DOI:94 http://doi.org/10.18941/venus.74.3-4_94 VENUS 74 (3–4), 2016 ©The Malacological Society of Japan

Description of Monstrotyphis takashigei n. sp. (: ) from Akino-hama, Izu-Oshima, Izu Islands, Japan

Roland Houart1* and Mitsuo Chino2 1Institut royal Des Sciences naturelles de Belgique, Rue Vautier, 29, B-1000 Bruxelles, Belgium; *[email protected] 26-23-18-202 Arima, Miyamae-ku, Kawasaki, Kanagawa 216-0003, Japan

The muricid subfamily Typhinae is currently Monstrotyphis Habe, 1961 divided into 19 genera or subgenera. Fourteen of Type species by original designation: those include Recent as well as some fossil species () tosaensis Azuma, 1960, Recent, Japan. and five contain only fossil species. Monstrotyphis Habe, 1961 was a monotypical genus until Houart Monstrotyphis takashigei n. sp. (2002) moved some species from , in (Figs 1, 2A–N, 4 A–B) which they were originally or later classified, to Monstrotyphis. Another species was described from Type material: Holotype, NSMT-Mo 78955, 6.4 New Zealand by Houart & Marshall (2012), raising mm SL; paratypes: 1 IRSNB I.G. 33215/MT. 3368, the total number of Monstrotyphis species to 11, 1 MNHN IM-2000-31739, 1 RH, 1 MC, 2 HT (as with 10 from the Indo-West Pacific and one from listed below). the western Atlantic. Type locality: Akino-hama, Izu-Oshima, Izu Four of these occur in Japan, namely Islands, Japan, 55 m depth. Monstrotyphis imperialis (Keen & Campbell, 1964), Distribution: Currently known from Akino- M. montfortii (A. Adams, 1863), M. teramachii hama, Izu-Oshima, Izu Islands, Japan, living in (Keen & Campbell, 1964) and M. tosaensis (Azuma, depth range of 20–55 m. 1960). Material examined: Akino-hama, Izu-Oshima, Monstrotyphis montfortii was illustrated as Izu Islands, Japan, 55 m, 20 March 2013 (holotype nitens Hinds, 1843 by Tsuchiya (2000: 381, pl. 189, fig. 83), but Typhis nitens is actually a valid species of Typhina Jousseaume, 1880 (= Talityphis Jousseaume, 1882) (Houart, 2002: 155). A fifth Japanese species is here described as new from Izu-Oshima, Izu Islands, off central Honshu, Japan. Abbreviations: ADP, adapical spiral cord on siphonal canal; HT, collection of Hiroshi Takashige; IRSNB, Institut royal des Sciences naturelles de Belgique, Bruxelles, Belgium; MC, collection of Mitsuo Chino; MNHN, Muséum national d’Histoire naturelle, Paris, France; NSMT, National Museum of Nature and Science, Tsukuba, Japan; P1-P6, primary spiral cords on convex part of teleoconch whorl; RH, collection of Roland Houart; SL, shell length; TT, Teramachi collection in Toba Aquarium.

Taxonomy

Family Muricidae Rafinesque, 1815 Fig. 1. Map of Japan with the location of Monstrotyphis Subfamily Typhinae Cossmann, 1903 takashigei n. sp. http://zoobank.org/urn:lsid:zoobank.org:pub:F97C72D8-0DC9-48F6-9D67-E7B298B816D6 Short Notes 95

Fig. 2. Monstrotyphis takashigei n. sp. A–C. Holotype, NSMT-Mo 78955, 6.4 mm SL, Akino-hama, Izu-Oshima, Izu Islands, Japan (type locality), 55 m, 20 March 2013. D–G. Paratypes from the type locality, 55 m, 6 March 2015; D–E, MNHN IM-2000-31739, 7.3 mm SL; F–G, RH, 7.3 mm SL. H–I. Paratype from the type locality, 25 m, 11 January 2015, MC, 8.5 mm SL. J. Protoconch, holotype. K. Operculum, paratype, RH. L–M. Anal tube; L, holotype; M, paratype, MC. N. Primary spiral cords morphology. Scale bars: J–M, 500 µm; N, 2 mm.

NSMT, paratype IRSNB); 55 m, 6 March 2015 Shell brown, tan or tan-white, subsutural ramp (paratypes MNHN, RH); 25 m, 11 January 2015 and anal tube darker colored, abapertural part of (paratype MC); 20 m, under stone, 28 April 2014 axial lamellae whitish; occasional small brown spot (paratype HT); 45 m, on rock, 11 February 2013 at base of siphonal canal. Aperture with whitish (paratype HT). columellar lip and outer apertural lip, light tan Etymology: Named after Mr. Hiroshi Takashige, within. Protoconch lighter colored. Tokyo, diving photographer of marine molluscs, Spire high with 1.5-2 protoconch whorls and who first found these remarkable specimens and teleoconch of up to 4.25 whorls. Suture deeply provided them to the authors for identification. impressed. Protoconch moderately large, smooth. Description: Shell small for genus, up to 9.3 mm First whorl small, shouldered, last whorl rounded. in length (paratype HT). Length/width ratio 1.7–2.0, Maximum width 600 µm; terminal lip shallow, broadly biconical, smooth, lightly built. Subsutural delicate. ramp broad, weakly sloping, almost straight. Axial sculpture of teleoconch whorls consisting 96 VENUS 74 (3–4), 2016

Fig. 3. A–F. Monstrotyphis montfortii; A–B, E, RH, 10 mm SL, Sagami Bay, Honshu, Japan; C–D, RH, 10 mm SL, Cebu, Mactan Id., Punta Engano, tangle nets, 50–100 m, April 2015; F, RH, 9.3 mm SL, Aliguay Id., Sulu Sea, Philippines, tangle nets. G–J. Monstrotyphis teramachii; G–H, holotype, TT no. 1011, 20.7 mm SL, trawled off Kii (Wakayama), Japan, over 100 m, 33°48´N, 134°53´E (photo by K. Hasegawa); I–J, RH, 17.5 mm SL, off Tanabe (Wakayama), Japan, trawled in 366–421 m. K–N. Monstrotyphis singularis; Channel of Touho, New Caledonia, 20°46´–20°47´S, 165°15´–165°16.5´E, 45–56 m; K–M, holotype, MNHN-IM-2000- 0293, 6.3 mm SL (photo by M. Caballer); N, protoconch, RH. Scale bars: 500 μm. of 4 low, narrow, webbed, serrated lamellae, abapically; smooth or with short, narrow spinelet abaperturally with 5 crenulations corresponding to corresponding to ADP. P2-P6 (Fig. 2N), adaperturally smooth. P1 spiral Operculum rounded with concentric ridges and cord corresponding to anal tube, P2 shoulder cord apical nucleus (Fig. 2K). Radula unknown. ending as short, adapical curved spinelet, P3-P6 Remarks: Monstrotyphis montfortii (Figs 3A–F, indistinct on shell. 4C) is rather similar to the new species but Aperture small, rounded, forming continuous M. takashigei n. sp. differs constantly in having peristome. Columellar lip broadly expanded, a comparatively smaller shell, a weakly keeled erect, smooth. Outer lip erect, smooth within. protoconch compared to the rounded protoconch of Siphonal canal moderately long, narrow, strongly M. montfortii (Figs 2J, 3E) and a siphonal canal that dorsally bent at tip, ventrally sealed, narrowly open is strongly dorsally bent at its tip. The siphonal canal Short Notes 97

M. takashigei differs by the same characters as for M. montfortii and in having a more rounded shell, compared to the elongate shell in M. teramachii. Monstrotyphis singularis Houart, 2002 from New Caledonia and the Austral Islands has a somewhat similar shell but M. takashigei differs in having a comparatively larger shell with a broader, less keeled and less acute protoconch (Fig. 3K–N), a strongly sculptured anal tube and a smooth siphonal canal or a narrower, more acute spinelet corresponding to ADP, compared to the relatively broader spine in M. singularis.

Acknowledgements: We are very grateful to Hiroshi Takashige (Tokyo, Japan) for providing all the specimens for study and for the beautiful images in situ, to Kazunori Hasegawa (National Museum of Nature and Science, Tokyo, Japan) for information and for the photographs of the holotype of Monstrotyphis teramachii and to John Wolff Fig. 4. A–B. Monstrotyphis takashigei n. sp.; A, paratype, (Lancaster, Pennsylvania, USA), for checking the HT, 9.3 mm SL, Akino-hama, Izu-Oshima, Izu Islands, English text. We also extend our thanks to Kazunori Japan, 20 m; B, paratype, HT, 7.5 mm SL, Akino-hama, Hasegawa and to an unknown referee for their Izu-Oshima, Izu Islands, Japan, 45 m (photos by H. valuable comments on the manuscript. Takashige). C. Monstrotyphis montfortii; HT, Akino- hama, Izu-Oshima, Izu Islands, Japan, 50 m (photo by References H. Takashige). Hasegawa, K. 2006. Sublittoral and bathyal shell- bearing gastropods chiefly collected by the R/V of M. montfortii is also dorsally bent, but to a lesser Rinkai-Maru of the University of Tokyo around degree and in its whole length, not only at its tip the Miura Peninsula, Sagami Bay, 2001–2004. (Figs 3B, D, 4C). Monstrotyphis takashigei differs Memoir of the National Science Museum, Tokyo further from M. monfortii in the uneven growth of (40): 225–281. the anal tube, giving it a saw-tooth profile. Its base Hasegawa, K., Hori, S. & Ueshima, R. 2001. A is also narrower compared to the broader base of the preliminary list of sublittoral shell-bearing gastropods in the vicinity of Shimoda, Izu anal tube in M. montfortii (Fig. 2L–M). Peninsula, Central Honshu, Japan. Memoir of Although Monstrotyphis montfortii has been the National Science Museum, Tokyo (37): recorded from similar sublittoral depths, within 203–228. a slightly deeper range of 50–200 m in a similar Houart, R. 2002. Description of a new typhine geographical range, it usually inhabits sandy bottoms (: Muricidae) from New Caledonia (Tsuchiya, 2000; Hasegawa et al., 2001; Hasegawa, with comments on some generic classifications 2006). On the other hand, the present new species within the subfamily. Venus 61: 14–159. Houart, R. & Marshall, B. . The Recent seems to prefer hard (rocky) bottoms. The short and 2012 Typhinae (Gastropoda: Muricidae) of New small shell with shorter siphonal canal and anal tube, Zealand. Molluscan Research 32: 137–144. as well as its darker coloration, may be related to Tsuchiya, K. 2000. Muricidae. In: Okutani, T. (ed.), the adaptation of the species to such rocky habitats. Marine Mollusks in Japan, pp. 364–421. Tokai The identity of M. montfortii was detailed and University Press, Tokyo. commented by Houart (2002: 153). From Monstrotyphis teramachii (Fig. 3G–J), (Accepted June 20, 2016) 98 VENUS 74 (3–4), 2016

伊豆大島より採集された 殻表は滑らか，縫合下の斜面は広く，やや傾斜す トサパイプヨウラク属の 1 新種 るがほぼ平坦である。殻色は褐色，黄褐色，白黄 褐色。縫合下の斜面，後水管は濃褐色，前水管基 部に褐色小斑を生じることがある。殻口部は白色， R. Houart・知野光雄 軸唇から殻口内部は黄褐色，原殻は淡色になる。 原殻はやや大きく，1.5～2 層。後生殻は 4.25 層 要 約 で，縫合は明瞭，初層は小さく肩が張り体層は丸 い。螺層には 4 列の低く狭い水掻き状で，鋸歯状 パイプヨウラク亜科 Typhinae は現在現生 14 属・ の薄板縦張肋を生じ，殻口縦張肋に 5 本の縮れと 亜属で構成される。このうちトサパイプヨウラク なる（Fig. 2N: P2-P5）。螺条（Fig. 2N: P1）は後水 属 Monstrotyphis Habe, 1961 は当初単型 monotypy で 管となる。殻口は小さく，丸く，筒状に突き出し， あったが，現在ではインド・西太平洋に 10 種，西 連続した囲口を呈する。内唇は広く突き出し滑ら 大西洋に 1 種の合計 11 種が含まれる。本邦産種は か。外唇も突き出し内側は滑らか。前水管はやや M. imperialis ミカドパイプヨウラク，M. montfortii 長く狭い，先端部が背側に強く反り曲がる。後水 パイプヨウラク，M. teramachii テラマチパイプヨ 管は腹側で密閉され殻頂側に狭く開く。短く狭い ウラク，M. tosaensis トサパイプヨウラクの 4 種が 小棘を生じる。 数えられる。 蓋は丸く同心円状の隆起，下端に核がある。舌 今般，伊豆大島秋の浜より SCUBA によって得 歯は不詳。 られた標本より本属の 1 新種を認めたので記載す 比較：本種は最近似種のM. montfortii（A. Adams, る。本新種を加え本邦産は 5 種となる。 1863）パイプヨウラクに比べやや小型，初生殻は ややキールを生じる。前水管先端部は背方に反り Monstrotyphis takashigei n. sp. ノコギリバパイプ 返る。後水管は鋸歯状を呈し，基部は狭まる。ま ヨウラク（新種・新称） た，生息環境はパイプヨウラクが水深 50～200 m タイプ標本：ホロタイプ，殻長 6.4 mm（国立科 の砂地であるのに対し，本種は 20～55 m 岩礁上で 学博物館 NSNT-Mo 78955）；パラタイプ，殻長 7.3 あることで異なる。その他，テラマチパイプヨウ mm（仏国立自然史博物館 IM-2000-31739），殻長 ラクはより短小であること，ニューカレドニア産 7.3 mm（R. Houart），殻長 8.5 mm（知野光雄），殻 の M. singularis とはより大型で初生殻が尖らない 長 9.3 mm，殻長 7.5 mm（高重 博）。 こと，後水管が刻まれることで区別される。 産地：タイプ産地は伊豆大島秋の浜，水深 55 m。 種小名は本種を発見された東京都在住の高重 他には，同所の水深 20～55 m から得られた。 博氏に因む。和名は後水管が鋸歯状に刻まれる本 同属種の中ではやや小型，殻長は最大 9.3 mm。 種の特徴による。 殻長／殻幅比は 1.7～2.0。外形は幅広の両円錘形，