Short Notes

A New Species, Primovula panthera (: ) from Japan

Yoshihiro Omi 4-20-8-4 Sendagaya, Shibuya-ku, Tokyo 151-0051, Japan; [email protected]

The family Ovulidae is a highly diverse group Diagnosis: Shell roundly pyrifor m with of Gastropoda in worldwide oceans, and the numerous transverse striations, columella convex; genus Primovula is regarded as one of the largest columellar fold indistinct; columellar margin well groups in the Japanese ovulid fauna. In the genus developed; fossula distinct, widely developed, Primovula, three new species have recently been white; siphonal canal flared at end; terminal ridge described from Japan (Omi, 2007, Omi & Clover, twisted, obliquely protruding; labrum broadened, 2005; Omi & Iino, 2005). I obtained material of flattened; labral denticles coarse; funiculum an additional undescribed species, and hereby triangular. Shell entirely reddish orange to describe it as new. yellowish orange in color. Description: Shell (Figs. 1-8): Outline roundly Abbreviations: SL – shell length; NSMT – pyriform, broadest at approximately 2/5 position National Museum of Nature and Science, Tokyo. from posterior end, gradually attenuate toward anterior terminal. Dorsum heavily and evenly incised with spiral striations that extend over ventral side. Anterior terminal obliquely squared Family Ovulidae Fleming, 1828 in front. Right margin callously rimmed. Posterior Genus Primovula Thiele, 1925 terminal abruptly tapered, pointed and beak-like. Type species, by original designation: Amphiperas Ventral side convex, striated. Columellar peristome beckeri Sowerby, 1900. well developed. Fossula smooth, distinct, widely developed. Aperture narrow, curved. Siphonal Primovula panthera n. sp. canal flared at end. Terminal ridge twisted, (Figs. 1-10, 14-17) obliquely protruding from canal ridge. Posterior canal opened to 45 degrees in left toward posterior Type material: H o l o t y p e , N S M T- M o end. Funiculum triangular, bearing two ridges, 76772, collected alive at a depth of 15-20 m, slightly depressed. Labrum glossy, broadened, off Myogane Promontory, Futtsu City, Chiba flattened. Denticles coarse, becoming longer Prefecture, Japan (35°09´N, 139°48´E), in toward posterior end, l ast three extending across November, 2007, by a diver. Paratype #1, NSMT- labrum and protruding from outer edge. Shell Mo 76773, collected alive at a depth of 50-70 entirely reddish orange. Anterior and posterior m, off Inami, Hidaka-gun, Wakayama Prefecture, portion of dorsum faded to yellowish orange. Japan (33°48´N, 135°14´E), in November, 2003, Marginal rim only slightly darker in color. Fossula by gill net for Spiny lobster Panulirus japonicus white. (von Siebold); paratype #2, NSMT-Mo 76774, (Figs. 9-10): Mantle smooth, yellowish collected dead, off Sakai, Minabe-Cho, Wakayama orange with scattered black splotches. Cephalic Prefecture, Japan (33°45´N, 135°19´E), on March tentacles slender and tapered, black with white 3, 1996, by gill ne t for Spiny lobster P. japonicus tips. Siphon translucent white at outer surface, by K. Noda; paratype #3, in the collection of K. black at inner tube. Foot yellowish orange with Noda, collected off Nada, Gobo City, Wakayama scattered black splotches. Prefecture, Japan (33°49´N, 135°10´E), November Radula (Figs. 14-19): Taenioglossate with 8, 2005, by gill net for Spiny lobster P. japonicus formula 2:1:1:1:2. Rachidian teeth sectorial in by K. Noda. shape with large central cusp and 8-9 lateral Additional material examined: Photographs of denticles on both sides; mid-basal margin convex. one live specimen taken by H. Takaishi, at a depth Lateral teeth triangular, leaf-shaped, with elongate of 15 m, off Zushi, Kanagawa Prefecture, Japan shaft upheaving on marginal side, major cusps (35°17´N, 139°32´E), in November 14, 2005. remarkably large, strongly curved inwardly, 86 VENUS 67 (1-2), 2008

Figs. 1-10. Primovula panthera n. sp. 1-4. Holotype, NSMT-Mo 76772. 5-6. Paratype #1, NSMT-Mo 76773. 7-8. Paratype #3, NSMT-Mo 76774. 9. Live animal with host Minabea sp. (Photo by K. Akasaka) 10. Live animal of holotype (Photo by H. Takaishi). Figs. 11-13. Primovula cuspis. 11-12. Yellowish form. 13. Live animal (Photo by K. Nin). forming minute 2 lateral denticles on inner side shell height in mm): Holotype ̶ 8.3 × 4.5 × 3.5. and 3 on outer side. Inner marginal teeth narrow, Paratype #1 ̶ 6.3 × 3.2 × 2.9; paratype #2 ̶ 6.5 triangular in shape, rake-like in appearance, × 3.3 × 3.0; paratype #3 ̶ 5.2 × 2.6 × 2.5. split approximately halfway distally into 4-5 Type locality: Off Myogane Promontory, Futtsu long denticles, further subdivided into 2-3 City, Chiba Prefecture, Japan, at a depth of 15-20 denticles, forming total 14-16 denticles. Outer m. marginal teeth narrow triangular in shape, rake- Distribution: Off Boso peninsula, Miura like in appearance, with 7-8 denticles extending peninsula and Kii peninsula, at depths of 15-70 m. approximately 1/3 distally, further subdivided into Etymology: From the Latin “panthera”, 2-4 tiny denticles on top, forming total 20-26 meaning panther, which refers to the color pattern denticles; inner 2-3 denticles pointed, outer on mantle and foot. denticles turgid and roundly formed on tip, finger- Discussion: The assignment of the present like in appearance, outermost denticles broader new species to the genus Primovula is based on than others, overlapping inner marginal teeth. the characteristic shell m orphology, such as the Dimensions (shell length × shell width × small and pyriform outline, a narrow aperture, Short Notes 87

Figs. 14-17. Radula of Primovula panthera n. sp., holotype, NSMT-Mo 76772. 14. Dorsal view of radula ribbon. 15. Rachidean tooth. 16-17. Lateral teeth, inner and outer marginal teeth. Figs. 18-19. Radula of Primovula cuspis. 18. Dorsal view of radula ribbon. 19. Lateral teeth, inner and outer marginal teeth. the thickened and denticulate labrum, and distinct in middle of beige in P. cuspis. Furthermore, the funiculum. two species differ in radula morphology (Figs. Primovula panthera n. sp. is most closely 14-19). The rachidian teeth have particularly similar to the yellowish form of Primovula significant differences. A pair of small cusps are cuspis (Cate, 1973) (Figs. 11-1 3) in overall shell formed alongside the large central cusp on the morphology and coloration. However, the present rachidian tooth, which is almost even on the size new species is distinguished from the latter by and shape in P. panthera (Figs. 14-15), but is possessing: (1) a more roundly inflated outline; irregular in P. cuspis (Fig. 18). Also, the rachidian (2) a semi-conically shaped posterior extremity; tooth of P. panthera (Figs. 14-15) has 8-9 lateral (3) a convex columella without a thickened callus; denticles on both sides, compared with 10-12 in P. (4) no columellar folds on the outer wall; (5) a cuspis (Fig. 18). These lateral denticles are almost smaller funiculum; (6) a strongly twisted and evenly formed on both sides in P. panthera (Figs. obliquely developed terminal ridge; (7) terminals 14-15), but they are non-uniform and some are that are not tinted with orange. The two species split into 2-3 tips in P. cuspis (Fig. 18). The inner also differ in soft part characters. The mantle of and outer marginal teeth are rounded and finger- P. panthera is smooth and yellowish orange with like in appearance at the tips in P. panthera (Figs. distinct black splotches (Fig. 10), whereas that 16-17), but in P. cuspis are shapely pointed (Fig. of P. cuspis possesses minute white papillae and 19). beige coloration with finer and denser reddish Among the similar-looking ovulids hitherto spots (Fig. 13). In P. panthera the foot has the known from Western Pacific waters, Primovula same color pattern as the mantle, whereas in P. beckeri (Sowerby, 1900) superficially resembles cuspis it has a yellowish orange line. The cephalic P. panthera. However, P. beckeri differs by having tentacles are black with white tips in P. panthera a narrower labrum, finer labral denticles, less (Fig. 9), whereas they are faint brownish yellow developed columellar peristome and fossula, a 88 VENUS 67 (1-2), 2008 straight, open posterior canal, a whitish transversal Omi, Y. & Clover, W. P. 2005. Description of band on the dorsum and terminals tinted in orange. a new species of Primovula (Gastropoda: Primovula tropica (Schilder, 1931) described Ovulidae), with the designation of the type from the Amirante Islands in the Seychelles, also species for the genus Dentiovula. Venus 63: 101-108. resembles P. panthera, but differs by having a Omi, Y, & Iino T. 2005. Two new species of the callus on the ventral side, a narrow labrum, finer family Ovulidae (Gastropoda) from Japan. labral denticles and a straightly opened posterior Venus 64: 141-149. canal. Biological note: Approximately 10 individuals (Accepted February 12, 2008) of Primovula panthera were observed and photographed by divers at two different localities in Japan. All the specimens were found to 日本産ウミウサギガイ科貝類の 1 新 be associated with the octocoral Minabea sp. 種クロマルケボリの記載 (Alcyonidae). Thus, P. panthera is considered to be stenophagous. P. panthera has unique coloration on the 淤見慶宏 mantle and foot. Most ovulid species are known to have defensive coloration matching that of 房総半島，三浦半島，紀伊半島沖の水深 15 ～ their host, but others, including Primovula tigris 70 1 Yamamoto, 1971, are known to be aposematic, ｍで発見されたベケリケボリ属の 種の貝殻形 with warning coloration. The present new 態，軟体部外部形態，歯舌を精査したところ，新 species may belong to the latter group, in having 種であることが確認されたので，クロマルケボリ conspicuous coloration that contrasts with the （黒丸毛彫）Primovula panthera n. sp.（新称） とし color of the host. て記載する。本種はトガリアヤメケボリ P. cuspis に近似するが，殻の丸みが強い点，後端が半円錐 Acknowledgement: I am grateful to Mr. Kazutaka Noda in Wakayama and Mr. Takashi 形に尖る点，腹面が膨らみ老成しても殆ど滑層に Osato in Chiba for providing the invaluable 覆われない点，軸襞が形成されない点，滑層瘤が specimens; Mr. Yukimitsu Imahara of Wakayama Natural History Museum for identifying the 小型な点，末端襞がねじれ斜めに長く発達する点， Alycyonacean host; Mr. Naoki Adachi, Tokyo, 殻両端が橙色に彩色されない点など殻形態から区 for providing scanning electron micrographs 別される。また，外套膜や足部が黄色地に黒斑が of the radula; Mr. Katsuya Akasaka in Tokyo, Mr. Hideo Takaishi in Chiba for providing the 散る彩色となり，触角が黒色で先端が白色になる photographs of P. panthera and Mr. Kenji Nin など軟体部からも区別される。歯舌形態も異な in Kanagawa for those of P. cuspis; Mr. Hitoshi り，中歯は歯先数が少なく，中心の大歯尖を対称 Ikeda, Hayama Shiosai Museum in Kanagawa; and Dr. Kazunori Hasegawa, National Museum of にして左右均一に小歯尖が形成される点，内・外 Nature and Science, Tokyo for valuable comments 縁歯の先端が指状に膨らむ点で異なる。本種はベ that improved the manuscript. I also thank the ケリケボリ P. beckeri にも似るが，外唇が幅広い点， following p ersons who helped in various ways: Mr. Shingo Habu in Wakayama, Mr. Kin’ya 外唇歯が粗い点，内唇縦溝と軸唇窩が発達する点， Mase and Mr. Takashi Kuramochi in Kanagawa, 後水管溝が後端に向かって斜め左方向に開口する Mr. Shoichi Kato and Mr. Masanori Ishii on 点，背面に白色横帯が入らず，前後端も橙色に彩 Hachijojima Island, Tokyo. 色されない点で異なる。 References タイプ標本：ホロタイプ，NSMT-Mo 76772，殻 長 8.3 mm。 Cate, C. N. 1973. A systematic revision of the タ イ プ 産 地： 千 葉 県 富 津 市 明 鐘 岬 沖， 水 深 Recent cypraeid family Ovulidae (: 15-20 Gastropoda). The Veliger15, supplement: ｍ。 1-116. 分布：房総半島，三浦半島，紀伊半島沖，水深 Omi, Y. 2007. A new species of Primovula 15-70 m。 (Gastropoda: Ovulidae) from Japan. Venus 66: 11-17. 寄生宿主：ウミトサカ科ミナベトサカ属の 1 種。