On Some Octocorallia (Alcyonacea) from Hong Kong, with Description of a New Species, Paraminabea rubeusa1 Y. Benayahu2,4 and K. Fabricius3 Abstract: Octocorals from Hong Kong were studied at 18 sites down to a depth of 25 m in 1999. The collection of @90 specimens yielded nine species distrib- uted in seven genera of the families Alcyoniidae, Nephtheidae, and Xeniidae (all are new zoogeographical records for Hong Kong), plus ca. 70 samples of azoo- xanthellate octocorals of the genera Dendronephthya (family Nephtheidae), Chiro- nephthya, and Nephthyigorgia (family Nidaliidae), which were not identified to species level. The collection included Paraminabea rubeusa Benayahu & Fabri- cius, n. sp., which is described here. The impoverished nature of the zooxan- thellate octocorals is reflected in the low number of species found in the families Alcyoniidae and Xeniidae (seven and one, respectively), families that typically contribute a high proportion of species in the Indo-Pacific region. It is crucial to implement effective conservation policies in Hong Kong to preserve its remaining zooxanthellate octocoral species and thereby prevent the local ex- tinction of these species, including the newly described Sarcophyton tumulosum Benayahu & Ofwegen, 2009, and Lobophytum mortoni Benayahu & Ofwegen, 2009, which may be endemic to the region. Hong Kong (latitude 22 N) represents a Kong have been studied extensively and are marginal environment for corals within the considered subtropical formations (e.g., Clark South China Sea (Morton and Blackmore 1998, McCorry 2002, Lam et al. 2007, and 2001). Its coral communities are nonreef- references therein). Notably, coral cover has building communities, due to winter seawater declined to low levels in several areas, appar- temperature minima averaging 17C (with ently due to impaired coral recruitment occasional brief drops to 14–16C in surface (McCorry 2002). waters), and freshwater intrusions frequently Taxonomic studies of the Hong Kong Oc- reducing salinity. Furthermore, the reefs of tocorallia have recently been reviewed by Hong Kong are affected by a variety of Lam and Morton (2008). Those studies were anthropogenic perturbations that have led initiated in 1854 during the North Pacific Ex- to their gradual deterioration (e.g., Morton ploring Expedition by Stimpson (1855), who 1994, 2002). The stony corals of Hong described the new species Nephthya coccinea, which was placed in Echinomuricea by Nutting (1910). They were followed by Verrill 1 Manuscript accepted 1 February 2009. (1865a,b), who identified and described a 2 Department of Zoology, George S. Wise Faculty of further six new species from the specimens Life Sciences, Tel Aviv University, Ramat Aviv 69978, collected earlier by Stimpson. Later, Shen Tel Aviv, P.O.B 39040, Israel. (1940) described Dendronephthya sp. and 3 Australian Institute of Marine Science (AIMS), Nephthya sp. from Hong Kong. After a gap PMB No. 3, Townsville MC, Queensland 4810, Austra- lia. of 40 yr in the study of octocorals from the 4 Corresponding author: (phone: 972-3-6409090; fax: area, Zou and Scott (1982) surveyed the gor- 972-3-6409403; e-mail: [email protected]). gonians from the northeastern part of Hong Kong, recording a total of 26 species belong- ing to 15 genera and six families: Antho- Pacific Science (2010), vol. 64, no. 2:285–296 doi: 10.2984/64.2.285 thelidae (one species), Subergorgiidae (two : 2010 by University of Hawai‘i Press species), Acanthogorgiidae (three species), All rights reserved Paramuriceidae (12 species), Plexauridae (five 285 286 PACIFIC SCIENCE . April 2010 species), and Ellisellidae (three species). Based materials and methods on a collection conducted in Hong Kong dur- ing 1980, Li (1986) recorded the families Al- Collection of material was conducted during cyoniidae (six species) and Nephtheidae (four November 1999 and comprised the following species), all of which were new records from 18 sites in Hong Kong: Bokhara Rocks (22 China. Based on a collection carried out in 13 0 25.71 00 N, 114 16 0 45.0900 E); Tai Tau 1995, Clark (1997) listed several octocorals Chau (Shek O) (22 13 0 56.63 00 N, 114 15 0 in the Cape d’Aguilar Marine Reserve (Hong 10.1900 E); Sham Wan (22 23 0 05.5900 N, Kong) in the families Paramuriceidae (nine 114 08 0 30.49 00 E); Pak Shau (Round Island) species), Telestidae (one species), Plexauridae (22 32 0 25.4500 N, 114 19 0 51.5800 E); Tsung (three species), Ellisellidae (two species), and O Wan ( Junk Bay) (22 16 0 39.4800 N, 114 Alcyoniidae (two species), including two new 15 0 12.45 00 E); Kung Chau (22 28 0 56.9100 N, records for the region. Based on a survey con- 114 220 14.1800 E); Ping Chao (22 32 0 22.30 00 ducted in 1999 on the shallow reefs of Hong N, 114 23 0 31.32 00 E); Breakers Rock (22 28 0 Kong, Fabricius and McCorry (2006) listed 39.5200 N, 114 50 13.72 00 E); Lo Chau Mun 42 octocoral species distributed among 23 (Po Toi Channel) (22 11 0 23.31 00 N, 114 genera of the families Alcyoniidae (six spe- 15 0 26.85 00 E); Waglan (22 11 0 02.6100 N, cies), Nephtheidae (six species), Nidaliidae 114 18 0 19.1600 E); Pak Kwo Chau (North (two species), Xeniidae (one species); Acan- Ninepin) (22 15 0 26.2300 N, 114 21 0 00.26 00 thogorgiidae (four species), Plexauridae (18 E); Nam Kwo Chau (South Ninepin) (22 species), and Ellisellidae (three species). Most 35 0 15.0500 N, 114 20 0 49.40 00 E); Fo Shek of the taxa mentioned in the study were not Chau (Basalt Island) (22 18 0 51.08 00 N, 114 identified to species level and are referred to 22 0 01.20 00 E); Long Ke Wan (22 190 12.83 00 as sp. (see table 2 of Fabricius and McCorry N, 114 22 0 58.25 00 E); Mat Chau (Po Toi) 2006). That survey presented results on the (22 10 0 12.67 00 N, 114 15 0 31.0200 E); Nam abundance of zooxanthellate and azooxan- Kok Tsui (Po Toi South) (22 12 0 12.29 00 N, thellate octocorals along the main spatial and 114 15 0 47.62 00 E); Lo Chau Pak Pai (Castle water quality gradients in Hong Kong, and Rock) (22 10 0 30.1500 N, 114 14 0 13.67 00 E); the authors concluded that the former are Luk Chau (Lamma) (22 13 0 42.43 00 N, 114 strongly affected by water clarity and that 07 0 28.4200 E) (Figure 1). their disappearance is associated with a dra- These sites were reached by boat, and a matic reduction in stony coral communities. careful examination of a variety of niches Recently, Lam and Morton (2008) reported was carried out by scuba diving down to 25 22 octocoral species from two submarine m. Approximately 90 samples were collected, caves in the oceanic southeastern waters of encompassing the variety of octocoral taxa Hong Kong, including one new species, Para- found at the various sites. Before collection minabea hongkongensis Lam & Morton, and an most of the colonies were photographed in additional 11 species that were new records situ. Samples were fixed in 4% formalin in for the region. In addition, that study pre- seawater overnight, then rinsed in freshwater, sented a list of 60 octocorals previously re- and transferred to 70% alcohol. Sclerites corded from Hong Kong. were obtained by dissolving the tissues in The study reported here deals with octo- 10% sodium hypochlorite and prepared for corals of the families Alyconiidae, Nephthei- scanning electron microscopy as follows: the dae, and Xeniidae from Hong Kong collected sclerites were carefully rinsed with double- by us in 1999. We provide a systematic list of distilled water, dried at room temperature, the species and describe a new species, Para- coated with gold, and then examined with an minabea rubeusa Benayahu & Fabricius. Nota- electron microscope ( Jeol 840A) operated bly, this collection has recently yielded two at 25 kV. Identification of species was in part other new species, Lobophytum mortoni Be- facilitated by comparisons with permanent nayahu & Ofwegen, 2009, and Sarcophyton sclerite preparations of type material kept tumulosum Benayahu & Ofwegen, 2009. in the Zoological Museum, Department of Octocorallia from Hong Kong . Benayahu and Fabricius 287 Figure 1. Map of Hong Kong showing the study sites. 1, Bokhara Rocks; 2, Tai Tau Chau (Shek O); 3, Sham Wan; 4, Pak Shau (Round Island); 5, Tsung O Wan ( Junk Bay); 6, Kung Chau; 7, Ping Chao; 8, Breakers Rock; 9, Lo Chau Mun (Po Toi Channel); 10, Waglan; 11, Pak Kwo Chau (North Ninepin); 12, Nam Kwo Chau (South Ninepin); 13, Fo Shek Chau (Basalt Island); 14, Long Ke Wan; 15, Mat Chau (Po Toi); 16, Nam Kok Tsui (Po Toi South); 17, Lo Chau Pak Pai (Castle Rock); 18, Luk Chau (Lamma). Zoology, Tel Aviv University, Israel (zmtau). results The specimens are deposited in zmtau and in Nationaal Natuurhistorisch Museum, Leiden, The examined material yielded nine species The Netherlands (rmnh). Members of the in the three families Alcyoniidae, Nephthei- families Nephtheidae and Nidaliidae are still dae, and Xeniidae (Table 1), of which three being examined. are new species (Benayahu and Ofwegen 288 PACIFIC SCIENCE . April 2010 TABLE 1 description: The holotype is an arbo- List of Species of Octocorallia of the Order Alcyonacea rescent colony, 60 mm long and 55 mm wide (Lamouroux, 1816) from Hong Kong, with Museum (Figure 2a). Its has a low base, ca. 3–6 mm Inventory Numbers (zmtau Co), RMNH Coel high, that gives rise to a number of branching primary lobes. Lobes and lobules are finger- Family Alcyoniidae Lamouroux, 1912 like, stout with tapering ends, and compose Genus Cladiella Gray, 1869 most of the total length of the colony.