Leocratides kimuraorum, Jimi & Tanaka & Kajihara, 2017

Jimi, Naoto, Tanaka, Masaatsu & Kajihara, Hiroshi, 2017, Leocratides (Annelida: Hesionidae) from the Pacific Coast of Middle Honshu, Japan, with a Description of Leocratides kimuraorum sp. nov., Species Diversity 22, pp. 133-141 : 134-137

publication ID	https://doi.org/ 10.12782/sd.22_133
publication LSID	lsid:zoobank.org:pub:CD308AA8-CCA0-4831-B7CB-3052E946588F
persistent identifier	https://treatment.plazi.org/id/8F2F701C-FFCE-5C66-E7C3-8E4EFE3AF7AE
treatment provided by	Felipe
scientific name	Leocratides kimuraorum
status

Treatment

Genus Leocratides Ehlers, 1908 View in CoL

[New Japanese name: hanakago-otohime-gokai-zoku] Leocratides kimuraorum sp. nov. [New Japanese name: Kimura-hanakago-otohime-gokai (previously called “oni-otohime-gokai”)] ( Figs 1 View Fig , 2 View Fig )

? Leocrates ehlersi View in CoL (non Horst, 1921); Hessle 1925: 14–15, fig. 3. Leocratides filamentosus View in CoL (non Ehlers, 1908); Imajima and

Hartman 1964: 82–83; Imajima 2003: 136–138, fig. 80 (in part); Imajima 2007: 444, fig. 138 (in part). Leocratides sp. ; Okanishi et al. 2016: 14.

Material examined. Holotype: NMST-Pol H- 622, 29 mm long, 5 mm wide, sex unknown, off Shima Peninsula, St. 1, 103–104 m depth, 12 October 2016, collected by NJ (right parapodium of chaetiger 5 was removed for observation; it is preserved in 70% ethanol in a 2.0 ml plastic tube, which is contained in the same glass vial together with the rest of the body). Paratypes (14 specimens): NSMT-Pol P-623–624, five specimens, 11–19 mm long, 2 mm wide, sex unknown, off Shima Peninsula, St. 1 (NSMT-Pol P-623, four specimens) and St. 2 (NSMT-Pol P-624, one specimen), 12 October 2016, collected by NJ; NSMT-Pol P-625, one specimen, 25 mm long, 4 mm wide, male (sperm present in each segment’s gonads), Sagami Bay St. 2, 104–111 m depth, 27 April 2016, collected by MT; NSMT-Pol P-626, three specimens examined by Okanishi et al. (2016), 6–16 mm long, 2 mm wide, sex unknown, off Shirahama, 164–169 m depth, 27 May 2015, collected by NJ; NSMT-Pol R 176, two specimens examined by Imajima (2003, 2007), 21–24 mm long, 3 mm wide, sex unknown, Sagami Bay, 110–120 m depth, 14 March 1954, collected by the late Emperor Showa; NSMT-Pol R 968, one specimen examined by Imajima (2003, 2007), 21 mm long, 3 mm, sex unknown, Sagami Bay, 85–90 m depth, 24 January 1965, collected by the late Emperor Showa; NSMT-Pol P-627: one specimen examined by Imajima (2007), 16 mm long, 3 mm wide, sex unknown, Suruga Bay, 92 m depth, 4 October 1995, collected by the late Dr. Minoru Imajima (MI); NSMT-Pol P-628: one specimen examined by Imajima (2007), 24 mm long, 3 mm wide, sex unknown, Suruga Bay, 86–91 m depth, 8 February 1978, collected by MI.

Sequence. LC258082 View Materials , COI gene, 630 bp, determined from the holotype .

Description. Holotype 29 mm long, 5 mm wide in chaetiger 7 (not including parapodia), 21 segments, 16 chaetigers. Body cylindrical, tapered in posterior region ( Fig. 1A, B View Fig ), transparent in life ( Fig. 1A View Fig ) and whitish in ethanol; dorsal integument annulated, with 15–17 transverse wrinkles per segment. Dorsum with numerous, thin, transverse discontinuous brown lines, extended into lateral cushions, varying in length, decreasing in size laterally ( Fig. 1A, C View Fig ); ventrally, black spots of different size and shape arranged along mid-ventral groove, in chaetal lobe regions, two larger spots better developed along chaetigers 4–15 ( Fig. 1B View Fig ). Prostomium rectangular, slightly wider than long, mid-dorsally with shallow depression, square in shape from dorsal view ( Fig. 1D View Fig ). Median antenna cirriform, smooth, tapered, inserted in central part of prostomium, extended beyond anterior prostomial margin, 1.1 times longer (and thinner) than lateral antenna, surpassing palpophores. Lateral antennae tapered, smooth, on anterior edge of prostomium. Palps bi-articulated, 0.9–1 times longer than lateral antennae, palpophore two times longer than palpostyle, bent laterally, pointed to body sides, external to antennae ( Fig. 1D View Fig ). Eyes brownish, two pairs, on mid-lateral part of prostomium; anterior pair slightly larger and more separated than posterior one ( Fig. 1D View Fig ). Facial tubercle present mid-ventrally on prostomium; cushion-shaped appendage present between palps and tentacular cirri on each side ( Fig. 1E View Fig ); papillose peristomial membrane absent.

Tentacular cirri eight pairs, long, thick; longest one reaching chaetiger 10. Lateral cushions low, barely projected dorsally, slightly projected laterally, undivided, with 17–18 longitudinal wrinkles per side ( Fig. 1C View Fig ).

Parapodia uniform throughout; with chaetal lobes tapered, truncate, as long as wide ( Fig. 2A View Fig ); dorsal cirri with cirrophores, latter being cylindrical, smooth, about twice longer than wide ( Fig. 2B View Fig ); cirrostyle very long, whip-like, smooth basally, annulated medially and distally, longer than body width (including parapodia). Ventral cirri basally smooth, rugose medially and distally, surpassing chaetal lobe, reaching up to half length of neurochaetal bundle ( Fig. 2C View Fig ).

Neuropodial acicula black, tapered; acicular lobe single, thick, digitate, tapered into a small mucro ( Fig. 2D View Fig ). Neurochaetae about 20 per bundle ( Fig. 2E View Fig ); handle greenish; blade pale brownish, bidentate, 5 times longer than wide; with subdistal tooth short, blunt, 0.4 times longer than apical tooth; guard tooth absent ( Fig. 2F View Fig ).

Cirri of prepygidial segment broken; pygidium smooth, depressed, with paired cirri; anus located dorso-terminally, with about 10 anal papillae.

Pharynx dissected in holotype, about 20 low cushion-like terminal papillae present ( Fig. 1F View Fig ); dorsal jaw two plates, ventral jaw one plate.

Variation. Dorsal transverse lines and ventral black spots faded in some paratype specimens.

Etymology. The specific name is a noun in the genitive plural, after a Japanese marine ecologist Dr. Taeko Kimura and a malacologist Mr. Shoichi Kimura, who organized the cruise of the TRV Seisui -maru of Mie University, during which a part of the type specimens, including the holotype, of the new species were collected.

Distribution. Pacific coast of middle Honshu, Japan: 85–169 m depth, collected with hexactinellid sponges.

Remarks. Our specimens undoubtedly belong to Leocratides because their body consists of 21 segments, the anterior cirri are in eight pairs, the neurochaetae are bidentate, the palps are bi-articulated, the parapodia are uniramous, and the jaws are present, all agreeing with the generic diagnosis provided by previous researchers ( Pettibone 1970; Pleijel 1998; Rizzo and Salazar-Vallejo 2014; Salazar-Vallejo 2016).

Leocratides kimuraorum sp. nov. differs from L. filamentosus in the lateral antennae because they are as long as palps in L. kimuraorum sp. nov. but shorter than palps in L. filamentosus , and there is no papillose peristomial membrane in L. kimuraorum sp. nov. whereas it is present in L. filamentosus . It can also be distinguished from L. ehlersi by the pharyngeal terminal papillae (present in L. kimuraorum sp. nov. vs. absent in L. ehlersi ) ( Horst 1921; Pleijel 1998).

Because we were not able to examine Hessle’s (1925) voucher material from Misaki, identified as “ Leocrates ehlersi ”, its taxonomic identity remains uncertain, inasmuch as the morphological features illustrated in his figure ( Hessle 1925: fig. 3) apply both to L. ehlersi and L. kimuraorum sp. nov.

We examined some of Imajima’s (2003, 2007) voucher material from Sagami and Suruga Bays and noticed that his descriptions contain several errors. For instance, Imajima (2003, 2007) noted that there were two to five transverse wrinkles on the dorsal integument in each segment, whereas there are actually 15–17 wrinkles per segment. When it comes to the pharyngeal terminal papillae, Imajima (2003, 2007) stated that these were absent, although the papillae are in fact present in his voucher specimens. Therefore, we can confidently regard his material as belonging to L. kimuraorum sp. nov.