Anim. Syst. Evol. Divers. Vol. 32, No. 3: 197-206, July 2016 http://dx.doi.org/10.5635/ASED.2016.32.3.028 Review article New Records of Cold-Water Corals from Korea Jun-Im Song* College of Natural Sciences, Ewha Womans University, Seoul 03760, Korea ABSTRACT Two cold-water coral taxa, Octocorallia in the class Anthozoa and Stylasteridae in the class Hydrozoa, were identified. Deep-water samples were collected in fishing nets at depths ranging between 20 and 200 m along the coasts of the East Sea in Korea from 1976 to 1993. The two species found in this study represent new records for Korea: Paragorgia arborea (Linnaeus, 1758) in the class Anthozoa, and Stylaster profundiporus Broch, 1936 in the class Hydrozoa. Two families, Paragorgiidae and Stylasteridae, are also newly recorded in Korea. Furthermore, the species name of another cold-water gorgonian species, Primnoa pacifica (Kinoshita, 1907) in the family Primnoidae, is amended in this report. The two newly recorded cold-water coral species from Korea are described in detail based on their morphological characteristics. Paragorgia arborea is characterized by its growth form, medulla and cortex, zooid dimorphism, canal system, and spicule composition. Stylaster profundiporus is distinguished by its external skeletal characteristics, such as the coordination of dactylopores and gastropores, presence or absence of gastrostyles and dactylostyles, cyclosystem orientation, ampullar position, gastropore tube shape, and coenosteal texture. Keywords: deep-sea corals, Paragorgiidae, Primnoidae, Stylasteridae, Korea INTRODUCTION in the ocean (Sánchez, 2005), and are broadly distributed, occurring as deep as 4,152 m (Freiwald et al., 2004; Roberts The distribution of five cold-water coral taxa (Scleractinia, et al., 2009). While the medulla of these corals is not well Zoanthidae, Antipatharia, Octocorallia, Stylasteridae) is in- consolidated, it contains a dense concentration of calcareous fluenced by various environmental factors, including depth, spicules that are bound by strands of gorgonin. Furthermore, slope, temperature, substratum, and current velocity (Frei- the medulla is not separated from the cortex by a ring of wald et al., 2004; Roberts et al., 2009). The specific morphol- boundary canals (Dunn, 1982). There are two genera of ogical characteristics of Octocorallia in the class Anthozoa paragorgids, Paragorgia and Sibogagorgia. The genus and Stylasteridae in the class Hydrozoa that have developed Paragorgia is distinguished from the genus Sibogagorgia by in response to the cold-water conditions are reviewed below. the presence of polyp sclerites and medullar canals (Sánchez, Two gorgonian families of the class Anthozoa, specifical- 2005). The genus Paragorgia contains 15 species according ly, Paragorgiidae within the suborder Scleraxonia and to the World Register of Marine Species (van Ofwegen, Primnoidae within the suborder Calcaxonia, are well known 2010a), including Paragorgia arborea. Paragorgia arborea as cold-water coral taxa. These octocorals have a certain is a cold-water gorgonian species that is characterized by its degree of flexibility, with their non-rigid internal axis allow- growth form, medulla and cortex, zooid dimorphism, canal ing them to bend with water currents. This characteristic is system, and spicule composition. not found in the Scleractinia or Stylasteridae (Roberts et al., Five species of primnoids from the family Primnoidae have 2009). been recorded in Korea (Song, 1981, 2004): Primnoa reseda The paragorgids or “bubblegum corals” of the family Par- pacifica (Kinoshita, 1907), Callogorgia pseudoflabel lum agorgiidae have dimorphic polyps, and are among the largest Bayer, 1949, Plumarella spinosa Kinoshita, 1907, P. rigida corals (up to 10 m in height). These corals represent the most Kükenthal and Gorzawsky, 1908, and P. adhaerans Nutting, ecologically important sessile benthic deep-water organisms 1912. The other cold-water gorgonian species, Prim noa This is an Open Access article distributed under the terms of the Creative *To whom correspondence should be addressed Commons Attribution Non-Commercial License (http://creativecommons.org/ Tel: 82-2-3277-2364, Fax: 82-2-3277-2385 licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, E-mail: [email protected] and reproduction in any medium, provided the original work is properly cited. pISSN 2234-6953 eISSN 2234-8190 Copyright The Korean Society of Systematic Zoology Jun-Im Song pacifica (Kinoshita, 1907) in the present study, was reported of tissue from each body part was dissolved in a diluted in Korea as P. reseda pacifica by Song (1981). According solution of Clorox for 5 min. to the World Register of Marine Species (van Ofwegen, Before fixation, the specimens were photographed using 2010b), the genus Primnoa contains 6 species, including P. a digital camera (G7; Canon, Tokyo, Japan). Photographs pacifica. of the arrangement of the polyps and branches, as well as One family of the class Hydrozoa, the Stylasteridae or cyclosystem orientation, were taken using two separate ster- “hydrocorals” within the order Stylasterina, is the second eomicroscopes (Semi SV-11; Carl Zeiss and S8APO; Leica) most species-rich of the 77 hydrozoan families. This family mounted with two different digital cameras respectively contains 224 valid species, including 24 exclusively fossil (5060-WZ; Olympus, Tokyo, Japan and DFC 290; Leica). species. Some stylasterid species have commercial value in The sizes and intervals of the polyps and cyclosystems were jewelry manufacturing. Consequently, all stylasterids are then measured using an image analyzer (LAS Version 3.6; listed in Appendix II of the Convention on International Trade Leica). Images of sclerites were taken using a light micro- in Endangered Species of Wild Fauna and Flora (CITES) in scope (Eclipse 80i; Nikon) mounted with a camera (DS-5Mc; 1990 (Cairns, 2011a). Nikon). Then, the sizes of sclerites were determined using an The stylasterids or “lace corals” are a significant cold-water image analyzer (NIS-Elements BR 3.0; Nikon). In addition, taxon. They are fragile, usually small, uniplanar to slightly an image editing program (HeliconFocus 5.1 Pro; Helicon arborescent colonial hydrozoans of the phylum Cnidaria. Soft, Kharkov, Ukraine) was used to create a single comple- This taxon is distributed from the Antarctic to the Arctic cir- tely focused image of a sclerite from several partially focus- cle and occurs at depths ranging from 0 to 2,789 m (Cairns, ed images by combining the focused areas. 2011a). The genus Stylaster contains 97 valid species and Close observation of the cyclosystems and coenosteal includes 24 fossil species, with 153 records matching the texture was achieved using a scanning electron microscope species in the World Register of Marine Species (Cairns, (Model JSM 35CF; JEOL, Tokyo, Japan) at 25 kV accelera- 2010). The stylasterids have dimorphic polyps that are cha- ting voltage. An ion sputter (Model JFC-1000; JEOL) was racterized by the coordination of dactylopores and gastro- used for gold coating. pores, presence or absence of gastrostyles and dactylostyles, For identification and classification, the generic revision cyclosystem orientation, ampullar position, gastropore tube of the Stylasteridae by Cairns (2011a) and the systematic shape, and coenosteal texture (Cairns, 1992). revision of the Paragorgiidae by Sánchez (2005) were used, This study provides a detailed description of two new along with the review of phylogenetic patterns in the phy- records of cold-water corals from Korea based on their mor- lum Cnidaria by Daly et al. (2007). Some of the samples phological characteristics, Paragorgia arborea of the class examined in this study were deposited in the Korean Coral Anthozoa and Stylaster profundiporus of the class Hydrozoa. Resource Bank (KCRB), while other samples were housed in the Natural History Museum, Ewha Womans University, Seoul, South Korea. MATERIALS AND METHODS All specimens examined in this study were collected in fish- SYSTEMATIC ACCOUNTS ing nets at depths ranging between 20 and 200 m along the coasts of the East Sea, Korea, from 1976 to 1993. The speci- Phylum Cnidaria Hatschek, 1888 mens were anesthetized with menthol for 6-8 h and fixed in Class Anthozoa Ehrenberg, 1834 4%-5% (v/v) formalin with seawater. The specimens were Subclass Octocorallia Haeckel, 1866 then washed with tap water and preserved in 70% alcohol (v/ Order Alcyonacea Lamouroux, 1816 v). Suborder Scleraxonia Studer, 1887 For identification, the internal and external morphological characteristics of each specimen were examined using ste- Diagnosis. Colonies with an axis or internal axial-like layer reomicroscopes (Semi SV-6 and SV-11; Carl Zeiss, Jena, (medulla) composed predominantly of sclerites that are Germany; and S8APO; Leica, Wetzlar, Germany) and a light either unfused or fused with calcite. Medulla contains endo- microscope (Eclipse 80i, Nikon, Tokyo, Japan). Characteris- dermal canals and solenia, without a central cord. Colonies tics included growth form, branching pattern, size of each generally cylindrical, composed of two layers separated by part of the colony, arrangement of polyps on stems and bran- a ring of longitudinal boundary canals. Proximal portion of ches, coloration, and shape and size of sclerites in the polyps polyps embedded in coenenchyme (cortex) with endodermal and coenenchymes. To examine the sclerites, a small piece canals and solenia. 198 Anim. Syst. Evol. Divers. 32(3),