Iphione coriolis Hanley & Burke, 1991

Salazar-Vallejo, Sergio I., Piotrowski, Christina N. & Paulay, Gustav, 2024, Revision of Iphione Kinberg, 1856 (Annelida, Aphroditiformia, Iphionidae), Zootaxa 5548 (1), pp. 1-84 : 44-48

Iphione coriolis Hanley & Burke, 1991

Figs 15–17 , 36

Iphione coriolis Hanley & Burke, 1991: 45 , Fig. 14A–E ; Solís-Weiss et al. 2004: S14.

Type material. Coral Sea, Chesterfield Islands. Holotype ( MNHN POLY TYPE 574), RV Coriolis, Cruise Corail 2, Sta. RH 88-65 (19°06’ S, 158°53.26’ E), 32–60 m, coral, coral rubble and coral sand with some Halimeda , 27 Jul. 1988, R. Hanley, coll.

Additional material

Philippines. One specimen ( CASIZ 214326 ), Batangas Province, Verde Island Pinnacles dive site, sea mount with coral rubble, on red sponge, 2015 Verde Island Passage Expedition , sta. VER-02 (15°31’59.088” N, 121°01’14.52” E), 6–20 m, 30 Mar. 2015, J. Comendador coll. (markedly bent, elytra yellowish, 4 rows of low curved falcate macrotubercles directed mid-dorsally and decreasing in size posteriorly; body approximately 10 mm long, 5 mm wide, chaetigers not counted) .

Northern Mariana Islands. One specimen ( UF 77 ), Mariana Islands , Guam Island . Orote Northern Tip, Harry’s Rubble Field (13°30’00.0” N, 144°48’00.0” E), 25 m, under coral rubble, 20 Jun. 2002, L. Kirkendale, coll. (complete, markedly bent ventrally; elytra yellow, with 9–10 rows of macrotubercles darker, decreasing in size towards margins; largest tubercle towards middorsal line; left parapodium of chaetiger 12 removed for observation, kept in container; basal tubercle of dorsal cirrophore projected with minute globular black glands; body length not measured, 9 mm wide, chaetigers not counted) . One specimen ( UF 162 ), Mariana Islands , Pagan Island (18°07’ N, 145°46’ E), Southwestern side, rock wall, 23 m, 22 May 1992, P. Schupp, coll. (complete, slightly bent ventrally; elytra yellow, with largest macrotubercles darker, arranged along first row, decreasing in size towards margins; largest tubercle towards middorsal line; body 15 mm long, 7.5 mm wide, 29 chaetigers) . One specimen ( UF 168 ), Guam Island , Double Reef (13°30’00.0” N, 144°48’00.0” E), 3–10 m, under rocks, 3 Feb. 1998, G. Paulay & J. Starmer, coll, (complete; elytra yellow, first row of macrotubercles slightly larger than those present along following rows, largest middorsal tubercle barely projected; left parapodium of chaetiger 14 removed for observation; body 22 mm long, 12 mm wide, 29 chaetigers;) .

Papua New Guinea. One specimen ( MNHN IA 2014-218 /2021-685), Papua Niugini Expedition, Sta. PB 29 (05°18’ S, 145°46.1’ E), 17 m, 27 Nov. 2012. S. Hourdez et al., coll. (markedly bent ventrally; elytra yellowish, with one series of macrotubercles, without fimbriae; cirrigerous segments with basal tubercle of dorsal cirrophore projected; body 9 mm wide, 29 chaetigers) .

French Polynesia, Society Islands, Moorea. One specimen ( UF 1429 ), Atiha Bay, inside barrier reef, on West side of pass (17°35’44.448” S, 149°50’44.304” W), near pass channel, 0.5–1.0 m, 8 Dec. 2009, S. McPherson, G. Paulay, C. Meyer, coll. (bent ventrally; left elytra 6 and 10 removed for observation (kept in container), each with 5–6 rows of macrotubercles, largest ones in first row; body 14 mm long, 7 mm wide, chaetigers not counted to avoid damaging the specimen) .

Hawaii. One specimen ( LACM 12809 ) , Northwestern Hawaiian Islands, French Frigate Shoals , lagoon patch reef (23°49’01.2” N, 166°17’20.4” W), 10.7 m, 25 Oct. 2006, S. Godwin, R. Most, J. Starmer, J. Maragos, G. Paulay & S. McKeon, coll. (bent ventrally; some elytra previously removed (kept in container); elytra yellowish, macrotubercles in 5 rows, progressively smaller posteriorly; cirrigerous segments with basal tubercle of dorsal cirrophore not projected; body 13.5 mm long, 9 mm wide, 29 chaetigers). Two specimens ( LACM 12810 ) , Northwestern Hawaiian Islands, French Frigate Shoals , fore reef (23°51’46.8” N, 166°11’02.4” W), 25.9 m, 12 Oct. 2006, G. Paulay, S. McKeon, B. Zgliczinski, R. Brainard, J. Maragos & J. Starmer, coll. (bent ventrally; some elytra previously removed (kept in container), elytra yellowish with 3–4 rows of macrotubercles, progressively smaller posteriorly; cirrigerous segments with basal tubercle of dorsal cirrophore not projected; body 8–11 mm long, 6–8 mm wide, 29 chaetigers). One specimen ( LACM 12811 ) , Northwestern Hawaiian Islands, French Frigate Shoals, La Perouse Pinnacle (23°46’12.0” N, 166°15’39.6” W), 9.8 m, 21 Oct. 2006, G. Paulay, S. McKeon, T. Lotufo, S. Godwin, J. Starmer, J. Maragos, A. Collins & E. Soto, coll. (left elytra of chaetigers 1, 2, and left parapodia of chaetiger 11 removed for observation; elytra yellowish with 4 rows of macrotubercles decreasing in size posteriorly; cirrigerous segments with basal tubercle of dorsal cirrophore not projected; body 14 mm long, 6 mm wide, 28 chaetigers). One specimen ( UF 5449 ) , Honolulu, Kaneohe Bay, North of Kapapa Island (21°30’05.652” N, 157°47’47.148” W), 15–18 m, outer reef slope, 27 May 2017, Invertebrate Zoology team, coll. (data in variation). One specimen ( UF 5450 ) , Honolulu, Kaneohe Bay, North of Kapapa Island (21°30’05.652” N, 157°47’47.148” W), 15–18 m, outer reef slope, 27 May 2017, Invertebrate Zoology team, coll. (complete, breaking in two; right parapodia of chaetigers 11–19 removed for molecular analysis; body 14 mm long, 6.5 mm wide, 29 chaetigers) .

Diagnosis. Iphione with median antenna reduced to nuchal papilla; elytra with margins smooth, non-fimbriate; macrotubercles blunt conical with distal spines, often eroded, in 3–4 rows, first row with macrotubercles markedly larger than those in other rows; cirrigerous segments with dorsal cirrophores with basal tubercle indistinct; neurochaetae bidentate.

Description. Holotype (MNHN POLY TYPE 574) bent ventrally, first few right parapodia slightly distorted by compression, all elytra and right parapodium of chaetiger 10 previously removed (25 elytra and parapodium kept in container). Elytra yellowish, with macrotubercles arranged in 5–6 rows, without dark spots; notochaetae whitish, neurochaetae golden; midventrally paler than surrounding darker bands; ventral cirrophores pale. Body 10.5 mm long, 6 mm wide, 29 chaetigers.

Elytra without fimbriae; macrotubercles conical, slightly falcate, smaller ones with single distal spine (eroded in larger ones), directed middorsally; macrotubercles largest in first rows, slightly decreasing in size towards margins ( Fig. 15B, C ).

Prostomium roughly hexagonal, as long as wide, with a deep longitudinal depression along anterior prostomial third ( Fig. 15A ). Anterior lobes projected into ceratophores, about as long as prostomium, blackish, ceratostyles pale, directed ventrally, subdistally swollen, tips tapered. Palps paler than ceratophores, barely longer than lateral antennae. Eyes black positioned in posterior prostomial half; anterior eyes displaced laterally, slightly larger than posterior round, dorsal eyes; anterior and posterior eyes very close to each other in lateral view. Nuchal papilla not seen dorsally, covered by nuchal hood, slightly wider than long.

Tentacular segment dorsally reduced, tentacular cirrophores blackish, cirrostyles pale, without chaetae. Facial tubercle visible dorsally, blackish.

Segments 2–4 directed anteriorly. Second segment visible dorsally, with a projected, semicircular nuchal lappet, lobate, wider than long, completely covering nuchal papilla. Ventral buccal cirri inserted ventrally, twice larger than following ventral cirri, extending beyond chaetal tips. Dorsal nodules indistinct (probably after ventral contraction). Segments 2–3 with finer neurochaetae, barely swollen subdistally, with a longer region covered by series of transverse denticulations.

Median cirrigerous segments with dorsal cirri markedly surpassing chaetal tips ( Fig. 15D ), shape resembling lateral antennae; dorsal cirrophore smooth, with projected basal tubercle. Notochaetae whitish, very abundant, delicate capillaries with series of transverse funnel-shaped spinose rows, tips bare. Neuropodia with neuracicular lobe about three times longer than wide, truncate; neurochaetal lobe with very long papillae. Neurochaetae thick, abundant, basally smooth, subdistally swollen, with series of fine denticulations along swollen region, tips falcate, bidentate.

Anus dorsal, positioned between elytral pairs 12 and 13.

Variation. Large specimen (UF 5450) breaking into two parts ( Fig. 16A ). Elytra yellowish, with macrotubercles slightly darker, arranged in 5–6 rows, with first row with larger macrotubercles ( Fig. 16B ), becoming larger in more posterior chaetigers ( Fig. 16C ), but progressively smaller towards posterior margin. Notochaetae whitish, neurochaetae golden; venter pale, ventral cirrophores pale.

Elytrae without fimbriae; macrotubercles conical, falcate, with a single distal spine (mostly eroded), directed middorsally; pairs or elytra 10–11 with largest macrotubercles in the first row, largest ones approaching middorsal elytral edge ( Fig. 16C ).

Median cirrigerous segments ( Fig. 16D ) with dorsal cirri markedly surpassing neurochaetal tips, subdistally swollen; dorsal cirrophore smooth, cirrostyle subdistally swollen, papillate. Notochaetae very abundant, opaque, with a series of transverse funnel-shaped spinose rows, tips bare. Neuropodia with neurochaetal lobe blunt, neuracicular lobe with long papillae, longest ones 5–6 times longer than tip width. Neurochaetae abundant, basally smooth, subdistally swollen, especially the lower ones, with many rows of fine denticulations along swollen region, tips falcate, bidentate ( Fig. 16E ). Anus not seen.

Small, mature female (UF 5449), anterior and posterior ends bent ventrally ( Fig. 17A, B ); right parapodia of segments 7–20 previously removed for molecular studies; left parapodia of segments 11 and 13 removed for observing parapodial features (kept in container): body 12 mm long, 6 mm wide, 28 chaetigers. Elytra yellowish, with macrotubercles slightly darker, arranged in 2–3 rows of larger ones, and 1–2 others with fewer, smaller tubercles, with scattered brownish spots forming irregular areas; notochaetae whitish, neurochaetae golden, parapodia with densely packed, irregular oocytes; venter pale, ventral cirrophores barely brownish.

Elytra without fimbriae; macrotubercles conical, falcate, with a single distal spine, directed middorsally ( Fig. 17C ), pairs of elytra 10–11 with largest macrotubercles approaching middorsal elytral edge ( Fig 17D ).

Median cirrigerous segments ( Fig. 17E ) with dorsal cirri surpassing neurochaetal tips, subdistally swollen; dorsal cirrophore smooth, cirrostyle subdistally swollen, papillate. Notochaetae very abundant, dirty white to opaque, with series of transverse funnel-shaped spinose rows, tips bare. Neuropodia with neurochaetal lobe blunt, neuracicular lobe with long papillae, longest ones 3–4 times longer than tip width ( Fig. 17F ). Neurochaetae abundant, basally smooth, subdistally swollen, especially the lower ones, with many rows of fine denticulations along swollen region, tips falcate, bidentate ( Fig. 17G ). Anus not seen. Oocytes in densely packed masses in coelom, each oocyte about 80–90 μm in diameter.

The small female ( UF 5449 ) differs from the holotype of I. coriolis because it has 2–3 rows of larger macrotubercles against 5–6 rows in the holotype. However, there are other, smaller macrotubercles, but it is regarded as belonging to the same species because the size of macrotubercles decreases towards posterior margin, as is the case in the holotype.

The additional specimens were 8–22 mm long, 6–12 mm wide. Macrotubercles are arranged in rows, and their number is size dependent. The size of macrotubercles show a consistent trend; the first row has the largest macrotubercles, and the other rows have tubercles progressively smaller posteriorly.

Remarks. Iphione coriolis Hanley & Burke, 1991 was described with a 10.5 mm long specimen from the Coral Sea, and its accompanying illustrations include the anterior end, the right cirrigerous parapodium of chaetiger 12 in anterior view, and a midbody elytron with 5–6 rows of macrotubercles, with the first row having larger macrotubercles. It has been unique among Iphione by having bidentate neurochaetae (but see I. harrisae sp. nov. and I. corbari sp. nov. described below); besides, its elytra have smooth margins, with low, blunt macrotubercles, and neuracicular lobes have papillae 3–4 times longer than neuracicular tip width.

Iphione coriolis and I. harrisae sp. nov. are very similar by having elytra without fimbriae and bidentate neurochaetae, but they are different species, and their main difference lies in the size of macrotubercles. In I. coriolis elytra have a single row of macrotubercles progressively larger posteriorly, but the other rows have macrotubercles decreasing in size posteriorly, whereas in I. harrisae sp. nov. the size of macrotubercles is progressively larger towards posterior margin.

Distribution. From the Philippines and Coral Sea to Hawaii and French Polynesia, in reef habitats (0.5–60.0 m).

Figures

FIGURE 14. Iphione treadwelli Pettibone, 1986, non-type specimen (ECOSUR). A. Dorsal view. B. Right elytron 6, dorsal view (asterisks indicate enlarged areas). C. Same, one macrotubercle. D. Same, outer fimbriae. E. Left parapodium of chaetiger 12, posterior view (inset: close-up of basal tubercle showing darker glandular area). F. Same, upper neurochaetae. Scale bars: A, 0.9 mm; B, 0.6 mm; C, 140 μm; D, 30 μm; E, 0.2 mm; F, 50 μm.

FIGURE 15. Iphione coriolis Hanley & Burke, 1991, holotype (MNHN TYPE 574). A. Anterior end, dorsal view. B. Right elytron from median chaetiger. C. Left elytron from postmedian chaetiger. D. Chaetiger 12, right parapodium, posterior view. Scale bars: A, B, 0.4 mm; C, 0.5 mm; D, 0.2 mm.

FIGURE 16. Iphione coriolis Hanley & Burke, 1991, non-type specimen (UF 5450). A. Dorsal view. B. Left, elytron 6, dorsal view. C. Left, elytron 10, dorsal view. D. Chaetiger 12, left parapodium, posterior view (notochaetae removed). E. Same, tips of upper neutochaetae. Scale bars: A, 1.4 mm; B, 0.8 mm; C, 0.6 mm; D, 0.3 mm; E, 50 μm.

FIGURE 17. Iphione coriolis Hanley & Burke, 1991, non-type specimen (UF 5449). A. Dorsal view (asterisks indicate largest macrotubercles in posterior elytra). B. Ventral view (asterisks indicate same as above). C. Left elytron 9, posterior and external margins. D. Left elytron 10 (previously detached), posterior and external margins. E. Chaetiger 12, left parapodium, posterior view. F. Same, anterior view after removing most notochaetae, neuracicular lobe showing long papillae (Ne: neurochaetae, Pa: papilla). G. Upper and lower neurochaetae showing bidentate tips. Scale bars: A, B, 1 mm; C, 0.6 mm; D, 0.5 mm; E, 0.3 mm, F, 40 μm, G, 100 μm (left), 40 μm (right).

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).