Karyotypes of Three Species of the Gennus Draco (Agamidae: Lacertilia) from Sabah, Malaysia

Home , Agama agama, Draco (lizard), Japalura

HIDETOSHI OTA AND TSUTOMU HIKIDA

Abstract: The first karyological survey was made for D. cornutus, D. haematopogon, and D. quinquefasciatus by bone marrow cell preparations. Despite the distinct in- terspecific diversification in external characteristics, the three species have identical karyotypes: somatic chromosomes, 2n=34, consisting of six pairs of large metaccen- tric, two pairs of small metacentric, and nine pairs of small acrocentric elements. The results seem to indicate the relative chromosomal conservativeness of the genus. Key words: Draco cornutus; Draco haematopogon; Draco quinquefasciatus; Karyotype; Sabah

The Genus Draco is a morphologically highly the bone-marrow air-dry method of Ota diversified group of the family Agamidae, con- (1989a). In the laboratory, all slides were soak- sisting of some 15 arboreal species distributed ed in 2% Giemsa solution for 20 minutes, and throughout tropical Asia eastward to Papua were investigated for metaphase cells. The New Guinea. On the basis of morphological karyotype of each species was determined on the features, a few recent authors revised the tax- basis of at least 10 well-spread metaphase cells. onomy and relationships of species included in In describing the chromosome morphology, we the genus (Inger, 1983; Musters, 1983; Lazell, follow the terminology suggested by Green et al. 1987). On the other hand, no systematic ap- (1980). proaches have been attempted based on cytological and biochemical evidence. Pro- RESULTS bably, this is due, at least partially, to the D. cornutus had a karyotype comprising specialized food habits of this lizard (Inger, 2n=34 chromosomes in two discontinuous size 1983), which makes it difficult to provide live groups. Of these, six pairs belonging to the specimens for laboratory experiments. Regard- larger size-group (Nos. 1-6) and the largest two ing the karyotype, only Olmo (1986) listed the pairs of microchromosomes (Nos. 7 and 8) were diploid chromosome number of 34 for Draco metacentrics, whereas the other nine, assigned to sp., but on the basis of a problemattic citation the smaller size-group (Nos. 9-17), were acrocen- (see the footnote in Appendix). tric elements (Fig. 1: A). The fundamental During a herpetological survey in Sabah, number (N. F.) was therefore calculated as 50. Malaysia, we succeeded in obtaining metaphase No heteromorphic sex chromosomes were evi- preparations from three Draco species in the dent. field. In the present paper, we describe their The karyotypes of both D. haematopogon karyotypes for the first time in order to provide (Fig. 1; B) and D. quinquefasciatus (Fig, 1; C) data for further cytotaxonomic studies of the seemed identical with that of D. cornutus describ- genus. ed above; their somatic cells also possessed 34 chromosomes with 12 large metacentric, four MATERIALSAND METHODS small metacentric, and 18 small acrocentric Three species, Draco cornutus (or D. volans elements. sensu Inger, 1983), D. haematopogon, and D. quinquefasciatus, collected from the tropical DISCUSSION rain forest of Sepilok, Sabah, were examined. Musters (1983), on the basis of morphological Sex and sample size for each species are given in analyses, suggested a dendrogram to schematize Table 1. Voucher specimens were deposited in the phylogenetic relationships of Draco species. the herpetological collection of the Department Accepting this tree, D. cornutus is distantly of Zoology, Kyoto University (KUZ; see related to D. haematopogon or D. quin- Specimens Examined). quefasciatus within the genus. However, present Mitotic preparations were made in the field by investigations revealed that karyotypes of the three species are identical with each other, at Accepted 15, Apr. 1989 least in general morphology exhibited by the con- 2 Jpn. J. Herpetol. 13 (1). 1989 ventional Giemsa staining. The results indicate macrochromosomes and 24 uniarmed micro- that the karyotype of the genus Draco is relative- chromosomes) represents the primitive condition ly conservative, and that the divergence among of the agamid karyotype, and that the other species in the genus involved little chromosomal chromosome counts have derived from this differentiation. Accumulation of data for other primitive 36 chromosome type through centric species is required to confirm this assumption. fission/fusion, pericentric inversion, etc. (e. g., Several authors argued that the chromosome Moody and Hutterer, 1978; King, 1981; Witten, number of 2n=36 (consisting of 12 biarmed 1983; Bickham, 1984). Following this

FIG. 1. Karyotypes of Draco cornutus (A: female), D. haematopogon (B: female), and D. quinquefasciatus (C: female). The scale indicates 10μm. OTA & HIKIDA-LIZARD KARYOTYPE 3

TABLE 1. Sex and sample size of each Draco species used in the present study.

hypothesis, it is probable that the 2n=34 karyotypes of the three Dacro species, consisting LITERATURE CITED of 12 metacentric macrochromosomes and 22 ADEGOKE, J. A. 1988. Studies on the chromosomes microchromosomes, have reduced the micro- of the rainbow lizard Agama agama agama (L.) with chromosome number by Robertsonian fusion. notes on polyploidy in the spermatocytes. Cytologia The presence of the biarmed microchromosomes 53 (2): 233-239. in these karyotypes supports this postulation. BICKHAM, J. W. 1984. Patterns and modes of In the family Agamidae, 84 species or chromosomal evolution in reptiles. In: A. K. Shar- subspecies of 24 genera have hitherto been ma and A. Sharma (eds.), Chromosome in Evolu- karyotyped, of which 18 species belonging to tion of Eukaryotic Groups. Vol. 2. p. 13-40. CRC Press, (city) Florida. seven genera (Agama, Calotes, Ceratophora, DESMET, W. H. O. 1981. Description of the orcein Draco, Japalura, Ptycolaemus and Uromastyx) stained karyotypes of 27 lizard species (Laceritilia are known to have 2n=34 chromosomes (see Reptilia) belonging to the families Iguanidae, Appendix). However, considering the extensive Agamidae, Chamaeleontidae and Gekkonidae karyological variability in some genera (e. g., (Ascalabota). Acta Zool. Pathol. Antverp. (76): 35- Agama, Japalura), it seems unlikely that the 72. agreements in the diploid count consistently DEY, S. K., W. HENRY AND A. RAI. 1988. reflect the close phylogenetic relationships Chromosomes of the agamid lizard Japalura among the 18 species. Instead, we assume that variegata Gray (Reptilia: Agamidae). Chrom. Inf. there have been several independent lineages to Serv. 45: 8-10. GORMAN, G. C. AND D. SHOCHAT. 1972. A tax- attain the 34-chromosome type from the onomic interpretation of chromosomal and elec- primitive 36 chromosome type. To substantiate trophoretic data on the agamid lizards of Israel with this assumption, further systematic analyses are notes on some East African species. Herpetologica required for the morphological, as well as more 28 (2): 106-112. detailed karyological, characteristics within the GREEN, D. M., J. P. BOGART,E. H. ANTHONYAND family Agamidae. D. L. GENNER. 1980. An interactive, microcom- puter-based karyotype analysis system for SPECIMENSEXAMINED. Draco cornutus: KUZ 8699, phylogenetic cytotaxonomy. Comput. Biol. Med. 8700, 8701, 8799, 8801, 8802, 8860, 8861, 8930; D. 10: 219-227. haematopogon: 8656, 8702, 8703, 8704, 8705, 8752, HALL, W. P. 1970. Three probable cases of par- 8763, 8805, 8806, 8862, 8880, 8881, D. quin- thenogenesis in reptiles (Agamidae, Chamaeleon- quefasciatus: KUZ 8706, 8804, 8879. tidae, Gekkonidae). Experientia 26 (11): 1271-1273. INGER, R. F. 1983. Morphological and ecological ACKNOWLEDGMENTS.-We wish to express our variation in the flying lizards (Genus Draco). Field- gratitude to T. Hidaka, M. Ishii, M. Kon, K. Otsuka, iana Zool. New Ser. (18): 1-35. S. Furukawa, B. A. Fauziah, R. Goh, R. F. Goh, L. KING, M. 1981. Chromosome change and speciation Saikeh, V. Chey and the staff of the entomological sec- in lizards. In: W. Atchley and D. Woodruff (eds.), tion of the Forest Research Center, Sepilok, for pro- Evolution and Speciation: Essays in Honour of viding us with valuable company and continuous sup- M. J. D. White. p. 262-285. Cambridge University port during the fieldwork in Sabah. We also thank M. Press, Cambridge. Matsui and T. Hidaka for critically reading the KUPRIYANOVA,L. A. 1984. Karyotypes of three manuscript, and M. Matsui, H. Nakamura, and T. species of the agamid lizards. In: L. J. Borkin (ed.), Seto for literature cited here. This research was par- Ecology and Faunistics of Amphibians and Reptiles tially supported by a Grant-in-Aid from Japan of the USSR and Adjacent Countries. p. 115-118. Ministry of Education, Science and Culture (Oversea Zoological Institute, Academy of Sciences, Len- Researches No. 62041049 to T. Hidaka, and A- ingrad. (in Russian with English summary) 63790257 to H. Ota). LAZELL,J. D., JR. 1987. A new flying lizard from the 4 Jpn. J. Herpetol. 13 (1). 1989

Sangihe Archipelago, Indonesia. Breviora (488): 1-9. Copeia: in press. LI, S., Y. WANG, R. WANG, C. LI ANDG. LIU. 1981. RONG,S., Q. LUOAND S. DAI. 1987. The karyotype A karyotypical study of Japalura varcoae of Leiolepis belliana belliana. Zool. Res. 8(2): 164. (Boulenger). Zool. Res. 2 (3): 223-228. (in Chinese (in Chinese) wtih English abstract) SOLLEDER,E. and M. Schmid. 1988. Cytogenetic MOODY,S. AND R. HUTTERER. 1978. Karyotype of studies on Sauna (Reptilia). I. Mitotic chromosomes the agamid lizard Lyriocephalus scutatus (L., 1758), of the Agamidae. Amphibia-Reptilia 9 (3): 301-310. with a brief review of the chromosomes of the lizard WANG,X., W. CHEN,Z WANG,Z. GAOAND G. WU. family Agamidae. Bonn. Zool. Beitr. 29 (1-3): 165- 1987. Studies on the karyotypes of Japalura 170. szechwanensisand J. flaviceps. Acta Herpetol. Sini- MUSTERS, C. J. M. 1983. Taxonomy of the genus ca 6 (1): 9-11. (in Chinese with English abstract) Draco L. (Agamidae, Lacertilia, Reptilia). Zool. WITTEN,G. J. 1978. A triploid male individual Am- Verhand. (199): 1-120. phibolurus nobbi nobbi Witten (Lavertilia: OLMO,E. 1986. Reptilia. In: B. John (ed.), Animal Agamidae). Aust. Zool. 19(3): 305-308. Cytogenetics Vol. 4: Chordata 3A. p. 1-100. WITTEN,G. J. 1983. Some karyotypes of Australian Gebruder Borntraeger, Berlin & Stuttgart. agamids (Reptilia: Lacertilia). Aust. J. Zool. 31(4): OTA, H. 1988. Karyotypic differentiation in an 533-540. agamid lizard, Japalura swinhonis swinhonis. Ex- WU, M. 1987. The karyotype of Agama stoliczkana. perientia 44 (1) : 66-68. Acta Herpetol. Sinica 6(1): 74-75. (in Chinese) OTA, H. 1989a. Methods for preparation of lacer- tilian karyotypes in the field. In: M. Matsui, T. Department of Zoology, Faculty of Science, Hikida and R. C. Goris (eds.), Current Herpetology Kyoto University, Kitashirakawa-oiwakecho, in Eastern Asia: in press. OTA, H. 1989b. Japalura brevipes Gressitt Sakyo-ku, Kyoto, 606 JAPAN; Present Address (Agamidae: Reptilia), a valid species from high (HO): Department of Biology, University of the altitude area of Taiwan. Herpetologica 45 (1): 55-60. Ryukyus, Nishihara, Okinawa, 903-01 JAPAN OTA, H. 1989c. A new species of Japalura (Agamidae: Lacertilia: Reptilia) from Taiwan.

APPENDIX Published data for the diploid chromosome numbers (2n) in agamid species. Triploidy has also been reported for Leiolepis belliana (3n=54; Hall, 1970) and Amphibolurus nobbi nobbi (3n=48; Witten, 1978). See following notes for the explanations of *, **, and ***. OTA & HIKIDA-LIZARD KARYOTYPE 5 6 Jpn. J. Herpetol. 13 (1). 1989

要旨マレーシア・サバ州産トビトカゲ属 (Draco)3種の核型太田英利*・疋田努トビトカゲ属3種(D.cornutus, D. 動原体型,2対は小型の中部動原体型,そして haematopogon, D.quinquefasciatus)の核型を 9対は小型の端部動原体型であった.以上の結はじめて記載した.これらの種は外部形態につ果から,トビトカゲ属は核学的分化を生じにくいてはお互いに著しく分化しているが,核型にいグループであると考えられる. ついてはお互いに非常によく似ていることがわ (606京都市左京区北白川追分町京都大学かった.すなわちいずれの種においても染色体理学部動物学教室.*現住所:903-01沖縄県中数は2n=34本で,そのうち6対は大型の中部頭郡西原町千原1琉球大学理学部生物学科)