Palythoa cf. mutuki (Haddon & Shackleton, 1891b)

Reimer, James D., Poliseno, Angelo & Hoeksema, Bert W., 2014, Shallow-water zoantharians (Cnidaria, Hexacorallia) from the Central Indo-Pacific, ZooKeys 444, pp. 1-57 : 8-9

Taxon classification Animalia Zoantharia Sphenopidae

6. Palythoa cf. mutuki (Haddon & Shackleton, 1891b) Figures 6A, B, 7

Specimens examined

(n=13): RMNH Coel 40458, harbor pier, Cebu City, Cebu, Philippines, collected in 1976 by M.L. Esmeno; RMNH Coel 40459, harbor pier, Cebu City, Cebu, Philippines, collected in 1976 by M.L. Esmeno; RMNH Coel. 40468, Rumphius Biohistorical Expedition station 29, Hitu, Ambon Bay, Ambon, Moluccas (03°38'05"S, 128°12'36"E), depth = intertidal, collected on November 28, 1990 by M.S.S. Lavaleye; RMNH Coel. 40470, Rumphius Biohistorical Expedition station 4, Leitimur, outer Ambon Bay, Wainitu, Moluccas (03°42'10"S, 128°09'15"E), depth = littoral on old shipwreck, collected on November 7-8, 1990 by H. Strack; RMNH Coel. 40475, Rumphius Biohistorical Expedition station 27, Leitimur, south coast, Hutumuri, Moluccas (03°41'50"S, 128°17'00"E), depth = intertidal, on November 26, 1990 by M.S.S. Lavaleye; RMNH Coel. 40514, Fauna Malesiana Maluku Expedition station MAL.15, Ambon Bay, south coast, cape west of Amahusu, Moluccas (03°44'S, 128°08'E), collected on November 16, 1996; RMNH Coel. 40528, Snellius–II Expedition station 4.096, northeast Komodo, Komodo (08°29'S, 119°34'E), depth = to 30 m, collected on October 26, 1984; RMNH Coel 40532, NNM–LIPI–WWF Bali–Lombok Strait 2001 Expedition station BAL.09, Loloan Batu Agung, Sanur, eastern Bali (08°43'31"S, 115°15'57"E), depth = 10 to 15 m, collected on April 3, 2001 by B.W. Hoeksema; RMNH Coel. 40540, Snellius–II Expedition station 4.010, near Tawiri, Ambon Bay, Moluccas (03°42'S, 128°07'E), depth = 1 to 5 m, collected on September 5, 1984; RMNH Coel. 40559, Snellius–II Expedition sta 4.012, north Pulau Mai, Maisel Islands, Banda Sea (05°28'S, 127°31'E), depth = 0 to 1.5 m, collected on 07.09.1984; RMNH Coel. 40561, Snellius–II Expedition station 4.133, east Pulau Tarupa Kecil, Taka Bone Rate (06°29'S, 121°08'E), depth = 11 m, collected on September 26, 1984; RMNH Coel. 40562, Snellius–II Expedition station 4.096, northeast Komodo, Komodo (08°29'S, 119°34'E), depth = to 30 m, collected on September 20, 1984; RMNH Coel. 40741, Rumphius Biohistorical Expedition station 11, Leitimur, Tanjung Nasaniwe, Moluccas (03°47'10"S, 128°05'20"E), depth = littoral, collected on November 12, 1990;

Photographic records

(n=2). Main coast, West Bali (08°06'50"S, 114°30'40"E), May 22, 1998; west Pulau Bone Batang, South Sulawesi, Spermonde Archipelago (05°01'00"S, 119°19'15"E), October 22, 1997.

Description.

Originally described from the Torres Strait, Australia, this species was redescribed in detail in Ryland and Lancaster (2003).

Although all specimens in this grouping match with previously reported Palythoa mutuki based on sizes (average polyp height 9.6 mm, range 3-31 mm, average width 4.8 mm, range 2-8 mm, n=12 specimens) and overall morphology ( ‘intermediae’ or ‘liberae’ [ Pax 1910]; visible capitulary ridges on closed polyps [ Ryland and Lancaster 2003]) (Figure 6B), we have identified all specimens in this study as “cf.”. Recent work has shown the presence of more than two closely related species groups within Palythoa mutuki ( Reimer et al. 2006b, 2013a) that are exceedingly difficult to distinguish without molecular data. For this reason, we have preliminarily assigned “cf.” to these specimens.

Distribution.

Regions recorded in this study (Figure 7). West Bali (4), eastern Bali (5), Komodo Island (8), Spermonde Archipelago (9), Taka Bone Rate (11), Maisel Islands (13), Moluccas (14), Cebu (21).

Previous records. Ryland and Lancaster (2003) in their treatment of Palythoa mutuki also mentioned records from Fiji, and synonymized records of other species from Tuvalu ( Gemmaria willeyi Hill & Whitelegge, 1898), eastern Australia ( Gemmaria arenacea Wilsmore, 1909; Palythoa yongei Carlgren, 1937; Palythoa australiensis Carlgren, 1950) and Singapore ( Palythoa singaporensis Pax & Müller, 1956) with this species. However, asides from the specimens directly examined by Ryland and Lancaster, there is much confusion over the true identity of these species. For example, Ryland and Lancaster (2003) themselves state that Gemmaria willeyi is likely a Zoanthus species based on the figures in the original description. Ryland and Lancaster state "Probably only the use of genetic methods, so successfully applied by Burnett et al. (1997), will settle identities over wide geographic areas".

However, in the Pacific, records of this species with phylogenetic confirmation have previously been reported from the Great Barrier Reef in Australia ( Burnett et al. 1997), Singapore ( Reimer and Todd 2009), to the south Pacific coast of Japan (e.g. Reimer et al. 2006b, 2007b), New Caledonia ( Sinniger 2006), and across to the Galapagos ( Reimer and Hickman 2009), and thus it is known that this species has a very wide Indo-Pacific distribution.

Remarks.

This species is likely common in Indonesia as in other regions such as Okinawa ( Irei et al. 2011) and Taiwan ( Reimer et al. 2011c). However, species delineation in Palythoa is confused due to the close phylogenetic relationships between Palythoa mutuki , Palythoa tuberculosa , and some other undescribed species, and a potential reticulate evolutionary history ( Reimer et al. 2007b, Shiroma and Reimer 2010, M. Mizuyama and J.D. Reimer unpubl. data). Furthermore, distinguishing Palythoa mutuki , from other, more distantly related species such as Palythoa heliodiscus based solely on morphology is often difficult ( Ryland and Lancaster 2003). For this study, we have included all " Palythoa mutuki -like" specimens as one species group for convenience, although it is likely the specimens will encompass more than one species once the taxonomy of this genus is clarified.