Paraleocrates djangkarensis (Augener & Pettibone in Pettibone, 1970 ) Salazar-Vallejo, 2020

Salazar-Vallejo, Sergio I., 2020, Revision of Leocrates Kinberg, 1866 and Leocratides Ehlers, 1908 (Annelida, Errantia, Hesionidae), Zootaxa 4739 (1), pp. 1-114 : 104-106

Paraleocrates djangkarensis (Augener & Pettibone in Pettibone, 1970) n. comb.

Figure 61

Leocrates djangkarensis Augener & Pettibone in Pettibone, 1970: 227–229 , Figs 25–26 .

Leocrates chinensis: Horst 1924: 193 (partim, Sta. 105) (non Kinberg, 1866).

Type material. Philippines. Holotype ( ZMA V. Pol. 534.3), Sulu Islands, off NE Gujangan Island , R / V Siboga, Sta. 105 (06°08’ N, 121°19’ E), 275 m, dredge, coral, 4 Jul. 1899 . Indonesia, paratype ( ZMA V. Pol. 2104), off Djangkar, Java Island, R / V Siboga, Sta. 5 (07°46’ S, 114°30.5’ E), 330 m, deep-sea trawl, muddy bottom, 10 Mar. 1899 (used for variation).

Description. Holotype (ZMZ V. Pol. 534.3), complete, slightly distorted, dehydrated, most body cirri missing ( Fig. 61A ). Body obconic, wider anteriorly, tapered posteriorly, 12 mm long, 2 mm wide, 16 chaetigers; right parapodium of chaetiger 3, and left parapodia of chaetigers 3, 8, 9, and 14 previously removed (three ones removed by Pettibone in a small vial, others missing); a slightly lateral anteroventral dissection for observing pharynx features previously made. Body brownish, venter with two wide longitudinal brown bands ( Fig. 61C ), leaving a paler midventral region (purple in recently preserved specimens after Horst).

Prostomium slightly wider than long, slightly wider anteriorly ( Fig. 61B ). Lateral antennae with ceratophores distinct, left one corrugated, right one missing, slightly longer than left palp (right palp distorted, directed laterally); palpophore 2–3 times longer than palpostyles. Median antenna missing, scar inserted centrally, between eyes. Eyes barely pigmented, round, anterior ones twice larger and slightly more distant to each other than posterior ones. Lateral peristomial tubercles round, as long as wide.

Nuchal organs lobes horizontal C-shaped, completely concealed by anterior margin of tentacular belt; lateral ciliated bands visible dorsally. Tentacular cirri almost completely missing, one ventral cirrus without tip reaching chaetiger 3. Lateral cushions low, projected, most tripartite; longitudinal striae visible.

Pharynx not exposed; jaws observed through previous dissection. Lateral vesicles not seen. Anterior margin with about 20 irregular constrictions. Dorsal and ventral jaws single, fang-shaped brownish, exposed, tapered, ventral jaw smaller than dorsal one.

Peristomial dorsolateral tubercles as long as wide, slightly projected anteriorly, smooth.

Dorsal cirri broken, some remaining shorter than body width. Chaetigers 1–3 without notochaetae ( Fig. 61D ); notochaetae present along chaetigers 4–16, about 30 per bundle, delicate, arranged in bundles, notochaetal surface smooth. Notacicular lobes tapered, blunt; neuracicular lobes projected, blunt, as long as wide ( Fig. 61E ). Ventral cirri surpassing neurochaetal lobes. Neurochaetae about 30 per bundle, decreasing in size ventrally, blades unidentate, 4–65 times longer than wide, guards projected beyond tooth as long aristae, tooth slightly falcate ( Fig. 61D, E , insets).

Posterior region tapered, almost without cirri. Prepygidial segment with dorsal cirrophores 4–5 thicker than ventral ones. Pygidium with anus terminal, anal cirri missing.

Oocytes not seen.

Variation. Paratype (ZMA V. Pol. 2104) damaged, soft, brownish. Body 35 mm long, 3 mm wide, 16 chae- tigers; cirri and many chaetae missing; left parapodia of chaetigers 4 and 6, and right parapodia of chaetigers 9 and 10 previously removed. An anteroventral dissection for observing pharynx features previously made. Notopodia from chaetiger 4, most notochaetae missing, a few remaining, smooth. Neuropodia with a few chaetae remaining (7–15), blades unidentate, most straight, a few bent dorsally, guards projected far beyond tip of tooth.

Remarks. Paraleocrates djankarensis (Augener & Pettibone in Pettibone, 1970) is newly combined into Paraleocrates by having unidentate blades, as opposed to bidentate blades present in Leocrates , as herein restricted.

Paraleocrates djankarensis differs from the other species in the genus, P. wesenberglundae ( Pettibone, 1970) n. comb. from the Gulf of Oman, in the size of eyes and in the type of neurochaetal blades. In P. djankarensis anterior eyes are twice larger than posterior ones, and neurochaetal blades are unidentate, with teeth round and have long, aristate guards, whereas in P. wesenberglundae eyes are of similar size, and neurochaetal blades have no guards at all, but their teeth are tapered but without aristae.

The paratype has neurochaetal blades slightly different because instead of having slightly falcate tooth, as in the holotype, it is rather straight, and even bent dorsally; because of the poor condition of the specimen, no other differences were found and consequently it is regarded as conspecific pending the finding of better specimens.

Distribution. Philippines and Indonesia, in mixed or muddy bottoms at 275–330 m depth.

Figures

FIGURE 25. Leocrates ahlfeldae n. sp., holotype (USNM 48942).A.Anterior region, dorsal view. B. Anterior end, dorsal view. C. Pharynx, frontal view, MGS. D. Chaetiger 7, left parapodium, anterior view (insets: notacicular and neuracicular lobes). E. Upper neurochaetal blades. F. Lower neurochaetal blades. Scale bars: A: 1.1 mm, B: 0.3 mm, C, D: 0.5 mm, E: 100 μm, F: 150 μm.

FIGURE 26. Leocrates chinensis Kinberg, 1866, holotype of L. anonymous Hessle, 1925 (UUZM 672). A. Anterior region, dorsal view. B. Anterior end, pharynx exposed with two lateral vesicles. C. Same, left lateral view. D. Same, frontal view of pharynx after pressing the body to swell lateral vesicles (inset: lateral view of wedge-shaped upper jaw tip). E. Chaetiger 7, left parapodium, anterior view (insets: notacicular lobe, neurochaetal blade). Scale bars:A: 1.9 mm, B: 1 mm, C, D: 0.6 mm, E: 0.4 mm.

FIGURE 61. Paraleocrates djankarensis (Augener & Pettibone in Pettibone, 1970), new combination, holotype (ZMA V. Pol. 534.3). A. Dorsal view. B. Anterior region, dorsal view. C. Anterior region, ventral view. D. Chaetiger 3, left parapodium, anterior view, MGS (inset: lower neurochaetal blade). E. Chaetiger 8, left parapodium, anterior view, MGS (insets: lower neurochaetal blades). Scale bars: A: 1.4 mm, B: 0.6 mm, C: 0.8 mm, D: 0.2 mm, E: 0.4 mm.