The Federated States of Micronesia (FSM) consists of four island states in the North Pacific Ocean, including Pohnpei, Chuuk, Yap, and Kosrae, totaling 607 small islands (65 inhabited), extending 2,900 km across the Caroline Islands, from Kosrae in the east to Yap in the west. Chuuk is situated at about 7° 08′ and 7° 41′N latitude and 151° 26′ and 152° 2′E longitude in the western Pacific and includes 12 volcanic high islands, 24 low coral-reef islands in a lagoon enclosed by a barrier reef forming a near-atoll, and 41 low coral islands along the atoll (Rehman et al., 2013). Specific information on the echinoderm fauna of Chuuk, Micronesia has been described in reports by Kerr (1994), Kerr et al. (2007, 2008), Korea Institute of Ocean Science and Technology (KIOST, 2009), and Lee and Shin (2013). We surveyed the echinoderm fauna at one intertidal site and 16 SCUBA diving points around Chuuk and assembled a checklist of echinoderms of this island.
We collected echinoderms at 17 sites in Chuuk from 11-25 Nov 2012 (Table 1, Fig. 1). One intertidal zone of Weno Island was coral sand and rocky, and other 16 subtidal zones were investigated by SCUBA diving at depths of 10-40 m. The GPS coordinates and depth of each site were recorded (Table 1). All collected specimens were preserved in 95% ethyl alcohol and were identified based on their morphological characteristics. Important morphological characteristics and live conditions were photographed by a digital camera (Nikon D7000; Nikon Co., Tokyo, Japan), stereo- and lightmicroscopes (Nikon SMZ1000, Eclipse 80
[Table 1.] Geological information for collection sites around Chuuk
Geological information for collection sites around Chuuk
A total of 165 specimens collected for the echinoderm faunistic study of Chuuk were identified as 35 species in 28 genera: two crinoids, eight asteroids, four ophiuroids, seven echinoids, and 14 holothuroids. Of these, five echinoderms including one asteroid (
Phylum Echinodermata Klein, 1734 Subphylum Crinozoa Matsumoto, 1929 Class Crinoidea Müller, 1821 Order Comatulida AH Clark, 1908 Family Comasteridae AH Clark 1908 Subfamily Comasterinae AH Clark, 1909 Genus Comaster L Agassiz, 1836
1.
Material examined. 1 specimen, Ferit Island diving, 14 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Philippines, Palau, Guam, South Pacific, northern Australia, Indo-West Pacific, Bengal Bay.
Genus Oxycomanthus Rowe, Hoggett, Birtles and Vail, 1986
2.
Material examined. 1 specimen, Holap diving, 17 Nov 2012; 1 specimen, Atoll diving-3, 19 Nov 2012; 1 specimen, Atoll diving-6, 20 Nov 2012; 1 specimen, Atoll diving-8, 21 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae), southern Japan, southern China, Philippines, Palau, Guam, South Pacific, northern Australia, Indo-West Pacific, Bengal Bay.
Subphylum Asterozoa von Zittel, 1895 Class Asteroidea de Blainville, 1830 Order Valvatida Perrier, 1884 Family Acanthasteridae Sladen, 1889 Genus Acanthaster Gervais, 1841
3.
Material examined. 1 specimen, Atoll diving-8, 21 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), Guam, Palau, New Zealand (Kermadec Islands), Indo-West Pacific, eastern Africa (Mauritius, Madagascar), Red Sea.
Family Ophidiasteridae Verrill, 1870 Genus Gomophia Gray, 1840
*4.
Material examined. 1 specimen, Mokumok Island diving, 13 Nov 2012; 1 specimen, Sand Island diving, 14 Nov 2012.
Distribution. Micronesia (Chuuk), southern Japan, China, northern Australia, Indo-West Pacific, Red Sea.
Remarks. Body color is scarlet, and yellowish irregular patterns are on dorsal, lateral, and ventral sides of arms.
Genus Linckia Nardo, 1834
5.
Material examined. 1 specimen, Sand Island diving, 14 Nov 2012; 1 specimen, Atoll diving-2, 16 Nov 2012; 1 specimen, Atoll diving-3, 19 Nov 2012; 1 specimen, Atoll diving-8, 21 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), Korea (Jeju Island), Japan, southern China, Taiwan, Hong Kong, Guam, Hawaii, Australia, Indo-West Pacific, eastern Africa (Mauritius, Madagascar, Mozambique, Tanzania), Red Sea.
6.
Material examined. 1 specimen, Weno Island intertidal, 12 Nov 2012; 1 specimen, Mokumok Island diving, 13 Nov 2012; 2 specimens, Weno Island intertidal, 13 Nov 2012; 1 specimen, Ferit Island diving, 14 Nov 2012; 3 specimens, Sand Island diving, 14 Nov 2012; 2 specimens, Weno Island intertidal, 15 Nov 2012; 1 specimen, Weno Island intertidal, 17 Nov 2012; 1 specimen, Holap diving, 17 Nov 2012; 1 specimen, Atoll diving-5, 19 Nov 2012; 1 specimen, Atoll diving-7, 20 Nov 2012; 2 specimens, Atoll diving-8, 21 Nov 2012; 2 specimens, Xavier school diving, 22 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern China, Guam, Australia, Indo-West Pacific, eastern Africa (Madagascar), Red Sea.
Family Goniasteridae Forbes, 1841 Genus Fromia Gray, 1840
7.
Material examined. 1 specimen, Ferit Island diving, 14 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Philippines, Palau, Guam, South Pacific, northern Australia, Indo-West Pacific, Bengal Bay.
Family Oreasteridae Fisher, 1911 Genus Choriaster Lütken, 1869
8.
Material examined. 1 specimen, Sand Island diving, 14 Nov 2012; 1 specimen, Atoll diving-1, 16 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Philippines, Guam, Palau, New Caledonia, Indo-West Pacific, eastern Africa, Red Sea.
Genus Culcita (L Agassiz, 1836)
9.
Material examined. 1 specimen, Weno Island intertidal, 13 Nov 2012; 1 specimen, Weno Island intertidal, 17 Nov 2012; 1 specimen, Holap diving, 17 Nov 2012; 1 specimen, Atoll diving-5, 19 Nov 2012; 1 specimen, Atoll diving-6, 20 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Philippines, Guam, Palau, Marshall Islands, Hawaii, northern Australia, Bengal Bay, Indo-West Pacific, eastern Africa (Madagascar, Mozambique).
Order Spinulosida Perrier, 1884 Family Echinasteridae Verrill, 1867 Genus Echinaster Müller and Troschel, 1840
10.
Material examined. 1 specimen, Benedict diving, 13 Nov 2012; 1 specimen, Weno Island intertidal, 13 Nov 2012; 1 specimen, Holap diving, 17 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Philippines, Guam, Palau, South Pacific, northern Australia, New Caledonia.
Class Ophiuroidea Gray, 1840 Order Ophiurida Müller and Troschel, 1840 Infraorder Gnathophiurina Matsumoto, 1915 Family Ophiactidae Matsumoto, 1915 Genus Ophiactis Lütken, 1856
11.
Material examined. 7 specimens, Mokumok Island diving, 13 Nov 2012; 5 specimens, Ferit Island diving, 14 Nov 2012; 2 specimens, Holap diving, 17 Nov 2012; 4 specimens, Atoll diving-8, 21 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), Korea (Korea Strait, Jeju Island), Japan (Honshu, Kyushu), China, Philippines, Guam, northern Australia, Singapore, Indo-West Pacific, eastern Africa (Tanzania, Madagascar), Red Sea, Mediterranean Sea, Atlantic Ocean.
Family Ophicomidae Ljungman, 1867 Genus Ophiocoma L Agassiz, 1835
12.
Material examined. 1 specimen, Weno Island intertidal, 12 Nov 2012; 1 specimen, Weno Island intertidal, 15 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Philippines, Guam, Hawaii, South Pacific, northern Australia, Indo-West Pacific, eastern Africa, Red Sea.
Family Ophionereididae Ljungman, 1867 Genus Ophionereis Lütken, 1859
*13.
Ophionereis squamata Ljungman, 1867: 310. Ophionereis crassispina Ljungman, 1867: 311. Ophionereis sophiae Brock, 1888: 490.
Material examined. 1 specimen, Ferit Island diving, 14 Nov 2012.
Distribution. Micronesia (Chuuk), Saipan, Guam, Mariana Islands, Indo-West Pacific, eastern Africa (Madagascar, Tanzania), Red Sea.
Remarks. This species was collected inside hole of the sponge. Disk color is pale brown, and pale brown line is represented along width of arm.
Family Ophiotrichidae Ljungman, 1867 Genus Ophiothrix Müller and Troschel, 1840
14.
Material examined. 1 specimen, Holap diving, 17 Nov 2012; 2 specimens, Atoll diving-10, 21 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae), southern China, Guam, Indo-West Pacific, eastern Africa (Madagascar, Tanzania), Red Sea.
Subphylum Echinozoa Class Echinoidea Leske, 1778 Order Diadematoida Duncan, 1889 Family Diadematidae Gray, 1855 Genus Echinothrix Peters, 1853
15.
Material examined. 1 specimen, Benedict diving, 13 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Philippines, Guam, Hawaii, South Pacific, northern Australia, Indo-West Pacific, eastern Africa, Red Sea.
Order Camarodonta Jackson, 1912 Family Temnopleuridae A Agassiz, 1872 Genus Mespilia Desor, 1846
16.
Material examined. 2 specimens, Weno Island intertidal, 12 Nov 2012; 3 specimens, Weno Island intertidal, 15 Nov 2012; 1 specimen, Weno Island intertidal, 17 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), Korea (Jeju Island), southern Japan, southern China, Philippines, Guam, Hawaii, South Pacific, northern Australia, Indo-West Pacific, eastern Africa, Red Sea.
Family Parasaleniidae Mortensen, 1903 Genus Parasalenia A Agassiz, 1863
17.
Material examined. 2 specimens, Weno Island intertidal, 12 Nov 2012; 1 specimen, Ferit Island diving, 14 Nov 2012; 3 specimens, Weno Island intertidal, 15 Nov 2012; 1 specimen, Weno Island intertidal, 17 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae), southern China, Guam, Indo-West Pacific, eastern Africa (Kenya, Madagascar, Mozambique), Red Sea.
Family Echinometridae Gray, 1855 Genus Echinostrephus A Agassiz, 1863
18.
Material examined. 1 specimen, Benedict diving, 13 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Taiwan, East Australia, Indo-West Pacific.
Genus Echinometra Gray, 1825
19.
Material examined. 1 specimen, Weno Island intertidal, 13 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), Korea (Jeju Island), southern Japan, southern China, Philippines, Guam, Solomon Islands, Hawaii, North Australia, Indo-West Pacific, Red Sea, eastern Africa.
Order Clypeasteroida L Agassiz, 1835 Family Laganidae L Agassiz, 1835 Genus Laganum Link, 1807
20.
Material examined. 2 specimens, Weno Island intertidal, 12 Nov 2012.
Distribution. Micronesia (Chuuk), southern Japan, southern China, Philippines, Hawaii, South Pacific, northern Australia, Indo-West Pacific, West Indian Ocean, eastern Africa.
Order Spatangoida L Agassiz, 1840 Family Schizasteridae Lambert, 1905 Genus Schizaster L Agassiz, 1836
*21.
Material examined. 1 specimen, Sand Island diving, 14 Nov 2012.
Distribution. Micronesia (Chuuk), Korea (Korea Strait, Jeju Island), Japan (Sagami Bay-Kagoshima Bay), East China Sea, Hong Kong, Arafura Sea, northern Australia, Indo-West Pacific, East Africa.
Remarks. This species was found at the Korea Strait and Jeju Island of South Korea, and it is widely distributed in subtropical and tropical regions from the Pacific to Atlantic. Naked test collected at depth of 13 m and covered with coral sand.
Class Holothuroidea de Blainville, 1834 Order Apodida Brandt, 1835 Family Synaptidae Burmeister, 1837 Genus Opheodesoma Fisher, 1907
*22.
Material examined. 1 specimen, Weno Island intertidal, 17 Nov 2012.
Distribution. Micronesia (Chuuk), Guam, Hawaii, Philippines, Indo-West Pacific, eastern Africa (Kenya, Madagascar), Red Sea.
Remarks. This species was collected at sea grass region. Body color was dark reddish brown. Morphological characteristics of ossicles are as follows: symmetrical anchor plates with six large toothed holes; handle with one large hole and four or five small smooth holes along the edge of handle; anchor with smooth flukes, and about seven to 10 minutely tubercles on the middle of head.
Genus Synaptula Örsted, 1849
23.
Material examined. 4 specimens, Weno Island intertidal, 12 Nov 2012; 5 specimens, Weno Island intertidal, 13 Nov 2012; 2 specimens, Weno Island intertidal, 15 Nov 2012; 2 specimens, Weno Island intertidal, 17 Nov 2012.
Distribution. Micronesia (Chuuk, Phonpei), Papua New Guinea, Guam, Vietnam, Philippines, Malaysia, Indonesia, northern Australia, Indo-West Pacific, Sri Lanka, Maldive Island, Ceylon, Red Sea.
Order Aspidochirotida Grube, 1840 Family Holothuriidae Ludwig, 1894 Genus Actinopyga Bronn, 1860
24.
Material examined. 1 specimen, Atoll diving-4, 19 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae), Palau, New Caledonia.
Genus Bohadschia Jaeger, 1833
25.
Material examined. 1 specimen, Atoll diving-4, 19 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae), southern Japan, southern China, Philippines, Guam, South Pacific, northern Australia, Indonesia, Bengal Bay.
26.
Material examined. 1 specimen, Weno Island intertidal, 12 Nov 2012; 1 specimen, Weno Island intertidal, 15 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Philippines, South Pacific, northern Australia, Indo-West Pacific, Bengal Bay, eastern Africa, Red Sea.
Genus Holothuria Linnaeus, 1767
27.
Material examined. 1 specimen, Sand Island diving, 14 Nov 2012; 1 specimen, Atoll diving-7, 20 Nov 2012; 1 specimen, Atoll diving-9, 21 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae), southern Japan, southern China, Philippines, Guam, South Pacific, northern Australia, Indonesia, Indo-West Pacific, Bengal Bay.
28.
Material examined. 3 specimens, Weno Island intertidal, 12 Nov 2012; 1 specimen, Mokumok Island diving, 13 Nov 2012; 3 specimens, Weno Island intertidal, 15 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae), Korea (Korea Strait, Jeju Island), southern Japan, Guam, Hawaii, Australia, Indo-West Pacific, Africa (Zanzibar).
29.
Material examined. 1 specimen, Mokumok Island diving, 13 Nov 2012; 1 specimen, Benedict diving, 13 Nov 2012; 1 specimen, Weno Island intertidal, 15 Nov 2012; 1 specimen, Atoll diving-6, 20 Nov 2012; 1 specimen, Xavier school diving, 22 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae), southern China, Guam, Indo-West Pacific, West Indian Ocean, eastern Africa (Madagascar), Red Sea.
30.
Material examined. 1 specimen, Weno Island intertidal, 12 Nov 2012; 1 specimen, Weno Island intertidal, 13 Nov 2012.
Distribution. Micronesia (Chuuk, Yap), eastern Thailand, Philippines, Guam, South Pacific Islands, Australia, Indo-West Pacific, eastern Africa (Madagascar).
31.
Material examined. 1 specimen, Weno Island intertidal, 12 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae), Korea (Jeju Island), southern China, Philippines, Guam, Hawaii, South Pacific, northern Australia, Indo-West Pacific, Indian Ocean, eastern Africa, Red Sea.
Genus Pearsonothuria Levin, 1984
32.
Material examined. 1 specimen, Atoll diving-25, 16 Nov 2012; 1 specimen, Weno Island intertidal, 17 Nov 2012; 1 specimen, Atoll diving-5, 19 Nov 2012; 1 specimen, Atoll diving-7, 20 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern China, Philippines, Guam, Indo-West Pacific, Africa (Comoros, Madagascar), Red Sea.
Genus Stichopus Brandt, 1835
33. Stichopus horrens Selenka, 1867 (
Material examined. 2 specimens, Weno Island intertidal, 12 Nov 2012; 3 specimens, Weno Island intertidal, 17 Nov 2012.
Distribution. Micronesia (Chuuk, Kosrae, Yap), southern Japan, southern China, Philippines, Hawaii, South Pacific, northern Australia, Indonesia, Maldive Island.
34.
Material examined. 1 specimen, Xavier school diving, 22 Nov 2012.
Distribution. Micronesia (Chuuk, Yap), Papua New Guinea, Palau Islands, Indonesia, northern Australia.
Genus Thelenota Brandt, 1835
*35.
Material examined. 1 specimen, Atoll diving-1, 16 Nov 2012; 1 specimen, Atoll diving-5, 19 Nov 2012; 1 specimen, Atoll diving-10, 21 Nov 2012.
Distribution. Micronesia (Chuuk), Japan (Ryukyu Islands), southern China, Fiji, New Caledonia, Papua New Guinea, Marshall Islands, Guam, Palau Islands, South Pacific, northern Australia, Indonesia, Malaysia, Maldive Island, Madagascar.
Remark. This species has a unique body color and shape. Specimens have huge body sizes, and the longest length reached about 49 cm.
The echinoderm fauna of Micronesia was firstly reported by Kerr (1994) with regard to Holothuroidea in Kosrae. Kerr et al. (2007) investigated 19 locations of Yap over 2 weeks (27 Jul-9 Aug 2007) and reported 66 species, including 16 unidentified species: five crinoids (four unidentified), 14 asteroids (two unidentified), 14 echinoids (three unidentified), and 33 holothuroids (seven unidentified). Kerr et al. (2008) also surveyed 21 locations of Kosrae over two weeks (22 Feb-7 Mar 2008) and reported 74 species, including 20 unidentified species. KIOST (2009) recorded list of 20 echinoderms, six asteroids (one unidentified), two echinoids and 12 holothuroids (three unidentified), from Weno Island of Chuuk. Lee and Shin (2013) surveyed at eight intertidal areas and 12 SCUBA diving points of 10-50 m depths in the subtidal zone of Kosrae (23-30 Jan 2011 and 8-15 Jan 2012) and reported 50 species of three crinoids, 11 asteroids, seven ophiuroids, 10 echinoids, and 19 holothuroids, including 16 newly recorded species. Our faunistic study of echinoderms was performed at one intertidal site as well as 16 subtidal sites at depths of 8-40 m in Chuuk from 11-25 Nov 2012 (Table 1, Fig. 1). In total, 165 specimens were collected and classified as 35 species, excluding one unidentified species, and they were identified based on morphological characteristics. Seven echinoderms, including one asteroid (