The first record on the spider genus Trogloneta Simon in the southern hemisphere (Araneae, Mysmenidae), with descriptions of three new species from Brazil and remarks on the morphology

Abstract

We provide a taxonomic description of three new species of the spider genus Trogloneta from Brazil, providing the first record of this genus in the southern hemisphere. We also present the first detailed morphological study on the genus, describing for the first time its spinneret spigot morphology and its tracheal system, which are crucial for reconstructing the cladistic relationships of araneoid families. Some aspects of the male and female genitalia are also discussed. New diagnostic features are proposed for the genus. The respiratory system of Trogloneta resembles that of the mysmenid genera Maymena and Isela, with reduced booklungs and only one posterior spiracle leading to tracheae. The spinneret spigot arrangement in Trogloneta conforms to the typical araneoid spigot composition, with one major ampullate spigot separated by a deep furrow from the piriform field, and piriform spigots with reduced bases and interspersed with tartipores in the anterior lateral spinnerets. A third distinct field in the anterior lateral spinnerets comprising modified setae of unknown function is present in Trogloneta. This field seems to be unique for the genus. The typical shape of the male palpal cymbium, as well as the shape of the cymbial conductor could be synapomorphic for Trogloneta. Also, females of Trogloneta present accessory glands as part of their genitalic conformation, which have never been reported for mysmenids, and therefore might be also synapomorphic for the genus. This is the first mysmenid genus proposed to be haplogyne, further suggesting additional synapomorphies for the genus.