Two new species of the subgenus Asteroporpa (Asteromoana) (Ophiuroidea: Euryalida: Gorgonocephalidae) from Japan Author Okanishi, Masanori Author Fujita, Toshihiko text Zootaxa 2011 2751 25 39 journal article 10.5281/zenodo.206579 d02a1a04-922c-443d-b60d-8f30075211a7 1175-5326 206579 Asteroporpa ( Asteromoana ) muricatopatella sp. nov. [New Japanese name: Toge-moana-moduru] ( Figs 2–5 ) Type materials. NSMT E- 6548, holotype , collected by fishing boat Mio-maru , off Kume-jima Island, Okinawa Prefecture, southwestern Japan , 26˚14.116’N, 126˚50.120’E, 410 m deep, 20 February 2010 . NSMT E- 5619-B, one paratype , collected with ROV Hakuyo of a manned submersible Shinyu-maru , off Yaku-shima Island, Kagoshima Prefecture, southwestern Japan , 30˚49.5’N, 130˚48.52’E, 140 m deep, 26 September 2007 . NSMT E- 6547, two paratypes , collected off Kagoshima Prefecture or off Okinawa Prefecture, southwestern Japan , approximately 200–300 m (no further data are available and this site is not shown in Fig. 1 ), 16 November 2007 ( Fig. 1 ). Description of holotype . Size is 4.8 mm in disc diameter, 35 mm in arm length ( Fig. 2 ). Disc. Disc is five-lobed in shape with notched interradial edges ( Figs 2 , 3 A–B). On the aboral side, radial shields and their surrounds are tumid ( Fig. 3 A). There are no conspicuous ridges of rows of raised hooklet-bearing plates and the hooklet-bearing plates are scattered on periphery of each radial shield ( Fig. 3 E). Each hooklet-bearing plate possesses eight to eleven tubercle-shaped articulations for hooklets. Each hooklet has two inner teeth. Except for the hooklet-bearing plates, the aboral disc is covered by cone-shaped dermal ossicles with one or two terminal projections which are approximately one-fourth the length of the height of the cone-shaped dermal ossicles ( Fig. 3 D). The cone-shaped dermal ossicles are approximately 150–230 µm in length and 270 µm in height at the periphery of the disc ( Fig. 3 D), and approximately 130–210 µm in length and 240 µm in height at center of the disc ( Fig. 3 C). Radial shields are completely concealed by dermal ossicles, oval shape, approximately 4.5 mm in length, 3.0 mm in width distally, 1.5 mm in width proximally, and do not reach the disc center ( Fig. 3 A). The oral surface of the disc is covered both by flat, polygonal plate-shaped dermal ossicles and by cone-shaped dermal ossicles with mostly one or rarely two terminal projections similar to the aboral disc ( Fig. 3 G). The coneshaped dermal ossicles are scattered only on the disc periphery, not on the oral plates ( Fig. 3 G–H). The plateshaped dermal ossicles are approximately 140–190 µm in length and 50 µm in height on periphery of the disc, and approximately 60–80 µm in length and 20 µm in height on oral plates ( Fig. 3 G–H). The cone-shaped dermal ossicles are approximately 150–190 µm in length and 190 µm in height ( Fig. 3 G). Oral shields, adoral shields, oral plates and ventral arm plates are completely concealed by dermal ossicles ( Fig. 3 B, G). Uniformly acute and spineformed teeth are situated on the jaws ( Fig. 3 H). Teeth length varies with their position of the jaw. On the top of jaws, they are approximately 190 µm in length, and toward the basal part of the jaws, the teeth gradually decrease in length to approximately 135 µm ( Fig. 3 H). The lateral interradial surface of the disc is slightly inclined to the oral side and covered only by cone-shaped dermal ossicles with mostly one or rarely two terminal projections which are approximately one-third length of the height of the cone-shaped dermal ossicles ( Fig. 4 A). The cone-shaped dermal ossicles are approximately 150–190 µm in length and 240 µm in height ( Fig. 4 A). Two genital slits ( 0.3 mm long and 0.05 mm wide) are present in each interradius ( Fig. 4 A). One circular madreporite is situated on oral interradius, approximately 440 µm in diameter ( Fig. 4 B). Diagnosis. Dermal ossicles are cone-shaped with terminal projections on the aboral disc; plate-shaped on oral plates; cone-shaped with relatively short terminal projections at the lateral interradial disc. Arms. Arms are simple, five in number, have no abrupt gap in thickness. The basal portion of the arm is 2.2 mm wide and 2.1 mm high, with an arched aboral surface and flattened oral surface. Arms taper gradually toward the arm tip ( Figs 2 , 4 C–G). FIGURE 2. Asteroporpa ( Asteromoana ) muricatopatella sp. nov. , holotype (NSMT E-6548). A, aboral side; B, oral side. FIGURE 3. Asteroporpa ( Asteromoana ) muricatopatella sp. nov. , holotype (NSMT E-6548). A, aboral disc and basal portion of the arm; B, oral disc and basal portion of the arm; C, aboral central part of the disc; D, aboral periphery of the disc; E, aboral periphery of the disc, a hooklet-bearing plate is indicated by an arrow; F, aboral basal portion of the arm, hooklet-bearing plates are indicated by arrows; G, oral disc, a cone-shaped dermal ossicle is indicated by an arrow; H, jaws. FIGURE 4. Asteroporpa ( Asteromoana ) muricatopatella sp. nov. , holotype (NSMT E-6548). A, lateral interradius of the disc; B, a madreporite; C, aboral view of basal portion of the arm; D, oral view of basal portion of the arm; E, lateral view of middle portion of the arm; F, oral view of distal portion of the arm; G, aboral view of distal portion of the arm. Abbreviations: AS, arm spine; GS, genital slit; M, madreporite. Arrows indicate transverse rows of hooklet-bearing plates (C, E, G). On the aboral and lateral surface, each arm segment is surrounded by single annular transverse row of hookletbearing plates ( Figs 3 F, 4C, E, G). Each hooklet bears two inner teeth. On the basal one or two arm segments, each hooklet-bearing plate is separated by plate-shaped dermal ossicles. On third and subsequent distal segments, those plates are fully in contact with each other ( Figs 3 F, 4C, E, G). Except for hooklet-bearing plates, the aboral and lateral surface of the basal arm is completely covered by domed and polygonal plate-shaped dermal ossicles of approximately 150–220 µm in length and 200 µm in height ( Fig. 4 C). The oral surface is covered by flat and polygonal plate-shaped dermal ossicles, similar to those on the oral disc of approximately 80–160 µm in length and 60 µm in height ( Fig. 4 D). In the middle portion of the arm, the aboral and lateral surface is covered by domed and round granule-shaped dermal ossicles of approximately 120–150 µm in length and 130 µm in height ( Fig. 4 E). There are also some smaller, round, relatively flat and round granule-shaped dermal ossicles of approximately 100– 120 µm in length and 110 µm in height. In the distal portion of the arm, the aboral and lateral surface is covered by flat and round granule-shaped dermal ossicles of approximately 80–120 µm in length and 100 µm in height ( Fig. 4 G). The oral surface is covered by flat and round plate-shaped dermal ossicles of approximately 60–80 µm in length and 30 µm in height ( Fig. 4 F). Throughout the arm, lateral arm plates and ventral arm plates are completely concealed by dermal ossicles ( Fig. 4 D, F). First tentacle pores have no arm spine; second has four, third has five or six, and from fifth pores to the pores at middle arm segments there are six arm spines ( Fig. 4 D). Subsequently, the number of the arm spines decreases gradually to one toward the arm tip. Throughout the arm, all arm spines are approximately half the length of the corresponding arm segment, and are covered by thin integument ( Fig. 4 D, F). Arm spines in the basal one-fourth of the arm are ovoid, carrying two or three terminal projections. The inner most arm spine has three and the others have two terminal projections. In the middle portion, from one-fourth to three-fourths of the arm length, the arm spines have two terminal projections. In the distal quarter of the arm, arm spines are transformed into hooks. Those hook-shaped spines have one inner tooth, and they can be distinguished from hooklets on aboral and lateral surface of the arm by the reticular structure on their basal portion. Color. Aboral side of the body is basically gray. Distal half of each radial shield are white and the disc center is dark brown ( Fig. 2 A). Between the proximal part of paired radial shields, one yellow spot is present ( Fig. 2 A). On basal aboral median line of three arms, there are two yellow spots. Lateral interradial disc is also basically gray. In the central part of each lateral oral interradial disc, one larger yellow spot is present ( Fig. 2 B). The oral side of the body is uniformly white ( Fig. 2 B). FIGURE 5. Asteroporpa ( Asteromoana ) muricatopatella sp. nov. , one paratype (NSMT E-5619-B). SEM photographs of internal ossicles. A–B, a hooklet-bearing plate (A) and a hooklet (B) at the aboral periphery of the disc; C–D, cone-shaped dermal ossicles at the aboral periphery of the disc, external (C) and lateral (D) views; E, a hooklet at the middle portion of the arm; F–G, plate-shaped dermal ossicles at the aboral basal portion of the arm, external (F) and lateral (G) views; H–I, plate-shaped dermal ossicles at the aboral distal portion of the arm, external (H) and lateral (I) views; J–K, arm spines from basal portion of the arm (J) and distal portion of the arm (K) with an arc indicating reticular structure. Arrows indicate the orientation (D, G, I): ext, external side; int, internal side. Ossicle morphology of the paratype . E-5619-B: Size is 9.1 mm in disc diameter, 45 mm in arm length. Hooklet-bearing plates on radial shield possess eight to eleven tubercle-shaped articulations for hooklets ( Fig. 5 A). The tubercle-shaped articulations form two or three parallel rows ( Fig. 5 A). The hooklets bear two inner teeth ( Fig. 5 B). The hooklets on middle portion of the arm also bear two inner teeth ( Fig. 5 E). Dermal ossicles on aboral periphery of the disc are cone-shaped, approximately 180 µm in length and 200 µm in height, with two or three terminal projections ( Fig. 5 C–D). The length of the terminal projections are approximately one-fourth the height of the cone-shaped dermal ossicles ( Fig. 5 C–D). Dermal ossicles on the aboral basal portion of the arm are domed, round and plate-shaped, approximately 220 µm in length and 200 µm in height ( Fig. 5 F–G). Dermal ossicles on aboral distal portion of the arm are flat, round and granule-shaped, approximately 70 µm in length and 30 µm in height ( Fig. 5 H–I). The inner most arm spines on the basal one-fourth of the arm are ovoid, carrying two or three terminal projections on the tip ( Fig. 5 J) Inner most arm spines on the distal quarter of the arm are hook-shaped, with one inner teeth along inner edge and reticular structure on basal portion ( Fig. 5 K). Variation. Some color variations can be observed in four specimens. The periphery of the aboral disc and aboral surface of the arms are gray for the holotype , dark red for one paratype (NSMT E-5619-B), and the entire bodies of the other two paratypes (NSMT E-6547) are creamy white. Distribution . JAPAN : off Yaku-shima Island, 140 m (present study), off Kume-jima Island, 410 m (present study), southwestern Japan ( Fig. 1 ). Etymology . The specific name is a feminine noun in apposition formed as a compound of Latin words, muricatus (adjective, meaning “covered by spines”) and patella (feminine noun, meaning “disc”), referring to the disc covered by spiny cone-shaped dermal ossicles.