Revision of Chloeia Savigny in Lamarck, 1818 (Annelida, Amphinomidae) Author Salazar-Vallejo, Sergio I. text Zootaxa 2023 2023-02-07 5238 1 1 134 http://dx.doi.org/10.11646/zootaxa.5238.1.1 journal article 53418 10.11646/zootaxa.5238.1.1 751096f2-4b5b-43c3-9748-4d07afe044c3 1175-5326 7621793 768E9932-2D18-4115-8359-3FF800328BCD Chloeia fusca M’Intosh, 1885 restricted Figs 4 , 22–26 Chloeia fusca M’Intosh, 1885: 14–15 , Pl. 2, Figs 1 , 2 , Pl 1A, Figs 14 , 15 , Pl. 2A, Figs 1,2; Horst 1912: 22–24 , Pl. 7, Fig. 7 ; Hartman 1959: 131 . Chloeia flava : Treadwell 1906: 1164 ; Hartman 1966: 178–179 ; Bailey-Brock & Hartman 1987: 245 ( non (Pallas, 1766)). Type material . Indonesia , Banda Sea, Banda Islands. Holotype ( BMNH 1885.12.1.9), H.M.S. Challenger, unnumb. station, depth not indicated (in M’Intosh 1885 : XXV; Admiralty Islands, Papua New Guinea but this is wrong, 36–54 m ; after Tizard et al. 1885: 569 ), 1 Oct. 1874 (during these days, some people remained in Neira Island, whereas the ship was sent to Ceram trying to help another ship in trouble). Additional material . Indonesia , Banda Sea, Banda Islands. Six specimens ( RMNH 1245), Maluku , RV Siboga Exped., Sta. 240 (Banda anchorage), 9–45 m , trawl + dredge + reef expl., black sand and coral, 22 Nov. – 1 Dec. 1899 (bipinnate branchiae from chaetiger 5; median antenna as long as caruncle (2/3–1/1); mouth in chaetiger 2; 11–22 mm long, 2.8–4.0 mm wide, 18–25 chaetigers). Three specimens ( ZMA VPol 156.1), epitokes, Lesser Sunda Islands , RV Siboga Exped., Sta. 37, Paternoster Islands, Sailus Ketjil (Pulau Sailus Kecil), close to reef, 27 m , dredge, coral and coral sand, Monaco-trap in 100 m , close to reef, 30–31 Mar. 1899 . Ten specimens ( ZMA VPol 156.5), Maluku , RV Siboga Exped., Sta. 240 (Banda anchorage), 9–45 m , trawl + dredge + reef expl., black sand and coral, 22 Nov. – 1 Dec. 1899 (bipinnate branchiae from chaetiger 5; median antennae 4/5 as long as caruncle or slightly longer; mouth in chaetiger 2; 8–21 mm long, 2.5–5.0 mm wide, 18–24 chaetigers). One specimen ( ZMA VPol 156.7), Maluku , RV Siboga Exped., Sta. 240 (Banda anchorage), 9–45 m , trawl + dredge + reef expl., black sand and coral, 22 Nov. – 1 Dec. 1899 (bipinnate branchiae from chaetiger 5; median antenna longer than caruncle; mouth in chaetiger 2; 15 mm long, 3.5 mm wide, 23 chaetigers). Indonesia . Three specimens ( ZMA VPol 156.2), Sulawesi , RV Siboga Exped., Sta. 66 (Bank between islands of Bahuluwang and Tambolungan, S of Saleyer), 8–10 m , dredge, dead coral, Halimeda, Lithothamnion , 7–8 May 1899 (body dark purple; bipinnate branchiae from chaetiger 5; median antenna as long as caruncle in one specimen , broken in the others; mouth in chaetiger 2; 6.3–7.5 mm long, 1.5–2.0 mm wide, 17 chaetigers). One specimen ( ZMA VPol 156.6), Maluku , RV Siboga Exped., Sta. 251 ( 05°28.4´S , 132°00.2´E ), 204 m , trawl, coral + sand, 8 Dec. 1899 (dorsal bands blackish; body pale; bipinnate branchiae from chaetiger 5; median antenna as long as caruncle; mouth in chaetiger 2; 19 mm long, 4.5 mm wide, 24 chaetigers). Philippines . One specimen ( CAS 187295), Hearst Philippine Biodiversity Expedition, Luzon, Batangas Province , Calumpan Peninsula, Mainit Bubbles dive site ( 13.69° N , 120.90° E ; 13°41´24.00″ N , 120°54´00.00″ E ), night dive, 0–19 m , 29 Apr. 2011 , M. Weber, coll. (complete, with some medioposterior dissection for molecular studies; pigmentation pattern retained; body 20 mm long, 4 mm wide, 23 chaetigers). One specimen ( CAS 214530), Verde Island Passage Expedition, Mindoro, Puerto Galera, Batangas Channel, School Beach ( 13.52° N , 120.96° E ; 13°31´12.00″ N , 120°57´36.00″ E ), 7–31 m , 8 Apr. 2015 , C. Piotrowski, coll. (complete, chaetae bright yellowish, anterior eyes 2× larger than posterior ones; median antenna slightly shorter than caruncle; body 24 mm long, 4 mm wide, 26 chaetigers). One specimen ( CAS 214561), Luzon Island, Batangas Province , Verde Island, Blackfish Corner dive site ( 13.57° N , 121.05° E ; 13°34'12.00" N , 121°03'00.00" E ), 8–33 m , 9 Apr. 2015 , P.J. Aristorenas, coll. (complete, bent ventrally, dorsal bands discontinuous after extension after ventral bent, chaetae colorless, anterior eyes 6× larger than posterior ones; median antenna as long as caruncle; body 12 mm long, 3 mm wide, 24 chaetigers). Four specimens ( CAS 218217), Visayas, Negros Island, Zamboanguita, off Bask Barangay ( 09°10´N , 123°21´E ), 7–14 m , sand, 3 Apr. 2016 , C. Piotrowski, coll. (complete; anterior eyes 3–4× larger than posterior ones, in darker areas in larger specimens; median antenna longer than caruncle; 27–48 mm long, 4–7 mm wide, 25–28 chaetigers). Seven specimens ( UF 4368), Oriental Mindoro Province , Mindoro, Puerto Galera, off Sabang Beach ( 13.52207 , 120.97522 ; 13°31´15.42″ N , 121°58´30.792″ E ), gentle sand slope with reef heads, 4–6 m , 13 Apr. 2015 , G. Paulay, coll. (all with pharynx partially exposed; anterior eyes 5–6× larger than posterior ones; longitudinal bands reddish, of similar width throughout dorsum; some specimens with dorsal oblique reddish bands continued towards parapodial anterior surface, usually covered by bipinnate branchiae; chaetae reddish to pale yellowish, sometimes with a wide median golden band; body 16–19 mm long, 4–5 mm wide, 22–23 chaetigers; one specimen dissected for anatomy). Two specimens ( UF 4392), Oriental Mindoro Province , Mindoro, Puerto Galera, Sabang Beach ( 13.52095 , 120.97439 ; 13°31´15.42″ N , 121°58´27.804″ E ), sand, seagrass flat, 0–1 m , 23 Apr. 2015 , G. Paulay, coll. (shorter without posterior end, showing branching gonads each branch slightly wider than corresponding blood vessel; larger complete, bent ventrally; anterior eyes 3–4× larger than posterior ones; black anterior prostomial area split in two halves; median antenna without tips, shorter than caruncle; 31–43 mm long, 6–7 mm wide, 18–27 chaetigers). One specimen ( UF 4394), Oriental Mindoro Province , Mindoro, Puerto Galera, off Point West of Bayanan Beach ( 13.5118 , 120.9088 ; 13°30'42.48" N , 120°54'31.68" E ), 10–13 m , sand slope with few corals, 28 Apr. 2015 , G. Paulay, coll. (atoke; thin transverse black intersegmental bands in addition to other typical banding; anterior eyes 3–4× larger than posterior ones; anterior prostomial area barely split; median antenna slightly longer than caruncle; 29 mm long, 6 mm wide, 26 chaetigers). Two specimens ( ZMA VPol 156.3), Sulu Islands, anchorage off North Ubian, RV Siboga Exped., Sta. 99 ( 06°07.5’ N , 120°26’ E ), 16–23 m , dredge and tow-net, lithothamnion bottom, 28–30 Jun. 1899 (bipinnate branchiae from chaetiger 5; median antenna longer than caruncle; mouth in chaetiger 2; 9–21 mm long, 2–4 mm wide, 17–24 chaetigers). One specimen ( ZMA VPol 156.4), Sulu Islands, RV Siboga Exped., Sta. 104 ( Sulu Harbour), 14 m , dredge, sand, 2–3 Jul. 1899 (pale purple, dorsal bands almost completely faded off; bipinnate branchiae from chaetiger 5; median antenna longer than caruncle; mouth in chaetiger 2; body 15 mm long, 3 mm wide, 21 chaetigers). Papua New Guinea . One specimen ( NTM W5050), Horseshoe Reef, 10 m , Aug. 1980 , N. Coleman, coll. (colorless; anterior prostomial area blackish; eyes black, anterior ones 3–4× larger than posterior ones; body 17.5 mm long, 4 mm wide, 22 chaetigers). Line Islands. One specimen ( UF 576), Kiritimati, just N of main reef passage, West side of atoll, outer reef slope ( 1.9841 , -157.4819 ; 01°59´02.76″ N , 157°28´54.84″ W ), outer reef slope, 10–12 m , from Halimeda sample, 5 Aug. 2005 , G. Paulay & N. Knowlton, coll. (without posterior end; median antenna twisted, about as long as caruncle; anterior eyes 3–4× larger than posterior ones; 13 mm long, 4 mm wide, 16 chaetigers). Loyalty Islands. Two specimens ( MNHN Musorstom P1231), Sta. 1231 ( 20°31.2´S , 166°22.9´E ), 23 m , 3 Sep. 1992 (slightly damaged, depressed; dorsal bands fading off; anterior eyes 6–8× larger than posterior ones; body 18–19 mm long, 3.5–4.0 mm wide, 22–24 chaetigers). French Polynesia . One specimen ( UF 2921), Society Islands , Moorea Island, Moorea, off Motu Ahi, north of Afareitu Pass ( -17.55258 , -149.77347 ; 17°33´09.288″ S , 149°46´24.492″ W ), deep reef slope, large rubble, 57 m , 27 Jan. 2012 , R. Whitton, coll. (anterior fragment; anterior eyes 3× larger than posterior ones; two dorsal longitudinal bands; 3.5 mm long, 1.2 mm wide, 9 chaetigers). Hawai’i. One specimen ( BM R3441), KOK Pisces V, Expedition HURL-09, Sta. P5-716, 22 Feb. 2009 (no further data; complete, juvenile, dorsal pigmentation with two irregular longitudinal lines, paler than in more recent specimens; dorsal cirri purple, bipinnate branchial tips purple; chaetae colorless; Prostomium with anterior brownish area as a half-moon; eyes blackish, anterior eyes about 6× larger than posterior ones; median antenna slightly longer than caruncle; 6 mm long, 2 mm wide, 17 chaetigers). One specimen ( UF 418), Maui Island, Buzzs Wharf, caught swimming, 25 May 2005 , C. Pittman & D. Kheler, coll. (epitoke, complete, chaetae yellowish; anterior eyes 7–8× larger than posterior ones; median antenna without tip, longer than caruncle; 55 mm long, 11 mm wide, 31 chaetigers). Diagnosis . Chloeia with bipinnate branchiae from chaetiger 5, progressively smaller posteriorly; dorsum with two longitudinal bands; caruncle pale; lips darker than adjacent ventral areas; notochaetae include furcates and furcate harpoon-chaetae; neurochaetae furcates. Description . Holotype (BMNH 1885.12.1.9), almost without chaetae, with a midventral dissection along chaetiger 4–19, cut into two portions ( Fig. 22A, D ): anterior region 5 mm long, 4 mm wide, 8 chaetigers, and a median to posterior region 10.5 mm long, 4 mm wide, 14 chaetigers; body narrow fusiform, 15.5 mm long, 4 mm wide, 22 chaetigers ( 18 mm long, 23 segments in original description). FIGURE 22 . Chloeia fusca M’Intosh, 1885 . A. Holotype (BMNH 1885.12.1.9). A. Anterior fragment, dorsal view. B. Anterior end, dorsal view. C. Posterior fragment, anterior chaetigers. D. Posterior fragment, dorsal view. E. Largest topotype specimen (RMNH 1245), chaetiger 3, notochaetae (inset: close-up of notochaetal tip). F. Same, neurochaetal tips. G. Chaetiger 13, notochetae (inset: harpoon notochaetal tip). H. Same, neurochaetae (insets: shorter and longer tines). Scale bars: A, 0.7 mm; B, 0.3 mm; C, 0.4 mm; D, 1.6 mm; E, 60 μm; F, 50 μm; G, 90 μm; H, 110 μm. Holotype brownish; anterior prostomial margin blackish; middorsal bands brownish, continued throughout body, slightly expanded medially ( Fig. 22C ). Dorsal cirri with cirrophores pale, cirrostyles dark purple. Venter pale with a midventral paler band. Prostomium anteriorly entire. Eyes blackish, separate, anterior eyes 3–4× larger than posterior ones ( Fig. 22B ). Median antenna pale, inserted at anterior caruncular margin, slightly longer than caruncle, 2× longer than lateral antennae. Lateral antennae blackish, bases separate from each other, 2× longer than palps. Mouth ventral on chaetiger 2. Pharynx not exposed. Caruncle pale, sigmoid, trilobed, tapered, reaching chaetiger 5. Median ridge plicate, with about 18 vertical folds, partially concealing lateral lobes. Lateral lobes narrow, with about 28 vertical folds. Bipinnate branchiae from chaetiger 5, continued throughout body, partially eroded, parallel along body; progressively larger to chaetiger 9, about half as long as successive segments, decreasing in size posteriorly (becoming as long as successive segments); median segments with 5–6 lateral branches. Parapodia biramous, notopodia with purple cirriform branchiae along chaetigers 1–4, 2/3 as long as dorsal cirri. Dorsal cirri 3–4× longer than bipinnate branchiae along median chaetigers, 5–6× longer in posterior chaetigers. Second ventral cirri with cirrophores 2× longer and wider, and cirrostyle 3× longer than adjacent ones, directed dorsally. Other ventral cirri directed ventrolaterally, as long as 1.5× subsequent segments. FIGURE 23 . Chloeia fusca M’Intosh, 1885 , epitokes (ZMA VPol 156.1). A. Largest epitoke (35x6 mm), anterior region, dorsal view. B. Same, posterior region, dorsal view. C. Smallest epitoke (16x4 mm), anterior region, dorsal view. D. Same, posterior region, dorsal view. E. Medium-sized epitoke (22x4 mm), anterior region, dorsal view. F. Same, posterior region, dorsal view. Scale bars: A, B, 1.4 mm; C, D, 0.9 mm; E, F, 1.3 mm. FIGURE 24 . Chloeia fusca M’Intosh, 1885 , epitokes (ZMA VPol 156.1). A. Largest epitoke, anterior end, right lateral view. B. Chaetiger 3, notochaetae. C. Same, neurochaetal tips. D. Chaetiger 14, harpoon notochaetae and capillary furcates. E. Same, furcates and capillary furcates (inset: capillary furcates furca and tips). F. Smallest epitoke, anterior end, right lateral view. G. Medium-sized epitoke, anterior end, right lateral view. Scale bars: A, 1.2 mm; B, 80 μm; C, 30 μm; D, 35 μm; E, 90 μm; F, 0.6 mm; G, 1 mm. Chaetae most broken, a few remaining (not removed for avoiding further damage). Complete chaetae (after largest topotype RMNH 1245 ) with distal hoods. Anterior notochaetae furcates ( Fig. 22E ), major tines 3—4× longer than minor ones; median chaetigers with harpoon-chaetae and furcates of two types ( Fig. 22G ), thinnest golden, with major tines 5–14× longer than minor ones, and wider with major tines 4× longer than minor ones. Harpoonchaetae with short, almost blunt denticles and smooth tines (denticulate tines 3–6× longer than smooth ones). Neurochaetae all furcates, major tines 4–6× longer than minor ones, anterior chaetigers with tines longer ( Fig. 22F ), than those present in median chaetigers ( Fig. 22H ) . Posterior region tapered ( Fig. 22D ); pygidium with anus terminal, anal cirri lost. Epitokes Epitokes (ZMA VPol 156.1), complete, posterior end bent ventrally or laterally ( Fig. 23 ), lateral antennae lost in largest epitoke; body fusiform, 16–35 mm long, 4–6 mm wide, 23–26 chaetigers. Largest epitoke (ZMA VPol 156.1) pale; anterior prostomial area grayish ( Figs. 22A , 23A ); middorsal bands purple ( Fig. 23A, B ); accessory lateral bands barely pigmented, continued along internotopodial space. Dorsal cirri blackish. Bipinnate branchiae with stems pale, lateral branches purple. Venter pale, midventral band shiny, slightly paler. Prostomium anteriorly entire. Eyes blackish, coalescent, anterior eyes 6× larger than posterior ones. Median antenna pale, inserted at anterior caruncular margin, half as long as caruncle, size relationship to lateral antennae unknown. Lateral antennae with blackish ceratophores, ceratostyles lost, bases separate from each other, size relationship to palps unknown. Mouth ventral on chaetiger 2. Pharynx not exposed. Caruncle pale, straight, trilobed, tapered, reaching chaetiger 4. Median ridge plicate, with about 36 vertical folds, partially concealing lateral lobes. Lateral lobes narrow, with about 34 vertical folds. Bipinnate branchiae from chaetiger 5, continued throughout body, divergent along body; progressively larger to chaetiger 9–10, about half as long as successive segments, decreasing in size posteriorly (becoming as long as successive segments); median segments with 5–6 lateral branches. FIGURE 25 . Chloeia fusca M’Intosh, 1885 , non-type specimens (UF 4368) showing variation in reddish pigmentation and branchial contraction. A) Anterior region, dorsal view of specimen with visible dorsal oblique bands continued to the anterior notopodial surface, and bipinnate branchiae contracted. B) Same, right lateral view. C) Another specimen with oblique bands covered by fully extended bipinnate branchiae. D) Same, right lateral view, with less intense pigmentation along notopidal anterior surface. E) Another specimen with a few reddish chaetae, anterior region dorsal view, bipinnate branchiae covering oblique bands. F) Same, right lateral view showing pigmentation along a few anterior chaetigers on notopodial anterior surface. Scale bars: A, 1.1 mm; B, 1.4 mm; C, 1.8 mm; D, 1.3 mm; E, 0.9 mm; F, 1.5 mm. Parapodia biramous, notopodia with purple cirriform branchiae along chaetigers 1–4, half as long as dorsal cirri in chaetiger 1, progressively shorter becoming 1/3–1/4 as long in chaetiger 4. Dorsal cirri 2× longer than bipinnate branchiae along median and posterior chaetigers. Second ventral cirri with cirrophores 2× longer and wider, and cirrostyle 2× longer than those present in chaetiger 3, directed dorsally. Other ventral cirri directed ventrolaterally, as long as subsequent segment. Chaetae most complete with distal hoods. Anterior notochaetae furcates ( Fig. 23B ), major tines about 4× longer than minor ones; median chaetigers with harpoon-chaetae and furcate capillaries with major tines about 12× longer than minor ones; harpoon notochaetae with short, almost blunt denticles and shorter tine, denticulate tines 3–6× longer than smooth ones ( Fig. 23D ). Neurochaetae all furcates; anterior chaetigers with major tines about 4× longer than minor ones ( Fig. 24C ); median chaetigers with furcates with major tines 5–12× longer than minor ones, and capillary furcates with major tines 7–15× longer than minor ones ( Fig. 24E ). Posterior region tapered; pygidium with anus terminal, anal cirri pale, digitate, 4–5× longer than wide. Live pigmentation of atokes (after freshly collected specimens UF 4368, Fig. 25 , and Belle 2022b ). Dorsum pale to pinkish; middorsal bands reddish, continued throughout body, each band slightly expanded towards lateral margins. Brownish to reddish lateral bands approaching middorsal bands, running towards anterior notopodial surfaces. Caruncle pale. Dorsal cirri dark purple to blackish. Branchiae pale brownish to reddish. Notochaetae and neurochaetae with a distal yellowish band, rarely with red bases. Venter with midventral band pale ( Fig. 4A ) Live pigmentation of epitokes . Recently collected specimens (CAS 218217) have dark brown to blackish longitudinal middorsal bands ( Fig. 26A ); in each segment, there are two thick orange-brownish thick bands, roughly parallel along anterior chaetigers, and in median chaetigers become divergent, connected laterally in darker wide bands, running along anterior parapodial surfaces, and another orange thinner band runs along the posterior parapodial surface ( Fig. 26C ). Prostomium grayish, anterior prostomial area pale. Eyes blackish, anterior eyes 4–6× larger than posterior ones, often in a dark area. Lateral antennae and palps purple, at least basally ( Fig. 26B ), median antennae colorless to pale orange, with a purple basal ring below the base, slightly longer than caruncle when complete. Caruncle brownish with median ridge darker. Cirriform branchiae and dorsal cirri purple. Branchiae with orange stems, pinnules purple to paler with reddish tips. Chaetae with a wide yellow band. Venter with longitudinal median pale band. Anal cirri whitish ( Fig. 26D ). FIGURE 26 . Chloeia fusca M’Intosh, 1885 , freshly collected epitokes (CAS 218217). A. Anterior region, dorsal view. B. Anterior end, dorsal view. C. Chaetigers 10-11, dorsal view. D. Posterior region, slightly oblique dorsal view. Scale bars: A, 1.4 mm; B, 0.7 mm; C, 0.8 mm; D, 1.2 mm. Variation of atokes . Seventeen topotype specimens (RMNH 1245, ZMA VPol 156.5, ZMA VPol 156.7) complete, retaining pigmentation pattern. Body 10.5–23 mm long, 3–5 mm wide, 18–24 chaetigers. All with anterior prostomial area blackish; several specimens with darker lips, and a wide, diffuse brownish transverse ventral band, often displaced towards the anterior segmental half. Eyes blackish, separate; anterior eyes 3–4× larger than posterior ones, Median antenna pale, often long as caruncle, and even longer in some specimens, 2× longer than lateral antennae; lateral antennae and palps darker, often dark purple. Caruncle pale. Branchiae from chaetiger 5. Paired longitudinal bands dark purple, ill-defined along anterior chaetigers of smallest specimens ( 8–11 mm long, 2.5–2.8 mm wide), bands discontinuous with 1–2 wider areas per segment, becoming continuous and medially wider along posterior segments, band margins ill-defined. Median-sized specimens ( 13–17 mm long, 4–5 mm wide) with additional bands visible, brownish, roughly parallel to middorsal bands, continued laterally along anterior notopodial surfaces; longitudinal bands thin to wide, not depending on segment contraction. Longest specimens ( 18-22 mm long, 3–5 mm wide) with thinner brownish bands anteriorly, blackish posteriorly; lateral bands ill-defined, roughly parallel to middorsal bands. Lateral bands paler, parallel to middorsal ones, continued along anterior notopodial surfaces. Branchiae from chaetiger 5, with pale stems, lateral branches purple. Anal cirri fragile, easily detached, yellowish, ovoid to digitate, 2–4× longer than wide. Non topotype specimens from Indonesia (ZMA VPol 156.2, 156.6), and from the Philippines (ZMA VPol 156.3, 156.4) match the topotype specimens and are regarded as conspecific. Variation of epitokes . Smaller epitokes ( ZMA VPol 156.1) complete, with darker pigmentation than described for the largest epitoke ( Fig. 21C–F ). Both with anterior prostomial area barely pigmented. Eyes blackish, coalescent, anterior eyes 6× larger than posterior ones. Median antenna pale to blackish basally, 2/3–4/5 as long as caruncle, 3 × longer than lateral antennae; lateral antennae bases separate from each other. Caruncle pale, reaching chaetiger 4. Mouth in chaetiger 2. Paired longitudinal bands dark purple to reddish, well defined along body; lateral bands pales, parallel, continued into internotopodial space. Branchiae from chaetiger 5, stem pale, lateral branches purple, parallel along body; median segments with branchiae with 6–7 lateral branches. Anal cirri yellowish (present in smallest paratype ), ovoid, 2× longer than wide . Remarks . Chloeia fusca M’Intosh, 1885 was described with a single specimen collected in Indonesia and it is characterized by having a brownish body and two dorsal longitudinal dark bands. By this pigmentation and having bipinnate branchiae from chaetiger 5, it belongs in the group fusca, together with C. bistriata Grube, 1868 , originally described from the Red Sea. As indicated above, the main differences between these species are the size of eyes and caruncular complexity. In C. fusca the anterior eyes are 3–4× larger than posterior ones, and the median ridge of its caruncle has 18 vertical folds, whereas in C. bistriata anterior eyes are 6× larger than posterior ones, and its caruncular median ridge has 12 vertical folds. M’Intosh (1885: 14) indicated the body of his holotype was dusky brown (hence the specific name; Latin fuscus, -a, -um : dark, dim, black, brown). The dorsum also had two longitudinal brownish lines with a paler median area. In comparison with the original description, most pigmentation patterns are retained in the specimen which has been almost 150 years in ethanol; the only difference is in the chaetal pigmentation because the greenish yellow banding is gone. Treadwell (1906: 1164) recorded this species with specimens collected in five stations in Hawaii , in depths of 38–108 m , but he identified them as C. flava . He noted there were no middorsal dots but instead “two continuous brown lines extending along the dorsal surface.” Hartman (1966: 179) indicated that the Hawaiian form has a dorsal “row or dark spots and two continuous brown lines, one on each side of the median line” and that “branchiae start “from fifth segment”. This pigmentation pattern does not match with typical C. flava , but resembles C. fusca M’Intosh, 1885 . Horst (1912: 22–24) included several specimens, some from the type locality (Banda Islands), and provided additional details to the original description. He noted, however an interesting difference regarding the size of eyes among some of his material; he indicated “among the worms collected with the tow-net near the Paternoster islands (ZMA V.Pol 156.1) there is a gigantic specimen, measuring 37 mm in length; its eyes are extraordinarily developed and coalesced, whereas in the dorsal fascicles the long and slender bristles are prevailing” ( Horst 1912: 24 ). There are actually two other, smaller specimens in the same lot, and all have coalescent eyes; they are herein regarded as epitokes and were described above. Fauvel (1953: 97) indicated C. longisetosa Potts, 1909 was the epitoke of C. fusca . Horst (1917: 285) recorded it from Natal, and his specimens matched the thinner longitudinal bands found in the Seychelles by Potts (1909: 356) ; however, Natal specimens had shorter median antenna, about half as long as caruncle, whereas in the topotype specimens, median antennae are as long as, or longer than caruncle ( Horst 1917: 286 ). These records might belong in C. fusca sensu Potts, 1909 , ande belong to a different species. There is little information regarding morphological modifications among amphinomids for reproduction; for example, in the closely related euphrosinids, an increase in the number of capillary chaetae, and in eye size were documented ( Naville 1933 ), and this would imply these specimens are epitokes. Nevertheless, these differences are regarded as sufficient for separating these coalescent-eyes specimens as a different species. The epitokes described above match C. fusca M’Intosh, 1885 by having two longitudinal bands along dorsum, although there are some differences regarding the color of the longitudinal bands, the pigmentation of the anterior prostomial region, and the pigmentation of dorsal cirri along chaetigers 1–3. In the epitokes the longitudinal bands are reddish, the anterior prostomial region is pale to gray, and the first three dorsal cirri are pale, whereas in the nonepitoke specimens the bands are brownish, dark purple or blackish, the anterior prostomial region is black, and all dorsal cirri are dark purple or blackish. Chaetae are very similar in these two species, although in the epitokes there are more abundant long, thin furcates in notopodia, and neuropodia giving their chaetal fascicles a wooly outlook. This difference, however, is related to epitoky resulting in swimming specimens, as indicated by the fact that they were collected in the water column ( Horst 1912 ). The main difference is the size of eyes; in epitokes eyes are coalescent, anterior eyes about 6× larger than posterior ones, whereas in atoke specimens they are separate, anterior eyes 3–4× larger than posterior ones. All images or videos made after living atoke specimens ( Belle 2022b , Charpin 2022 ) corresponding to this species show reddish longitudinal bands over a pale background. The shift to brownish might be explained after the preservative used during the Challenger Expedition, which made the reddish bands turn brownish, and the pale dorsum became darkened, and this explains the name M’Intosh (1885) introduced for the species. On the other hand, after the clarification of the variations in pigmentation, the surprisingly wide distribution of this species, from the Indian to the Western Pacific should be reassessed with molecular indicators. Distribution . Indonesia , Papua New Guinea , Line and Loyalty Islands, French Polynesia to Hawaii, from the intertidal to 204 m water depth.