COEXISTING IN SYMPATRY: evaluating the phenotypic variation of multiple morphological traits in two species of mountain scorpions

OVIEDO DIEGO, MARIELA; PERETTI, ALFREDO V.; MATTONI, CAMILO I.; SOTO, EDUARDO

Congreso; American Arachnological Society Virtual Summer Symposium; 2020

American Arachnological Society

In sympatric areas, the correct sexual recognition among conspecifics is critical to ensure reproductive isolation. However, the recognition can fail resulting in processes like reproductive interference (RI). For this, certain reproductive traits can suffer reproductive character displacement (RCD), allowing species´ coexistence. Two species of closely related scorpions (Urophonius brachycentrus, U. achalensis) have sympatric populations with synchronic reproduction (Argentina). Antecedents in these species reveal the occurrence of heterospecific mating and chemical communication overlapping, which allows us to test if certain traits experiment RCD in response to RI. We perform linear and geometric morphometrics of several non-sexual and sexual traits (involved in different mating stages and sperm transfer). We observed RCD in both sexes of U. brachyentrus in the pedipalp´ shape, a key trait in courtship behavior. However, in both species most of the structures size experiment convergence towards sympatry, which would evidence some ecological processes. These results are extremely interesting in terms of the occurrence of asymmetric RCD and the possible competitive exploitation of mates by U. achalensis. Furthermore, a scenario with scramble competition, a short reproductive period and the existence of strong sperm competition make our findings an important piece in the puzzle of the reproductive biology of these species.