Chloeia entypa Chamberlin, 1919

Yáñez-Rivera, Beatriz & Salazar-Vallejo, Sergio I., 2022, Revision of Chloeia Savigny in Lamarck, 1818 from tropical American seas (Annelida, Amphinomidae), Zootaxa 5128 (4), pp. 503-537 : 511

Chloeia entypa Chamberlin, 1919

Fig. 3

Chloeia entypa Chamberlin, 1919: 30 , Pl. 13, Figs 7 , 8 ; Pl. 14, Figs 1 , 2 .

Type material. Eastern Pacific. Holotype [ USNM 19346 ], off Mexico, between Guerrero and Oaxaca, R/ V Albatross, Sta. 3418 (16°31’N, 99°52’W), 1207 m, 11 Apr. 1891.

Diagnosis. Chloeia with dorsum colorless; caruncle rectangular, pale; bipinnate branchiae from chaetiger 4; ventral cirri of chaetiger 2 markedly longer than following ones; chaetal bundles homogeneously pale.

Description. Holotype complete; body fusiform, pale ( Fig. 3A ), 9 mm long, 4.2 mm wide, 22 chaetigers. Remaining pigmentation includes a dark region on buccal lips in front of lateral antennae.

Prostomium semicircular with four red eyes, anterior eyes 5× larger than posterior ones ( Fig. 3B ). Anterior prostomial area blackish. All antennae of similar size, median antenna arising from anterior margin of caruncle (0.6 mm long). Palps inserted laterally on buccal lips, slightly shorter than antennae (0.5 mm). Mouth ventral on chaetiger 3.

Caruncle colorless, oblong (1.1 mm long, 0.4 mm wide). Median lobe elevated with about seven folds. Lateral lobes narrow, each with seven folds, without pigmentation, hidden by median lobe ( Fig. 3B ). Bipinnate branchiae from chaetiger 4, present throughout body.

Parapodia biramous. Notopodia with single cirri; cirriform branchiae along chaetigers 1–3. Second ventral cirri (3 mm long) about 3× longer than following ones (1 to 1.2 mm).

All chaetae furcates ( Fig. 3C–F ). Notochaetae longer and wider than neurochaetae. Length proportions between chaetal tines vary from 1: 3 in notochaetae to 1: 5 in neurochaetae.

Anus dorso-terminal in last chaetigers.

Remarks. The original description of C. entypa does not indicate the start of branchiae, and the relative size of the second ventral cirri. Chamberlin’s (1919) illustrations show a serrated edge in the notochaetae; however, in the holotype no serrated edges were observed in median notochaetae. Additionally, the dark violet pigmentation of the dorsal cirri is now lost. Chamberlin (1919: 31) noted that the depth was exceptional for the genus but the locality depth data was mistakenly listed as 66 fm (121 m) instead of 660 fm (1207 m), the correct sampling depth, as can be confirmed in Townsend (1900: 465), and also indicated in the label ( Fig. 3G ).

Hartman (1940), through the examination of six shallow water samples from Ecuador (1), Colombia (2), Panamá (1) and California (2), characterized this species as having a dorsal reddish-brown, continuous stripe, and emphasized the dark purple dorsal cirri. The violet pigmentation in dorsal cirri is a shared feature among several species of the genus but the dorsal stripe pointed out by Hartman (1940) was not mentioned by Chamberlin (1919) in the original description. The specimens that Hartman studied had been collected up to five years before her publication, whereas Chamberlin’s specimens were collected about 30 years before he studied them. Pigmentation might fade off after such a long time in ethanol. However, the dorsal stripe is a reliable diagnostic feature used to characterize specimens from different habitats, and, on the other hand, C. entypa has been recorded as an intertidal species from California to Ecuador (Kudenov 1975; Dean 2004). However, C. entypa was described from deep water sediments and probably lacks such dorsal stripe, but it has not been found again in large-scale dredging cruises in the region ( Fauchald 1972; Méndez 2007).

Kudenov (1995) suggested that this species could be a junior synonym of C. pinnata from California, since both share violet pigmentation in dorsal cirri and the second ventral cirri is larger than the others; nevertheless, they have differences in the first appearance of branchiae, in chaetal features, and in dorsal pigmentation pattern ( Table 1 ). We disagree and think that these shallow water records might belong to a different species, whose abundance does not match the high numbers of C. pinnata off Southern California ( Hartman 1963; Jones & Thompson 1988). Consequently, in so far as these records can be assessed after their descriptions or illustrations, they could be regarded as Chloeia nuriae sp. n. (see below).

On the other hand, C. entypa resembles C. kudenovi Barroso & Paiva, 2011 from Brazil. Both species were found in deep waters, they lack dorsal pigmentation patterns, have larger second ventral cirri, and their furcates are smooth. However, the position of the mouth in C. kudenovi is on chaetiger 2, dorsal cirri lack pigmentation, and has dark purple eyes, whereas in C. entypa the mouth is on chaetiger 3, has deep violet dorsal cirri, and red eyes.

Distribution. Only known from the type locality off Western Mexico, in sediments at 1200 m water depth.

Figures

FIGURE 1. Living specimens of Chloeia Savigny in Lamarck, 1818 from tropical American seas. A. Chloeia euglochis Ehlers, 1887, non-relaxed. B. Chloeia pinnata Moore, 1911, relaxed. C. Chloeia pseudeuglochis Augener, 1922, relaxed. D. Chloeia viridis Schmarda, 1861, non-relaxed (Photos: A, Paul Humann; B, Greg Rouse; C, Art Anker; D. Jean-Michel Sutour).

FIGURE 2. Chloeia pinnata Moore, 1911, non-type specimens (LACM 992-39), epitokes, anterior end after cropping chaetae of right parapodia of chaetigers 1–3, after Methyl Green staining for caruncle.A. Smallest specimen (11 mm long), dorsal view. B. Same, lateral view. C. Same, after Metyhl Green staining. D. Medium-sized specimen (18 mm long), dorsal view. E. Same, lateral view. F. Same, after Methyl Green staining. G. Largest specimen (23 mm long), dorsal view. H. Same, lateral view. I. Same, after Methyl green. Scale bars: A, 0.25 mm; B, 0.33 mm; C, 0.26 mm; D, G, 0.29; E, 0.44 mm; F, 0.35 mm.

FIGURE 3. Chloeia entypa Chamberlin, 1919. A. Holotype (USNM 19346), ventral view; B. Prostomium and caruncle (Li: lips; MA: median antenna; ML: medial lobe; Pa: palps; PA: paired antenna). C. Neurochaeta from first chaetiger. D. Neurochaeta from chaetiger 10. E. Notochaeta from first chaetiger. F. Notochaeta from chaetiger 10. G. Holotype and original label (photo: Elizabeth Borda). Scale bars: A, 2 mm; B, 0.3 mm; C, D, 5 μm; E, 2 μm; F, 10 μm.

FIGURE 7. Chloeia nuriae sp. n., holotype (EMU 13145). A. Dorsal view, recently collected. B. Anterior end, dorsal view. C. Prostomium and caruncle. D. Neurochaeta from first chaetiger. E. Neurochaeta from same chaetiger 10. F. Notochaetae from first chaetiger. G. Notochaeta from chaetiger 10. H. Pigmentation pattern from median segments. I. Posterior end with cirriform lobes. A, D–I. Holotype; B, C. Paratypes (ADC: accessory cirriform branchiae, Br: bipinnate branchiae, DC: dorsal cirri, Li: lips, LL: lateral lobes, MA: median antenna, ML: median lobe, Pa: palps, PA: paired antennae). Scale bars: A, 5 mm; B, C, 1 mm; D, 20 μm; E, 15 μm; F, G, 50 μm; H, 2 mm; I, 0.5 mm.

FIGURE 8. Chloeia paulayi sp. n. A. Holotype (UF 493), dorsal view, depressed by glass slide, after Methyl Green staining. B. Same, anterior region, dorsal view. C. Same, left lateral view. D. Same, ventral view. E. Paratype (UF 493b), anterior region, dorsal view. F. Same, close-up of anterior end. Scale bars: A, E 2.2 mm; B, F, 1.3 mm; C, 0.9 mm; D, 1.8 mm.