Together but not intertwined: differences in sexual behavior between two sympatric and synchronized spider species, including one new synonymy (Araneae, Tetragnathidae, Tetragnatha)

CARGNELUTTI, F; BOLLATTI, F.; IZQUIERDO, M. A.; CASTANHEIRA, P. DE S.; CERQUEIRA BAPTISTA, R. L.; BARRANTES, G.; AISENBERG, ANITA

JOURNAL OF ARACHNOLOGY

AMER ARACHNOLOGICAL SOC

Lugar: Nueva York; Año: 2022 p. 67 - 80

0161-8202

Species recognition and reproductive isolation are critical for organisms to prevent expensive and unsuccessful matings. This may be particularly important in closely related species that coexist synchronously in the same habitat, and for which reproductive barriers are not entirely effective. Tetragnatha nitens and T. argentinensis are two long-jawed orb weaver spiders whose feeding grounds and reproductive phenology overlap extensively. Since general patterns of sexual behavior observed in the field showed no apparent differences between these two species, we proposed to explore the existence of reproductive isolation mechanisms between them by analyzing fine scale mating behaviors in both species and sexes. In addition, we evaluated the ocurrence of heterospecific matings. We found that both species showed similar general mating patterns, however, there are some subtle differences. In T. nitens males clasped the female´s chelicerae with their own, but the opposite occurred in T. argentinensis. Moreover, males of T. nitens produced less inflations, lower number of flubs, and briefer insertions than males of T. argentinensis. Females of T. argentinensis vibrated their abdomen at a higher rate. We observed only one heterospecific mating, and little or no sexual interaction occurred in the other crossed matings, indicating that these sympatric Tetragnatha species have successful reproductive isolation that probably occurs through other recognition mechanisms prior to mating. Finally, after analyzing an extensive number of specimens from museum collections, we were able to recognize one new synonym for T. argentinensis. We provide a short note on its taxonomic status and update the distribution of this species.