Chloeia keablei, Salazar-Vallejo, 2023

Salazar-Vallejo, Sergio I., 2023, Revision of Chloeia Savigny in Lamarck, 1818 (Annelida, Amphinomidae), Zootaxa 5238 (1), pp. 1-134 : 77-79

Chloeia keablei sp. n.

urn:lsid:zoobank.org:act:98A164BE-8251-4242-922D-EFBAB4FDAE6A

Fig. 35

Type material. Papua New Guinea. Holotype ( AM W24926 ), and 10 paratypes ( AM W53392 ), Madang Lagoon, between Padoz Natun reef and north end of Paeowai Island (05°09.60´S, 145°49.77´E), baited trap, soft mud, burrows, and Ampelisca-like tubes, 35 m, 17–18 Mar. 1991, J.K. Lowry & S.J. Keable, coll. (paratype data in variation).

Additional material. Australia. One specimen ( AM W28125 ), MV Cherry Lee , Sta. NSW 887 (30°15.75´S, 153°21.98´E), 100 m, 12 Aug. 1993, P. Berents, coll. (pinkish, bent ventrally, body wall broken laterally along left size of chaetigers 11–12; dorsal cirri mostly lost, colorless; branchiae colorless; anterior eyes reddish, 4–5× larger than posterior ones; median antenna 1/3 as long as caruncle, slightly longer than lateral antennae; body 30 mm long, 8 mm wide, 31 chaetigers) . Philippines. One specimen ( CAS 186937 ), Lubang Islands, Lubang (13.93° N, 120.31° E), mixed bottom, rocks and sand, 115–124 m, 2 Jun. 2011, R. Mooi et al., coll. (colorless, dorsal cirri purple, caruncular median ridge blackish, many notochaetae broken; anterior eyes 6× larger than posterior ones; bipinnate branchiae in median chaetigers with 14–16 lateral branches; body 76 mm long, 15 mm wide, 37 chaetigers) .

Diagnosis. Chloeia with bipinnate branchiae from chaetiger 4, progressively smaller posteriorly, colorless; dorsum without pigmentation pattern; anterior eyes 4× larger than posterior ones; caruncle tapered, with about 40 folds; harpoon notochaetae without spurs; neurochaetae spurred and furcates.

Description.

Holotype ( AM W24926 ), with body fusiform, posterior end in regeneration; branchiae of chaetiger 12 removed for observing segmental pigmentation; body bent laterally, 46 mm long, 10 mm wide, 30 chaetigers.

Holotype with dorsum reddish ( Fig. 35A ), each segment with anterior third or fourth darker than posterior region, better defined along anterior ( Fig. 35C ) and median chaetigers; dorsal cirri purplish; branchiae pale; chaetae golden. Venter cream, midventral band barely visible.

Prostomium anteriorly entire, anterior prostomial area reddish ( Fig. 35B ). Eyes reddish, anterior eyes 5–6× larger than posterior ones. Median antenna pale, inserted at anterior caruncular margin, without tip, half as long as caruncle, slightly longer than lateral antennae. Lateral antennae bases close to 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, colorless, with about 46 vertical folds, partially concealing lateral lobes?. Lateral lobes narrow, with about 36 vertical folds.

Bipinnate branchiae from chaetiger 4, divergent throughout body, progressively larger to chaetiger 15–16, smaller posteriorly; in median segments with 11–12 lateral branches.

Parapodia biramous, notopodia with cirriform branchiae along chaetigers 1–3, ½–1/3 as long as dorsal cirri, progressively smaller. Dorsal cirri slightly longer than bipinnate branchiae along body. 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 two subsequent segments.

Chaetae most complete, hoods rarely eroded. Notochaetae in anterior chaetigers furcates ( Fig. 35D ), major tines 4–6× longer than minor ones. Median chaetigers with two types of notochaetae: a few smaller acicular or spurred chaetae, and mostly harpoon-chaetae without tines or spurs ( Fig. 35F ). Neurochaetae furcates; anterior chaetigers with major tines 5–12×longer than minor ones ( Fig. 35E ), median chaetigers with major tines 5–10× longer than minor ones ( Fig. 35G ).

Posterior region tapered ( Fig. 35H ); pygidium with anus terminal; anal cirri whitish, digitate, 4× longer than wide.

Live pigmentation. Unknown; likely more intense than in holotype.

Etymology. The species name is derived after Dr. Stephen Keable, Collection Manager in the Australian Museum, Sydney, in recognition of his long-term support of my research activities, and especially because he collected the type specimens for this description. The specific epithet is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Variation. Paratypes (AM W24926 b) slightly distorted by compression. Body pink, dorsal cirri and branchiae pale; chaetae golden; venter cream with a diffuse reddish area along a few anterior chaetigers; smaller four paratypes with some dorsal cirri and branchiae purplish, three with blackish eyes, all other paratypes with eyes reddish, 2–3× larger than posterior ones in smaller paratypes, larger ones with anterior eyes 4–6× larger than posterior ones. Body 11–46 mm long, 3–10 mm wide, 24–35 chaetigers.

Remarks. Chloeia keablei sp. n. is described with specimens from The Philippines to Australia, including Papua New Guinea, its type locality. Because it has no pigmentation pattern, bipinnate branchiae from chaetiger 4, progressively smaller posteriorly, it belongs in the group tumida. Further, because it has a tapered caruncle, and colorless bipinnate branchiae, it resembles C. pinnata Moore, 1911 , from Southern California. As indicated in the key above, these two species differ in the relative size of eyes, in the type of harpoon notochaetae, and of neurochaetae. Thus, in C. keablei the anterior eyes are 4× larger than posterior ones; harpoon notochaetae have no spurs or smooth tines, and its neurochaetae are furcates with small minor tines, whereas in C. pinnata anterior eyes are 2× larger than posterior ones, its harpoon notochaetae have spurs, and neurochaetae are spurred.

Distribution. The Philippines, Papua New Guinea and Australia, in sediments at 35–124 m water depth.

Figures

FIGURE 35. Chloeia keablei sp. n., holotype (AM W24926). A. Anterior region, dorsal view. B. Anterior end, dorsal view, after Methyl green staining. C. Chaetigers 9-11, dorsal view. D. Chaetiger 3, notochaetal tips. E. Same, neurochaetal tips. F. Chaetiger 15, harpoon notochaetal tips. G. Same, neurochaetal tips. H. Posterior region, dorsal view. Scale bars: A, 2.3 mm; B, C, 0.9 mm; D, 100 μm; E, 30 μm; F, 120 μm; G, 40 μm; H, 2.2 mm.