A comparative morphological study of the epiandrous apparatus in mygalomorph spiders (Araneae, Mygalomorphae)

Abstract

Many adult male spiders have silk glands which are not associated with the spinnerets. They occur on the anterior margin of the genital furrow and are used during the building of the sperm web and sperm droplet induction. These epiandrous glands exit the body through ducts which lead to specialized spigots. In the taxon Mygalomorphae, the presence of epiandrous spigots is just reported for a couple of species but their morphology has not been investigated. In this paper we provide a detailed study of the ultrastructure morphology of eighteen species belonging to eight families using light and scanning electron microscopy (SEM). We describe and present images of the epiandrous spigots above the genital opening. Also, we compare the morphology of spigots between families and describe the epiandrous glands through histology.

Taxonomy and phylogeny of the genus Trichopelma Simon, 1888 (Araneae: Theraphosidae: Trichopelmatinae) in Cuba, with the descriptions of seven new species and a new species of Thalerommata Ausserer, 1875

“…Urticating setae are present only in Theraphosinae and Aviculariinae of New World and their morphology is an important character in several genera, even between subfamilies (Guadanucci et al, 2020). Other cuticular structures that have been found in mygalomorph spiders are trichobothria (Guadanucci, 2012), adhesive tarsal setae (Pérez-Miles et al, 2017), labial and maxillary cuspules (Pérez-Miles & Montes de Oca, 2005), epiandrous glands (Ferretti et al, 2017) and chemosensory setae . Scales in spiders comprise a specific type of setae because they lack innervation (Townsend & Felgenhauer, 1999) and are defined as setae inserted in small sockets and bent immediately after their insertion (Townsend & Felgenhauer, 1998;Ramírez, 2014).…”

Multiscale Modeling of Silk and Silk‐Based Biomaterials—A Review

“…Production of silk fibers bioinspired from the spinning process in the spinnerets of spiders (Reproduced with permission . Copyright 2017, Elsevier).…”

Claw tuft setae of tarantulas (Araneae, Mygalomorphae, Theraphosidae) and the production of fibrous materials. Do tarantulas eject silk from their feet?

“…Spinnerets are equipped with spigots (nozzles), i.e., external outlets of glands. Spigots are considered to represent modified setae (Bond, 1994;Eberhard, 2010;Foelix, 2011). As well as the spinning glands themselves, the spigots are classified into several different types (Eberhard, 2010;Foelix, 2011).…”

“…Spigots are considered to represent modified setae (Bond, 1994;Eberhard, 2010;Foelix, 2011). As well as the spinning glands themselves, the spigots are classified into several different types (Eberhard, 2010;Foelix, 2011). Aside from the spinnerets, the adult males of some species are also equipped with epiandrous (or epigaster) glands, which are associated with genital furrow (Shultz, 1987).…”

“…The tarsal fluid probably improves adhesion of feet to the substratum (Peattie, Dirks, Henriques, and Federle, 2011). Several authors (Dunlop, 1995;Foelix, 2011;Foelix, Rast, and Peattie, 2012;Niederegger, 2013) proposed that when the tarantulas walk on vertical glass they only use claw tufts for adhesion, while the tarsal and metatarsal scopulae are used for hunting. Perez-Miles, Perafan, and Santamaria (2015) reported that tarsal scopulae could also participate in locomotory adhesion.…”