Cytotaxonomy and DNA taxonomy of lizards (Squamata, Sauria) from a tropical dry forest in the Chamela-Cuixmala Biosphere Reserve on the coast of Jalisco, Mexico
Author
Castiglia, Riccardo
Author
Annesi, Flavia
Author
Bezerra, Alexandra M. R.
Author
García, Andrés
Author
Flores-Villela, Oscar
text
Zootaxa
2010
2508
1
29
journal article
10.5281/zenodo.196005
4a013300-d475-4db9-a5cf-bff30510ac4a
1175-5326
196005
Urosaurus bicarinatus
Duméril
(Tropical tree lizard)
Specimens analysed:
one male from Chamela (CEAC19), one specimen from Rio Grande, Oaxaca (MZFC 12046), one specimen from Epatlan, Puebla (MZFC 6863).
Distribution:
Mexican endemic. Pacific coast of
Mexico
, from Sonora to Chiapas.
Subspecies:
U. b.
bicarinatus
, distributed from Michoacán to central Guerrero, and in the Río Balsas basin up to Morelos and southern Puebla;
U. b. anonymorphus
, found in east Guerrero, Oaxaca, and possibly western Chiapas;
U. b. nelsoni
, localized in northern Oaxaca;
U. b. tuberculatus
, distributed in Southern Sonora southward to Jalisco and Colima with isolated populations in Sinaloa;
U. b. spinosus
, from southwestern Chiapas. However,
Wiens (1993)
did not find morphological differences among the subspecies.
Karyotype:
Unfortunately, we did not obtained good metaphases from this species.
DNA taxonomy:
There is no sequence deposited in GenBank for this species. The available rDNA 16S sequences in GenBank are for
U. ornatus
,
U. nigricaudus
,
U. microscutatus
, and
U. graciosus
(
Reeder 1995
)
. We aligned these sequences with the sequence of
U. bicarinatus
from Chamela belonging to
U. b. tuberculatus
and with sequences from two additional individuals (Rio Grande, Oaxaca and Epatlan, Puebla) possibly belonging to
U. b. nelsoni
and performed a phylogenetic analysis using
Sceloporus utiformis
as the outgroup. The obtained tree is shown in
Figure 8
. Interestingly, the phylogenetic relationships among species are different from those identified using morphological characters by
Wiens (1993)
and are congruent with Reeder’s (1995) results. Molecular analysis shows that
U. bicarinatus
has an external position with respect to the other species, which form a monophyletic group (supported only by NJ, 62%). Moreover in our tree
U. ornatus
is clearly the sister species of
U. graciosus
(supported by 87–99%). Conversely, phylogenetic relationships based on morphological characters show that
U. graciosus
was external to
U. bicarinatus
,
U. nigricaudus
,
U. ornatus
and
U. microscutatus
(
Wiens 1993
)
. The topology obtained with molecular data is congruent with the distribution of the species.
U. bicarinatus
is nested in the southern part of the range of the genus while the other species, which cluster together in the tree, are localized in the northern part.
The highest interspecific distance has been found between
U. bicarinatus
and the other species (8.4– 9.4%), while lower values have been found between the other species (3.5–7.7%). A low divergence value (1.8%) was found between sequences of the Rio Grande (Oaxaca) and Epatlan (Puebla) populations of
U. bicarinatus
. Greater distance was found between these two localities and the sequences from Chamela (4.3– 4.5%) belonging to a different subspecies. In the absence of additional data, it is very difficult to infer a conclusion regarding the taxonomic status of the Chamela population. These findings suggest that a complete intra and interspecific revision of the genus is needed using additional molecular markers.