The first schizomid from a dry forest in South America  (Arachnida: Schizomida)

Abstract

Schizomids are arachnids typically found on the ground of areas with rainforest, living in the moist litter. Here we describe Surazomus algodoal sp. nov. from a coastal, dry environment on an island of the state of Pará, Brazil, in the Atlantic Ocean. Only one male has been collected, but the morphology of the flagellum is unique. Surazomus algodoal sp. nov. represents the first epigean schizomid living only in a dry forest and the easternmost record for Surazomus Reddell & Cokendolpher. The type of dry vegetation in which the animal was found covers only a small area and is endangered by human use. The new species is considered critically endangered using the IUCN criteria.

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

“…* ignored in the original description [17], but seen in Ruiz & Valente [17]: figs 9 and 10.** originally ignored [23], but present, according to Villarreal et al . [12].…”

“…: (E) dorsal view, (F) dorsolateral view. Redrawing from: A: Salvatierra [ 18 ]: fig 10; C: Ruiz & Valente [ 17 ]: fig 11; B, D, F: free-hand reconstructions based on dorsal views and on Salvatierra ([ 18 ]: fig 8) and Ruiz & Valente ([ 17 ]: fig 13). Abbreviations: AP: anterior pocket; PP: posterior pocket.…”

“…We also compared our new species with the recently described Surazomus algodoal Ruiz & Valente, 2017 and Surazomus rafaeli Salvatierra, 2018, in order to explain the proposals of homology for setae and coupling pockets of the male flagellum in the genus. Dorsal views of the flagellum of these two species were based on Ruiz & Valente ([ 17 ]: fig 11) and Salvatierra ([ 18 ]: fig 10), respectively, while the dorsolateral views are free-hand reconstructions based on these and on Ruiz & Valente ([ 17 ]: fig 13) and Salvatierra ([ 18 ]: fig 8). To elucidate our proposal of homologies for the coupling pockets, we prepared an illustration showing the position of a couple in mating march, based on Sturm ([ 7 ]: figs 1 and 21), showing our hypotheses for the anchorage of the female chelicerae onto the male flagellum.…”

“…To elucidate our proposal of homologies for the coupling pockets, we prepared an illustration showing the position of a couple in mating march, based on Sturm ([ 7 ]: figs 1 and 21), showing our hypotheses for the anchorage of the female chelicerae onto the male flagellum. We used the male chelicera of the new species to demonstrate a generalized hubbardiine chelicera, and the illustrations cited above [ 17 , 18 ] to show the different character states within the genus. The coupling pockets present on the male flagellum are herein named as “anterior coupling pocket” (AP) and “posterior coupling pocket” (PP).…”

“…Presently Surazomus Reddell & Cokendolpher, 1995 (Hubbardiidae: Hubbardiinae) includes 24 species distributed through Central and South America: seven species from Costa Rica, seven from the Andean foothills and ten from the Amazon region [ 3 , 13 , 17 , 18 ]. Within Surazomus we find different types of male flagella: some species have a rounded flagellum, such as Surazomus chavin Pinto-da-Rocha, 1996 and Surazomus uarini Santos & Pinto-da-Rocha, 2009 (see Armas [ 3 ]: figs 13A and 19A); many have a trilobed flagellum bearing a pair of membranous dorso-submedian eminences, with the median portion of the flagellum laterally widened (e.g.…”