Zoological Studies 50(3): 363-371 (2011) Shallow-Water Brachycnemic Zoanthids (Cnidaria: Hexacorallia) from Taiwan: A Preliminary Survey James D. Reimer1,2,*, Masami Obuchi1, Yuka Irei3, Takuma Fujii3, and Yoko Nozawa4 1Molecular Invertebrate Systematics and Ecology Laboratory, Rising Star Program, Transdisciplinary Research Organization for Subtropical Island Studies (TRO-SIS), Univ. of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan 2Marine Biodiversity Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima, Yokosuka, Kanagawa 237-0061, Japan 3Molecular Invertebrate Systematics and Ecology Laboratory, Graduate School of Marine Science, Univ. of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan 4Biodiversity Research Center, Academia Sinica, Nankang, Taipei 115, Taiwan (Accepted December 9, 2010) James D. Reimer, Masami Obuchi, Yuka Irei, Takuma Fujii, and Yoko Nozawa (2011) Shallow-water brachycnemic zoanthids (Cnidaria: Hexacorallia) from Taiwan: a preliminary survey. Zoological Studies 50(3): 363-371. Zoanthids are benthic cnidarians commonly seen in shallow coral reef and subtropical marine ecosystems, and are increasingly being utilized as research subjects for marine products and biodiversity studies. However, their distributions and overall species diversity remain relatively unknown except for in a few regions of the world, including southern Japan. Here, for the 1st time, the shallow-water diversity of zoanthids of the suborder Brachycnemina, which primarily includes zooxanthellate species, was examined in Taiwanese waters. Species diversity surveys conducted at coral reef (Kenting and Lyudao) and non-reefal (Keelung) locations revealed 12 zoanthid species (Acrozoanthus australiae, Isaurus tuberculatus, Zoanthus gigantus, Z. kuroshio, Z. sansibaricus, Z. aff. vietnamensis, Palythoa heliodiscus, P. mutuki, P. tuberculosa, Palythoa sp. tokashiki, unknown Palythoa spp., and another unknown zoanthid), most of which are new records for Taiwan. All 3 locations had totals of 7-10 species present, with the 2 coral reef locations resembling locations with coral reefs in Okinawa (e.g., by the presence of Z. kuroshio, P. heliodiscus, Palythoa sp. tokashiki), while the zoanthid community at Keelung was more similar to zoanthids observed at subtropical Shikoku, Japan (e.g., by the presence of Z. aff. vietnamensis and large Z. gigantus colonies). It is possible that the unknown Palythoa specimens constitute 1 or more species new to science, and further investigation of these zoanthids is needed. It is hoped that the species lists provided in this study will help provide a basis for future zoanthid research in Taiwan. http://zoolstud.sinica.edu.tw/Journals/50.3/363.pdf Key words: Taiwan, Kuroshio Current, Biodiversity, Zoanthid. Z oanthids are a hexacorallian order unique to zoanthids. Zoanthids are found in most (Zoantharia, Zoanthidea) of benthic cnidarians environments from shallow tropical coral reefs characterized by having 2 rows of tentacles, (Burnett et al. 1997) to cold seeps in the deep sea and are usually colonial, with individual polyps (Reimer et al. 2007). connected by a coenenchyme, or common tissue, Although often common in many ecosystems, similar to many hard coral species. Additionally, the taxonomy of zoanthids has historically been most zoanthids have sand and/or other detritus chaotic due to difficulty in correct identification, encrusted within their mesoglea to help provide caused by large amounts of intraspecific variation strength and structure, an unusual strategy (Burnett et al. 1997, Reimer et al. 2004), a lack of * To whom correspondence and reprint requests should be addressed. Tel: 81-98-8958542. Fax: 81-98-8958577. E-mail:[email protected] 363 364 Zoological Studies 50(3): 363-371 (2011) viable morphological characteristics that are easily 2009), and thus it very likely that many zoanthid examined, and difficulty in internal examinations species are present in these areas. As a neighbor due to sand encrustation (Reimer et al. 2010b). to Japan and connected by the Kuroshio Current, Thus, knowledge of the diversity and biogeography an understanding of brachycnemic zoanthid of zoanthids is relatively scant compared to diversity in Taiwan is critical to achieving a more related hexacorallian orders such as hard corals complete understanding of their biodiversity and (Scleractinia) and anemones (Actinaria). biogeography in the northwestern Pacific. Thus, Shallow-water tropical and subtropical a survey of brachycnemic zoanthid biodiversity zoanthids of the suborder Brachycnemina are was cooperatively carried out by the Univ. of ubiquitous in coral reef ecosystems, and often form the Ryukyus (UR), Japan and the Biodiversity large colonies on intertidal and shallow reef crests Research Center, Academia Sinica, Taipei, Taiwan (Karlson 1980). This suborder is distinguished at 3 different locations in Taiwan (2 coral reefs and from the other zoanthid suborder, Macrocnemina, 1 non-reef coral community) to create a preliminary by the status of the 5th mesentery from the dorsal species list. Herein, we report on the initial results directive, which is complete in Macrocnemina of that survey. and incomplete in Brachycnemina (see figure 2 in Reimer et al. 2010b). The Brachycnemina includes 3 families. The family Sphenopidae is sand- MATERIALS AND METHODS encrusted, and includes the colonial zooxanthellate Palythoa, and the unitary Sphenopus known only Surveys of zoanthids in Taiwan were carried from a handful of species. Neozoanthidae is out in Sept. 2009-Sept. 2010 by snorkeling and monogeneric and monospecific and known only scuba diving. Three different locations were from Madagascar, although other unidentified investigated (Fig. 1): (1) Wanlitung, Tiaoshi, and specimens point to a Pacific distribution (Reimer at Kenting, southern Taiwan (sampling permission 2010). The 3rd family, the Zoanthidae, is the only #989094/1400), which are coral reef ecosystems; zoanthid taxa that does not utilize encrustation, (2) Gueiwan, Gongguan, Shihlang, Dabaisha, and and includes 3 genera, Acrozoanthus, Isaurus, and Matichao at Lyudao (also known as Green I., off Zoanthus. Palythoa and Zoanthus in particular the southeastern coast of Taiwan) which are coral are the most speciose genera, are quite common reef ecosystems; and (3) Yehliu and Bitouchiao at on coral reefs, and are popular items in the pet Keelung, northeastern Taiwan, which are primarily industry, as well as subjects for research into subtropical non-reefal coral communities (Chen palytoxin (Palythoa) (Moore and Scheuer 1971) 1999, Chen and Shashank 2009). and fluorescent proteins (Zoanthus) (Labas et al. Specimens were photographed in situ prior to 2002). collection, and images were used to characterize Recently, much research focused on the external morphological features. Species were distribution of brachycnemic zoanthids in Japan identified primarily following Reimer (2010), with (Reimer 2007 2010, Ono et al. 2008), and know- Acrozoanthus specimens identified following ledge of their diversity and biogeography for this Ryland (1997). Specimens were preserved in region, while far from complete, exists at basic 70% or 99.5% ethanol, and examined at the UR. levels. However, data from surrounding regions Currently, specimens are deposited at the 1st remain scarce. Taiwan is located directly to the author’s laboratory at the UR, but once molecular south of the Ryukyu/Nansei chain of islands in examinations are completed, specimens will be southern Japan, and the east coast of this island is deposited in the National Museum of Natural also influenced by the warm Kuroshio Current. Science (NMNS), Taichung, Taiwan. Historically, there is almost no information or records in the literature on zoanthids from Taiwan, except for an excellent examination RESULTS of Sphenopus by Soong et al. (1999) and an examination of nitrogen fixation-utilizing P. Results of the surveys are summarized in tuberculosa collected from Kenting (Shieh and table 1. A dichotomous key to the majority of the Lin 1992), and there are no data on zoanthid species found in Taiwan is given in Reimer (2010). species diversity. However, coral reef and non- Nomenclature used is sensu Reimer (2010) unless reefal coral communities were described at many otherwise noted. sites in Taiwan (Chen 1999, Chen and Shashank Reimer et al. – Zoanthids in Taiwan 365 Species diversity by location Similarly, at both Lyudao (coral reef) and Keelung (non-reefal), 7-10 species of zoanthids At Kenting (coral reef) in southern Taiwan, were confirmed from images and sampling (Table 7 brachycnemic zoanthid species were recorded 1). At Lyudao, Z. sansibaricus, Z. kuroshio, Z. (Table 1), and specimens were collected for 6 of aff. vietnamensis, Z. gigantus, A. australiae, P. these. The presence of Zoanthus sansibaricus, tuberculosa, P. mutuki, P. heliodiscus, Palythoa Z. kuroshio, Acrozoanthus australiae (detailed in sp. tokashiki, and 1 or 2 potentially undescribed Reimer et al. 2010a), Isaurus tuberculatus (images Palythoa species were noted; while at Keelung only), P. tuberculosa, P. mutuki, and Palythoa sp. Z. sansibaricus, Z. aff. vietnamensis, Z. gigantus, tokashiki was confirmed in this area. I. tuberculatus (images only), P. tuberculosa, P. East China N CHINA Sea Keelung Quanzhou JAPAN Taipei Taiwan Strait Iriomote- jima Kuroshio Ishigaki- Current jima Penghu Is. TAIWAN Tropic of Cancer Lyudao Kenting South China Sea