The Tree Gecko, Hemiphyllodactylus Typus Typus (Lacertilia: Gekkonidae): an Addition to the Herpetofauna of Japan

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The Tree Gecko, Hemiphyllodactylus typus typus (Lacertilia: Gekkonidae): an Addition to the Herpetofauna of Japan

HIDETOSHI OTA

Abstract: One female of a gekkonid lizard, Hemiphyllodactylus typus typus, was collected from Iriomotejima Island of the Yaeyama Group, Ryukyu Archipelago. This is the first record of this species from Japan. External characteristics of the present specimen are described and discussed. This animal seems to represent a recent colonization of Iriomotejima Island by H. t. typus. Key words: Hemiphyllodactylus typus typus; Gekkonidae; Iriomotejima Island; Ryukyu Archipelago; colonization

It has been pointed out that many reptilian RESULTS species can extend their distribution over oceanic Morphological features.-An adult female islands rapidly by artificial transportation or raf- (Fig. 1); snout to vent length 37.5mm; body ting across the sea. Many insular populations much elongated, not much depressed; head of geckos offer good examples for such mode of length 8.3mm, head breadth 5.2mm, head dispersal (e. g., Hunsaker, 1967; Brown and depth 3.6mm; snout tapering, rounded at tip, its Alcala, 1970). In East Asia, recent distribu- length 3.7mm; eye diameter 2.2mm; rostral tional expansion of a parthenogenetic gecko, quadrangular, 1.5mm in breadth and 0.9mm in Lepidodactylus lugubris, is regarded as being at- height, deeply notched and grooved to the mid- tributable to human activities involving transpor- way dorsomedially; nostril surrounded by tation of wood and other goods to which this rostral, first supralabial, supranasal, and two lizard may attach itself or its eggs (Ota, 1986). small scales posteriorly; supranasals separated During a recent survey on Iriomotejima Island from each other by three scales bordering of the southern Ryukyus, I collected one rostral; 14 supralabials, 9th and 10th beneath specimen of the tree gecko Hemiphyllodactylus center of eye; 12 infralabials; mental triangular, typus typus, a subspecies known from Oceania, almost as large as adjacent labials; scales in and South and Southeast Asia including Taiwan, postmental region not much enlarged, graded in- but formerly unknown from Japan (Wermuth, to granular scales in gular region; axilla to groin 1965; Ota, 1989; Ota and Ross, 1990). The pre- length 22.0mm; dorsal and lateral surfaces of sent specimen seems to represent a recent col- body covered with small granular scales, lacking onization of this lizard from outside Japan by enlarged tubercles; scales on venter of body flat, means of artificial transportation. cycloid, slightly larger than those on dorsum. Limbs short; hind limbs 12.0mm when extend- MATERIALS AND METHODS ed laterally, but not reaching halfway between The specimen was collected from O-hara, axilla and groinwhen adpressed forward; digit I eastern part of Iriomotejima Island, Yaeyama vestigial, not clawed; the other digits well- Group, Ryukyu Archipelago, on 22 October developed, clawed, with subterminal phalanges 1989 by H. Ota, and was deposited in the moderately dilated, most strongly distally; sub- herpetological collection of the Department of digital scansors occupying distal one third to one Zoology, Kyoto University (catalogued as KUZ half of dilated portion, 5-5 (left-right) on fingers 13216). I, II, III, and V, 5-6 on finger IV, 6-5 on toe I, Hindlimb length was measured in life. The 5-5 on toe II, and 6-6 on toes III, IV and V; scan- other measurements were taken after fixation in sors on digit I entire; terminal scansors on the 10% formalin, and preservation in 70% other digits small, triangular, also entire, the ethanol. Terminology for the description of ex- other scansors more or less curved to base of ternal characters follows that of Brown and digits ("V" or "U"-shaped) and divided medial- Alcala (1978). ly; distal, compressed claw-bearing phalanges arising from within dilated portion; interdigital Accepted 9 Apr. 1990 webs absent. 88 Jpn. J. Herpetol. 13 (3). 1990

FIG. 1. The specimen of Hemiphyllodactylus typus typus collected from O-hara, Iriomotejima Island , Ryukyu Archipelago.

No preanal or femoral pores observed; tail sub- and limbs reddish brown, and original portion cylindrical, depth 1.8mm, breadth 2.3mm at of tail creamy yellow in life, all fading to grayish base; total length of tail 20.2mm, with distal tan in ethanol; regenerated portion of tail dark 16.0mm regenerated; scales in regenerated por- gray both in life and in ethanol; supra- and in- tion somewhat enlarged and irregularly arranged fralabial regions dark with several white spots; when compared with those in original portion; an indistinct dark stripe from posterior margin subcaudal scales in both original and of nostril through eye and upper margin of ear regenerated portions almost as large as scales on opening to shoulder, followed by a longitudinal dorsal and lateral surfaces. row of dark spots reaching midst of axilla-groin Color.-Dorsal ground color of head, body, region; another longitudinal row of dark spots in dorsolateral region of neck and body, reaching above vent; many white spots scattered in middorsal and dorsolateral regions; ventral surface light gray, darker in subdigital regions and regenerated portion of tail, with numerous dark dots. Habitat.-The present specimen was collected from between the trunk and the leaf sheath (ca. 1.5m above the ground) of a coconut palm, Cocos nucifera, planted along a path in the vicinity of human houses (Fig. 2). Two other gekkonids, Hemidactylus frenatus and Lepidodactylus lugubris, were observed in the same tree. The path was bordered on both sides by secondary vegetation chiefly consisting of Leu- caena glauca (Leguminosae) and Pinus luchuen- sis (Pinaceae). Another individual was observed beneath the bark of a tree, Casuarina equisetifolia, about 200m northeast of the present sampling site. This animal fell into the grass around the base of that tree immediately after the bark was rinded, and was not captured.

DISCUSSION FIG. 2. The coconut palm tree (Cocos nucifera) from which the specimen of H. t. typus was collected. Three subspecies are presently recognized for The arrow indicates the exact point where the animal Hemiphyllodactylus typus-H. t. typus Bleeker, was found. 1860, from Oceania, South and Southeast Asia, OTA-NEW RECORD OF TREE GECKO 89 and Taiwan, H. t. aurantiacus (Beddome, 1870) LITERATURE CITED from South Asia, and H. t. chapaensis Bourret, BOURRET,R. 1937. Notes Herpetologiques sur l'In- 1937, from Vietnam (see Wermuth, 1965). The dochine Francaise. XV. Bull. Gen. Instr. Publ. present specimen differs from the latter two in 1937: 57-82. having six scansors on toe IV (two or three in H. BROWN, W. C. AND A. C. ALCALA. 1970. The t. aurantiacus: Smith, 1935), small scales in the zoogeography of the herpetofauna of the Philippine chin region, and hindlimbs not reaching halfway Islands, a fringing archipelago. Proc. Calif. Acad. between the axilla and groin (more or less enlarg- Sci. 4th Ser. 38 (6): 105-130. ed chin shields, and hindlimb reaching more BROWN,W. C. ANDA. C. ALCALA.1978. Philippine lizards of the family Gekkonidae. Silliman Univ. than halfway between the axilla and groin in H. Nat. Sci. Monogr. Ser. No. 1. Silliman University t. chapaensis: Bourret, 1937). All these Press, Dumaguete, 146p. characteristics are identical with those in the HUNSAKER,D., II. 1967. Notes on the population ex- nominotypical subspecies (Smith, 1935; Brown pansion of the house gecko, Hemidactylus frenatus. and Alcala, 1978; Ota and Ross, 1990), and, Philipp. J. Sci. 95 (1): 121-122. therefore, it is evident that the specimen from MCCOY, M. 1980. Reptiles of the Solomon Islands. Iriomotejima Island belongs to H. t. typus. Wau Ecology Institute Handbook No. 7. Wau H. t. typus has a wide range of distribution, Ecology Institute, Wau, 80p. and many insular populations are considered as OLIVER, J. A. AND C. E. SHAW. 1953. The amphi- bians and reptiles of the Hawaiian Islands. nonnative and artificially introduced (e. g., Zoologica 38 (5): 65-95. several Philippine populations: Brown and OTA, H. 1983. On the herpetofauna of the Yaeyama Alcala, 1970). Despite previous intensive Group, Ryukyu Archipelago (I). Biol. Mag. surveys in the Yaeyama Group, this lizard has Okinawa (21): 13-19. (in Japanese, with English never been recorded from Iriomotejima or other abstract) islands (Ota, 1983; Toyama, 1985). To these OTA, H. 1986. The mourning gecko Lepidodactylus islands, many nonnative plants such as the lugubris (Dumeril and Bibron, 1836); an addition to coconut palm have recently been imported from the herpetofauna of Taiwan. J. Taiwan Mus. 39 (1): Southeast Asia and Taiwan, where H. t. typus oc- 55-58. OTA, H. 1989. A review of the geckos (Lacertilia: Rep- curs, as roadside trees. Since H, t. typus is essen- tilia) of the Ryukyu Archipelago and Taiwan. In: M. tially arboreal and lives under the bark or leaf Matsui, T. Hikida and R. C. Goris (eds.), Current sheath (Oliver and Shaw, 1953; Brown and Herpetology in East Asia. p. 222-261. The Alcala, 1978; McCoy, 1980), it is highly pro- Herpetological Society of Japan, Kyoto. bable that this gecko has been introduced into OTA, H. AND C. A. Ross. 1990. Records of the southern Ryukyus with those trees. The pre- Hemiphyllodactylus typus typus (Reptilia: Sauria) sent specimen seems to represent such recent ar- from Lanyu and Lutao Islands, Taiwan. J. Taiwan tificial entry rather than an undiscovered native Mus.: in press. SMITH, M. A. 1935. The fauna of British India in- population. Since another individual was cluding Ceylon and Burma. Reptilia and Amphibia. observed in a different place, it is highly pro- II-Sauna. Taylor and Francis, London, 440p. bable that H. t. typus has already established a TOYAMA,M. 1985. The herpetology of the Ryukyu Ar- local population on Iriomotejima Island. chipelago. In: W . W . F. Japan Scientific Committee (ed.), Conservation of the Nansei Shoto, Part II, Acknowledgments. -I thank Yasukazu Miyagi and p. 54-152. World Wildlife Fund, Tokyo. (in Masatsugu Yokota for the identification of the plant Japanese) from which the specimen of H. t. typus was collected, WERMUTH,H. 1965. Liste der rezenten Amphibien and Ronald I. Crombie for literature. This research nd Reptilien. Gekkonidae, Pygopodidae, u Xan- was partially supported by a Grant-in-Aid from the tusiidae. Das Tierreich Lief. 80. Walter de Gruyter, Japan Ministry of Education, Science and Culture (A- Berlin, 246p. 63790257). Department of Biology, University of the Ryukyus, Nishihara, Okinawa, 903-01 JAPAN 90 Jpn. J. Herpetol. 13 (3). 1990

要旨キノボリヤモリ(新称),Hemiphyl- lodactylus typus typus:日本の爬虫両棲類相への追加太田英利ついて記載し,検討を加えた.この標本は,本琉球列島八重山諸島の西表島より,キノボリ亜種が西表島へ最近移入されたことを示すものヤモリ(Hemiphyllodactylus typus typus)の1雌と思われる. が採集された.これは本種の日本からの最初の (903-01沖縄県中頭群西原町千原1琉球大記録である.今回採集された標本の外部形態に学理学部生物学科)