Cubophis Hedges & Vidal

Hedges, Blair, Couloux, Arnaud & Vidal, Nicolas, 2009, Molecular phylogeny, classification, and biogeography of West Indian racer snakes of the Tribe Alsophiini (Squamata, Dipsadidae, Xenodontinae), Zootaxa 2067, pp. 1-28 : 14-16

Genus Cubophis Hedges & Vidal , New Genus

Type species. Coluber cantherigerus Bibron, 1840:27 .

Diagnosis. Species in this genus have 17 midbody scale rows, 159–187 ventrals, 101–133 subcaudals, 2 apical scale pits, 8 upper labials, 10 lower labials, 13–17 total maxillary teeth, and 17–21 dentary teeth ( Table 2). Cubophis differs in at least one of these characters from all other alsophiine genera except Hypsirhynchus . It differs from Hypsirhynchus in hemipenial characters such as the presence of enlarged papillate body calyces in the basal region and medial surface of the lobes ( Zaher 1999).

Content. Five species (13 species + subspecies) are included in the genus ( Table 1).

Distribution. The genus is distributed in the western Caribbean: Cuba, the Cayman Islands, Bahamas, Turks and Caicos Islands, and Swan Islands ( Fig. 2 ).

Etymology. The generic name refers to its distribution, centered on Cuba and nearby islands.

Remarks. Species of Cubophis ( Fig. 3 C) are large species of racers which occur sympatrically with small ( Arrhyton ) and moderate-sized ( Caraiba ) species of racers on Cuba. Our finding that the Cayman Island taxa are most closely related to Cubophis vudii supports their elevation from subspecies of Cubophis cantherigerus to full species. Zaher et al. (2009) classified all of these species together with Borikenophis portoricensis and other West Indian species in Ocyophis Cope , but our results ( Figs. 1 and 4 ) contradict that decision (see Remarks in Hypsirhynchus )

Figures

FIGURE 2. Map showing the West Indies (including the southern tip of Florida above, Central America to the west, and the northern edge of South America below) and the distributions of the genera of the Tribe Alsophiini, Subfamily Xenodontinae, Family Dipsadidae.

FIGURE 3. Representatives of genera of the snake Tribe Alsophiini (Dipsadidae: Xenonodontinae). Subtribe Alsophiina: Alsophis manselli (Woodlands Spring, Montserrat), Borikenophis portoricensis (1.5 km W. Playa de Tamarindo, Puerto Rico), Cubophis cantherigerus (2.0 km W Viñales, Pinar del Rio, Cuba), Hypsirhynchus ferox (Barahona, Barahona, Dominican Republic), Ialtris dorsalis (3 km N Bois Sec, Grand’Anse, Haiti), and Magliophis stahli (1.9 km NE Vista Alegre, Puerto Rico). Subtribe Arrhytonina: Arrhyton taeniatum (0.2 km WE Windmill Beach, Guantanamo Bay Naval Station, Cuba). Subtribe Uromacerina: Uromacer oxyrhynchus (4.4 km W Canada Honda, La Altagracia, Dominican Republic). Photos by S. B. Hedges.

FIGURE 1. A phylogeny of Alsophiini. Bayesian tree obtained from the combined data set of six genes (RAG 2, 12 S & 16 S rRNA, cytochrome b, ND 2 and ND 4; 3387 sites). Alsophis portoricensis portoricensis and A. p. anegadae have identical sequences at all genes sampled, and therefore the latter taxon is not shown. Values are ML bootstrap values above 70 % followed by Bayesian posterior probabilities above 90 %. The generic taxonomy in this tree reflects usage prior to this study and shows paraphyly and polyphyly of Alsophis (blue), Arrhyton (purple), and Antillophis (orange). See Table 1 and Figure 4 for the new classification proposed here.

FIGURE 4. A timetree of Alsophiini. Divergence times and credibility / confidence intervals are shown in Table 3. Plei = Pleistocene. The generic taxonomy in this tree reflects the new classification proposed here and detailed in Table 1.