Chloeia conspicua Horst, 1910

Salazar-Vallejo, Sergio I., 2023, Revision of Chloeia Savigny in Lamarck, 1818 (Annelida, Amphinomidae), Zootaxa 5238 (1), pp. 1-134 : 38-41

Chloeia conspicua Horst, 1910

Fig. 16

Chloeia conspicua Horst, 1910: 173, 1912: 20–21 , Pl. 7, Fig. 5 , Pl. 8, Figs 4 , 5 ; Fauvel 1953: 95, Fig. 46g ; Hartman 1959: 131; Gibbs 1971: 131; Barroso & Paiva 2011: 422, Tab. 1; Salazar-Vallejo et al. 2014: 11 (list); Yáñez-Rivera & Salazar-Vallejo 2022: 509 (diagn.).

Chloeia flava pulchella: Sabith et al. 2022: 21–24 , Figs 2 , 3 (non Baird, 1868).

Type material. Indonesia, Java. Syntype ( RMNH Ver 1246 ), Dirk de Vries Bay , South coast of Java, Dec. 1909, P.N. van Kampen, coll. One slide ( RMNH 10660 ) made with chaetal bundles from an anterior parapodium of a specimen from another lot; slide with thicker furcate notochaetae and thinner furcate neurochaetae (this would explain the lack of harpoon chaetae in Horst 1912 illustrations; type material not listed by Bleeker & van der Spoel 1992).

Additional material. Indonesia, Java. Two specimens ( ZMA V.Pol 150 ), West coast of Atjeh , depth not indicated (largest specimen caught with a fishing hook), Jun. 1895, W. Baerts, coll. Hong Kong. One specimen ( AM V24650 ), Pin Chau (22°28´N, 114°20´E), Flat Island , Hoi Hawan , 7 m, boulders, 52% coral cover, 17 Apr. 1986, P. Hutchings, coll. (bent laterally; middorsal band thin, lateral bands surrounding it, fused anteriorly and posteriorly, projected laterally along notopodial anterior surface, another band connecting branchiae and running behind notochaetal bundles; median antenna and dorsal cirri purplish; caruncular median ridge purplish; branchial stems blackish, branches pale; anterior eyes diffuse, 3–4× larger than posterior ones; body 75 mm long, 12 mm wide, 34 chaetigers) . 10 specimens ( AM W24651 ), Pin Chau (22°28´N, 114°20´E), Flat Island, Hoi Hawan , 7 m, 17 Apr. 1986, P. Hutchings, coll. (almost colorless, a few with thin middorsal band, and lateral bands visible, along anterior chaetigers; bent ventrally; dorsal cirri purplish; branchiae brownish; venter pale, midventral band indistinct; body 46–52 mm long, 18–22 mm wide, 32–35 chaetigers) . Papua New Guinea. One specimen ( UF 3965 ), Madang Province, Madang , Bode Point (-5.2073, 145.8012; 05°12´26.2800″ S, 145°48´04.3200″ E), 23–25 m, 6 Nov. 2012, no collector data (complete, pigmentation reduced to middorsal band; left median segments removed for molecular studies; pharynx partially exposed; body bent ventrally, 30 mm long, 5 mm wide, 31 chaetigers) . Solomon Islands. One specimen ( BMNH 1970.215 ), New Georgia Group, Marovo Lagoon , Sta. 196, silty sand, 2 m, Oct. – Nov. 1965, P.E Gibbs, coll. (splendid specimen; branchiae from chaetiger 4; 27 mm long, 5 mm wide, 28 chaetigers) .

Diagnosis. Chloeia with bipinnate branchiae from chaetiger 4, progressively smaller posteriorly; middorsal band medially constricted, surrounded by anterior expansions of lateral dark bands; median notochaetae acicular and harpoon chaetae without spurs; neurochaetae spurred and furcates.

Description. Syntype (RMNH Ver 1246), complete ( Fig. 16A ); most notochaetae broken; branchiae of chaetiger 13 removed; body subrectangular, 48 mm long, 11 mm wide, 36 chaetigers.

Syntype pale, pigmentation pattern blackish; middorsal bands roughly rectangular up to chaetiger 7 ( Fig. 16B ), thereafter slightly expanded anteriorly and with a median constriction throughout body, last five chaetigers with a posteriorly tapered, anteriorly swollen bar; oblique lateral bands without anterior expansions to chaetiger 7, thereafter with larger, roughly circular widened areas, expanded anteriorly up to chaetiger 25, almost fused with middorsal spots. Segments with two lateral bands; anterior band running along notopodial anterior surface, posterior band running to branchiae, slightly interrupted, continued along notopodia ahead of notochaetal fascicles ( Fig. 16D ). Dorsal ceratophores with blackish posterior surfaces, ceratostyles blackish. Branchial stems with blackish inner surfaces. Venter brownish, midventral band slightly paler, with darker lining.

Prostomium anteriorly entire; anterior prostomial area blackish. Eyes blackish, small, anterior eyes 2× larger than posterior ones ( Fig. 16C ). Median antenna lost (blackish in largest additional specimen ZMA V.Pol 150), inserted at anterior caruncular margin (without tip, half as long as caruncle, 2× longer than lateral antennae in ZMA V.Pol 150). Lateral antennae pale, bases separate from each other, 2× longer than palps. Mouth ventral on chaetiger 2. Pharynx not exposed.

Caruncle pale, slightly bent laterally, reaching chaetiger 4; median ridge smooth, blackish, with about 24 vertical folds, partially concealing lateral lobes. Lateral lobes narrow, with about 20 vertical folds.

Bipinnate branchiae from chaetiger 4, parallel throughout body; progressively larger to chaetiger 10–11, smaller posteriorly, about as long as one successive segment; in median chaetigers each with 6–7 lateral branches.

Parapodia biramous, notopodia with cirriform branchiae along chaetigers 1–3, ½–1/3 as long as dorsal cirri (in chaetigers 2–3; others lost). Dorsal cirri slightly longer than bipinnate branchiae along median chaetigers, 2–3× longer in posterior chaetigers. Second ventral cirri with cirrophores and cirrostyles slightly longer and wider than adjacent ones, directed dorsally. Other ventral cirri directed ventrolaterally, as long as one subsequent segment.

Notochaete broken in almost all chaetigers; neurochaetae most complete. Notochaetae in anterior chaetigers (in ZMA V.Pol 150) acicular or spurred, major tines 4–9× longer than minor ones ( Fig. 16E ). Median chaetigers with harpoon chaetae without spurs or tines, and shorter aciculars ( Fig. 16G ), some with a subdistal constriction (in ZMA V.Pol 150). Neurochaetae spurred to furcates, major tines 4× longer than minor ones, often slightly incurved, shorter in anterior chaetigers ( Fig. 16F ), than in median chaetigers ( Fig. 16H ).

Posterior region tapered; pygidium with anus terminal; anal cirri pale, digitate, 5–6× longer than wide ( Fig. 16I ).

Live pigmentation (after one internet photo from Indonesian specimen by Offermans 2022, and video by Senja 2021, 0:48). Body yellowish with blackish dorsal cirri, central branchial stems, and complex dorsal pigmentation pattern; middorsal spots longer than wide, often with a median constriction, and two oblique lateral blackish bands running towards anterior notopodial surfaces, lateral bands sometimes widened close to middorsal spots. Branchial lateral branches whitish. Chaetae yellowish to transparent. Another photograph from an undefined locality, now unavailable, showed a pinkish body background, with dorsal cirri and middorsal spots blackish, medially constricted; oblique lateral bands and branchial stems brownish; lateral bands widened medially into circular spots. Chaetae brownish to transparent.

Variation. Additional specimens (ZMA V.Pol 150) complete, largest one with a piece of thread coming out from the mouth, indicating its capture with a fishing hook, anterior region stiff, swollen, posterior region depressed; body depressed, 38–74 mm long, 7–16 mm wide, 31–37 chaetigers. Larger specimen with middorsal spots roughly rectangular up to chaetiger 10, thereafter with a median constriction throughout body, last two chaetigers with a rectangular bar; oblique lateral bands without lateral expansions to chaetiger 7, thereafter with larger, roughly circular widened areas, expanded anteriorly up to chaetiger 25, almost fused with middorsal spots, following chaetigers without anterior expansions, narrower, continued to last chaetigers. Branchiae with blackish stems along anterior two-thirds of body, posterior third with blackish pigmentation restricted to inner stem surfaces. Venter brownish, midventral band slightly paler. Eyes blackish, small, anterior eyes 2× larger than posterior ones. Median antenna blackish, without tip, half as long as caruncle. Mouth ventral on chaetiger 3–4. Caruncle pale, strongly bent laterally, reaching chaetiger 4. Bipinnate branchiae from chaetiger 4, parallel throughout body; progressively larger to chaetiger 10–11, smaller posteriorly, about as long as one successive segment; in median chaetigers each with 6–7 lateral branches. Chaetae with hoods rarely eroded. Anterior notochaetae furcate, major tines 4–9× longer than minor ones. Median chaetigers with harpoon chaetae without spurs or tines, some with a subdistal constriction. Neurochaetae all furcates, major tines 4× longer than minor ones, often slightly incurved. Anal cirri pale, digitate, 4× longer than wide.

Smaller specimen with middorsal spots roughly rectangular along chaetigers 4–6, 8-shaped to chaetiger 17–18, faded off in following chaetigers, ill-defined along last chaetigers; oblique lateral bands visible to chaetiger 19, none with circular expanded areas. Branchiae with blackish stems along anterior body half, posteriorly paler, lateral branches brownish. Chaetae brownish. Venter pale, midventral band barely defined. Eyes partially decolored, anterior eyes 2× larger than posterior ones. Median antenna brownish, without tip, 2/3 as long as caruncle, 2× longer than lateral antennae; lateral antennae 2× longer than palps. Branchiae as long as one successive segment, with 6–7 lateral branches in median segments. Anterior notochaetae furcate, major tines 4–6× longer than minor ones. Median chaetigers with harpoon-chaetae, subdistally constricted. Neurochaetae furcates, major tines 3–4× longer than minor ones. Anal cirri pale, tapered, 6–7× longer than wide.

Remarks. Chloeia conspicua Horst, 1910 belongs in the group viridis by having a complex pigmentation pattern, bipinnate branchiae from chaetiger 4, progressively smaller towards posterior end. By having middorsal bands medially constricted, it resembles C. amphora Horst, 1910 described from Indonesia and C. bimaculata Wang, Zhang, Xie & Qiu, 2019 from Hong Kong. The main difference lies in the dorsal banding pattern because in C. conspicua the segmental middorsal band is surrounded by anterior expansions of lateral dark bands, whereas in the two other species the middorsal band is surrounded by a pale area, without lateral bands or, if present, are barely pigmented.

On the other hand, C. conspicua resembles C. incerta de Quatrefages, 1866 ( C. parva Baird, 1868 ) described from Sulawesi, by having a large middorsal band and oblique lateral bands continued to anterior parapodial surfaces. These two species were described from nearby localities, but they differ after their pigmentation pattern. In C. conspicua the middorsal band is rectangular to 8-shaped, with lateral bands often swollen into circular spots close to middorsal spots, whereas in C. incerta the middorsal spots are wider anteriorly and narrower posteriorly, and the lateral bands never expand into forming circular spots.

Brown (1954: 229) indicates the Latin word conspicuus means manifest, visible, prominent. Horst (1910) did not explain the etymology, but the pigmentation pattern might explain why he found it prominent: “each segment shows a violet longitudinal stripe, somewhat narrower in the middle of its length and interrupted in the intersegmental grooves. On both sides this stripe is accompanied with a>-shaped band, including thus a rhomboid area on the middle of the back, from which a dark band emerges, running along the anterior side of the parapodium” ( Horst 1910: 173).

On the other hand, there is a difference regarding the number of lots and specimens that Horst studied. Horst (1910: 173) listed three specimens in two lots; one from the West coast of Atjeh, Java, with two specimens collected in August 1893, and the other from the South coast of Java, with one specimen collected in 1909. These two lots and its three specimens must be regarded as syntypes ( ICZN 1999, Art. 72.1.1, 73.2). In his next publication, Horst (1912) included another lot (ZMA V.Pol 150) with two specimens collected from the West coast of Atjeh in 1895; these two specimens were not included in the original description and cannot be regarded as syntypes. However, one of the original lots is lost (J. Bleeker 2021 in litt.), and the other is the only remaining syntype. Further, the species has not been found after the original description and subsequent illustrations ( Horst 1910, 1912); the other record by Fauvel (1953) only includes the original figure for the dorsal pigmentation pattern, but no specimens had been found.

The syntype described above is not designated as a lectotype because it is the only specimen of the type series available; other specimens were not found and are presumed lost (J. Bleeker 2021 in litt.). Despite the fact the species was not found after the original description, the additional specimens indicated above match the original description and the current redescripton; consequently, the specific status is not problematic or needing any clarification which are formal requirements for proposing a lectotype.

Distribution. Indonesia, Hong Kong, Papua New Guinea and Solomon Islands, in sediments at 2–25 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 3. Chloeia mezianei sp. n., non-type specimen (NHMD 915074). A. Left lateral view. B. Anterior end and pharynx, seen from above. C. Same, right lateral view. Scale bars: A, 1 mm; B, 0.6 mm, C, 0.5 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 5. Chloeia bemisae sp. n., paratype, anterior fragment (UF 4388b). A) Chaetiger 3, right parapodium, posterior view, cirriform branchia cut (insets matched: 1, branchial cut tip; 2, branchial basal region; 3, dorsal cirrophore; 4, dorsal cirrostyle tip). B) Chaetiger 5, right parapodium, posterior view (insets matched: 1 and 2, branchial filament tip; 3, dorsal cirrostyle tip) (Br: branchia, DCs: dorsal cirrostyle). Scale bars: A, 0.20 mm; B: 0.38 mm.

FIGURE 16. Chloeia conspicua Horst, 1910, syntype (RMNH Ver 1246).A. Depressed by glass slide, dorsal view. B. Anterior region, dorsal view. C. Anterior end, dorsal view. D. Chaetigers 13-16, dorsal view (branchiae from chaetiger 14 removed). E. Chaetiger 3, notochaetal tips. F. Same, neurochaetal tips. G. Chaetiger 20, notochaetal tips. H. Chaetiger 16, neurochaetal tips. I. Posterior region, dorsal view. Scale bars: A, 5.2 mm; B, 3.5 mm; C, 1 mm; D, 1.8 mm; E, 40 μm; F, 60 μm; G, 50 μm; H, 45 μm; I, 2.7 mm.

FIGURE 46. Chloeia pulchella Baird, 1868, reinstated.A. Holotype of C. p. pallida Baird, 1868 (BMNH 1846.10.14.60), anterior end, dorsal view, after Methyl green staining. B. Chaetigers 17-20, dorsal view. C. Posterior region, dorsal view. D. Syntype of C. incerta de Quatrefages, 1866 (MNMH IA-TYPE 248), beheaded, anterior end, dorsal view. E. Chaetigers 16-19, dorsal view. F. Posterior region, dorsal view. Scale bars: A, E, 0.9 mm; B, 1.1 mm; C, 1.5 mm; D, 1.4 mm; F, 1.9 mm.