Lygodactylus ornatus

Rediscovery of Lygodactylus ornatus View in CoL

Specimens clearly assignable to L. ornatus based on the diagnostic throat pattern and morphological character states were observed, photographed, and (some of them) collected on 23 and 24 October 2023 at a field site located approximately 6 kilometers NW of Mandritsara along the National Road 32 ( Fig. 1 View FIGURE 1 ). The site, located on the western slopes of the mountain chain along Madagascar's east coast, consists of a hilly and rocky area with large granitic boulders ( Fig. 2 View FIGURE 2 ), and is biogeographically part of the North West of Madagascar (as defined in Glaw & Vences 2007). At the base of the mountain, there is a semi-open forest with shrubs alongside the rocks. The habitat is heavily degraded, characterized by significant ecological damage and loss of vegetation, as we observed several instances of logging in the area. The place is surrounded by expansive rice fields and crop plantations, which dominate the landscape. Many individuals were observed to be active beneath the rocks during the daytime, particularly between 09:00 and 12:00. Some individuals were also found in tree trunks, but our observations suggest an adaptation to primarily saxicolous habits. All individuals of L. ornatus observed in the course of our fieldwork had a dorsal coloration composed of brown, gray, red-brown, whitish and black elements, differing from most other Malagasy Lygodactylus by the stark contrast among some of these elements ( Fig. 3 View FIGURE 3 ). Typically, rather broad dorsolateral bands of reddish brown color were present, fusing on the tail which typically also had a reddish brown tint. On the anterior dorsum and flanks, distinct and sharply delimited black patches were present, and the dorsolateral bands were typically interrupted by narrow whitish crossbands that extended somewhat onto flanks and the central dorsum. The ventral side ( Fig. 4 View FIGURE 4 ) was rather bright orange-yellow in all specimens, including juveniles, with a more orange tint towards the belly and especially the tail. The throat ( Fig. 5 View FIGURE 5 ) had 4–6 transverse black stripes, typically interrupted centrally, and more distinct and continuous close to the snout tip. Three measured females had body lengths (SVL) of 23–28 mm ( Table 1). Additional scale counts of these three female specimens are given in Table 1. Whorls on the tail were weakly developed or absent in the new specimens examined (in agreement with the holotype specimen as examined and described by Pasteur 1965a and Puente et al. 2009).

The multigene phylogeny ( Fig. 6 View FIGURE 6 ) to which sequences of the 16S, ND4, CMOS, KIAA1239, and RAG1V gene fragments were added for L. ornatus , firmly embeds the species within the Lygodactylus verticillatus group, in a clade containing L. arnoulti , L. blancae , and L. heterurus (bootstrap support, BS = 85%), and sister to L. heterurus with low support (BS=61%). The species is genetically highly differentiated from its congeners, with uncorrected pairwise distances in the 16S gene of>13% to all other species of Lygodactylus , with the lowest distance of 13.2% to L. verticillatus .