Title Resurrection of Staurois Parvus from S. Tuberilinguisfrom Borneo (Amphibia, Ranidae) Author(S) Matsui, Masafumi; Mohamed
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View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Kyoto University Research Information Repository Resurrection of Staurois parvus from S. tuberilinguisfrom Title Borneo (Amphibia, Ranidae) Matsui, Masafumi; Mohamed, Maryati; Shimada, Tomohiko; Author(s) Sudin, Ahmad Citation Zoological Science (2007), 24(1): 101-106 Issue Date 2007-01 URL http://hdl.handle.net/2433/85328 Right (c) 日本動物学会 / Zoological Society of Japan Type Journal Article Textversion publisher Kyoto University ZOOLOGICAL SCIENCE 24: 101–106 (2007) © 2007 Zoological Society of Japan Resurrection of Staurois parvus from S. tuberilinguis from Borneo (Amphibia, Ranidae) Masafumi Matsui1*, Maryati Mohamed2, Tomohiko Shimada1 and Ahmad Sudin2 1Graduate School of Human and Environmental Studies, Kyoto University, Sakyo, Kyoto 606-8501, Japan 2Institute for Tropical Biology and Conservation, University Malaysia Sabah, Teluk Sepanggar, Locked Bag 2073, 88999 Kota Kinabalu, Sabah, Malaysia Two forms of Staurois that are differentiated by body size occur parapatrically in the Crocker Range, Sabah, Borneo. Analyses of a total of 1,499 bp of the mitochondrial cytochrome b, 12S rRNA, and 16S rRNA genes revealed that the two forms could be completely split genetically. The two forms could be also clearly differentiated morphologically, not only by snout-vent length but also by the relative sizes of snout, eye, and finger disk. Comparisons of the two forms with all known species of the genus revealed the large and small forms to be S. tuberilinguis and S. parvus, respectively. The latter species has long been synonymized with the former, but we here consider them to rep- resent different species. Key words: biodiversity, cryptic species, molecular phylogeny, Southeast Asia, taxonomy and the large form from the Crocker Range and Sarawak, INTRODUCTION as well as of S. natator and S. latopalmatus for compari- In our survey of amphibians in Sabah, Borneo, we found sons. We also made a morphological comparison of the two frogs of the genus Staurois Cope, 1865, which is character- forms with available specimens, as well as with descriptions, ized by very large finger disks, each of which has a distinct of known species of the genus to determine their taxonomic transverse border proximally on the ventral surface, and status. complete webbing on all toes (Boulenger, 1918; Inger, 1966). These frogs were generally uniform in their habitus MATERIALS AND METHODS and color, but could be clearly differentiated as two forms by For genetic comparisons, we studied a total of 15 specimens body size (small and large forms). of “S. tuberilinguis”: eight specimens of the small form from two Staurois is a small genus occurring in the Philippines localities in the Crocker Range, Sabah, and seven specimens of the and Borneo and includes small- to moderate-sized torrent large form from two localities in the Crocker Range and one locality dwellers (e.g., Inger, 1966; Malkmus et al., 2002). All recent in Sarawak (Appendix 1, Fig. 1). For comparisons, S. natator from authors (e.g., Inger and Tan, 1996; Malkmus et al., 2002) Sabah and Sarawak, S. latopalmatus from Sabah, and another have recognized three species, S. latopalmatus (Boulenger, ranid, Amolops marmoratus (Blyth, 1855) from Thailand, were used. Microhyla fissipes Boulenger, 1884, a member of the ranoid family 1887), S. natator (Günther, 1858), and S. tuberilinguis Bou- Microhylidae from Thailand, was chosen as an outgroup species. lenger, 1918, as the members of this genus from Borneo. DNA was extracted from small amounts of frozen or ethanol- Preliminary examination of our two forms in conjunction preserved tissues using standard phenol-chloroform extraction pro- with the key to the above three Bornean species (Inger, cedures (Hillis et al., 1996). Amplification was done by the poly- 1966; Malkmus et al., 2002) revealed that both could be ten- merase chain reaction (PCR), using primers L14841 (light chain; 5’- tatively identified as S. tuberilinguis because they lack CCA TCC AAC ATC TCA GCA TGA TGA AA-3’) / H15548 (heavy webbed outer fingers and vomerine teeth, but possess a chain; 5’-AAT AGG AAG TAC CAC TCT GGT TTA AT-3’) newly well-developed lingual papilla. This species includes S. par- designed by Tomoko Tanaka-Ueno, and L14850 of Tanaka et al. vus Inger and Haile, 1960, which is the smallest species of (1994) / H15502 of Tanaka-Ueno et al. (1998) for cyt-b; primers the genus ever described, as a synonym (Inger, 1966). 12SH of Cannatella et al. (1998) and H1548 of Matsui et al. (2005) for 12S; and primers L2188 of Matsui et al. (2005) and 16H1 of In order to clarify their relationships, we analyzed mito- Hedges (1994) for 16S. The amplified fragments were sequenced chondrial cytochrome b (cyt-b), 12S rRNA, and 16S rRNA with an automated DNA sequencer (ABI PRISM 3100) using the gene sequences of the small form from the Crocker Range PCR primers and following the manufacturer's instructions. Newly obtained sequences were deposited in GenBank (accession num- * Corresponding author. Phone: +81-75-753-6846; bers AB259717–259738). Fax : +81-75-753-6846; Sequence data for each sample were obtained and checked by E-mail: [email protected] eye using ABI PRISM Sequencing Analysis Software (V3.6.2). doi:10.2108/zsj.24.101 Alignments of data from all samples were performed with the clustal 102 M. Matsui et al. or absence of differences in frequency distributions. The signifi- cance level was set at 0.05. RESULTS DNA sequences We obtained sequences of 583 bp for cyt-b, 436–443 bp for 12S and 458–463 bp for 16S, and the aligned 12S (449 bp) and 16S (467 bp) data set combined with cyt-b yielded 1,499 nucleotide positions. Of these sites, 553 were variable and 355 were informative for parsimony analyses. We obtained a single most parsimonious tree with 923 evolu- tionary steps, a consistency index of 0.807, and a retention index of 0.873. For cyt-b, the small and large forms of “S. tuberilinguis” from Sabah showed low within-population sequence diver- gence (K2p=0 to 0.012 and 0 to 0.014, respectively). The sequence divergence between populations from Sabah and Sarawak was also low (K2p=0 to 0.012) for the large form, contrasting with much higher divergence in S. natator (K2p=0.028–0.032). Sequence divergence was lower (K2p=0 to 0.002) for 16S than for cyt-b, both within the Sabah populations and between the Sabah and Sarawak populations of the small and large forms of “S. tuberilinguis”. The Sabah and Sarawak populations of S. natator also showed low divergence (K2p=0.013). For 12S, no sequence divergence was observed either within the Sabah popula- tions or between the Sabah and Sarawak populations of the small and large forms of “S. tuberilinguis”, and S. natator showed only low divergence (K2p=0.002) between Sabah and Sarawak. All phylogenetic analyses resulted in the same topology, and only the NJ tree from the combined data set is shown Fig. 1. Map of Borneo showing the localities where sampling of in Fig. 2. The following relationships were indicated by full Staurois species was conducted. 1, Mahua; 2, Base camp; 3, Trail bootstrap support (100%) in both the NJ and MP analyses: 4; 4, Trail 5; 5, Trail 11; 6, Bareo; 7, Serapi; 8, Sematan; 9, Mulu. (i) monophyly of genus Staurois with respect to Amolops Hatched area shows the Crocker Range (CR). See Appendix 1 for and Microhyla; (ii) monophyly of S. natator with respect to details. “S. tuberilinguis”; (iii) monophyly for each of the small and large forms of “S. tuberilinguis”; and (iv) a sister-group rela- option of BioEdit software (Hall, 1999). Initial ClustalX alignments of tionship of the small and large forms of “S. tuberilinguis”. In 12S and 16S were then inspected by eye and adjusted slightly. addition, (v) monophyly of S. natator and “S. tuberilinguis”, Prior to analysis, we tested for consistency among genes using with respect to S. latopalmatus, was supported by a boot- incongruence length difference (ILD) tests with 1,000 randomized strap value of 100% for the NJ analysis, but by 94% for the partitions (Farris et al., 1994). No significant heterogeneity was MP analysis. observed among the cyt-b, 12S, and 16S genes. We therefore com- Thus, the small and the large forms of “S. tuberilinguis” bined them into a single data set of 1,499 bp. Neighbor-joining (NJ) were clearly separated genetically, although the sequence phylogenies based on Kimura two-parameter (K2p) distances divergences between them (K2p=0.096 for cyt-b, 0.018 for (Kimura, 1980) and maximum parsimony (MP) phylogenies obtai- 12S, and 0.027 for 16S) were much smaller than the diver- ned by heuristic searches with TBR branch swapping were calcu- lated in PAUP*4.0b10 (Swofford, 2002). The robustness of NJ and gences between these forms and S. natator (0.248, 0.099, MP tree topologies was tested by bootstrap analyses (Felsenstein, and 0.105, respectively, for the small form; 0.243, 0.097, 1985) with 1,000 replicates (Hedges, 1992). and 0.109, respectively, for the large form) or S. latopalma- For morphological comparisons, we studied a total of 89 spec- tus (0.305, 0.121, and 0.129, respectively, for the small form; imens of “S. tuberilinguis” from Sabah and Sarawak (31 specimens 0.303, 0.116, and 0.132, respectively, for the large form), of the small form and 58 specimens of the large form) and 16 spec- and between the latter two species (0.287, 0.127, and imens of S. natator from Sarawak (Appendix 1). Five body mea- 0.156, respectively). surements were taken, following Matsui (1984): 1) snout-vent length (SVL), 2) head width (HW), 3) tibia length (TL), 4) snout length (SL), Morphology and 5) eye length (EL).