Sexual dimorphism and reproductive behavior in the Brazilian scorpionTityus pusillus(Scorpiones, Buthidae)

Abstract

We studied sexual dimorphism (SD) and reproductive behavior in the litter‐dwelling scorpion, Tityus pusillus. SD was determined by measuring seven body structure attributes (prosoma, mesosoma, and metasoma lengths, and pedipalp chelae and metasomal segment V lengths and widths) in 634 individuals (211 males and 423 females) from the Arachnological Collection of the Universidade Federal de Pernambuco. Reproductive behavior was observed in 55 couples during nocturnal activity observations conducted in the laboratory. In addition, we evaluated gestation time, hemispermatophore replacement, and sequential courtship. Individuals of T. pusillus exhibited typical reproductive behavior, with a short courtship time (averaging 10±5 min). Males only accepted new partners at least 48 h after first mating, suggesting that this period may be necessary for hemispermatophore production. Females did not accept new partners for 24–48 h after their first mating. The average gestation period was 85±12 d, ranging 60–100 d. Our results showed a more complex picture of SD than previously described for this species, including features characteristic of both sexual size dimorphism (SSD) and sexual body component dimorphism in scorpions. In general, considering the relatively large size of the prosoma and mesosoma in T. pusillus, it seems reasonable to conclude that female‐biased SSD exists in the species, and that male‐biased sexual body component dimorphism is evident in the metasoma and chelae.

Notes on the courtship behavior of the parthenogenetic scorpion <I>Tityus stigmurus</I>

“…This study describes, for the first time, the courtship behavior of the parthenogenetic species T. stigmurus. Overall, we noted that their reproductive repertoire is similar to that of other species in the Buthidae family, especially the congeneric species T. bahiensis, T. fasciolatus, T. magnimanus Pocock 1897, T. pusillus, T. trinitatis Pocock 1897, and T. trivittatus Kraepelin 1898 (Polis & Sissom 1990;Ross 2009;Lira et al 2018). Juddering behavior, for instance, was observed in the courtship trials in our study, as well as in the congeneric T. magnimanus and T. trinitatis (Alexander 1959;Ross 2009).…”

Sex-based defensive behavior influenced by threat level in the scorpion Tityus pusillus (Scorpiones: Buthidae)

“…The scorpion species studied in this work, T. pusillus, is widely distributed across northeastern Brazil, and is considered to be the most abundant scorpion in the Atlantic Forest, where it predominantly occurs in the litter layers (Lira et al 2013(Lira et al , 2018a. Individuals are approximately 30-35 mm long, with a reddish yellow color with brown spots over the entire body (Lourenço 2002;Lira et al 2018b). This species exhibits sexual dimorphism (Fig.…”

“…This species exhibits sexual dimorphism (Fig. 1), with females being larger than males, while males have robust pedipalp chelae and elongated metasomal segments (Lira et al 2018b). Females of this species can generate up to three litters per year, each consisting of 4-12 juveniles, which undergo 4-5 molts before reaching adulthood (Albuquerque & Lira 2016).…”