Phyllodactylus sp. 3 (P. tuberculosus species group, lineage A11 sensu Blair et al. 2015)

Castiglia, Riccardo, Flores-Villela, Oscar Alberto, Bezerra, Alexandra M. R., Gornung, Ekaterina, Annesi, Flavia, Munoz-Alonso, Luis Antonio & Solano, Emanuela, 2020, Detection of cryptic diversity in lizards (Squamata) from two Biosphere Reserves in Mesoamerica, Comparative Cytogenetics 14 (4), pp. 613-638 : 613

Phyllodactylus sp. 3 (P. tuberculosus species group, lineage A11 sensu Blair et al. 2015)

Distribution.

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).

Samples.

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

DNA taxonomy.

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.

Chromosomes.

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).

Figures

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 " A 11 " and the new specimens here analysed are indicated (see text for further explanation).

Figure 5. Karyotypes of A Phyllodactylus sp. 3 (2 n = 38, RCMX 69 male) B Holcosus festivus (2 n = 50, RCMX 224 female) C Holcosus undulatus parvus (2 n = 50, RCMX 77 female) D Aspidoscelis deppii (2 n = 52, RCMX 76 female).