Taxonomic revision of the genus Trechaleoides Carico, 2005 (Araneae: Trechaleidae: Trechaleinae)

• Grant number: 23/14911-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2024
• End date: December 31, 2024
• Field of knowledge: Biological Sciences - Zoology - Taxonomy of Recent Groups
• Principal Investigator: Facundo Martin Labarque
• Grantee: Luciana Seixas Carone
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The family Trechaleidae Simon, 1890 has 133 species classified into 17 genera widely distributed in the Neotropical Region, with the exception of one species in Japan. Most spiders in this family are considered semi-aquatic, as they are frequently found near streams and/or bodies of fresh water, have flexed tarsi and metatarsals - a possible adaptation for walking on the surface of the water - and courtship behavior where males deliver a "nuptial gift" to females. Trechaleidae is divided into two subfamilies by the presence or secondary loss of the retrolateral process of the tibia, separating the Trechaleinae Simon, 1890 from the Rhoicininae Simon, 1898 respectively. Trechaleoides Carico, 2005, our focus of study, is one of the genera that make up Trechaleinae, featuring two species: T. biocellata (Mello-Leitão, 1926) and T. keyserlingi (F. O. Pickard-Cambridge, 1903). Recent phylogenetic analyzes with genomic data recovered Trechaleoides as a sister group of the genus Paratrechalea Carico, 2005, a hypothesis also supported by the combination of several morphological characters. One of the particularities of both genera is the intraspecific variation in the morphology of the genitals of their males (palp) and females (epigynous). However, many of these variations are not recorded or documented, especially in Trechaleoides. Therefore, the present work aims to review the taxonomic genus Trechaleoides, focusing on recording the interspecific variations of reproductive structures through digital drawings, light microscopy photographs and scanning electron microscopy, and three-dimensional reconstructions with nano-tomography computerized.