Antipathozoanthus remengesaui, Kise, Hiroki, Fujii, Takuma, Masucci, Giovanni Diego, Biondi, Piera & Reimer, James Davis, 2017

Kise, Hiroki, Fujii, Takuma, Masucci, Giovanni Diego, Biondi, Piera & Reimer, James Davis, 2017, Three new species and the molecular phylogeny of Antipathozoanthus from the Indo-Pacific Ocean (Anthozoa, Hexacorallia, Zoantharia), ZooKeys 725, pp. 97-122 : 102-105

Antipathozoanthus remengesaui sp. n. Fig. 2c

Antipathozoanthus sp. sensu Reimer et al. 2014a, 2, fig. 1d

Antipathozoanthus sp. 1 sensu Reimer and Fujii 2017, 304, fig. 14.4c.

Material examined.

Holotype: NSMT-Co1603 (MISE-PALAU2), colony of approximately 70 polyps connected by poorly developed white coenenchyme on genus Antipathes antipatharian ( Hexacorallia: Antipatharia : Antipathidae ). Preserved polyps approximately 1.5-3.0 mm in diameter, and approximately 1.5-2.0 mm in height from coenenchyme. Collected from Blue Hole, Palau (7°8'29.4"N, 134°13'23.3"E) at a depth of 23 m by JDR, 15 September 2014.

Paratypes: RMNH.Coel.42321 (MISE-MAL84), collected from Wall Street, Maldives (3°07'14.2"N, 72°58'46.5"E) at a depth of 9 m by JDR, 7 May 2014; RUMF-ZG-4397 (MISE-MAL85), collected from Wall Street, Maldives (3°07'14.2"N, 72°58'46.5"E) at a depth of 9 m by JDR, 7 May 2014; RUMF-ZG-4398 (MISE-JDR209), collected from Yanbu, Saudi Arabia, (24°26'N, 37°14'E) at a depth of 11 m by JDR, 4 October 2013; RUMF-ZG-4399 (MISE-TF102), collected from Okoga-shima Island, Kagoshima, Japan (31°33'58.75"N, 130°35'32.01"E) at a depth of 20 m by TF, 26 July 2011; RUMF-ZG-4400 (MISE-TF103), collected from Okoga-shima Island, Kagoshima, Japan (31°33'58.75"N, 130°35'32.01"E) at a depth of 40 m by TF, 26 July 2011.

Other materials examined: MISE-PALAU3, collected from Siaes Tunnel, Palau (7°18'54.8"N, 134°13'13.3"E) at a depth of 37 m by JDR, 15 September 2014; MISE-PALAU4, collected from Blue Hole, Palau (7°8'29.4"N, 134°13'23.3"E) at a depth of 28 m by JDR, 12 September 2014; MISE-KINKO2, collected from Hakamagoshi, Sakurajima, Kagoshima, Japan (31°35'23.5"N, 130.35.27.8"E) at a depth of 21 m by JDR, 20 September 2015; MISE-TF173, collected from Onna, Okinawa, Japan (26°26'20.9"N, 127°47'7.22"N) at depth of 15 m by TF, 27 June 2014; MISE-MAL46, collected from Coral Garden, Maldives (3°05'24.3"N, 72°58'04.5"E) at a depth of 24 m by JDR, 6 May 2014; MISE-MAL82, collected from Wall Street, Maldives (3°07'14.2"N, 72°58'46.5"E) at a depth of 9 m by JDR, 7 May 2014; MISE-MAL83, collected from Wall Street, Maldives (3°07'14.2"N, 72°58'46.5"E) at a depth of 9 m by JDR, 7 May 2014; MISE-MAL2502602, collected from Capital Reef, Maldives (3°02'55.8"N, 72°53'21.2"E) at a depth of 19 m by Marco Oliverio, 16 May 2014; MISE-MAL145, collected from Wall Street, Maldives (3°07'14.2"N, 72°58'46.5"E) at a depth of 12 m by JDR, 10 May 2014; MISE-MAL147, collected from Wall Street, Maldives (3°07'14.2"N, 72°58'46.5"E) at a depth of 10 m by JDR, 10 May 2014; MISE-MAL261, collected from Wall Street, Maldives (3°07'14.2"N, 72°58'46.5"E) at a depth of 9 m by JDR, 17 May 2014; MISE-HK70, collected from Siaes Tunnel, Palau (7°18'54.8"N, 134°13'13.3"E) by Hiroki Kise (HK), 12 September 2014, depth not available; MISE-HK90, collected from Blue Hole, Palau (7°8'29.4"N, 134°13'23.3"E) at a depth of 22 m by HK, 15 September 2014; MISE-JDR211, collected from Yanbu, Saudi Arabia, (24°26'N, 37°14'E) at a depth of 12 m by JDR, 4 October 2013; MISE-JDR214, collected from Yanbu, Saudi Arabia, (24°26'N, 37°14'E) at a depth of 12 m by JDR, 4 October 2013.

Diagnosis.

External morphology: Polyps in situ are approximately 4-8 mm in diameter, and approximately 3-8 mm in height in situ when oral disks expanded (Fig. 2). Colonial zoantharian, white or off-white polyps that may be solitary or connected by a white and poorly developed coenenchyme on Antipathes substrate. Antipathozoanthus remengesaui sp. n. has approximately 40-42 tentacles that are pinkish or/and translucent. Tentacles are usually as long as open oral disk diameter. Oral disk is pink or bright brown in color, and the capitulum is also pinkish or bright brown in color when polyps are closed. Polyps encrusted with visible sand particles (1-3 mm) in their coenenchyme and ectodermal tissue. Colonies attached on axis from proximal extremity to base of Antipathes .

Internal morphology: Cteniform endodermal marginal muscle sensu Swain et al. 2015 (Fig. 4). Azooxanthellate. The large scattered lacunae in ectoderm and mesogleal are present due to their encrustations.

Cnidae: Holotrichs (large and medium), basitrichs and microbasic p-mastigophores (usually difficult to distinguish), spirocysts (Fig. 3; Table 2).

Habitat and distribution.

Antipathozoanthus remengesaui sp. n. has been found on the sides and/or floors of cave entrance, and always on Antipathes . Specimens were collected from depths of 9 to 40 m. This species is known from Palau, Kagoshima in Japan, the Maldives, and the Red Sea.

Differential diagnosis.

In the Pacific, Antipathozoanthus remengesaui sp. n. can be distinguished from A. hickmani by the development of the coenenchyme and in part by polyp size; the larger polyps (4-12 mm in diameter and 4-15 mm in height) of A. hickmani are connected by a well-developed coenenchyme on Antipathes galapagensis , while the slightly smaller polyps (4-8 mm in diameter and 3-8 mm in height in situ) of A. remengesaui sp. n. are either connected by a poorly developed coenenchyme or may even be solitary on Antipathes . Additionally, the cnidomes of these species are different; A. hickmani does not have spirocysts in the column, while A. remengesaui sp. n. has spirocysts in the column.

Remarks.

The Antipathozoanthus remengesaui sp. n. specimens found in Kagoshima, Japan have different morphological features compared to the specimens found in all other regions. Specimens collected from Kagoshima have relatively large polyps (6-8 mm in diameter, and approximately 5-8 mm in height in situ) compared to specimens from other regions. The coloration of oral disks is also different between Kagoshima and other regions; A. remengesaui sp. n. from Kagoshima has a bright brown oral disk, while those from other regions have pink oral disks. However, sequences of these specimens collected from all regions formed a monophyletic clade for all genetic markers including ITS-rDNA. In terms of substrate organisms, A. remengesaui sp. n. collected from all regions in this study was associated with black corals of the genus Antipathes . Here, we have described this group as a single species, A. remengesaui sp. n., based on phylogeny and substrate specificity, although we have excluded some specimens for which we could not amplify ITS-rDNA successfully from the type series.

Etymology.

Antipathozoanthus remengesaui sp. n. is named after Tommy Esang Remengesau, Jr., the current president of the Republic of Palau, who has greatly contributed to marine research and conservation in Palau.

Common name. Momoiro-mame-tsuno-sunaginchaku (new Japanese name).