Neozoanthus uchina, Reimer, James Davis, Irei, Yuka & Fujii, Takuma, 2012

Reimer, James Davis, Irei, Yuka & Fujii, Takuma, 2012, Two new species of Neozoanthus (Cnidaria, Hexacorallia, Zoantharia) from the Pacific, ZooKeys 246, pp. 69-87 : 72-75

Neozoanthus uchina sp. n. Figures 145BTables 23S1

Neozoanthus uchina Synonymy: " Neozoanthus sp. okinawa" - Reimer 2010: 25, 27, fig. 8.

Neozoanthus uchina : Reimer et al. 2011a: 986, 989, fig. 4.

Neozoanthus uchina : "Japan clade" of Neozoanthus - Reimer et al. 2011a: fig. 2.

Material examined.

Type specimens.

Holotype, specimen number NSMT-Co1553. Colony of 17 polyps connected by stoloniferous coenenchyme on a rock approximately 4.5 × 3.0 cm. Polyps approximately 2.0-4.4 mm in diameter, and approximately 2.0-5.4 mm in height from coenenchyme. Polyps and coenenchyme encrusted with irregularly sized and colored sand grains. There was no noticeable variation between holotype and other specimens. Preserved in 99.5% ethanol. Original label.

Paratypes (all from Japan): Paratype 1. Specimen number USNM 1194728. Collected from Teniya, Nago, Okinawa, at 1 to 2 m by JDR, September 5, 2008. Paratype 2. Specimen number RMNH Coel 40098. Collected from Manza, Onna, Okinawa I., Japan, at 25 m by JDR, 1 September, 2008.

Type locality. Japan, Okinawa Prefecture, Okinawa Island: Nago City, Teniya, 26.563832°N, 128.140822°E, in small cracks on reef flat at 1 to 2 m depth, 5 September 2008, J.D. Reimer (JDR) leg.

Other material (all from Japan, coll. JDR unless noted): Teniya, Okinawa I., Okinawa, MISE 545, 546, 549 (n=3), 1-2 m 5 September 2008; Yona, Okinawa I., Okinawa, MISE 560, 13 m, coll. JDR and Takuma Fujii (TF), 24 September 2008; Teniya, Okinawa I., Okinawa, MISE 1092, 1093 (n=2), intertidal - 1 m, 1 July 2008; Tinyuhama, Korijima I., Okinawa, MISE 1115, 1116 (n=2), 24 m, 28 December 2008; Omonawa, Tokunoshima I., Kagoshima, MISE 1400, 9 m, 9 March 2010; San, Tokunoshima I., Kagoshima, MISE 1401, 1402 (n=2), 10-12 m, 10 March 2010; Zampa, Okinawa I., Okinawa, MISE 1403, at unknown depth, 29 August 2008 (see also Table 2); Tebiro Beach, Amami-Oshima I., Kagoshima, MISE MO-100, 10 m, coll. Masami Obuchi, 16 March 2011.

Description.

Size: Polyps in situ approximately 2.2-5.1 mm in diameter when open, and approximately 2-8.5 mm in height.

Morphology: Neozoanthus uchina sp. n.has 32 to 42 (average 38 ± 3.0, n=24 polyps on 9 colonies) conical tentacles. Tentacles are usually shorter than the expanded oral disk diameter (e.g. 50-80% of oral disk width). Tentacles may be grayish-blue, rust red, or transparent, often with black, white, or fluorescent blue bands or patterning (Figure 4). No bractae are visible, and all specimens were zooxanthellate. Polyps are externally heavily encrusted with sand and other particles of irregular sizes, excepting the oral end, which is free of encrustation and appears a bluish-gray similar to as seen in some Zoanthus species. When fully contracted, the sand free oral end is often not visible, and polyps resemble small balls of sand. Polyps extend well clear of reduced or stoloniferous coenenchyme (Figure 4). Oral disks may be a variety of colors, such as light gray-blue, white, rust or deep wine red. Occasionally, white or light blue dots may be seen on the oral disk in regular circular patterns, and the oral opening (mouth) is often white or cream in color. A “skirt” of different coloration (usually white or lighter coloration than remainder of oral disk) covering up to approximately 90 degrees of the oral disk is often seen in the area of the dorsal directive. Colonies consisted of tens to <100 polyps, connected by stolons with no well-developed coenenchyme.

Cnidae: Basitrichs and microbasic p-mastigophores (often difficult to distinguish), holotrichs (large and small), spirocysts (see Table S1, Figure 5).

Differential diagnosis.

Differs from Neozoanthus tulearensis Herberts, 1972 and Neozoanthus caleyi sp. n. with regards to distribution (Ryukyu Archipelago as opposed to Madagascar and southern Great Barrier Reef, respectively), coloration (yellow observed in some Neozoanthus caleyi sp. n.), and tentacle count ( Neozoanthus tulearensis = 38 to 44 tentacles, Neozoanthus caleyi sp. n. = average 33 ± 3.9 tentacles). The two new Neozoanthus species’ tentacle counts are statistically significant (t-test, p<0.001). Often polyps are much taller (to 8.5 mm) than Neozoanthus caleyi sp. n. (to 3.0 mm), although height ranges overlap (Table 3). The two new Neozoanthus species mt 16S rDNA sequences differ by three base pairs ( Reimer et al. 2011a).

Neozoanthus uchina sp. n.is currently the only partially encrusted zoanthid described from the Ryukyu Archipelago.

Etymology.

Named for the Okinawan dialect word for Okinawa, “uchina”, the prefecture where this species was first found. Noun in apposition.

Habitat, ecology, and distribution.

Specimens from the Ryukyu Archipelago were found at depths from the intertidal zone to 25 m. Despite repeated surveys focused on zoanthids, no Neozoanthus uchina sp. n.have been found further north on Yakushima Island or mainland Japan, nor further south in the Miyako and Yaeyama Islands of southern Okinawa, and it may be that this species is limited to a subtropical distribution in the Middle Ryukyu Islands. Additionally, despite surveys, thus far no specimens have been reported from neighboring Taiwan ( Reimer et al. 2011d) or the Ogasawara Islands ( Reimer et al. 2011b).

Neozoanthus uchina sp. n., although not found at many locations surveyed, was locally common, particularly at locations that were characterized by strong currents and some sedimentation, with large coarse sand particles scattered over the bottom or rocks. Preference for such environments may be related to its encrustation patterns. Colonies were almost always found in cracks and holes in rocks partially exposed to light, and usually not in locations completely exposed to light. Most colonies were relatively small, consisting of tens (not hundreds) of polyps, with polyps spread out and connected by thin stolons (Figure 4).

Notes.

This species can close its polyps much more rapidly than species of other zooxanthellate zoanthid genera (Reimer pers. obs).

DNA Sequences.

Originally listed in Table S1 in Reimer et al. (2011a).

Cytochrome oxidase subunit I: HM991243-HM991246

Mitochondrial 16S ribosomal DNA: HM991227-HM991229