Chloeia boucheti, Salazar-Vallejo, 2023

Salazar-Vallejo, Sergio I., 2023, Revision of Chloeia Savigny in Lamarck, 1818 (Annelida, Amphinomidae), Zootaxa 5238 (1), pp. 1-134 : 36-37

Chloeia boucheti sp. n.

urn:lsid:zoobank.org:act:379696D1-12B7-4E11-A099-82C2C2A6D01F

Fig. 15

Type material. Indonesia. Holotype ( MNHN IA-TYPE 2048 ) and paratype ( MNHN IA-TYPE 2050 ), RV Baruna Jaya I, Sta. CP85 (09°22´S, 131°14´E), 245– 240 m, beam trawl, 4 Nov. 1991 (paratype darker; anterior eyes reddish, minute, posterior ones not seen; caruncle grayish, median ridge blackish; branchial bases orange; anal cirri pale orange; body markedly bent ventrally; 46 mm long, 12 mm wide, 33 chaetigers). One paratype ( ECOSUR 307 ), RV Baruna Jaya I, Sta. CP84 (09°23´S, 131°09´E), 275– 246 m, beam trawl, 4 Nov. 1991 (paratype bent ventrally, many chaetae broken; bipinnate branchiae with orange bases; body 25 mm long, 8 mm wide, 31 chaetigers).

Diagnosis. Chloeia with bippinate branchiae from chaetiger 4, progressively smaller posteriorly, branchial bases orange, with 11–12 tapered, lateral branches; anterior prostomial area pale; dorsum without middorsal spots; notochaetae furcates and harpoon-chaetae; neurochaetae furcates.

Description. Holotype (MNHN IA-TYPE 2048) complete, bent ventrally; body tapered, 44 mm long, 13 mm wide, 34 chaetigers.

Holotype pale; dorsum without pigmentation ( Fig. 15A ). Dorsal cirrophores orange, cirrostyles pale. Bipinnate branchiae pale, bases orange ( Fig. 15H ). Venter pale, with a midventral whitish band.

Prostomium anteriorly entire, anterior prostomial area pale. Eyes reddish, anterior ones minute, posterior ones not seen. Median antenna inserted at anterior caruncular margin, pale, ¼ as long as caruncle, about 2× longer than lateral antennae. Lateral antennae bases close to each other. Palps 2/3 as long as lateral antennae. Mouth ventral on chaetiger 2. Pharynx not exposed.

Caruncle grayish, trilobed, straight, tapered, reaching chaetiger 4 ( Fig. 15B ); middorsal ridge blackish, with about 46 vertical folds. Lateral lobes narrow, barely visible, with about 40 vertical folds.

Bippinate branchiae from chaetiger 4, continued throughout body, parallel along most body segments, with bases orange ( Fig. 15C, H ); progressively larger to chaetigers 10–16, diminishing in size in posterior chaetigers. In median segments each branchia with 11–12 lateral branches.

Parapodia biramous, notopodia with cirriform branchiae along chaetigers 1–3, progressively smaller, ¼–1/5 as long as dorsal cirri. Dorsal cirri with cirrophores orange distally, cirrostyles pale, cirri slightly longer than branchiae along anterior chaetigers, about 3× longer in posterior chaetigers. Second ventral cirri with cirrophores 2× longer, and cirrostyles almost 3× longer than adjacent ones, directed dorsally. Other ventral cirri directed ventrolaterally, 2× as long as following segments in median and posterior regions.

Chaetae very abundant, many with broken tips. Complete chaetae with distal fragile hoods, rarely eroded. Notochaetae in anterior chaetigers furcates, major tines brownish, 4–8× longer than minor ones, ( Fig. 15D ). Median chaetigers with furcates and abundant harpoon-chaetae, both with short spurs ( Fig. 15F ). Neurochaetae all furcates, tips brownish, major tines 2–3× longer than minor ones in anterior chaetigers ( Fig. 15E ), 2—5× longer in median chaetigers ( Fig. 15G ).

Posterior region tapered; pygidium with anus terminal; anal cirri pale orange ( Fig. 15C ), digitate, 4× longer than wide.

Live pigmentation. Unknown. Bipinnate branchial bases and dorsal cirrophores orange.

Etymology. The specific epithet is derived after Dr. Philippe Bouchet, a taxonomist of marine molluscs from the Muséum National d’Histoire Naturelle, Paris, in recognition of his many publications on molluscs, and especially because he participated in the Karubar Expedition ( Crosnier et al. 1997), which collected the type material for this species. The derived name is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Variation. The paratype (MNHN IA-TYPE 2050) is more colorful than the holotype, especially regarding bases of bipinnate branchiae, and tips of dorsal cirrophores. The other paratype ( ECOSUR 307 ) is paler, orange pigmentation barely seen along bipinnate branchiae bases; eyes indistinct, and its anal cirri are 6–7× longer than wide.

Remarks. Chloeia boucheti sp. n. is being described with specimens from Indonesia and belongs in the group tumida because its dorsum has no pigmentation pattern, and its bipinnate branchiae start in chaetiger 4 and are progressively smaller posteriorly. By having a tapered body, and bipinnate branchiae with 11–12 tapered lateral branches, it resembles C. richeri sp. n. from New Caledonia. The main differences are the pigmentation of the anterior prostomial area, the coloration of bipinnate branchiae bases, and the type of notochaetae. In C. boucheti , the anterior prostomial area is pale, its bipinnate branchiae have orange bases, and its notochaetae are furcates and harpoon-chaetae, whereas in C. richeri , the anterior prostomial area is blackish, its branchial bases are pale, and only has furcate notochaetae.

Distribution. Indonesia, in sediments at 240–275 m water depth.

Figures

FIGURE 15. Chloeia boucheti sp. n., holotype (MNHN IA-TYPE 2048). A. Anterior region, dorsal view. B. Anterior end, dorsal view. C. Posterior region, dorsal view. D. Chaetiger 4, notochaetal tips. E. Same, neurochaetal tips. F. Chaetiger 15, notochaetae furcate and harpoon-chaetae. G. Same, neurochaetal tips. H. Paratype (MNHN IA-TYPE 2050), chaetigers 13-16, dorsal view (most chaetae trimmed). Scale bars: A, 1.7 mm; B, 0.6 mm; C, 1.6 mm; D, 140 μm, E, 30 μm; F, 200 μm; G, 40 μm, H, 1.5 mm.