THE RAFFLES BULLETIN OF ZOOLOGY 2010 THE RAFFLES BULLETIN OF ZOOLOGY 2010 58(1): 1–13 Date of Publication: 28 Feb.2010 © National University of Singapore ON SOME OCTOCORALLIA (CNIDARIA: ANTHOZOA: ALCYONACEA) FROM SINGAPORE, WITH A DESCRIPTION OF A NEW CLADIELLA SPECIES Y. Benayahu Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel Email: [email protected] (Corresponding author) L. M. Chou Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, Singapore 117543 Email: [email protected] ABSTRACT. – Octocorallia (Cnidaria: Anthozoa) from Singapore were collected and identifi ed in a survey conducted in 1999. Colonies collected previously, between 1993 and 1997, were also studied. The entire collection of ~170 specimens yielded 25 species of the families Helioporidae, Alcyoniidae, Paraclcyoniidae, Xeniidae and Briareidae. Their distribution is limited to six m depth, due to high sediment levels and limited light penetration. The collection also yielded Cladiella hartogi, a new species (family Alcyonacea), which is described. All the other species are new zoogeographical records for Singapore. A comparison of species composition of octocorals collected in Singapore between 1993 and 1977 and those collected in 1999 revealed that out of the total number of species, 12 were found in both periods, whereas seven species, which had been collected during the earlier years, were no longer recorded in 1999. Notably, however, six species that are rare on Singapore reefs were recorded only in the 1999 survey and not in the earlier ones. It is not yet clear whether these differences in species composition indeed imply changes over time in the octocoral fauna, or may refl ect a sampling bias. The inclusion of octocorals in Singapore reef-monitoring programs will undoubtedly shed light on possible temporal changes in their species composition. The fi ndings do indicate, however, that the fl eshy octocoral fauna of Singapore is rather impoverished compared to other reefs in the region. KEY WORDS. – Cnidaria, Octocorallia, Alcyonacea, new species, Cladiella, new records, coral reefs, Singapore. INTRODUCTION Taxonomic studies of the Singapore Octocorallia are relatively limited in number and deal mainly with gorgonians Singapore consists of a main island and over 60 small (sea fans and sea whips: see Fabricius & Alderslade, 2001). offshore islands with fringing and patch-reefs. The marine These studies were initiated by Verrill (1864) and Studer environment is an important resource that supports one of (1880), who recorded Mopsella elongata and Juncella the world’s busiest ports and one of the largest oil refi neries gemmacea, respectively. Shann (1912) listed for Singapore 11 (Chou, 2006). Close to 60% of the total coral reef areas of species, among which four were new ones, of the following Singapore has been lost through foreshore land reclamation, families: Alcyoniidae (one species), Telestidae (one species), while the remaining reefs are exposed to stress from the high Nephthyidae (four species), Siphonogorgiidae (one species), sediment load (Chou, 1996; Dikou & van Woesik, 2006) Sclerogorgiidae (one species) and Melitodidae (three species). and concerns have been raised regarding the conservation To date, Shann’s study is the only taxonomic account to of these reefs (Todd & Chou, 2005; Chou & Tun, 2007). A have dealt with the fl eshy octocorals (families Alcyoniidae mass bleaching event occurred in 1998 on a scale previously and Nephtheidae) from Singapore. Following a gap of 82 unknown (http://coralreef.nus.edu.sg/; Tun et al., 2004) years, a preliminary survey of the gorgonian octocoral fauna affecting 50% to 90% of reef organisms, including Sinularia of Singapore was published by Goh & Chou (1994), which octocorals (family Alcyoniidae), which suffered particularly revealed six families, comprising at least 11 genera and 21 high mortality rates. species. That study concluded that the gorgonian taxonomy for the region is in a poor state and therefore species identifi cation is uncertain. Based on these fi ndings and also combined with 1 Benayahu and Chou: Octocorallia (Alcyonacea) from Singapore newly collected material, Goh & Chou (1996) published an The present study deals with octocorals from Singapore of the annotated checklist of the gorgonians of Singapore, totaling families Helioporidae, Alyconiidae, Paralcyoniidae, Xeniidae 31 species of 12 genera and six families (Anthothelidae: and Briareidae. It provides for the fi rst time a systematic list Solenocaulon; Subergorgiidae: Subergorgia; Melithaeidae: of octocorals of these families for the area and describes Melithaea, Mopsella and Acabaria; Acanthogorgiidae: Cladiella hartogi, new species. It also compares the fl eshy Acanthogorgia; Plexauridae: Echinomuricea, Astrogorgia, octocoral fauna recorded in the current survey (1999) to the Echinogorgia and Euplexaura; and Ellisellidae: Junceella previous ones (1993–1997). and Ctenocella. Notably, that study identifi ed to species level only part of the specimens. Later, Ofwegen et al., (2000) dealt with species of the family Melithaeidae in Singapore MATERIALS AND METHODS and identifi ed four species of the genera Melithaea, Mopsella and Acabaria, also with reference to Shann (1912). Several During Jul.1999 collections were conducted by us from studies have dealt with other aspects of Singapore gorgonians the following sites: Pulau [=Island] Hantu; Pulau Satumu, other than their taxonomy, such as distribution (Goh & Chou, Raffles Lighthouse; Terumbu Pempang Laut; Raffles 1994), annual growth rate (Goh & Chou, 1995), zonation Marina; Terumbu Pempang Tengah (artifi cial reef site); and (Goh et al., 1997), associated fauna (e.g., Goh et al., 1999) The Sisters (Fig. 1). These sites were reached by boat. An and bioactivity (e.g., Koh et al., 2000, 2002). Recently, examination of a variety of niches was carried out by scuba Goh et al. (2009) identifi ed the following octocoral genera diving, and samples were obtained at a maximal depth of 4–6 from Singapore: Carijoa, Cladiella, Sinularia, Lobophytum, m. At the artifi cial reef site at Terumbu Pempang Tengah, Sarcophyton, Stereonephthya and Nephthea, and indicated the survey included concrete modules and tyre structures the high abundance of the family Alcyoniidae and the lack of and samples were obtained down to its maximal depth knowledge on the species diversity of the fl eshy octocorals. of 14 m. During the nine day-long survey, 14 dives were Furthermore, that study demonstrated high levels of toxicity conducted, each lasted 60–80 minutes and approximately in extracts of Sarcophyton spp. and Cladiella spp. collected 90 samples were collected of the octocoral taxa found at the in Singapore reefs. various sites. Prior to collection some of the colonies were Fig. 1. Map of Singapore showing location of the study sites. 2 THE RAFFLES BULLETIN OF ZOOLOGY 2010 Table 1. List of species of Octocorallia of the orders Helioporacea Bock, 1938, and Alcyonacea (Lamouroux, 1816) from Singapore with indication of inventory numbers of Raffl es Museum of Biodiversity Research (ZRC) and of Zoological Museum Tel Aviv University (ZMTAU Co), collection sites and date of collection. Previous ZRC numbers of material deposited at Tel Aviv University are given in square brackets. Classifi cation Helioporidae Blainville, 1830 Genus Heliopora Moseley, 1786 Heliopora coerulea (Pallas, 1766) 6 colonies (ZRC 1999.2280), Pulau Satumu (Raffl es Lighthouse), coll. Y. Benayahu, 15 Jul. 1999; 1 colony (ZMTAU Co 34544) [ZRC 1999.2282], Sisters, coll. Y. Benayahu, 19 Jul. 1999; 3 colonies (ZRC 1999.2282), Sisters, coll. Y. Benayahu, 19 Jul. 1999. Alcyoniidae Lamouroux, 1912 Genus Cladiella Gray, 1869 Cladiella hartogi, new species Holotype (ZRC 1999.2256), Terumbu Pempang Tengah, 2–4 m, coll. Y. Benayahu, 14 Jul.1999. Paratypes: 1 colony (ZRC 1999.1065), Pulau Hantu (north side of island), reef fl at, coll. S. L. M. Teo & C. S. C. Lee, 30 May 1994; 1 colony (ZMTAU Co 34539) [ZRC 1999.2207], Pulau Hantu, 1 m, coll.Y. Benayahu, 6 Jul. 1999;1 colony and 2 fragments (ZRC1999.2207), Pulau Hantu, 1 m, coll. Y. Benayahu, 6 Jul.1999; 1 colony (ZMTAU Co 34540) [ZRC 1999.2221], Pulau Hantu, 1–4 m, coll. Y. Benayahu, 9 Jul.1999; 1 colony (ZRC 1999.2221), Pulau Hantu, 1–4 m, coll. Y. Benayahu, 9 Jul.1999; 1 colony (ZMTAU Co 34537) [ZRC 1999.2223], Pulau Hantu, 1–4 m, coll. Y. Benayahu, 9 Jul.1999; 2 colonies (ZRC 1999.2223), Pulau Hantu, 1–4 m, coll. Y. Benayahu, 9 Jul.1999; 1 colony (ZMTAU Co 34541) [ZRC 1999.2231], Pulau Hantu, 1–2 m, coll. Y. Benayahu, 9 Jul.1999; 2 colonies (ZRC1999.2231), Pulau Hantu, 1–2 m, coll. Y. Benayahu, 9 Jul.1999; 1 colony (ZMTAU Co 34536) [ZRC 1999.2232], Terumbu Pempang Laut, (patch reef), 2–6 m, coll. Y. Benayahu, 12 Jul.1999; 2 colonies (ZRC 1999.2232), Terumbu Pempang Laut, (patch reef), 2–6 m, coll. Y. Benayahu, 12 Jul.1999; 1 colony (ZRC 1999.2255), Terumbu Pempang Tengah, 2–6 m, coll. Y. Benayahu, 14 Jul.1999; 1 colony (ZMTAU Co 34535) [ZRC 1999.2262], Pulau Satumu (Raffl es Lighthouse), 3-6 m, coll. Y. Benayahu, 15 Jul.1999; 1 colony (ZRC 1999.2262), Pulau Satumu (Raffl es Lighthouse), 3-6 m, coll. Y. Benayahu, 15 Jul.1999; 1 colony (ZRC 1999.2266), Pulau Satumu (Raffl es Lighthouse), 3-6 m, coll. Y. Benayahu, 15 Jul.1999; 1 colony (ZMTAU Co 34538) [ZRC 1999.2281], Sisters Reef, 2-3 m, coll. Y. Benayahu, 19 Jul., 1999; 2 colonies (ZRC 1999.2281), Sisters Reef, 2-3 m, coll. Y. Benayahu, 19 Jul., 1999. Cladiella pachyclados (Klunzinger, 1887) 1 colony (ZRC 1999.1042), Pulau Semakau, coll. S.L.M. Teo & H. C. Tay, 7 Jun. 1995; 1 colony (ZRC 1999.1090), Pulau Semakau, west side of Is., coll. S.L.M. Teo, 20 Apr. 1995; 3 colonies (ZRC 1999.2259), Pulau Satumu (Raffl es Lighthouse), coll. Y. Benayahu, 15 Jul. 1999; 1 colony (ZRC 1999.2267), Pulau Satumu (Raffl es Lighthouse), coll.