This species is distributed from Colima state, Mexico, southwards to Chiapas state, on the Pacific coast, and towards the southwest to Guatemala and Honduras.

RCMX85 (male*), RCMX86 (female*) and RCMX92 (female*) from La Sepultura, Chiapas, Mexico.

See below under S. cherriei (Cope, 1893) account.

The karyotype, described in Castiglia et al. (2013a) shows a diploid number of 2n = 28 and heteromorphic sex chromosomes. The diploid complement present four pairs of large metacentrics, two pairs of medium sized metacentrics, and one pair of heteromorphic (XY) sex chromosomes (pair 7; one small subtelocentric and one microchromosome). The remaining chromosomes are microchromosomes.

This species inhabits Mexico, from central Veracruz to extreme southeastern Puebla, northern Oaxaca state, southwards to Central America on the Atlantic coast, including the Yucatan Peninsula in México, reaching the eastern Panama.

RCMX219 (male) and RCMX235 (male*) from Estación Chajul, Selva Lacandona, Montes Azules, Chiapas state, Mexico.

The BI phylogenetic tree has been performed on 448-bp alignment of the 16S gene for four individuals of Scincella cherriei [RCMX219 and RCMX235 from the Montes Azules, one from Costa Rica (JF498076) and one from Nicaragua (AB057392)] and three individuals of Scincella assata [RCMX92 from La Sepultura, and two from El Salvador (JF498074 and JF498075)]. Scincella lateralis (Say, 1822) (AB057402 and JF498077) and S. reevesii (Gray, 1838) (JF498078) were used as outgroups. The tree (Fig. 3) shows S. assata as a monophyletic and well supported group (p.p.: 1.0), including the individual from La Sepultura. The two individuals of S. cherriei from the Montes Azules, southern Mexico, form a well-supported group separated from the other two individuals from Costa Rica and Nicaragua that fall in a well distinct clade (p.p.: 1.0).

The genetic divergence between the two specimens of S. cherriei from the Montes Azules and S. cherriei from other localities is high (5.2%), comparable to the divergence between S. assata and S. cherriei (6.6%-6.2%). The nominal subspecies S. c. cherriei (Cope, 1893), was described from Palmar, Costa Rica, which is far from from the Montes Azules. The lineage of S. cherriei from the Montes Azules may represent a different taxon worthy of additional detailed morphological and genetic studies.

The karyotype, described in Castiglia et al. (2013a), shows a diploid number of 2n = 30 and in this case the presence of heteromorphic (XY) sex chromosomes. The diploid complement of S. cherriei differs from its sister species S. assata by the presence of an additional pair of microchromosomes.

Figure 3.

Bayesian phylogenetic tree (16S) of 16S haplotypes from Mexican Scincella species. In bold, the new individuals from this study; the geographic provenience of each individual is reported in brackets.

provisional distribution of this lineage, probably representing an undescribed species, is restricted to Pacific coast of eastern Oaxaca and western Chiapas states, Mexico (Blair et al. 2015).

RCMX67 (female*), RCMX69 (male*) and RCMX93 (female*) from La Sepultura, Chiapas state, Mexico.

Blair et al. (2015) reported the most complete phylogeny of the Phyllodactylus tuberculosus species group, defining the presence of 11 distinct lineages that represent separated species. We aligned the obtained 579-bp MT-CYB sequences from our samples to the 115 MT-CYB sequences of the 11 lineages reported by Blair et al. (2015) using Tarentola mauritanica (Linnaeus, 1758) (JQ425060) as the outgroup. The TCS network (Fig. 4) indicated that the haplotypes of our samples are similar those belonging to the lineage A11 (Blair et al. 2015), from Oaxaca and Chiapas states, and show a shallow genetic divergence (1.2%) compared to A11. Therefore, we provisionally assigned the samples from La Sepultura to this lineage.

Figure 4.

TCS network of MT-CYTB haplotypes of Phyllodactylus tuberculosus species group. The colors refer to the 11 lineages reported by Blair et al. (2015) for this species complex. The lineage “A11” and the new specimens here analysed are indicated (see text for further explanation).

The first description of the karyotype of one species of the P. tuberculosus complex is reported here (Fig. 5A). The three specimens analyzed (two females and one male) showed a 2n = 38 with no distinction in macro- and microchromosomes. All chromosomes are telocentric with exception of two pairs of small metacentric chromosomes (pair 14). We found no evidence of heteromorphic sex chromosomes.

As previously reported, 2n = 38 is the most common karyotype found in species of the genus Phyllodactylus from the Pacific coast of Mexico (Castiglia et al. 2009; Murphy et al. 2009). Exceptions are constituted by P. paucituberculatus Dixon, 1960 and P. lanei Smith, 1935 (sensu Ramírex-Reyes and Flores-Villela 2018), which have 2n = 32 and 2n = 33–34, respectively (Castiglia et al. 2009). The 2n = 38 karyotype is normally all-acrocentric, except for some records in P. bugastrolepis Dixon, 1966 and P. papenfussi Murphy, Blair et Mendes de la Cruz, 2019 (Murphy et al. 2009). The ZW sex determination system has been found in P. wirshingi Kerster et Smith, 1955 (Nielsen et al. 2019) and, probably, in P. lanei (King, 1981). In all taxa, there is no distinct break between macro- and microchromosomes. The karyotype of the specimens from La Sepultura described here, is similar to the gekkonid karyotype defined by Gorman (1973). In fact, the typical gekkonid karyotype is composed of a series of acrocentric chromosomes, gradually decreasing in size, with few or no bi-armed chromosomes and no distinct boundary between macrochromosomes and microchromosomes (Bickham 1984). The 2n = 38 acrocentric karyotype is considered to be the ancestral in the families Gekkonidae, Diplodactylidae, and Eublepharidae. In Phyllodactylidae the chromosomal number ranges from 2n = 32 to 2n = 44 (Pellegrino et al. 2009). While the karyotype of the genus Phyllodactylus seems rather conservative, the pair of metacentric chromosomes in the here studied specimens indicates presence of intrachromosomal rearrangements (Pokorná et al. 2015). Therefore, these chromosomes may represent chromosomal markers for further investigation in this genus characterized by multiple cryptic species (Blair et al. 2015).

Figure 5.

Karyotypes of A Phyllodactylus sp.3 (2n = 38, RCMX69 male) B Holcosus festivus (2n = 50, RCMX224 female) C Holcosus undulatus parvus (2n = 50, RCMX77 female) D Aspidoscelis deppii (2n = 52, RCMX76 female).

Bezy and Camarillo (2002) did not recognize subspecies, although they admitted that populations of this taxon form a complex, therefore representing more than one taxon. It is the only vertebrate species with unisexual parthenogenetic populations that are of non-hybrid origin (Sinclair et al. 2010).

Found on the Gulf of Mexico coast from Veracruz and Oaxaca, crossing the base of the Yucatan peninsula, through Central America to Panama.

RCMX207 (female*), RCMX208 (male*), RCMX212 (female*), RCMX213 (male*), and RCMX232 (female*) from Montes Azules, Chiapas state, Mexico.

Our samples have been identified on a morphological basis as Lepidophyma flavimaculatum, a species already reported for Chiapas. We aligned our 309 bp MT-CYB sequences to the 14 haplotypes of the same species published in Sinclair et al. (2010) from Honduras, Nicaragua and Belize, as well as the unisexual populations from Costa Rica and Panama; L. reticulatum Taylor, 1955 and L. lipetzi Smith et Del Toro, 1977 were used as outgroups. The phylogenetic trees (Fig. 6A) showed that our samples are sister to the L. flavimaculatum clade, but it forms a separate and well supported lineage (p.p. = 1) with 3.9% of genetic divergence. The TCS network (Fig. 6B) confirms that the samples from Chiapas are differentiated from all the other populations of L. flavimaculatum by 8 substitutions, whereas the other haplotypes differ from each other by not more than 3 substitutions. The shallow distinction of the Chiapas population may reflect the phylogeographic structure of the species, in accordance with its distant geographical location. Moreover, Bezy (1989) found that Chiapas specimens are morphologically distinct from other southern Mexican samples. Therefore, additional comparative studies at the northern edge of the species range are needed.

Figure 6.

Bayesian phylogenetic tree (A) and TCS network (B) of 16S haplotypes belonging to Lepidophyma flavimaculatum. The colors refer to the geographic provenience of individuals. In bold, the new specimens from this study.

Diploid chromosome complements vary from 2n = 24 to 2n = 40 in Xantusiidae (Olmo and Signorino 2005). Within Xantusia Baird, 1859 the karyotypic formula is highly conserved with all studied species displaying 2n = 40, while the genus Lepidophyma is much more variable with diploid number ranging from 2n = 32 to 2n = 38 (Olmo and Signorino 2005). There is no evidence of heteromorphic sex chromosomes within the family, but recently a ZZ/ZW sex chromosomes system was described in the X. henshawi Stejneger, 1893 (Nielsen et al. 2020). In L. flavimaculatum unisexual parthenogenetic populations are known from Panama and southeastern Costa Rica, whereas northern populations are bisexual. All unisexual populations so far studied are diploid (2n = 38), except one mosaic individual (2n/3n) (Bezy 1972). All individuals presently analysed (Fig. 7) showed 2n = 38 with 18 macrochromosomes and 20 microchromosomes, as previously reported by Bezy (1972).

Figure 7.

The karyotype of Lepidophyma flavimaculatum (2n = 38, RCMX208 male).

The species has a wide distribution from Morelos and Michoacan (Mexico) south to Guatemala, El Salvador, Honduras, Nicaragua and Costa Rica.

RCMX76 (female*) from La Sepultura, Chiapas, Mexico.

The MT-CYB sequence (294-bp) is 4% divergent from GenBank sequences of Aspidoscelis deppii (KF555517-21) from Mexico (Playa Miramar, Tabasco). Despite the wide distribution, there are no studies on the intraspecific genetic variability of this species. It is a pity because this slight divergence in the MT-CYB could match with a different karyotype (see below).

In the genus Aspidoscelis chromosomal number ranges from 2n = 44 to 2n = 56, with some species showing triploid numbers, such as Aspidoscelis tesselatus (Say, 1823), with 69 chromosomes (Walker et al. 1997). The 2n = 44 is the most common diploid number in this genus (Carvalho et al. 2015). Therefore, a low diploid number could represent an ancestral condition. All-acrocentric karyotypes with 2n = 52 (28M + 24m) (Lowe et al. 1970) and 2n = 50 (26M + 24m) (Manríquez-Morán et al. 2000) were reported in Aspidoscelis deppii from an unknown location and from Yucatan, respectively. Therefore, the two karyotypes differ in the number of macrochromosomes. Concurrently with Lowe et al. (1970), we found a 2n = 52 (28M + 24m) (Fig. 5D) all-acrocentric chromosome complement in our sample from Chiapas. This result is also consistent with phylogenetic relationships, since a diploid complement 2n = 52 (28M + 24m) was found in other two species so far analyzed, A. guttatus Wiegmann, 1834 and A. lineattissimus (Cope, 1878), which are closely related to A. deppii (Lowe et al. 1970; Carvalho et al. 2015).

This species is found in the lowlands of Tabasco and Mexico down to Colombia; it does not enter in the Yucatan Peninsula.

RCMX223 (female*), RCMX224 (female*), and RCMX233 (female) from Estación Chajul, Selva Lacandona, Montes Azules, Chiapas, Mexico.

The 600-bp PCR-amplified fragments of the MT-ND2 gene were identical in the two specimens (RCMX223 and RCMX233). The BLASTn search showed that this sequence belongs to Holcosus festivus, with 99.8% – 100% identity to H. festivus (KR058107, Montes Azules) and 96% identity to the other two H. festivus samples (KR058105 and KR058106, Costa Rica).

Here we report the first karyotype description for H. festivus (Fig. 5B). We analyzed two female individuals, both with the diploid number 2n = 50. The karyotype is composed of a gradual series of acrocentric chromosomes: 26 macro- and 24 microchromosomes. The largest pair of chromosomes shows a secondary constriction at the distal end (see discussion below under the H. undulatus account).

Meza-Lázaro and Nieto-Montes de Oca (2015), in a molecular phylogenetic study, proposed the elevation of 9 of the 12 H. undulatus subspecies to species rank. However, this change has not been widely accepted by other authors. Therefore, we formally use the previous classification, but we also take in account the results of the Meza-Lazaro and Nieto-Montes de Oca (2015) study.

The species is distributed along both coasts of Mexico from southern Nayarit to northern Costa Rica Pacific coast) and from southern Tamaulipas to central Nicaragua (Atlantic coast) including the peninsula of Yucatan.

RCMX77 (female*) from La Sepultura, Chiapas, Mexico.

The MT-ND2 sequence (556-bp) obtained from the individual from Chiapas has a 99% match to two GenBank sequences of H. undulatus parvus Barbour et Noble, 1915 (KR058051 and KR058063). According to Meza-Lazaro and Nieto-Montes de Oca (2015), this subspecies, distributed in the Pacific coast region of Southern Mexico and Northern Guatemala, should be elevated to species rank.

The specimen analyzed shows a 2n = 50 chromosome number (Fig. 5C). The karyotype comprises a gradual series of acrocentric chromosomes (26M + 24m), as previously described in Castiglia et al. (2010) for H. undulatus from Chamela, Biological Station (Jalisco). In the genus Holcosus, only H. festivus (Chiapas, Castiglia et al. 2010) and H. undulatus (Jalisco, present data) have been karyotyped. In Cnemidophorus, a possible sister group of Holcosus (Pyron et al. 2013), 2n = 50 chromosome complement with one biarmed pair has been reported (Carvalho et al. 2015). Different species of Kentropyx Spix, 1825 and Ameiva show a 2n = 50 all-acrocentric karyotype, similar to the one found in Holcosus (Carvalho et al. 2015). Since these genera span the entire phylogenetic tree of Teiidae, we hypothesize that 2n = 50 all-acrocentric karyotype may represent an ancestral condition. However, to reveal more reliable pattern of chromosomal change, an ancestral state analysis combining karyotype and molecular phylogeny should be made (e.g. Castiglia et al. 2013a).

Anolis capito has been found from Tabasco and northern Chiapas south to Central America on the Atlantic coast, to Costa Rica and Panama, where it is found on both coasts.

RCMX217 (female*), RCMX218 (female*) from Montes Azules, Chiapas, Mexico. The specimens were collected close to the northern part of species range and morphologically assigned to Anolis capito. Based on morphological studies from populations of almost all the species range, there is no evidence of cryptic species in A. capito (Köhler et al. 2005).

We obtained a 685-bp MT-ND2 sequence showing 9% genetic divergence respect to an A. capito sequence collected in Costa Rica (GenBank AY909744). Such a high genetic divergence spurred us to perform a complete phylogenetic analysis with the MT-ND2 gene of Anolis species available in GenBank (not shown). The sequences from our samples cluster with the GenBank A. capito sequence, and together were sister to A. tropidonotus Peters, 1863. This tree topology has been already reported by Poe et al. (2017). Summarizing, the very high genetic divergence and discrepancies in diploid chromosome numbers (see below) of morphologically similar individuals recognized as Anolis capito indicate the possible existence of cryptic taxa. Further, it is worth noting that the specimens described here seem to have shorter limbs than other A. capito (O. Flores-Villela personal observation).

Gorman (1973) described the karyotype of Anolis capito, under the name of Norops capito, as 2n = 40 (24M + 16m) with no evidence of heteromorphic sex chromosomes, but no details on the shape of the chromosomes were reported. Our specimens have a 2n = 42 chromosome complement, with 24 micro- and 18 microchromosomes, and no evidence of heteromorphic sex chromosomes but no males have been studied (Fig. 6A).

The specimens presently studied show, along with Anolis nebuloides Bocourt, 1973, the highest diploid number within the genus Anolis. The macrochromosomes include one pair of metacentric, six pairs of submetacentric, and five pairs of subtelocentric/acrocentric chromosomes. The chromosome shape of two pairs of microchromosomes appears to be biarmed. No heteromorphic sex chromosomes are discernible (unfortunately, no males have been analyzed).

The lack of description of chromosome morphology in Gorman’s study (Gorman 1973) did not allow detailed comparison among the 2n = 40 chromosomal complements. Thus, Anolis capito occurs within a group of species with 2n = 40 (Castiglia et al. 2013b) and its additional chromosomal pair is probably due to a fission event. It has already been hypothesized that chromosomal fission is a characteristic trait of Norops chromosome evolution (Castiglia et al 2013b; Gamble et al. 2014).

Occurs on the Atlantic coast from central Veracruz to central Panama, and on the Pacific coast from Costa Rica to central Panama.

RCMX214 (male*), RCMX225 (male*) Estación Chajul, Selva Lacandona, Montes Azules, Chiapas, Mexico.

BLAST analysis of the 630-bp MT-ND2 gene sequences from both individuals show 99.5% – 100% of identity with a sequence of A. lemurinus from Oaxaca (GenBank KT724761).

No previous chromosomal data are available for A. lemurinus and its karyotype is here described for the first time. Both male specimens from Montes Azules have a 2n = 40 (24M + 16m) karyotype (Fig. 8B). The 12 pairs of macrochromosomes include eight pairs of submetacentric and four pairs of subtelocentric/acrocentric chromosomes. The metacentric chromosomes of pair 10 are of different size and may represent heteromorphic sex chromosomes of the XY type.

This karyotype has the same composition in micro- and macrochromosomes as all Anolis species with 2n = 40 so far described. Molecular phylogenetics (Poe et al. 2017) place A. lemurinus nested within a clade in which all the species so far karyotyped show 2n = 40 (Castiglia et al. 2013b). Ancestral state analysis (Castiglia et al. 2013b) indicates that the 2n = 40 karyotype is derived from by five centric fissions of macrochromosomes from an ancestral 2n = 30. What that should be further investigated are the chromosomal rearrangements occurring within macrochromosomes in the 2n = 40 karyotype.

Figure 8.

Karyotypes of A Anolis capito (2n = 40, RCMX218 female) B Anolis lemurinus (2n = 40, RCMX214 male) and C Anolis uniformis (2n = 50, RCMX210 male) with YX₁X₂ sex chromosomes; in the box the X₁X₁X₂X₂ (RCMX206 female) sex chromosomes.

Occurs from southern Tamaulipas to north-central Honduras on the Atlantic coast.

RCMX201 (male), RCMX203 (male), RCMX205 (male*), RCMX206 (female*), RCMX209 (female), RCMX210 (male*), RCMX215 (male*) and RCMX226 (female*) from Estación Chajul, Selva Lacandona, Montes Azules, Chiapas, Mexico.

The species was formerly included in the A. humilis group, but it is now included in the Draconura clade (Poe et al. 2017). Over the 780-bp of the MT-ND2 fragment, the GenBank BLAST reports a 99% identity with A. uniformis from Belize (KJ954096 and KJ954099).

We report here the first description of the karyotype of this species (Fig. 8C). The species is characterized by X₁X₁X₂X₂/X₁X₂Y sex chromosome system. In fact, male individuals have a chromosome number 2n = 29 (14M + 15m) and females show 2n = 30 (14M + 16m). The macrochromosomes can be morphologically divided in two pairs of large metacentrics, three pairs of medium sized metacentrics, one pair of small metacentric and one pair of small acrocentric chromosomes. The X₁ was identified as an acrocentric chromosome and X₂ as a microchromosome. The Y chromosome is an acrocentric one similar in size to X₁.

Among the species of the genus Anolis with a known karyotype, this species is phylogenetically close to A. aquaticus Taylor, 1956 and A. biporcatus. Furthermore, A. biporcatus has also a similar composition of the sex chromosomes system, even if the morphology of sex chromosomes is different. In fact, the so-called 2n = 30 karyotype is one of the most common karyotypes in Anolis. However, three variants of this karyotype, based on the number and shape of macro- and microchromosomes, have been described. Among them, two types of 2n = 29–30 are present, type-A and type-B (Castiglia et al. 2010).

The type-A, typical of A. biporcatus, presents a multiple sex chromosomes system where X₁ is an acrocentric chromosome, X₂ is a microchromosome, and Y is metacentric similar in size to X₁.

In our case, the Y is a small acrocentric chromosome, which might have been derived from a pericentric inversion in the submetacentric Y chromosome of the 2n = 29–30 type-A karyotype.Thus, although it is believed that the onset of multiple sex chromosomes in Anolis occurs independently (Castiglia et al. 2013b; Gamble et al. 2014), present data suggest that this condition may represent a trait derived from the common ancestor of the two species.