Chloeia venusta de Quatrefages 1866
Creators: name: Salazar-Vallejo, Sergio I.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Amphinomida
Amphinomidae
Chloeia
Chloeia venusta

description: Chloeia venusta de Quatrefages, 1866
Figs 53, 54
Chloeia venusta de Quatrefages, 1866: 391; Baird 1868: 232; von Marenzeller 1893: 26–28, Pl. 1, Fig. 1; Fauvel 1913: 32; Fauvel 1914: 90; Rioja 1918: 26–27, Fig. 6; Fauvel 1923: 134, Fig. 48d–h; Fauvel 1936: 18–19; Fauvel 1950: 347; Guy 1964: 178–180, Figs 4, 6; Hartman 1959: 132; Amoureux 1972: 71; Amoureux 1973a: 51; Amoureux 1973b: 435 (Sta. W418); Intes & le Loeuff 1975: 290; Kirkegaard 2001: 394; Solís-Weiss et al. 2004: S2; Barroso & Paiva 2011: 422, Tab. 1; Alós & Núñez 2012: 51–53, Fig. 16.
Chloeia fucata: McIntosh 1876: 395–396, Pl. 71, Fig. 2 (non de Quatrefages, 1866).
Chloeia modesta: Fauvel 1936: 19 (non Ehlers, 1887).
Chloeia sp.: Wirtz 2020 (unnumbered pages or figures).
Type material. Mediterranean Sea, Italy, Sicily, Palermo. Holotype (MNHN IA-TYPE 99.
Additional material. Mediterranean Sea, Algeria. One specimen (MNHN A54.1), 1868, no further data (middorsal band visible along a few anterior chaetigers; most notochaetae lost; body 30 mm long, 5 mm wide, 27 chaetigers). One specimen (MNHN A54.2), 1902, M. Pollany, coll., no further data (details in variation). Seven specimens (BMNH 1921.5.1.12–13), Porcupine Expedition (specimens apparently combined after the depth in label; not matching publication data), 81–288 m, M. Carpenter, coll. (almost completely dried-out, stiff; some with reddish marks, others with a longitudinal dark middorsal band; body 12–35 mm long, 3–6 mm wide, 29–30 chaetigers). Northeastern Atlantic. Seine Seamount. Two specimens (SMF 16746), RV Meteor, Sta. 758 60/ 1, 186 m, 4 Dec. 2003 (juveniles; some notochaetae broken; middorsal band visible along body; body bent ventrally, 9–12 mm long, 3.5–4.o mm wide, 22–24 chaetigers). One specimen (SMF 16748), RV Meteor, Sta. 756b MUC 8/ 2, 178 m, 4 Dec. 2003 (early juvenile, colorless; pharynx partially exposed; body bent ventrally, 6 mm long, 2 mm wide, 17 chaetigers). Morocco. One specimen (MNHN A397.1), no depth or date data, Dolfus, coll. (bent ventrally; middorsal band visible; dorsal cirri dark purple 2–3× longer than branchiae; branchiae pale; body 22 mm long, 6 mm wide, 25 chaetigers). One specimen (MNHN A438.1), Sta. 10 (29°54´N, 09°58´W), 110 m, 5 Jul. 1923 (middorsal band barely visible along posterior chaetigers; dorsal cirri and branchiae pale; body 25 mm long, 7 mm wide, 29 chaetigers).
Diagnosis. Chloeia with bipinnate branchiae from chaetiger 4, progressively smaller posteriorly; anterior prostomial area pale; middorsal band regular; caruncle pale; notochaetae acicular and harpoon chaetae without spurs; neurochaetae spurred and furcates.
Description. Holotype (MNHN IA-TYPE 99) complete, markedly bent ventrally (Fig. 53A); body fusiform, 17 mm long, 5 mm wide, 26 chaetigers.
Holotype pale, chaetae colorless, almost transparent; blackish middorsal line visible along chaetigers 3–7 (Fig. 53B); branchiae and dorsal cirri pale. Venter pale, a wide paler midventral band visible from chaetiger 6, continued to far posterior segments.
Prostomium anteriorly entire. Eyes minute, blackish, anterior eyes slightly larger than posterior ones. Median antenna inserted at anterior caruncular margin, without tip, slightly shorter than caruncle (Fig. 53C), 2× longer lateral antennae. Lateral antennae bases separated (size variable?), slightly longer than palps. Mouth ventral on chaetiger 2. Pharynx not exposed.
Caruncle pale, sigmoid, trilobed, tapered, slightly surpassing chaetiger 4. Median ridge plicate, with about 25 vertical folds, partially concealing lateral lobes. Lateral lobes narrow, with about 15 vertical folds.
Bipinnate branchiae from chaetiger 4, not contracted, continued throughout body, parallel along most body segments; progressively larger to chaetiger 10, decreasing slightly posteriorly. Median segments with 7–8 lateral branches, each with a few secondary filaments.
Parapodia biramous, notopodia with cirriform branchiae along chaetigers 1–3, shorter than dorsal cirri. Dorsal cirri longer than bipinnate branchiae along median chaetigers, 2× longer in posterior chaetigers. Second ventral cirri with cirrophores 2× longer and 3× wider, and cirrostyle 2.0–2.5× longer than adjacent ones, directed dorsally. Other ventral cirri directed ventrolaterally, as long as two subsequent segments.
Chaetae most broken or with broken tips. Complete chaetae with distal fragile hoods, mostly eroded. Anterior notochaetae not removed for avoiding further damage. Median chaetigers with two types of notochaetae: furcates with tapered tines (Fig. 53D), major tines 4–6× longer than minor ones, and smooth aciculars (Fig. 53E); harpoon chaetae lost. Neurochaetae all furcates (Fig. 53F), major tines 2.5× longer than minor ones.
Posterior end tapered; pygidum with anus terminal; anal cirri pale, tapered, corrugated, bent ventrally (Fig. 53A), 6× longer than wide.
Live pigmentation (after Le Bris & M̧ller 2019). Middorsal band reddish, with two adjacent oblique oval white areas per segment, continued throughout body; branchiae pale orange; caruncular median ridge and dorsal cirri dark purple, almost blackish; cirriform branchiae with dark tips.
Variation. A slightly larger specimen (MNHN A54.2; 26 mm long, 7.5 mm wide, 28 chaetigers), is bent ventrally; middorsal band reddish (Fig. 54A), continued throughout body; dorsal cirri purplish, paler basally; anterior eyes 2× larger than posterior ones (Fig. 54B); caruncle pale, with median ridge brownish; branchiae from chaetiger 4, pale. Middorsal band slightly wider anteriorly (Fig. 54C). Anterior notochaetae mostly furcates (Fig. 54D), major tines 3–4× longer than minor ones, smaller notochaetae acicular; median chaetigers notochaetae include harpoonchaetae without basal spurs, and aciculars (Fig. 54F); neurochaetae spurred in anterior chaetigers (Fig. 54E), major tine 11—20× longer than spur; in median chaetigers with capillary furcate neurochaetae (Fig. 54G), major tine 5—8× longer than spur. Anal cirri with tips pinkish (Fig. 54H), tapered, 7–8× longer than wide.
Remarks. Chloeia venusta de Quatrefages, 1866 was described from the Mediterranean Sea; it belongs in the group venusta by the presence of a middorsal regular band, continuous along each segment, and bipinnate branchiae from chaetiger 4, progressively smaller posteriorly. Further, after the presence of furcate notochaetae in anterior chaetigers, and harpoon notochaetae in median chaetigers, it resembles C. poupini sp. n., described above from the French Polynesia. These two species differ, however, after the pigmentation of the anterior prostomial area, and furcate neurochaetae. In C. venusta the anterior prostomial area is pale, and its neurochaetae have major tines 2× longer than minor ones, whereas in C. poupini the anterior prostomial area is blackish, and the neurochaetae have major tines 5–6× longer than minor ones.
De Quatrefages (1866: 391) found the holotype beautiful, and hence the name (Latin venustus, -a, -um: beautiful, graceful, elegant, charming). The pigmentation pattern was not indicated, but the median antennae was as long as the caruncle, the branchiae were regarded as large, and chaetae were described as smooth.
M’Intosh (1876: 395) used C. fucata de Quatrefages, 1866, with hesitation since this species was described from Oman, for his specimens from the Mediterranean and Northeastern Atlantic, but his specimens match C. venusta instead, although it would be interesting to study some deeper water specimens. He noted “some have a brownish median line on the dorsum, and a band of the same hue at the anterior part of each segment” (M’Intosh 1876: 396), and these features match C. venusta instead, although the middorsal purple line turns brownish in preserved specimens.
Chloeia fucata de Quatrefages, 1866, described from Muscat, Oman, and C. venusta are herein regarded as distinct (see above). M’Intosh (1876) hesitation probably led Horst (1910), Fauvel (1914, 1923), and Hartman (1959: 131) to regard these two species as synonyms. On the other hand, Guy (1964) indicated some differences in chaetal tips between the Mediterranean and tropical West African specimens; the latter with notochaetae aciculars with tips slightly bent, against being straight, and neurochaetae with tapered tines, against being subcylindrical as illustrated by Fauvel (1923:135), or Alós & Núñez (2012: 52). The holotype has a few complete chaetae, and Fauvel’s figure, redrawn from Rioja (1918: 27, Fig. 6b), shows very thick, cylindrical tines, which might be explained because they were free-hand drawings.
Distribution. Mediterranean Sea and Northeastern Atlantic localities including Maroc, in subtidal environments to 288 m water depth.
description: Published as part of Salazar-Vallejo, Sergio I., 2023, Revision of Chloeia Savigny in Lamarck, 1818 (Annelida, Amphinomidae), pp. 1-134 in Zootaxa 5238 (1) on pages 113-115, DOI: 10.11646/zootaxa.5238.1.1, http://zenodo.org/record/7621793