11–34 mm long, 6–15 mm wide, 29 chaetigers) . Seven specimens ( NHM 1925.1.28.26–34), H.M.S. Alert, Port Molle , beach and coral reef (no further data; three markedly bent, one dried-out; elytra yellowish to brownish, often with a wide oblique longitudinal band, or darker posterior elytral margins, with 3–5 rows of macrotubercles (size-dependent); body 15–25 mm long, 8–15 mm wide, 29 chaetigers) . Three specimens ( NHM 1970.113 b), Grahams Point (no further data; one bent ventrally; elytra brownish, darker in posterior regions, oblique longitudinal wide darker bands, with 4–5 rows of macrotubercles; body 22–26 mm long, 12.0– 12.5 mm wide, 29 chaetigers) . One specimen ( ZMH V497 ), Bowen, Queensland (no further data; body incurved, anterior parapodia bent ventrally; elytra brownish, with fimbriae short (shrunk), with oblique darker band, and 4–5 rows of macrotubercles progressively smaller posteriorly; body 23 mm long, 14 mm wide, 29 chaetigers) .

Thailand. One specimen ( NHM 1925.1.28), Gulf of Siam (Thailand) (no further data; bent ventrally; elytra brownish with an oblique wide darker band; macrotubercles in 4 rows; basal tubercle of dorsal cirrophore projected; neurochaetae unidentate, slightly falcate; body 36 mm long, 14.5 mm wide, 29 chaetigers) .

Indonesia. One specimen ( RMNH unnumb.), Indonesian Snellius II Exped., Sta. 4.232 (06°32.1’ S, 121°09’ E), NE Taka Bone Rate, Tiger Islands, south of Pulau Tarupa Kecil , 59 m, calcareous nodules, sponges, 16 Oct. 1984 (markedly bent ventrally; elytra with oblique longitudinal black band poorly defined; macrotubercles in 5 rows, decreasing in size posteriorly; cirrigerous segments with basal tubercle of dorsal cirrophore projected; not measured) . One specimen ( ZMA V471.1 ), Lesser Sunda Islands, RV Siboga Exped., Stat. 34 (Lombok, anchorage off Labuan Pandan), 18 m, coral reef, shore-expl., 27 Mar. 1899 (slightly bent ventrally; elytra with silt and abundant epibionts, oblique longitudinal line barely visible; macrotubercles in three rows, progressively smaller posteriorly; basal tubercle of dorsal cirrophore projected; body 20 mm long, 11 mm wide, 29 chaetigers) . One specimen ( ZMA V471.4 ), Sulawesi, RV Siboga Exped., Sta. 115 (Kwandang Bay, E side of Pajunga Island ), reef-exploration, 9–11 Jul. 1899 (markedly bent ventrally; elytra with oblique longitudinal band barely visible, posterior margins darker; macrotubercles in 3–4 rows, progressively smaller posteriorly; not measured) . One specimen ( ZMA V471.5 ), Sulawesi, RV Siboga Exped., Sta. 125 ( Siau Island , anchorage off Sawan), 27 m, dredge, townet, Monaco trap, reef-exploration, stones, 18–19 Jul. 1899 (markedly bent; elytra brownish without black spots; macrotubercles in three rows; not measured) . Two specimens ( ZMA V471.8 ), Sulawesi, RV Siboga Exped., Stat. 131 ( Karakelang Island , anchorage off Beo), 13 m, muddy bottom, sand, 24–25 Jul. 1899 (largest markedly bent ventrally; elytra brownish, oblique longitudinal band barely visible, with abundant sediment particles and epibionts; macrotubercles in 3–4 rows, decreasing in size posteriorly; smaller one with body 15 mm long, 9 mm wide, 29 chaetigers) . One specimen ( ZMA V471.10 ), Maluku, RV Siboga Exped., Stat. 144 (anchorage N of Salomakiëe (Damar) Island ), 45 m, dredge, townet + reef exploration, coral, 7–9 Aug. 1899 (bent ventrally; elytra brownish with abundant white epibionts; macrotubercles in three rows, progressively smaller posteriorly; body 17.5 mm long, 10 mm wide, 29 chaetigers) . Three specimens ( ZMA V471.15 ), Sulawesi, RV Siboga Exped., Stat. 213 (Saleyer anchorage), 36 m, coral reef expl., muddy bottom + sand, 26 Sep. 1899 (markedly bent ventrally; elytra yellowish in smaller specimens, largest one with oblique longitudinal black band; macrotubercles in 1—two rows; smaller ones not measured, largest 15 mm long, 9 mm wide, 29 chaetigers) . One specimen ( ZMA V471.15 b), Sulawesi, RV Siboga Exped., Stat. 213 (Saleyer anchorage), 36 m, coral reef expl., muddy bottom + sand, 26 Sep. 1899 (bent ventrally; elytra brownish with oblique longitudinal black band, and darker posterior margins; macrotubercles in 4–5 rows, progressively smaller posteriorly; body 30 mm long, 12 mm wide, 29 chaetigers) . One specimen ( ZMA V471.17 ), Sulawesi, RV Siboga Exped., Sta. 225 (Lucipara Island, S point), reef (in label), coral + shells, 8 Nov. 1899 (slightly bent ventrally; several elytra previously removed (kept in container); elytra brownish, with oblique longitudinal black band, posterior margins darker, some with white epibionts; macrotubercles in 4 rows, progressively smaller posteriorly; body 26 mm long, 15 mm wide, 29 chaetigers) . Five specimens ( ZMA V471.18 ), Maluku, RV Siboga Exped., Sta. 231 (Ambon, at anchorage), 40 m, reef exploration, coral sand, 14–18 Nov. 1899 (markedly bent ventrally; several elytra removed from each specimen; elytra yellowish in smaller specimens, with oblique longitudinal black band and darker posterior margins in largest specimen; macrotubercles in 3–5 rows (size dependent), decreasing in size posteriorly; not measured) . One specimen ( ZMA V471.19 ), Maluku, RV Siboga Exped., Stat. 234 (Nusa Laut Isl., Nalahia Bay ), 46 m, reef exploration, stones, 19–20 Nov. 1899 (slightly bent ventrally; elytra brownish with abunant epibionts; macrotubercles in three rows, progressively smaller posteriorly); body 25 mm long, 11 mm wide, 29 chaetigers ). Two specimens ( ZMA V473 ), Java, Jakarta Bay ( Batavia Bay ), Sluiter, coll. (no further data; markedly bent specimens; some elytra previously removed; elytra with oblique longitudinal dark wide band; macrotubercles in 2–4 rows; basal tubercle of dorsal cirrophores projected; not measured) .

Philippines. One specimen ( LACM 6916 ), Palawan, North Verde Island , mangroves along shore (10°07’44.4” S, 119°14’27.6” E), 0.46 m, underside of coralline rock, 23 Apr. 1995, J.K. Fitzhugh, coll. (bent ventrally; pharynx exposed; elytra yellowish, oblique longitudinal band wide, diffuse; macrotubercles in 2—three rows, progressively smaller posteriorly; cirrigerous segments with basal tubercle of dorsal cirrophore projected; body 14 mm long, 9 mm wide, 29 chaetigers) . One specimen ( LACM 6917 ), Tubatatha (08°55’26.4” S, 119°59’56.4” E), 24–38 m, sand, 20 Apr. 1995, C. Arneson, coll. (bent ventrally; elytra yellowish, oblique blackish bands barely visible, posterior elytral region darker; macrotubercles in 3–4 rows, decreasing in size posteriorly; cirrigerous segments with basal tubercle of dorsal cirrophore projected; body 24 mm long, 16 mm wide, 29 chaetigers) . Two specimens ( LACM 6918 ), East side of Palawan Island, off Fondeado Island , Hondo Bay , 100 m from shore (09°55’51.6” N, 118°55’01.2” E), 0.6 m, beneath coral rubble, 24 Apr. 1995, J.K. Fitzhugh, coll. (one with pharynx slightly exposed; elytra yellowish, oblique black bands well-defined in one specimen, paler in the other; with 2–3 of macrotubercles, decreasing in size posteriorly; cirrigerous segments with basal tubercle projected; body 19.0– 19.5 mm long, 11 mm wide, 29 chaetigers) .

Marshall Islands. One specimen ( UF 719 ), Majuro Atoll, Eneko, channel, Western side of the island (07°08’57.552” N, 171°16’58.512” E), intertidal, tide pools, under rocks, 6 Apr. 2008, F. Michonneau & S. Kim, coll. (posterior end removed for molecular analysis; right elytron 8 and one of the last pair, and right parapodium of chaetiger 12 removed for observation; elytra brownish with an oblique black band, expanding laterally along posterior elytral margins; macrotubercles in four rows, decreasing in size towards posterior margins; ventral cirrophores blackish; body 22 mm long, 12.5 mm wide, 23 chaetigers) . One specimen ( USNM 81942 ), Bikini Atoll, 6.4 km from west end of island, 51 m, 25 Apr. 1946, J.P.E. Morrison, coll. (most elytra and some parapodia previously removed (kept in container); elytra brownish without black banding, macrotubercles in four rows, decreasing in size towards posterior margins; fimbriae ventral cirrophores barely darker than adjacent tissues, especially along posterior region; body 18 mm long, 10.5 mm wide, 29 chaetigers) .

Papua New Guinea. One specimen ( CAS 190471 ), Papua New Guinea Biodiversity Expedition 2012, Madang Province, Rempi , depth undefined, 20 Nov. 2012, V. Knutson, coll. (bent ventrally; elytra yellowish, with four rows of large spine-like macrotubercles; body 11 mm long, 6 mm wide, 28 chaetigers; two copepod parasites on dorsum, visible between elytra, they might be responsible of the lack of typical pigmentation) .

Solomon Islands. Three specimens ( USNM 97382 ), Guadalcanal, Raham Point , 21 Sep. 1965, P.E. Gibbs, coll. (two slightly bent ventrally, some elytra previously removed (kept in container); anterior and posterior eyes close to each other laterally; elytra with one row of large spine-like macrotubercles in smallest specimen, largest with 3–4 rows, slightly decreasing in size towards posterior margins; body 11–23 mm long, 6–12 mm wide, 28–29 chaetigers) .

New Caledonia. Two specimens ( UF 5020 ), Province Sud, Nouméa, Baie des Citrons, South end (22°18’13.536” S, 166°26’03.66” E), 0–2 m, shore and fringing reef, 5 Dec. 2016, G. Paulay & L. Moroz, coll. (one bent ventrally, pharynx fully exposed; right parapodia of chaetigers 15–18 removed for molecular analysis; elytra brownish, without black band, some with white epibionts, with three rows of macrotubercles; dorsal cirrophore with a low projected basal tubercle; body 21.5–25.0 mm long, 10.5–12.0 mm wide, 29 chaetigers) . Two specimens ( UF 5025 ), Province Sud, Nouméa Lagoon, Îlot N’Do (22°18’48.528” S, 166°28’12.9” E), 1–8 m, lagoon fringing reef, 7 Dec. 2016, G. Paulay & L. Moroz, coll. (one bent ventrally; some elytra removed; elytra brownish, without black band, some with white epibionts; with 3–4 rows of macrotubercles; dorsal cirrophore with a globular basal tubercle; body 25–26 mm long, 12–13 mm wide, 29 chaetigers) . One specimen ( UF 5620 ), Province Sud, Nouméa Commune, Baie des Citrons, South part (22°18’13.536” S, 166°26’03.66” E), 0–2 m, shore and fringing rocks, 31 Oct. 2017, G. Paulay & M. Hoban, coll. (slightly bent laterally; pharynx fully exposed, jaws with 3–4 additional denticles; right parapodia of chaetigers 17–25 removed for molecular studies; elytra brownish, some with white epibionts; macrotubercles in 3–4 rows; fimbriae along lateral margins, extended along posterior margins in last two elytral pairs; dorsal cirrophore with a globular basal tubercle; body 24.5 mm long, 11 mm wide, 29 chaetigers) . One specimen ( UF 5656 ), Province Sud, Banc Ouest (22°26’40.704” S, 166°28’54.336” E), 0–1 m, patch reef, flat top, 13 Nov. 2017, G. Paulay, D. Uyeno & L. Moroz, coll. (slightly bent ventrally; right parapodia of chaetigers 16–20 removed for molecular studies; left elytra 1–3, and right elytra 1–4, 6 removed for observation; prostomium pale, eyes black, similar-sized, anterior ones lateral, posterior ones dorsal; lateral antennae ceratophores blackish, ceratostyles pale; palps slightly longer than antennae; median antenna minute, blackish; nuchal lappet slightly longer than wide, not covering median antenna; elytra brownish, with a wide ill-defined oblique darker band, with macrotubercles in 2–3; dorsal cirrophore with projected basal tubercle; anus visible between last pair of elytra; body 21 mm long, 11 mm wide, 29 chaetigers) . One specimen ( UF 5677 ), Province Sud, Nouméa Commune, East side of Nouméa (22°17’28.248” S, 166°27’34.236” E), 0–2 m, sand flat and reef, under rocks, 2 Nov. 2017, G. Paulay & M. Hoban, coll. (right elytra 1–3, 7 removed; elytra brownish, most with double oblique longitudinal black lines, with white epibionts; macrotubercles in 3–4 rows; fimbria mostly lateral; dorsal cirrophore with basal tubercle barely projected; anus visible between last elytral pair; body 26 mm long, 13 mm wide, 29 chaetigers) .

Vanuatu. Two specimens ( MNHN IA 2022-930 ), Efate , Port Vila Bay, 28Aug. 2011, S. Hourdez, coll. (markedly bent ventrally; one median elytron removed for observation; elytra yellowish to brownish, with oblique longitudinal band ill defined, or without it; macrotubercles in 3–4 rows, progressively smaller posteriorly; cirrigerous segments with basal tubercle of dorsal cirrophore projected; not measured) .

Samoa. Two specimens (USNM 81972), from Samoa Investigations, 1902 (One with body 30 mm long, 14 mm wide, 29 chaetigers; pharynx exposed, it was dissected open previously (notes in variation); three parapodia previously dissected. Another specimen middorsally dissected and all elytra removed shows anterior eyes in lateral projections, very close to posterior ones).

Diagnosis. Iphione with median antenna reduced to nuchal papilla; elytra fimbriate, filaments markedly longer than wide; macrotubercles spine-like, up to twice longer than wide, with distal spines, in 3–5 rows, first row with macrotubercles slightly larger than those in other rows; cirrigerous segments with dorsal cirrophores with basal tubercle projected; neurochaetae unidentate.

Description. Holotype of Iphione fimbriata de Quatrefages, 1866 (MNHN TYPE 325) complete, slightly bent ventrally, some elytra detaching from body ( Fig. 7A ), right elytron 7 and left parapodium of chaetiger 16 previously removed; two punctions along anterior body third; body 31 mm long, 15 mm wide, 29 chaetigers. Elytra brownish, with abundant fine sediment particles; notochaetae whitish, neurochaetae golden. Body wall pale, venter pale.

Elytra with fimbriae ( Fig. 7B ), better developed along lateral margins throughout body; fimbriae incorporate abundant sediment particles, rarely without them ( Fig. 7B , inset), fimbriae 3–12 times longer than wide; abundant polygonal areas throughout most elytral surface, many with a projecting tip pointing posteriorly; macrotubercles conical, partially buried by sediment, visible after brushing off foreign particles, about 2–3 times longer than wide, arranged in 4–5 rows, decreasing in size posteriorly and laterally.

Prostomium roughly hexagonal, longer than wide, with anterior incision running along anterior prostomial third. Anterior lobes projected into ceratophores, as long as prostomium, shorter than ceratostyles, subdistally swollen, tips tapered. Eyes colorless, indistinct. Palps thick, bent ventrally, about twice longer than antennae, with longitudinal rows of papillae, tips mucronate (it seems de Quatrefages confused the palps with the antennae). Nuchal papilla visible under nuchal flap.

Tentacular segment dorsally reduced, without chaetae; tentacular cirri about half as long as palps. Facial tubercle visible dorsally, colorless.

Segments 2–4 directed anteriorly. Second segment visible dorsally, with a semicircular nuchal lappet, wider than long, covering nuchal papilla. Ventral buccal cirri inserted ventrally, almost three times longer than following cirri, projected beyond chaetal tips. Dorsal nodules not observed to avoid further damage to the specimen.

Median cirrigerous segments ( Fig. 7C, D ) with dorsal cirri markedly surpassing chaetal tips, subdistally swollen, cirrophore smooth, with a basal single tubercle. Cirrostyle subdistally swollen, surface papillate. Notochaetae very abundant, dirty white, with series of transverse funnel-shaped spinose rows, tips bare. Neuropodia with neuracicular lobe blunt, with globular papillae. Neurochaetal lobe with marginal papillae, neurochaetae abundant, basally smooth, subdistally swollen with many rows of fine denticulations along swollen region, tips barely falcate, unidentate, sharp ( Fig. 7E, F ).

Anus not seen.

Paratype of I. fustis Hoagland, 1919 (USNM 18969) complete, mature female, bent ventrally; 8 anterior elytra previously removed, left parapodium of chaetiger 14 dissected (kept in container); body 18 mm long, 13 mm wide, 29 chaetigers. Elytra brownish, often with calcareous epibionts; notochaetae whitish, neurochaetae golden. Body wall pale, transparent, parapodia with large coelomic spaces; venter pale.

Elytra with fimbriae, better developed along median and posterior segments but variably eroded; better developed in the other paratype (USNM 18968, 6–7 times longer than wide, extended along almost all exposed elytral margin); macrotubercles conical, largest ones 3–4 times longer than wide, longer towards central elytral areas, progressively shorter towards margins ( Fig. 8C , inset, Fig. 9D, E ).

First elytra lost, second pair with large conical macrotubercles each with 3–4 distal spines in 2–3 rows ( Fig. 8B , upper; Fig. 9A, B ). Following elytra with macrotubercles in 3–4 rows ( Fig. 8B , lower, C; Fig. 9D, E ), larger macrotubercles towards central elytral areas, progressively smaller towards margins. Fimbriae delicate, submarginal, along posterolateral margins, each with a thin spinous stem, and distal soft tubules, each about 3 times as long as fimbria stem ( Fig. 8C , inset).

Prostomium wider than long, with anterior incision running along 1/3 prostomial surface ( Fig. 8A ). Anterior lobes projected into pale ceratophores, as long as prostomium, shorter than ceratostyles (right one broken), ceratostyles markedly thinner than ceratophores, tapered. Palps thick, bent ventrally, longer than lateral antennae, with longitudinal rows of papillae, tips mucronate. Eyes black, anterior ones placed behind the median prostomial region, barely visible dorsally, posterior ones in posterior prostomial margins. Nuchal papillae not visible dorsally, broken.

Tentacular segment dorsally reduced, without chaetae; tentacular cirri slightly longer than palps, resembling lateral antennae. Facial tubercle not visible dorsally, pale.

Segments 2–4 directed anteriorly. Second segment visible dorsally, with a nuchal lappet, semicircular, wider than long (slightly broken), covering nuchal papilla. Ventral buccal cirri inserted ventrally, twice longer than following ventral cirri, projected beyond chaetal tips. From segment 3 one pair of globular dorsal nodules per segment, first pair connected by a transverse ridge, separated from each other. Segments 2–3 with fine neurochaetae, barely swollen distally, with a longer region covered by series of transverse denticulations.

Median cirrigerous segments ( Fig. 8D ) with dorsal cirri reaching chaetal tips, subdistally swollen; dorsal cirrophore smooth, with a basal single tubercle. Cirrostyle subdistally swollen, with papillae along its surface. Notochaetae very abundant, pale to transparent, with series of transverse funnel-shaped spinose rows, tips bare. Neuropodia with neurochaetal lobe posterior margin with small papillae. Neurochaetae abundant, basally smooth, subdistally swollen, sometimes with a pale or dark core, with many rows of fine denticulations along swollen region, tips barely falcate, sharp ( Fig. 8E, F ).

Anus not seen. Oocytes in irregular masses in coelom, each oocyte about 80 μm in diameter.

Variation. One specimen from Samoa (USNM 81972), middorsally dissected and all elytra removed; the anterior eyes are in lateral projections, very close to posterior ones ( Fig 9F ), although the prostomium has to be depressed to note the blackish eyes; another specimen had its pharynx exposed and it was dissected open previously; papillae digitate, middorsal one more opaque, jaws similar, apparently eroded, without accessory denticles ( Fig. 9G ); three parapodia previously dissected; neurochaetae all unidentate. Ventral cirrophore blackish in some specimens.

The additional specimens were 11–36 mm long, 6–16 mm wide. The number of rows of macrotubercles is size dependent. Smaller specimens (11–15 mm long) usually have 2–3 rows, whereas larger ones (20–36 mm long) have 4–5 rows.

Remarks. Iphione fimbriata de Quatrefages, 1866 was described with very long antennae, elytral margins fimbriate (hence the name), barely overlapping mid-dorsally, and without elytral macrotubercles. The holotype, however, has macrotubercles arranged in 4–5 rows as indicated above, but there are some sediment particles partially blocking their visibility. Haswell (1892: 277) indicated the “upper antennae very long”, but he was following the original description because no specimens were indicated. Pettibone (1986: 9) studied the holotype and regarded it as a junior synonym of I. muricata (Savigny in Lamarck, 1818). However, as noted above, the delineation by Pettibone of I. muricata was very wide, encompassing multiple species.

Iphione fustis Hoagland, 1920 was described from the Philippines, and a juvenile was selected as the holotype. Hartman (1938: 107) revised the holotype, not the paratypes, and noted and illustrated that neuracicular lobes are more projected than the indication in the original illustration, where it was shown truncate, with ventral cirri reaching the tip of neuracicular lobe.

Iphione fimbriata ( de Quatrefages, 1866) resembles I. ankeri sp. n, from Guam because both species have dorsal cirrophores with distinct basal tubercle, and posterior elytral margins with long filaments. They differ because in I. fimbriata there are 4–5 rows of macrotubercles (2–3 in specimens 11–15 mm long: 4–5 in larger than 20 mm), whereas in I. ankeri ther are only two rows (body 11.5–17.0 mm long). An additional difference is in the neurochaetae; in I. fimbriata they are brownish, and markedly falcate, whereas in I. ankeri they are golden, barely falcate.

Iphione fimbriata also resembles I. hyndmani sp. nov. from Hong Kong in its fimbriate elytra, macrotubercles conical arranged in 3–5 rows, and unidentate neurochaetae. The main difference between these two species lies in the development of the basal tubercle of dorsal cirrophores. In I. fimbriata the basal tubercle is distinct, whereas in I. hyndmani sp. nov. it is not projected (holotype 32 mm long).

Iphione fimbriata appears to be closely related to I. muricata based on COI sequence data ( Fig. 36 ).

Distribution. Thailand to Australia, east to the Marshall Islands and Samoa, on reefs and rocky or mixed bottoms in shallow water (0–48 m).

Figures

FIGURE 1. Iphione readi sp. nov. (incl. I. muricata sensu Savigny (1822)), non-type specimens, left elytra 7 of non-type specimens (NHM 1941.4.4.168–172), arranged vertically. A. 9 mm long specimen. B. 16 mm long specimen. C. 23 mm long specimen. D. Iphione muricata (Savigny in Lamarck, 1818) non-type small specimen (11.5 mm long, MAGNT W2894), elytron 6 (E, F indicate areas enlarged in E and F, and asterisk indicates the enlarged area in G). E. Close-up of macrotubercle (Mt) and fimbriae. F. Same. G. Close-up of microtubercles along posterior margin. Scale bars: A, 0.4 mm; B, D, 0.5 mm; C, 0.8 mm; E, F, 100 µm; G, 70 µm.

FIGURE 2. Iphione ovata Kinberg, 1856, non-type specimens (2 ECOSUR 0000, Sta. 30, 13 mm long). A) Ventral view. B. Ventral body wall and most muscle bundles removed, oval masses are ovaries. C. Pharynx and gut ventral wall removed (*: enteric caeca). D. Pharynx, upper jaws separated medially. E. Pharynx, lower jaws separated medially (Pa: papilla, Ph: pharynx, St: stomach). Scale bars: A, 1.38 mm; B, 1.43 mm; C, 1.48 mm; D, 0.32 mm; E, 0.27 mm.

FIGURE 4. Iphione muricata (Savigny in Lamarck, 1818), restricted. A. Syntype MNHN 334, dorsal view. B. Same, anterior elytron (inset: fimbriae from another elytron). C. Same, median elytron. D. Chaetiger 14, left parapodium, posterior view after removal of notochaetae. E. Same, median neurochaetal tips. F. Syntype MNHN 335, two detached elytra before cleaning. G. Same, median elytron. H. Same, posterior elytron. I. Fimbriae of posterior elytron. J. Chaetiger 12, left parapodium, posterior view, after removal of notochaetae. Scale bars: A, 2 mm; B, 0.7 mm; C, 1 mm; D, 0.4 mm; E, 30 µm; F, 1.3 mm; G, 1.2 mm; H, 1.6 mm; I, 30 µm; J, 0.6 mm.

FIGURE 5. Iphione muricata (Savigny in Lamarck, 1818), restricted, non-type specimen (CAS 227559). A. Dorsal view, depressed by glass slide. B. Left elytron 7, dorsal view (C–E: sections enlarged in following pictures). C. Close-up of fimbriae. D. Close-up of smaller, marginal spines. E. Close-up of larger, inner spines. F. Chaetiger 12, left parapodium, posterior view, notochaetae partially trimmed off (after Methyl green staining). G. Same, basal neurochaetal tips. Scale bars: A, 2.5 mm; B, 1.5 mm; F, 0.9 mm; G, 0.3 mm.

FIGURE 6. Iphione muricata (Savigny in Lamarck, 1818), restricted, non-type specimen (UF 9454), juvenile. A. Dorsal view, after Methyl green staining. B. Right elytron 6, dorsal view (insets: enlarged areas indicated by numbers). C. Chaetiger 12, left parapodium, posterior view after removal of notochaetae. Scale bars: A, 0.8 mm; B, 0.4 mm; C, 0.2 mm.

FIGURE 7. Iphione fimbriata de Quatrefages, 1866, reinstated, holotype (MNHN POLY TYPE 325). A.Anterior region, dorsal view. B. Left elytron 7, after brushing off sediment, dorsal view (inset: close up of dirty to clean fimbriae). C. Chaetiger 16, left parapodium, posterior view. D. Chaetiger 12, left parapodium, after removal of notochaetae and Methyl green stain. E. Same, upper notochaetae. F. Same, lower neurochaetae. Scale bars: A, 1.7 mm; B, 1 mm; C, 0.6 mm; D, 0.5 mm; E, 170 µm; F, 200 µm.

FIGURE 8. Iphione fimbriata de Quatrefages, 1866, reinstated, paratype of I. fustis Hoagland, 1920 (USNM 18969).A.Anterior end, dorsal view, after Methyl green staining. B. Anterior elytra, above: right elytron from chaetiger 2; below: left elytron from chaetiger 4. C. Left elytron from median chaetiger, dorsal view (insets: fimbriae, and smaller marginal spines). D. Chaetiger 14, left parapodium, posterior view after Methyl green staining. E. Same, upper and medial neurochaetae. F. Same, medial and lower neurochaetae. Scale bars: A, 1.1 mm, B, 1 mm; C, 2 mm; D, 0.6 mm; E, 100 μm; F, 80 μm.

FIGURE 9. Iphione fimbriata de Quatrefages, 1866, reinstated, paratype of I. fustis Hoagland, 1920 paratype (USNM 18968), elytra previously removed, seen from above.A. Second right elytron. B. Third right elytron. C. Fourth right elytron. D. Fifth left elytron. E. Sixt left elytron. F. Non-type specimen (USNM 81972), anterior end, dorsal view. G. Another specimen from same lot, pharynx previously dissected, seen from inside, depressed by glass slide. Scale bars: A, 0.7 mm; B, G, 0.8 mm; C, 1.1 mm; D, E, 0.6 mm, F, 1.3 mm.

FIGURE 36. Maximum Likelihood phylogeny of Iphione species with localities and catalog numbers. Numbers above branches are bootstrap support (>70 only) (PNG: Papua New Guinea) (modified after Piotrowski et al. 2024).