A Phylogenetic Analysis of Bungarus (Elapidae) Based on Morphological Characters

-The phylogenetic relationships among the species of the elapid genus Bungarus were examined using morphological characters. One of the 13 species listed by Golay (1985), B. javanicus, is synonymized with B. candidus. Six characters were found to be informative for kraits and an analysis of these characters using parsimony resulted in the following relationships: (B. flaviceps, B. bungaroides (B. fasciatus (B. andamanensis, B. caeruleus, b. candidus, B. ceylonicus, B. magnimaculatus, B. multicinctus, B. sindanus (B. lividus, B. niger)))). Snakes of the genus Bungarus Daudin, 1803, commonly known as "kraits," are moderate to large-sized (to 2 m), highly venomous elapids distributed from Pakistan eastward through southern Asia to Indonesia. Kraits are easily distinguished from other terrestrial elapids by a middorsal row of enlarged, hexagonal scales (Fig. 1 and Smith, 1943). Additionally, kraits have distinctive vertebrae with laterally expanded prezygapophysial and postzygapophysial processes (Fig. 2) and unusually high neural processes (Hoffstetter, 1939; Hoffstetter and Gasc, 1969). Externally, these high neural processes result in a raised middorsal ridge giving kraits a distinctive triangular appearance in cross-section. These characters are derived and indicate that Bungarus is monophyletic. Although no other elapids possess a comparable vertebral morphology, various colubrids do have laterally expanded zygapophysial processes and high neural processes (e.g., Mehelya, Synophis, Xenodermus, Xenopholis [Bogert, 1964; Hoffstetter and Gasc, 1969]). In Mehelya, this Bungarus-like vertebral morphology is combined with an enlarged vertebral scale row to result in an astonishing example of convergence (A. Savitzky, pers. comm.). Other features of scutellation and osteology in kraits are typical of other elapids and are described in Smith (1943) and Rosenberg (1968), respectively. Of the 13 species of Bungarus listed by Golay (1985), B. javanicus Kopstein, 1932, is probably the genus Bungarus Daudin, 1803, l known as "kraits," are moderate to i e (to 2 ), highly venomous elapids te fro Pakistan eastward through sia to Indonesia. Kraits ar easily disi e fro other te restrial elapids by a sal ro of enlarged, hexagonal scales S ith, 1943). A ditionally, kraits i ti ctive vertebrae with laterally exezygapophysial and postzygapophyesses (Fig. 2) and unusually high neural s ( offste ter, 1939; Ho fstetter and 9). Externa ly, these high neural pros lt in a raised mi dorsal ridge giving istinctive triangular a pearance in a melanistic variant of B. candidus (see below), and B. walli Wall, 1907, was shown (Khan, 1984) to be a junior synonym of B. caeruleus sindanus Boulenger, 1897, which was elevated to specific status (Khan, 1984, 1985). With these changes, there are 12 species of kraits: B. andamanensis, B. bungaroides, B. caeruleus, B. candidus, B. ceylonicus, B. fasciatus, B. flaviceps, B. lividus, B. magnimaculatus, B. multicinctus, B. niger, and B. sindanus. The key in Golay (1985) contains several errors and, hence, I present a revised key to the species in Appendix 2. Bungarus javanicus was described by Kopstein in 1932 based on a single specimen (RMNH 9007) that he collected in 1931 from "Soember, Cheribon" (=Sumber, Tjirebon), in northwestern Java. Later, Kopstein (1936) described two additional specimens from the same area. One f th se is RMNH 9008 (collected by Kopstein in 1932), but the location of the other individual is unknown and the specimen may no longer exis . Of the other species of Bungarus in Java, B. javanicus is most similar to-and occurs within the geographic range of-B. candidus, from which it differs only in its melanistic coloration. Based on my examination of RMNH 9007 and 9008, the coloration of B. javanicus can be described as follows: the dorsal scales are dominated by dark brown (probably black in life), but the dorsal and ventral margins of each scale are generally white. The interstitial skin is also white. The overall effect is a brown-and-white elanistic variant of B. candidus (see below), B. walli Wall, 1907, was shown (Khan, 1984) be a junior sy onym of B. ca ruleus sindanus lenger, 1897, w ich was el vated to specific tus (Khan, 1984, 1985). With these changes, ere are 12 species of kraits: B. andamanensis, B. garoides, B. caer leus, B. candidus, B. ceylonicus, . fasciatus, B. flaviceps, B. lividus, B. magnimacus, B. mult cinctus, B. niger, and B. sindanus. The in Golay (1985) contains sev al errors and, ce, I present a revised key to the species in endix 2. garus javanicus was descri ed by Kopstein 1932 based on a single specimen (RMNH 7) that he collected in 931 from "Soember, eribon" (=Sumber, Tjirebo ), in northwestJava. Later, Kopstein (1936) described two itional specimens from the same area. One these is RMNH 9008 (collected by Kopstein 1932), bu the locati n of the other ndividual nknown and the specimen may o longer ist. Of the other sp cies of Bungarus in Java, . javanicus is mo t s milar to-and occurs withthe geographic range of-B. candidus, from ich it di fers only n its melanistic coloration. sed on my examinati n of RMNH 9007 and 8, the c loration of B. javani us can be de440 This content downloaded from 157.55.39.27 on Mon, 05 Sep 2016 04:09:19 UTC All use subject to http://about.jstor.org/terms PHYLOGENY OF BUNGARUS FIG. 1. The skin of Bungarus fasciatus (LSUMZ 22074) showing the enlarged vertebral scales that characterize kraits. mottling with the white areas forming weakly defined longitudinal stripes. The venter is white with lateral suffusions of dark brown pigment on each ventral scale. Kopstein (1938) described several melanistic kraits from the same region as B. javanicus. Because the melanistic pigment extended onto the venter, as do the black bands in B. candidus, he considered the specimens to represent B. candidus, despite their possession of dorsal coloration similar to that of B. javanicus as described above. Melanistic individuals of B. candidus in Java have not been reported outside the range of B. javanicus. Mao (1961) described a melanistic individual of B. multicinctus from Taiwan with similar coloration to that of B. javanicus, i.e., a black-and-white mottling. Significantly, the black pigment does not extend onto the venter, despite the fact that the black bands in typical B. multicinctus do extend onto the venter. There are no differences between B. javanicus and B. candidus in cephalic scutellation, and the segmental counts of the former fall within the range of the latter (B. javanicus: ventrals 210-213, subcaudals 46-50 [Kopstein, 1932, 1936]; B. candidus: ventrals 210-222, subcaudals 40-50 [Wall, 1908]). I conclude that B. javanicus represents a melanistic variant of B. candidus. Thus, I consider B. javanicus Kopstein, 1932, a junior synonym of B. candidus. The present study was undertaken to elucidate the phylogenetic relationships among kraits employing morphological characters analyzed by the me hod of maximum parsimony.