Chloeia gilleti, Salazar-Vallejo, 2023

Salazar-Vallejo, Sergio I., 2023, Revision of Chloeia Savigny in Lamarck, 1818 (Annelida, Amphinomidae), Zootaxa 5238 (1), pp. 1-134 : 65-68

Chloeia gilleti sp. n.

urn:lsid:zoobank.org:act:99118C33-003B-40F0-85B8-9A38FB9085C2

Fig. 29

Chloeia euglochis: Fauvel 1913: 32 ; Fauvel 1914: 90–91; Augener 1918: 94–95; Fauvel 1950: 347–348 (partim; reddish specimens only) (non Ehlers, 1887).

Chloeia viridis: Tebble 1955: 82–83 ; Fauvel & Rullier 1957: 68–71, Fig. 2 (syn.); Fauvel & Rullier 1959a: 507; Fauvel & Rullier 1959b: 155 (partim, Sta. 30 only); Rullier 1964: 144–145; Amoureux 1973a: 51; Intes & le Loeuff 1975: 290–291; Kirkegaard 1983: 201–203, Fig. 4 .

Chloeia cf venusta: Guy 1964: 178–180 , Figs 4 , 6 .

Type material. West Africa, Democratic Republic of Congo. Holotype ( MMSUCO Amp 7), and paratype ( MMSUCO Amp 3), off Pointe-Noire , A. Crosnier, Sta. 113 (04°49´S, 11°28´E), 130 m, 19 Nov. 1969, A. Crosnier, coll. (details of paratype given in variation below).

Additonal material. Western Africa. Democratic Republic of Congo. One specimen ( MMSUCO Amp 4), anterior fragment, off Pointe-Noire , A. Crosnier, Sta. 22 (05°00´S, 11°23´E), 165 m, 18 Sep. 1969 (reddish, caruncle pale; eyes blackish, separate, anterior eyes 2–3× larger than posterior ones; fragment 11.5 mm long, 4 mm wide, 15 chaetigers). One specimen ( MMSUCO Amp 6), epitoke, WSW off Pointe-Noire , A. Crosnier , Sta. 59 (05°09´S, 11°28´E), 250 m, 28 Feb. 1968, A. Crosnier, coll. (data used for description of epitoke below). Nigeria. One specimen ( MNHN A 367.1 ), RV Calypso , Sta. 30 (03°50´N, 06°14´E), 90 m, 26 May 1956 (complete, pale purplish; middorsal band wide, anteronotopodial bands well defined along body, transverse bands better preserved along posterior chaetigers; dorsal cirri dark purple; anterior eyes 2× larger than posterior ones; bent ventrally, 17 mm long, 6 mm wide, 29 chaetigers). Namibia. Two specimens ( NHMD 915075 ), RV Galathea, Sta. 143 (23°16´S, 14°02´E), off Conception Bay, 150 m, 25 Dec. 1950, J.B. Kirkegaard, coll. (pinkish; one bent ventrally; anterior eyes 3–4× larger than posterior ones; lateral bands projected along anterior parapodial surfaces, visible in anterior chaetigers; dorsal cirri dark purple; caruncular median ridge purple, at least basally; branchiae from chaetiger 4; body 13–20 mm long, 4.8–5.0 mm wide, 26–27 chaetigers) .

Diagnosis. Chloeia with bipinnate branchiae from chaetiger 4, progressively smaller posteriorly; middorsal spots as inverted T per segment; harpoon notochaetae with spurs, or without spurs, and aciculars; notochaetae furcates.

Description. Holotype (MMSUCO Amp 7), complete, left parapodium of chaetiger 13 previously removed; branchiae of chaetiger 15 removed for illustrating pigmentation pattern; body bent ventrally, 30 mm long, 6 mm wide, 31 chaetigers.

Holotype reddish; middorsal longitudinal band continued throughout body, narrower along posterior chaetigers ( Fig. 29A ); segmental bands expanded laterally along posterior segmental half, continued laterally in paler tones, expanded laterally into wide darker bands along anterior parapodial surface, reaching base of neurochaetal bundles ( Fig. 29C ). Prostomium, antennae and ventral cirri pale. Dorsal cirri dark purple from chaetiger 4 (previous ones pale). Bipinnate branchiae pale. Notochaetae brownish, neurochaetae golden. Venter brownish centrally, lateral areas paler; midventral band narrow, paler.

Prostomium anteriorly entire, pale. Eyes blackish, coalescent, anterior eyes circular, well-defined, 4–5× larger than posterior oval ones. Median antenna inserted at anterior caruncular margin, 4/5 as long as caruncle, about 3× longer than lateral antennae. Lateral antennae bases close to each other, 3× longer than palps. Mouth ventral on chaetiger 2/3. Pharynx not exposed.

Caruncle dark gray, slightly bent laterally, trilobed, tapered, reaching chaetiger 4 ( Fig. 29B ). Median ridge plicate, blackish, with about 16 vertical folds, partially concealing lateral lobes. Lateral lobes narrow, with about 19 vertical folds.

Bipinnate branchiae from chaetiger 4, continued throughout body, parallel along anterior body half, divergent in posterior half; progressively larger to chaetiger 12–13, smaller posteriorly. Median segments branchiae with 6–7 lateral branches.

Parapodia biramous, notopodia with cirriform branchiae along chaetigers 1–3, ½–1/4 as long as dorsal cirri. Dorsal cirri 2× longer than bipinnate branchiae along median chaetigers, 3–4× longer in posterior chaetigers. Second ventral cirri with cirrophores 2× longer and 2× wider, and cirrostyle 2–3× longer than adjacent ones, directed dorsally. Other ventral cirri directed ventrolaterally, as long as two subsequent segments.

Notochaetae broken along median segments. Complete chaetae with fragile hoods, variably eroded. Notochaetae in anterior chaetigers furcate, major tines 2–3× longer than minor ones ( Fig. 29D ). Median chaetigers with two types of notochaetae: short aciculars, and harpoon-chaetae without spurs ( Fig. 29F ). Neurochaetae all furcates, major tines 6–7× longer than minor ones in anterior chaetigers ( Fig. 29E ), and in median ones ( Fig. 29G ).

Posterior end tapered ( Fig. 29H ); pygidium with anus terminal; anal cirri whitish, subcylindrical, blunt, 5–6× longer than wide.

Epitoke. Complete (MMSUCO Amp 6), pinkish, chaetae very thin, transparent; venter cream, midventral band wide, paler; right parapodium of chaetiger 17 previously removed; body bent ventrally, 40 mm long, 9 mm wide, 33 chaetigers.

Prostomium anteriorly entire, pale. Eyes colorless, size relationship unknown. Median antenna inserted at anterior caruncular margin, twisted, 4/5 as long as caruncle, 2× longer than lateral antennae. Lateral antennae bases close to each other, 2× longer than palps. Mouth ventral on chaetiger 3. Pharynx not exposed.

Caruncle brownish, slightly bent, trilobed, tapered, reaching chaetiger 4. Median ridge plicate, with about 19 vertical folds, partially concealing lateral lobes. Lateral lobes narrow, with about 19 vertical folds.

Bipinnate branchiae from chaetiger 4, parallel throughout body, progressively larger to chaetiger 11–12, smaller posteriorly. Median segments with 7–8 lateral branches.

Parapodia biramous, notopodia with cirriform branchiae along chaetigers 1–3, bent, progressively shorter than dorsal cirri. Dorsal cirri about as long as bipinnate branchiae along median chaetigers, 2–3× 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 one subsequent segment.

Chaetae most complete, distal hoods tiny. Notochaetae in anterior chaetigers furcate, major tines 3–4× longer than minor ones. Median chaetigers with two types of notochaetae: aciculars (very abundant), and harpoon-chaetae without spurs. Neurochaetae all furcates, very abundant in median and posterior chaetigers, up to 1.5× longer than body width along posterior chaetigers, major tines 4–5× longer than minor ones.

Posterior region tapered; anus terminal; anal cirri whitish, subcylindrical, tapered, 6–7× longer than wide.

Live pigmentation. Unknown, probably more intense than in holotype.

Variation. Paratype (MMSUCO Amp 3) complete, with some adsorbed salt particles; left parapodium of chaetiger 13 previously removed; body reddish-brown, 17 mm long, 4 mm wide, 27 chaetigers. Miidorsal band wide, continuous throughout body, lateral expansions difuse, giving a darker view for posterior segmental half, continued along anterior notopodial surface. Dorsal cirri brownish to dark purple. Branchiae pale. Chaetae pale. Venter brownish, paler laterally; midventral band wide, pale. Median antenna as long as caruncle. Caruncle pale. Eyes blackish, separate, anterior eyes 2–3× larger than posterior ones. Median chaetigers with notochaetae acicular, and harpoonchaetae with or without spurs, neurochaetae all furcates, major tines 3–4× longer than minor ones. Anal cirri whitish, tapered, 6× longer than wide.

The epitoke resembles the holotype by being pinkish, but its eyes have faded off. The most relevant modification is on chaetal features. Most chaetae are very long, longer than in the holotype, and they are also very thin along body. No parapodial modifications were noted, including the relative length of cirri. The fact that the epitoke was taken from the bottom, implies this is a pre-swimming stage, but nothing else can be added about it.

Remarks. Chloeia gilleti sp. n. is described with specimens from Western Africa; it belongs in the group viridis by having a complex pigmentation pattern, bipinnate branchiae from chaetiger 4, progressively smaller posteriorly. Because C. gilleti has middorsal spots as inverted T per segment, it resembles C. violacea Horst, 1910 described from Indonesia. The main differences between these two species are in the width of the middorsal band, and in the type of harpoon notochaetae. In C. gilleti , the middorsal band is wider, especially along median and posterior regions, and the harpoon chaetae lack spurs or smooth tines, whereas in C. violacea , the middorsal band is narrow, and the harpoon chaetae have smooth tines.

Some records from West Africa referred to reddish specimens and they are retained in the synonymy section above; other records for C. viridis Schmarda, 1861 , indicated three longitudinal dorsal bands ( Rullier 1964: 144–145), or for Iberian seas, under C. candida Kinberg, 1857 (Alós & Núñez 2012: 53–54, Fig. 17 ), and they are regarded as belonging to another species.

On the other hand, C. gilleti resembles C. mezianei sp. n., described below from Western Africa, and were both confused in the past with C. viridis . Pigmentation patterns are different but in case colors fade off, chaetael features also differ. Thus, in C. gilleti anterior notochaetae are furcates and median neurochaetae are furcates with small minor tines, whereas in C. mezianei anterior notochaetae are spurred, and median neurochaetae are acicular or spurred.

A few other records of C. viridis gave no details for dorsal pigmentation and cannot be related to any species, especially if their material was not available ( Amoureux 1973a: 51; Intes & le Loeuff 1975: 290–291).

Distribution. Democratic Republic of Congo to Namibia, in sediments at 90–250 m water depth.

Figures

FIGURE 2. Chloeia viridis Schmarda, 1861, non-type specimens (BMNH 1931.6.22.16-18). A. Black form, anterior region, dorsal view. B. Same, chaetigers 10-12, dorsal view (branchiae removed from chaetiger 11). C. Same, posterior region, dorsal view. D. Red form, anterior region, dorsal view. E. Same, chaetigers 12-14, dorsal view (branchiae removed from chaetiger 13). F. Same, posterior region, dorsal view. Scale bars: A, F, 0.9 mm; B, E, 0.7 mm; C, 1 mm; D, 1.2 mm.

FIGURE 4. Chloeia fusca M’Intosh, 1885, non-type specimen (UF 4368). A. Ventral view. B. Ventral view after body wall removed. C. Same, after Methyl Green staining. D. Same, lower half of digestive tube removed. (AI, anterior intestine; MB, midventral band (nerve chord); MR, muscular ridge; Oe, oesophagus; PI, posterior intestine; R, rectum; St, stomach). All scale bars: 1 mm.

FIGURE 6. Chloeia bistriata Grube, 1868, non-type specimens (from UF 4449, 4517). A) Small juvenile (1.4 mm long, 11- 12 chaetigers), dorsal view, depressed by a cover slip. B) Same, dorsal view (* indicates enlarged area of chaetigers 7-8). C) Chaetigers 7-8, right parapodia, seen from above (* convoluted dorsal cirri). D) Larger juvenile, chaetae combed backwards, depressed by cover slip, without posterior region (3.5 mm long, 14-15 chaetigers), after Shirlastain-A staining (5: left notopodium, chaetiger 5; MA: median antenna). E) Same (5: chaetiger 5). F) Same, close-up of anterior region, dorsal view (BB: bipinnate branchia, CB: cirriform branchia, DC: dorsal cirrus). Scale bars: A, 0.23 mm, B: 0.20 mm, C, F: 0.1o mm, D: 0.55 mm, E: 0.50 mm.

FIGURE 17. Chloeia fauveli sp. n., holotype (MNHN IA-TYPE 2049).A.Anterior region, dorsal view. B. Anterior end, dorsal view, after Methyl green staining. C. Same, right lateral view. C. Chaetigers 12-15, dorsal view, after Methyl Green staining. E. Chaetiger 3, furcate and harpoon notochaetae (inset: tip of harpoon chaetae). F. Same, tips of neurochaetae. G. Chaetiger 14, harpoon notochaetae (inset: tip of harpoon chaetae). H. Same, tips of neurochaetae. Scale bars: A, 2.2 mm; B, 0.7 mm; C. 0.9 mm; D, 1.8 mm; E, 250 μm; F, H, 80 μm; G, 300 μm; I, 2.o mm.

FIGURE 29. Chloeia gilleti sp. n., holotype (MMSUCO Amp 7). A. Anterior region, dorsal view. B. Anterior end, dorsal view. C. Chaetigers 14-16, dorsal view (branchiae removed from chaetiger 15). D. Chaetiger 3, notochaetal tips. E. Same, neurochaetal tips. F. Chaetiger 17, harpoon notochaetae. G. Same, neurochaetal tips. H. Posterior region, dorsal view. Scale bars:A, H, 1 mm; B, 0.6 mm; C, 0.7 mm; D, F, 100 μm; E, G, 40 μm.