Multiple approaches to understanding the taxonomic status of an enigmatic new scorpion species of the genus Tityus (Buthidae) from the biogeographic island of Paraje Tres Cerros (Argentina)

Abstract

Tityus curupi n. sp., belonging to the bolivianus complex, is described from the biogeographically distinct area of Paraje Tres Cerros in north-eastern Argentina. We also present a molecular species delimitation analysis between Tityus curupi n. sp. and its sister species Tityus uruguayensis Borelli 1901 to confirm species integrity. Furthermore, a cytogenetic analysis is presented for these two species which contain different multivalent associations in meiosis, as a consequence of chromosome rearrangements, and the highest chromosome numbers in the genus.

Insights into the origin of the high variability of multivalent-meiotic associations in holocentric chromosomes of Tityus (Archaeotityus) scorpions

“…Intraspecific variability in diploid number has been recorded in 40% of the 18 karyotyped Tityus species [ 42 , 69 ]. Similar to the species investigated herein, previous studies revealed variations at the inter- and intra-population levels and attributed differences in chromosome number to fission/fusion rearrangements [ 29 , 39 , 41 , 42 , 48 ]. In specimens of T .…”

“…Studies examining specific chromosomal regions in scorpions have increased significantly in recent years [ 29 , 39 – 42 , 48 , 83 – 87 ]. Data regarding the localization of NORs and rDNA has revealed remarkable stability, particularly in Tityus species, in which more than 80% of the species presented a similar pattern, i.e., NORs/rDNA in the terminal regions of two chromosomes.…”

“…confluens (2n = 5–6), Tityus curupi (2n = 32–31), T . obscurus (2n = 11–16) and Tityus uruguayensis (2n = 31) with holocentric chromosomes [ 40 – 42 , 48 ]. Thus, the telomeric chromosomal region is conserved despite extensive rearrangements.…”

“…Scorpions represent an intriguing group of animals characterized by a high incidence of heterozygous chromosomal rearrangements. In addition, the family Buthidae combines three unusual cytogenetic features: holocentric chromosomes, multivalent-meiotic associations and achiasmate meiosis in males [ 27 , 29 , 39 – 42 ]. Multivalent associations in meiosis have been observed in 50% of the species included in eight different buthid genera [ 27 , 29 , 39 – 48 ].…”

“…In buthid scorpions, heterozygous reciprocal translocations or fission/fusion rearrangements are hypothesized to be responsible for the origin of multi-chromosomal associations during meiosis I [ 27 , 29 , 39 – 42 , 48 ]. The mechanisms responsible for correct chromosome pairing and segregation of long chromosomal chains remain poorly characterized.…”