A new species of Melloina (Araneae: Paratropididae) from Venezuela

Abstract

Besides being rare in collections, Melloina is of critical importance for the knowledge of mygalomorph relationships, mainly of the Theraphosoidina clade, which contains the families Theraphosidae, Barychelidae and Paratropididae (RAVEN 1985). RAVEN (1985, 1999) extensively discussed the taxonomic position of Melloina, included originally in Theraphosidae (SCHENKEL 1953), and transferred by RAVEN (1985) to the Paratropididae. RAVEN (1985) showed that Melloina is a basal taxon in Paratropididae, presenting the plesiomorphic states of highly modified characters of Paratropis Simon, 1899 and related genera. Moreover, as Paratropididae is the proposed sister group of Theraphosidae (RAVEN 1985, GOLOBOFF 1993, 1995), its most basal taxon, i.e. Melloina, retains some of the most plesiomorphic character states of Theraphosidae, the most speciose mygalomorph family. However, results of recent analyses using molecular information (HEDIN & BOND 2006, BOND et al. 2012) conflict with the studies using morphological information, suggesting that Paratropididae is not closely related with Theraphosidae or Barychelidae. Therefore, any information on Melloina is important for the understanding of the evolution of Mygalomorphae, the Theraphosoidina, and, particularly, of Theraphosidae. A new species of Melloina is described herein. It is the first species from this genus based on male and female specimens. MATERIAL AND METHODS The general description format follows RAVEN (1999, 2005), with modifications. A Nikon SMZ1500 dissecting microscope was used for illustrations (with a camera lucida attachment). Figures were digitized and covered using a Wacom Bamboo tablet. All measurements are in millimeters. Leg and palp measurements were taken from the dorsal aspect of the left side (unless appendages were lost or obviously regenerated). Measurements were taken from the drawings made with the dissecting microscope and converted. Abbreviations: (ALE) anterior lateral eyes, (AME) anterior median eyes, (ITC) inferior tarsal claw, (PLE) posterior lateral eyes, (PLS) posterior lateral spinnerets, (PME) posterior median eyes, (PMS) posterior median spinnerets, (STC) superior tarsal claws. Specimens are deposited in the Museo del

The first Paratropididae (Araneae, Mygalomorphae) from Colombia: new genus, species and records

“…The general description format follows Raven (1999) and Bertani (2013), with modifications. Specimens were examined using an Advanced Optical stereomicroscope.…”

“…Paratropidids constitute a small family of spiders, currently comprising four genera and eleven species, distributed in Mexico, Central America, Lesser Antilles, and northern South America except Colombia (Raven 1985, WSC 2018). Their presence in Venezuela, Mexico, and Ecuador has been recently reported by Bertani (2013), Valdez-Mondragón et al (2014) and Dupérré (2015), respectively. Paratropidids are cursorial, medium to small-sized mygalomorphs, which hide themselves in the surface layers of the soil (West in Raven 1999); found in leaf litter and rotten logs, under rocks, moss, and burrows in ravines (personal observations).…”

“…4C, D; Raven 1999: fig. 2F; Bertani 2013: figs 12, 13). Females differ from all other paratropidids by the morphology of the spermathecal receptacles with a tubular neck and a wide globose fundus (mushroom shaped) (Figure 8D), and few spines on all legs.…”

First record of the mygalomorph spider family Paratropididae (Arachnida, Araneae) in North America with the description of a new species of Paratropis Simon from Mexico, and with new ultramorphological data for the family

“…Samples for future molecular studies are cold-stored in vials with ethanol (96%). The general description of the species and terminology of the chaetotaxy follows Raven (1999) and Bertani (2013) with some modifications. The description of the spinnerets follows Bertani (2013) .…”

“…As Rick West said in a personal communication to Raven (1999) , these spiders make no burrow and hide under objects in the top layers of the soil. One characteristic of this family is that usually the entire body (including legs) is encrusted with soil particles ( Raven 1985 ), although in some species such as Melloina santuario the cuticle has soil only in very restricted areas on the carapace ( Bertani 2013 ). The encrusted soil on the exoskeleton could provide protection from predators or serve as camouflage to deceive their prey; it is a fact that they are very cryptic, which coupled with lack of movement when exposed makes them quite difficult to find and collect.…”