Description of a new species of Surazomus (Arachnida: Schizomida), with comments on homology of male flagellum and mating march anchorage in the genus

Abstract

Surazomus saturninoae sp. nov. is described from eastern Amazon. The male has a pentagonal flagellum, similar to those of three other species in the genus. These four species are herein gathered as the arboreus-group of Surazomus. We present a brief synopsis of chaetotaxy description in hubbardiines and several homology proposals for the flagellum of the species in the arboreus-group: the posterior lobes may be homologous to the lateral lobes of hubbardiine species with trilobed flagella; the setal brush with 4–5 setae on the posterior lobe may be composed of one Dl2 seta and enlarged lobular microsetae; the single, median posterior coupling pocket may be homologous to the pair of posterior pockets seen in other hubbardiines; the single, median anterior coupling pocket may be homologous to the pair of pockets on the anterior border of the flagellum seen in other hubbardiines. Based on the morphology of these pockets and the chelicerae within Surazomus, we discuss the anchoring mechanism during the mating march.

First description of the male genitalia in a short-tailed whipscorpion (Arachnida: Schizomida), description of the female, and comments on pygidial glands and cuticular ultrastructure of Surazomus algodoal Ruiz & Valente, 2017

“…Microsetae Dl1, ignored by Ruiz & Valente [ 34 ], but indicated by Ruiz & Valente [ 3 ], is corroborated as present, inside AP (anterior pockets; see Ruiz & Valente [ 3 ]: figs 8C-D) ( Fig 17A , red arrow). All flagellar setae barbed ( Fig 17B, 17C ).…”

“…[ 30 ], for cheliceral setation. Pedipalp setation follows Monjaraz-Ruedas & Francke [ 23 , 24 ] and Ruiz & Valente [ 3 ], including the new terminology for setae of the pedipalpal trochanter: medial (TRm), ventral (TRv), subectal (TRs) and ectal (TRe) lines. Monjaraz-Ruedas & Francke’s [ 24 ] setae of the Tibial ectal row (Ter), Tibial medial row (Tmr), and Tibial internal row (Tir) are herein referred individually (Te, Tm, Ti).…”

“…Short-tailed whipscorpions (order Schizomida) are a small group of arachnids (about 380 species [ 1 ]) with minute bodies (generally less than 5 mm in length; [ 2 ]) and evident sexual dimorphism in the pygidial flagellum, which is modified in the male for use in the mating march (see Ruiz & Valente [ 3 ]; Kallal et al . [ 4 ]).…”

Tales of schizomid tails: patterns in schizomid flagellum shape from elliptical Fourier analysis

“…Despite its importance to species diagnoses 16,17 , only recently attempts have been made at homologizing aspects of the flagellum, namely annuli, setae, lobes, and depressions, in the hope that this knowledge will clarify evolutionary relationships. Those studies, however, focus on more specific lineages or solely on females 2,18 , leaving out the shape and size of the male flagella, which varies widely across schizomids. They differ in length by nearly an order of magnitude, ranging from 0.2 mm in Adisomus duckei Cokendolpher and Reddell, 2000 and Rowlandus littoralis Teruel, 2003 (~7% total body length) to 1.68 mm in Piaroa villarreali Armas and Delgado-Santa, 2012 (~30% of 5.56 mm total body length).…”

“…Schizomida is one of the less speciose orders of arachnids (scorpions, spiders, mites, and their relatives), with approximately 300 described species 1,2 and 72 described genera (Supplement S1). They are small (2-12.5 mm), active hunters exhibiting sexual or asexual reproduction.…”