1 7 an Identification Key to the Geckos of the Seychelles
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HERPETOLOGICAL JOURNAL. Vol. I. pp. 17-19 (19X5l 17 AN IDENTIFICATION KEY TO THE GECKOS OF THE SEYCHELLES, WITH BRIEF NOTES ON THEIR DISTRIBUTIONS AND HABITS ANDREW S. GARDNER Department of Zoology, University of Aberdren. Ti/lydrone Avenue, Aberdeen AB9 2TN. U. K. Present addresses: The Calton Laboratory. Department of Genetics and Biomet IT, Universif.I' Co/legr London. Wo/f�·on !-louse, 4 Stephenson Wa r London NWI 21-11'.. U.K. (A ccepted 24. /0. 84) INTRODUCTION 4. Scales on chest and at least anterior of belly keeled. Underside white. Phe!suma astriata The Republic of Seychelles, lying in the western Tornier. 5. Indian Ocean consists of a group of mountainous, granitic islands, and a large number of outlying coral Scales on chest and belly not keeled. 6. atolls and sand cays, distributed over 400,000 km2 of sea. There are over a hundred islands, ranging in size 5. Subcaudal scales keeled and not transversely from Mahe, at 148 km2 to islands little more than enlarged in original tails. Ground colour of emergent rocks. A total of eighteen species of lizard, rump and tail usually bright blue, and of from three families are recorded from the Seychelles nanks, green. Tail unmarked or spotted with (Gardner, 1984). The best represented family is the red. Red transverse neck bars often reduced or Gekkonidae with eleven species, fo ur of which are absent. Phe/suma astriata astriata Tornier i endemic to the islands. The identification key 90 1. presented here should enable interested naturalists to Subcaudal scales unkeeled and transversely identify any gecko encountered in the Seychelles to the enlarged in original tails. Ground colour of species level, and where there are clearly defined races. rump and tail usually green, and of flanks, to the subspecies level. grey-brown. Tail usually with a narrow In the past there has been frequent confusion of the transverse red band on each segment. Usually fo rms, particularly amongst the "house geckos" and two distinct red, transverse bars across neck. between the races of green day-geckos (Phelsuma Phe!suma astriata semicarinata Cheke 1982. species) (e.g. Gaymer, 1968; High, 1976; Temple, 1977). The classification of the Phe/suma forms presented 6. Eye ring bright blue. Three red bars across here is that of Gardner ( 1984) and diffe rs in several snout and back of head. Otherwise red aspects from the classifications given by Cheke (1982) marking restricted to a pattern of 3 large red and Meier ( 1983).That of Gardner (1984) is based on a spots anterior to a number of small red multivariate morphometric analysis of many body speckles on the lower back. Underside of chin proportion, scalation and colour pattern characters, white. Yellow scales dusting neck and upper using large samples taken over the complete range of back. Phelsuma /aticauda Boettger. the taxa. The species Urocotyledon inexpectata was Not as above. A dark chevron or chevrons transferred to that genus from Phyl/odactylus by Kluge under the chin, at least in preserved specimens ( 1983). and geckos in dark phase. 7. 7. Ground colour of live geckos a dull grey-blue, THE KEY with mottled fl anks and legs. Head marking usually consists of a median red spot behind 1. Digits gradually dilated distally, with more the internasals, red spots above the eye rings, 2. than 2 adhesive lamellae on the undersurface. and a rather variable pattern on the fo rehead Digits only dilated at apex, with only a single and in the interocular region. Eye ring pair of adhesive lamellae on the undersurface whitish. Basal tail segments with 5 rows of (Fig. I a). Urocotyledon inexpectata Stejneger. scales on the dorsal surface. Phelsuma abbolli Stejneger. 8. 2. Subdigital lamellae straight and undivided Ground colour of live geckos bright green. medially. 3. Usually a red chevron mark on the head, at Subdigital lamellae obliquely set and medially least in young geckos. Eye ring green or divided. 11. yellow. Basal tail segments with 7 or 8 rows of scales on the dorsal surface. Phe/suma 3. Digits clawed; all digits with a dilated apex. sundbergi Rendahl. 9. Pupil vertical. Ai/uronyx scchel/ensis Dumeril and Bibron. 8. Snout to vent length to 58 mm. Slender build. Digits clawless; thumb and inner toe vestigial. Ground colour of back usually a dull grey Remaining digits each with a dilated apex. green, with heavy flank and leg mottling. Pupil circular. Genus Phe!suma Gray. 4. Continuous, red, vertebral line up back. 18 A. S. GARDNER Underside white. other than a few yellow scale so. and uniformly grey, sometimes with small rows anterior to the preano-femoral row. black speckles. Hemidacty/us fr enatus Phe/suma abbotti abbotti Stej neger 1893. Dumeril and Bibron. Snout to vent length to 73 mm. Heavy build. Inner digit with phalanx well developed. Ground colour of back bright grey-blue, with extending fa r beyond the tip of the lamellae a broken, red vertebral line. Underside (Fig. Id). Back distinctly tuberculate. often orange-yellow with a reddish gular chevron. conspicuously marked with black. 14. Phe/suma abbotti sumptio Cheke 1982. 14. Body tubercles very large and strongly keeled. 9. Adult snout to vent length from 55 to 68 mm. Back with dark blotches. but without Eye ring yellow or yellow-green. Back pattern transverse stripes. Tail barred on every second highly variable. but often comprises three segment. 8 to I 0 upper labial scales on each longitudinal rows of red spots. with the side. Hemidactylus brookii Gray. median ones sometimes coalescing into a Body tubercles small. only slightly keeled. sinuous vertebral line. Tail often barred with Back with distinct transverse stripes. Tail red. No orange or yellow on underside. Some barred on every 3rd or 4th segment. 10 to 14 populations have very reduced red markings. upper labial scales on each side. Hemidactylus Chin shields flat, and white or grey. Phe/suma mercatorius Gray. sundbergi /onginsu/ae Rendahl 1939 n. comb. Adult snout to vent length from 60 to 95 mm. Back pattern consists of a fine vermiculation of red spots. Tails rarely barred. Chin shields NOTES ON THE DISTRIBUTIONS AND raised and tend to be greenish. Often yellow or HABITS OF THE SPECIES orange on throat and around vent. 10. I. Urocoty/edon inexpectata. Endemic. Nocturnal. 10. Adult snout to vent length from 75 to 95 mm. Widely distributed in the granitic islands, where it may Keeling on throat scales extending from the be fo und under loose bark or stones. The eggs are laid chin shields to the level of the forelimbs. and communally under flakes of granite. The smallest extending down the sides of the belly. Gular gecko species in the Seychelles. scales and chin shields well raised. Edges of mental scale strongly angled. Fourth toe 2. A i/uronyx seche//ensis. Endemic. Nocturnal. lamellae numbering 18 to 21 on the hind foot. Widely distributed in the granitic Seychelles. but most Preano-femoral pores numbering 32 to 37 in abundant on the seabird islands of Cousin. Cousine. males. Eye ring always green. Phe/suma Aride and Frigate. A very large species, it is found both sundbergi sundbergi Rendahl 1939. in buildings and on trees on the seabird islands. but is restricted to forest and coconut plantations on the Adult snout to vent length from 60 to 78 mm. other islands. Rare on Mahe. but frequently seen in the Keeling on throat scales restricted to a band Va llee de Mai on Praslin. across the posterior throat region. Gular scales and chin shields slightly raised. Edges of 3. Phe/suma astriata astriata. Endemic. Diurnal. mental scale usually straight. Fourth toe Occurs on Silhouette. and Mahe and its associated lamellae numbering 16 to 18 on the hind foot. islets in the granitic group and on Astove in the outer 28 to 34 preano-femoral pores in males. Eye islands. Abundant on fo rest trees. coconut plantations ring often yellow or green-yellow. Phe/suma and bananas. sundbergi /adiguensis Bohme and Meier 1982. 4. Phe/suma astriata semicarinata. Endemic. 11. Postmentals well developed, standing out Diurnal. Occurs on Praslin, La Digue and all the sharply from the small gular scales. 12. wooded islands associated with them. On the non Postmentals not distinct. but a number of granitic islands, it is found on Denis. D'Arros and St. polygonal scales merging gradually into the Joseph. Abundant on trees. rocks and in houses. smaller gular scales. Tail with sharp lateral edges. Lepidodacty/us /ugubris Dumeril and 5. Phe/suma /aticauda. Indigenous. Diurnal. Found Bibron. only in the Farquhar Group of Farquhar, Providence and Cerf in the outer islands. where it is abundant on 12. First digit without free terminal phalange and coconut and banana trees. only minutely clawed. Subdigital lamellae only present on the distal half of the digit 6. Phe/suma abbotti abbotti. Endemic subspecies (Fig. lb). Mental much shorter than the inner restricted to Aldabra. Diurnal. Abundant in all postmentals (Fig. le). No tubercles on tail. wooded habitats. Gehyra muti/ata Wiegmann. First digit with free. clawed terminal 7. Phe/suma abbotti sumptio. Endemic subspecies phalange. Subdigital lamellae run the whole restricted to Assumption Island. Diurnal and length of the digit (Fig. lc.d). Mental and abundant in the coconut plantation. inner postmentals nearly equal in length (Fig. If). Original tails with rings of tubercles. 8. Phe/suma sundbergi /onginsu/ae. Endemic. Genus Hemidacty/us Oken. 13. Diurnal. Occurs on Mahe, Silhouette. North and Frigate. and the smaller islands in the Mahe group. and 13. Inner digit with short phalanx. whose tip does on Cosmoledo, Remire and Bird Island in the non not extend far beyond the tip of the lamellae granitic islands.