Caraiba Zaher et al., 2009

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

Genus Caraiba Zaher et al., 2009

Type species. Liophis andreae Reinhardt & Lütken, 1862:214 .

Diagnosis. The species in this genus has 17 midbody scale rows, 131–157 ventrals, 90–120 subcaudals, 1 apical scale pit, 8 upper labials, 9 lower labials, 20–23 total maxillary teeth, and 25–28 dentary teeth ( Table 2). Caraiba differs in at least one of these characters from all other alsophiine genera except Hypsirhynchus . From that genus it differs in having a hemipene with enlarged papillate body calyces in the basal region and medial surface of the lobes ( Zaher 1999).

Content. One species (six species + subspecies) is included in the genus ( Table 1).

Distribution. The genus is distributed on Cuba, including Isla de Juventud ( Fig. 2 ).

Remarks. The single species of Caraiba is a moderate-sized species of racer, occurring sympatrically with smaller and larger genera of racers on Cuba. The finding here ( Figs. 1 and 4 ) that “ Antillophis ” andreae ( Cuba) groups with large Cuban racers of another genus (see below) and that “ Antillophis ” parvifrons (Hispaniola) groups with Hispaniolan species ( Hypsirhynchus ) is also supported by morphology: the former species ( Cuba) have 17 midbody scale rows whereas the latter species (Hispaniola) have 19 midbody scale rows. Myers (1973) also had reservations about Maglio’s (1970) recognition of Antillophis based on morphology. Zaher et al. (2009) described Caraiba for the single species, based only on its hemipenial differences.

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 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.