Chloeia richeri, Salazar-Vallejo, 2023

Salazar-Vallejo, Sergio I., 2023, Revision of Chloeia Savigny in Lamarck, 1818 (Annelida, Amphinomidae), Zootaxa 5238 (1), pp. 1-134 : 104-106

Chloeia richeri sp. n.

urn:lsid:zoobank.org:act:40D905E2-69E9-437C-874F-1E7F42E96671

Figs 48 , 49

Type material. New Caledonia. Holotype ( MNHN IA-TYPE 2053 ), and 10 paratypes (5 ECOSUR 308 ; 5 MNHN IA-TYPE 2054 ), RV Vauban , Sta. 169 (18°54.03´S, 163°11.20´E), 590 m (600 m after Richer de Forges 1990: 38), 17 Sep. 1985, B. Richer de Forges, coll.

Additional material. New Caledonia. One specimen ( ECOSUR), RV Vauban , Sta.202 (18°58.00´S, 163°10.50´E), 560 m (580 m after Richer de Forges 1990: 39), 20 Sep. 1985, B. Richer de Forges, coll. (damaged, many notochaetae broken; body 32 mm long, 11 mm wide, 31 chaetigers; anterior prostomial spot blackish, separated in two lateral halves, almost covering all prostomium; bipinnate branchiae with 11–12 lateral branches in median region). Two specimens ( MNHN), RV Vauban , Sta. 157 (18°52.50´S, 163°16.90´E), 575 m, 15 Sep. 1985, B. Richer de Forges, coll. (damaged, many notochaetae broken; anterior prostomial spot blackish, separated in two lateral halves, almost covering all prostomium; bipinnate branchiae with 11–12 lateral branches in median region; body 33–38 mm long, 8–9 mm wide, 31–36 chaetigers) . Indonesia. One specimen ( ECOSUR), Campagne KARUBAR , RV Baruna Jaya I, Sta. DW3 (05°32´S, 132°51´E), 243– 230 m, Warén dredge, 26 Oct. 1991 (anterior fragment, reddish, most branchiae and chaetae lost; anterior prostomial area blackish; 14 mm long, 4 mm wide, 19 chaetigers). One specimen ( ECOSUR), Campagne KARUBAR , RV Baruna Jaya I, Sta. CP24 (05°48´S, 132°13´E), 301– 278 m, Warén dredge, 22 Oct. 1991 (anterior fragment, reddish, most branchiae and chaetae lost; anterior prostomial area blackish; body 13 mm long, 7 mm wide, 11 chaetigers). One specimen ( ECOSUR), Campagne KARUBAR , RV Baruna Jaya I, Sta. DW28 (05°31´S, 132°54´E), 448–467 m, Warén dredge, 26 Oct. 1991 (anterior fragment, reddish, most branchiae and chaetae lost; anterior prostomial area blackish; body 14 mm long, 4 mm wide, 14 chaetigers). One specimen ( ECOSUR), Campagne KARUBAR , RV Baruna Jaya I, Sta. CP35 (06°08´S, 132°45´E), 390–502 m, beam trawl, 27 Oct. 1991 (reddish, anterior prostomial area blackish, separated in two lateral oval spots; body 40 mm long, 8 mm wide, 31 chaetigers) . Philippines. One specimen ( MNHN Musorstom 3 ), Sta. CP115 (12°32´S, 120°44´E), 794 m, beam trawl, 3 Jun. 1985 (anterior fragment, most chaetae broken; body reddish, 21 mm long, 5 mm wide, 18 chaetigers) .

Diagnosis. Chloeia with bipinnate branchiae from chaetiger 4, basally pale; progressively smaller posteriorly, each with 11–12 lateral branches, tapered; anterior prostomial area blackish; dorsum without pigmentation pattern; notochaetae furcates; neurochaetae furcates and spurred.

Description. Holotype (MNHN IA-TYPE 2053), complete, bent ventrally ( Fig. 48A ); body tapered, 37 mm long, 9 mm wide, 32 chaetigers.

Holotype brownish; dorsum without pigmentation. Dorsal cirri pale. Interramal areas whitish along chaetigers 5–25, usually present in both sides. Bipinnate branchiae pale. Venter pale, with a midventral whitish band.

Prostomium anteriorly entire, with a large black oval, wider than long spot almost completely covering anterior prostomial lobe ( Fig. 48B ). Eyes missing. Median antenna inserted at anterior caruncular margin, pale, 1/3–1/4 as long as caruncle, almost 2× longer than lateral antennae. Lateral antennae bases close to each other. Palps half as long as lateral antennae. Mouth ventral on chaetiger 2–3. Pharynx not exposed.

Caruncle pale, trilobed, completely bent anteriorly, reaching chaetiger 3; middorsal ridge barely pigmented, with about 40 vertical folds. Lateral lobes narrow, barely visible, with about 30 vertical folds.

Bipinnate branchiae from chaetiger 4, continued throughout body, parallel along most body segments; progressively larger to chaetigers 13–18, diminishing in size in posterior chaetigers. In median segments each branchia with 10–12 lateral branches.

Parapodia biramous, notopodia with cirriform branchiae along chaetigers 1–3, progressively smaller, 1/3–1/5 as long as dorsal cirri. Dorsal cirri slightly longer than bipinnate branchiae along median chaetigers, almost 2× longer in posterior ones. Second ventral cirri with cirrophores 2× longer and wider than adjacent ones, and cirrrostyles 2× longer than adjacent ones, directed dorsally. Other ventral cirri directed ventrolaterally, as long as two following segments in median region, up to three segments in posterior one.

Chaetae many with broken tips. Complete chaetae with distal fragile hoods, often eroded. Notochaetae in anterior chaetigers furcates ( Fig. 48C ), major tines 3–4× longer than minor ones. Median chaetigers with furcate notochaetae ( Fig. 48E ), major tines 3× longer than minor ones, without harpoon notochaetae. Neurochaetae all furcates, anterior neurochaetae with longer minor tines ( Fig. 48D ), in median chaetigers minor tines reduced to spurs ( Fig. 48F ); major tines 8—10× longer than minor ones.

Posterior region tapered; pygidium with anus terminal; anal cirri pale, digitate to tapered, 6–7× longer than wide.

Live pigmentation. Unknown.

Variation. Paratypes variably damaged, most with chaetae broken; body 36–44 mm long, 7–10 mm wide, 30– 33 chaetigers; anterior prostomial black spot as large as prostomia in 4 specimens, about half as large as prostomia in 3 specimens, one-quarter as larger in 1 specimens; large but barely pigmented in 2 specimens; caruncle turned anteriorly in all specimens; interramal whitish areas along chaetigers 3–31, diminishing posteriorly (less defined in more damaged specimens); bipinnate branchiae in median region with 11–13 lateral branches; midventral white band visible in all specimens. A non-type, complete specimen (ECOSUR) is less damaged, reddish ( Fig. 49A ), with black anterior prostomial area and caruncle with about 40 vertical folds ( Fig. 49B ); its posterior region has golden neurochaetae, and anal cirri tapered ( Fig. 49C ).

Etymology. This species is named after Dr. Bertrand Richer de Forges, a French carcinologist living in New Caledonia, in recognition for his many and sustained efforts for organizing sampling expeditions along the Western Pacific for the Muséum National d’Histoire Naturelle, Paris, including most of the so-called Musorstom Expeditions 4-10, which among the abundant materials, included the type specimens for this species. The derived name is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Remarks. Chloeia richeri sp. n. is described with specimens from New Caledonia, Indonesia and The Philippines, and belongs in the group tumida by having its dorsum with no pigmentation pattern, and its bipinnate branchiae start in chaetiger 4 and are progressively smaller along posterior region. Due to the presence of a tapered body, and bipinnate branchiae with 11–12 tapered lateral branches, it resembles C. boucheti sp. n., described above from Indonesia. As indicated in the key above, the main differences lie in the pigmentation of the anterior prostomial area, the bases of bipinnate branchiae, and the type of notochaetae. Thus, C. richeri has a blackish anterior prostomial area, pale bipinnate branchial bases, and its notochaetae are only furcates, whereas in C. boucheti the anterior prostomial area is pale, its bipinnate branchiae have orange bases, and its notochaetae are furcates and harpoonchaetae.

Distribution. New Caledonia to the Philippines and Indonesia, in sediments at 230–794 m water depth.

Figures

FIGURE 48. Chloeia richeri sp. n., holotype (MNHN IA-TYPE 2053). A. Anterior region, dorsal view. B. Anterior end, dorsal view. C. Chaetiger 3, notochaetae, reddish after Shirlastain-A (inset: close-up of notochaetal furca). D. Same, neurochaetae (inset: close-up of neurochaetal furca). E. Chaetiger 11, furcate notochaetal tip. F. Chaetiger 15, tips of neurochaetal furcates (oblique line on left chaetae is after another chaetae). Scale bars: A, 2 mm, B; 0.5 mm; C, 0.3 mm; D, E, 80 μm; F, 30 μm.

FIGURE 49. Chloeia richeri sp. n., non-type specimen (ECOSUR). A. Anterior region, dorsal view. B. Anterior end, dorsal view. C. Posterior region, dorsal view. Scale bars: A, C, 1.4 mm; B, 0.5 mm.