Abstract
The Lesser Antilles, in the Eastern Caribbean, is inhabited by three Iguana species: the Lesser Antillean iguanaIguana delicatissima, which is endemic to the northernmost islands of the Lesser Antilles, the introduced common iguana from South America, Iguana iguana iguana, represented also by the two newly described endemic subspecies Iguana iguana sanctaluciae from Saint Lucia and Iguana iguana insularis from Saint Vincent and the Grenadines, and Grenada, and the introduced Iguana rhinolopha from Central America. Drawing on both morphological and genetic data, this paper describes the Iguana populations from Saba and Montserrat as a new species, Iguana melanoderma. This species is recognized on the basis of the following combination of characteristics: private microsatellite alleles, unique mitochondrial ND4 haplotypes, a distinctive black spot between the eye and tympanum, a dorsal carpet pattern on juveniles and young adults, a darkening of body coloration with aging (except for the anterior part of the snout), a black dewlap, pink on the jowl, the high number of large tubercular nape scales, fewer than ten medium sized–triangular dewlap spikes, high dorsal spikes, and lack of horns on the snout. This new melanistic taxon is threatened by unsustainable harvesting (including for the pet trade) and both competition and hybridization from escaped or released invasive alien iguanas (I. iguana iguana and I. rhinolopha) from South and Central America, respectively. The authors call for action to conserve Iguana melanoderma in Saba and Montserrat and for further research to investigate its relationship to other melanistic iguanas from the Virgin Islands and coastal islands of Venezuela.
Highlights
In the 1960s, Lazell (1973) studied the morphological variation of the Common Green Iguana (Iguana iguana) and identified three groups of this species in the Lesser Antilles (Fig. 1)
We examined specimens at the Museum of Comparative Zoology (MCZ) at Harvard University, USA, based on photographs taken by Joseph Martinez and Corentin Bochaton (Muséum national Histoire naturelle, Paris)
John) and the British Virgin Islands (BVI: Tortola) as well as on the coastal islands of Venezuela, and on the coast in the vicinity of captured on the mainland (Cumana), there are melanistic iguanas (Lazell 1973; MacLean 1982; Buurt 2005; Falcón et al 2018), but we found no morphological and color differences from the melanistic iguanas of Saba-Montserrat
Summary
In the 1960s, Lazell (1973) studied the morphological variation of the Common Green Iguana (Iguana iguana) and identified three groups of this species in the Lesser Antilles (Fig. 1). The populations from Saba, Montserrat, and St. Croix were characterized by having large tubercular nape scales, highly developed dorsal crest spikes, a carpet pattern in 10–30 percent of the populations, an increasing incidence of melanistic individuals, and the absence of horns on the snout [1]. Populations of the Guadeloupian Archipelago and Les Saintes were distinguished by having very weak tubercular nape scales, and a high incidence of unpatterned and of grey individuals [2]. The southern Lesser Antillean populations, from Saint Lucia, Saint Vincent, the Grenadines, and Grenada were in turn characterized by very weakly tubercular nape scales, grey or green individuals with dorsolateral bands and highly developed, hornlike, median snout scales [3]. The southern Lesser Antillean populations, from Saint Lucia, Saint Vincent, the Grenadines, and Grenada were in turn characterized by very weakly tubercular nape scales, grey or green individuals with dorsolateral bands and highly developed, hornlike, median snout scales [3]. Lazell (1973) thought that geographic variation was clinal and concluded that the Common Iguana in Les Saintes and Guadeloupe was autochthonous rather than introduced
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call