DNA sequences of troglobitic nicoletiid insects support Sierra de El Abra and the Sierra de Guatemala as a single biogeographical area: Implications for Astyanax

Abstract

The blind Mexican tetra fish, Astyanax mexicanus, has become the most influential model for research of cave adapted organisms. Many authors assume that the Sierra de Guatemala populations and the Sierra de El Abra populations are derived from two independent colonizations. This assumption arises in part from biogeography. The 100 m high, 100 m wide Servilleta Canyon of the Boquillas River separates both mountain ranges and is an apparent barrier for troglobite dispersion. Anelpistina quinterensis (Nicoletiidae, Zygentoma, Insecta) is one of the most troglomorphic nicoletiid silverfish insects ever described. 16S rRNA sequences support that this species migrated underground to reach both mountain ranges within less than 12,000 years. Furthermore, literature shows a plethora of aquatic and terrestrial cave restricted species that inhabit both mountain ranges. Thus, the Servilleta canyon has not been an effective biological barrier that prevented underground migration of troglobites between the Sierra de Guatemala and the Sierra de El Abra. The Boquillas River has changed its course throughout time. Caves that in the past connected the two Sierras were only recently geologically truncated by the erosion of the new river course. It is likely that, with the geological changes of the area and throughout the 2-8 million years of evolutionary history of cave Astyanax, there have been opportunities to migrate across the Servilleta canyon.

The role of gene flow in rapid and repeated evolution of cave‐related traits in Mexican tetra, Astyanax mexicanus

“…Notably, many species of troglobites other than Astyanax inhabit caves spanning from southern El Abra to Sierra de Guatemala, and some were able to migrate among these areas within the last 12,000 years (Espinasa et al . 2014a).…”

Phylogeographical convergence between Astyanax cavefish and mysid shrimps in the Sierra de El Abra, Mexico

“…Barriers for dispersal for aquatic and terrestrial organisms in the El Abra caves appear to be different. Espinasa et al (2014) sequenced the 16S rRNA of Anelpistina quinterensis (Nicoletiidae, Zygentoma, Insecta), a highly troglomorphic nicoletiid silverfish insect that inhabits from southern Sierra de El Abra to Sierra de Guatemala. Using a calibrated molecular clock, their data supports that this species migrated underground to reach both mountain ranges within less than 12,000 years, implying relatively easy underground migration, with no isolating evolutionary barrier for the central Sierra de El Abra, in terrestrial cave populations.…”

Divergent evolutionary pathways for aggression and territoriality in Astyanax cavefish

“…Multiple authors (e.g. Bradic et al 2013;Gross 2012;Herman et al 2018) have suggested that each mountain range has independent evolutionary histories, although colonization independence has been disputed for the Sierra de Guatemala and Sierra de El Abra by Espinasa et al (2014). All cave localities (Molino, Caballo Moro, Jineo, Vásquez, and Escondido) involved in this study come from Sierra de Guatemala, with the exception of the Pachón and Tinaja cave populations, which are from Sierra de El Abra (Fig.…”