Cryptocellus Botero-Trujillo & Prendini 2025
Creators: name: Botero-Trujillo, Ricardo
name: Prendini, Lorenzo
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Ricinulei
Ricinoididae
Cryptocellus

description: Cryptocellus a rm asi sp. nov.
Figures 1–7; Table 1
Type material. VENEZUELA: Zulia: Municipio: Machiques de Perijá, Sierra de Perijá, Hacienda Medellín, Cueva de Toromo [10°03’20”N 72°40’00”W, ca. 260 m], galería n. 1, in bat guano, 18.viii.1997, A. Rincón, L. Cáceres & Y. Vargas, 2 ♂, 4 ♀ syntypes (MBLUZ / AMNH IZC 325115). Large body parts are stored in three vials and small body parts in four microvials. The fragments of males and females, stored separately, are labeled by sex. One vial and one microvial contain pieces that cannot be assigned to either sex.
The type material comprises the desiccated fragments of six individuals, all of which were originally in the same vial. The hardness of the ricinuleid cuticle enabled every structure (somatic and sexual) to remain intact. Study of the fragments revealed that the series comprises two adult males and four adult females. However, due to the pronounced appendage attenuation and absence of sexual dimorphism in the leg segments, it was impossible to assign every fragment (e.g., leg tarsal segments) to a male or female specimen and to reassemble any single individual as the holotype of the new species. Taking into consideration that (1) all the specimens were part of the same collection event inside a single cave, (2) all specimens comprising the series are conspecific, and (3) the individual specimens cannot be fully reassembled from the available fragments, a decision was taken to consider all six specimens as syntypes, according to the ICZN (1999) “specimens of a type series that collectively constitute the name-bearing type.”
Diagnosis. Cryptocellus armasi sp. nov. is one of only two species of the magnus species group that are associated with caves, the other being C. bordoni. Whereas C. bordoni “does not possess troglomorphic characters (… very elongated and thin appendages …)” (Salvatierra & Tourinho 2016: 12) and there is no indication of troglomorphies in its original description (Dumitresco & Juvara-Balş 1977), C. armasi exhibits a narrow opisthosoma (Figs. 2C–E, 3C, D) and pronounced attenuation of the appendages, with very long, slender legs (Fig. 4C–F) (e.g., leg II femur W:L = 1:8.1 [♂], 1:8.6 [♀]; carapace L:femur II L = 1:1.7 [♂]), and no apparent sexual dimorphism in the size of the leg segments, unlike other species of the magnus group. These characters, presumed to be associated to a troglobitic lifestyle, readily distinguish the new species from its closest relatives, C. bordoni (carapace L:femur II L = 1:1.5 [♂]), Cryptocellus brignolii Cokendolpher, 2000 (carapace L:femur II L = 1:1.1 [♂]), Cryptocellus chimaera Botero-Trujillo & Valdez-Mondragón, 2016 (carapace L:femur II L = 1:1.1 [♂]), Cryptocellus magnus Ewing, 1929 (carapace L:femur II L = 1:1.0 [♂]), Cryptocellus narino Platnick & Paz, 1979 (carapace L:femur II L = 1:1.2 [♂]), and Cryptocellus pseudocellatus Roewer, 1952 (male is unknown, but female illustrated by Roewer (1952: 47, fig. 4)).
Cryptocellus armasi also differs from C. bordoni, the most geographically proximate congener, in the shape of the male copulatory apparatus. The movable process of the apparatus is linear in lateral aspect, its dorsal and ventral surfaces parallel along its entire length (Figs. 6A, B, 7A, B), in C. armasi, unlike C. bordoni, in which the distal region of the movable process is curved dorsally and equipped with a large, proventral subdistal protrusion (Dumitresco & Juvara-Balş 1977: 168, 169, figs. 9A–C, 10A, B; Salvatierra & Tourinho 2016: 18, fig. 17A), structures that, in combination, create a “hammer-like” appearance. Additionally, the apex of the movable process bears a leaflike projection prodorsally (relative to the sperm transfer groove) and its L′ lobe is shorter and hook-shaped (Figs. 6A, E–G, 7A, B, F, G) in C. armasi, whereas there is no such leaflike projection and the L′ lobe is longer and sublinear in C. bordoni (Dumitresco & Juvara-Balş 1977: 168, 169, figs. 9A–C, 10A–C; Salvatierra & Tourinho 2016: 18, fig. 17A–C). The copulatory apparatus of the two species also differs in the morphology of the fixed process, notably the shape of its distal region in lateral aspect, being more linear and with the ventral surface slightly angular, in C. armasi (Figs. 6A, B, 7A, B, D, E), but curved dorsally and with the ventral surface arcuate, in C. bordoni (Dumitresco & Juvara-Balş 1977: 168, 169, figs. 9A–C, 10A; Salvatierra & Tourinho 2016: 6, fig. 5C, D).
Etymology. The species name (noun in the genitive case) is a eponym honoring Dr. Luis F. de Armas, formerly of the Instituto de Ecología y Sistemática, La Habana, Cuba, on the occasion of his 80 th birthday and in recognition to his contributions to the knowledge of troglobitic arachnids, including ricinuleids.
Description. Based on the syntypes (MBLUZ/AMNH IZC 325115).
Measurements: Total length, 7.49 mm (♂), 7.29 mm (♀) (Table 1).
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Coloration (of desiccated fragments): Soma and appendages reddish brown (Figs. 1–5). Carapace dorsolateral translucent areas yellow (Figs. 2A, 3A). Opisthosomal tergal and pleural membranes yellow, hyaline. Cheliceral manus yellowish; fingers and finger dentition dark red.
Setation: Soma and appendages covered with short to slightly elongate, translucent, bristle-like setae (Figs. 1–5). Polygonal setae absent.
Tegument surface macrosculpture: Tegument with bilaterally symmetric rows of oval or rounded, granulecontaining cuticular pits arranged as follows: on cucullus, along three partial longitudinal rows (median and paired lateral rows; Figs. 2B, 3B); on carapace, along pair of anterolateral longitudinal rows, pair of submedian oblique rows, pair of posterosubmedian oblique rows, pair of posterolateral longitudinal rows, pair of posteromarginal transverse rows, and median longitudinal row (Figs. 2A, 3A); on opisthosomal tergites XI–XIII, in rows along margins of median sclerites and along contiguous lateral margin of lateral sclerites (Figs. 2C, 3C); on opisthosomal sternites, in longitudinal rows along lateral margins (Figs. 2E, 3D). Carapace and opisthosoma predominantly smooth, except for pits. Cucullus, anterior surface coarsely granular ventrally, especially in male (Figs. 2B, 3B). Coxosternal region and legs granular (Fig. 4C–F). Opisthosoma, tergal and pleural membranes smooth. Pedipalp femur predominantly smooth, except ventral surface granular proximally (Fig. 4A); tibia smooth proximally, with elevated oval tubercles in distal half to two-thirds (Fig. 4A, B).
Carapace: Carapace trapezoidal, longer than wide (Table 1), broadest between coxae of legs II and III; lateral margins curved, converging anteriorly (Figs. 2A, 3A); anterior margin linear in dorsal aspect, sublinear in frontal aspect; posterior margin procurved; dorsolateral translucent areas oval, without well-defined borders, aligned with intersection between coxae of legs I and II.
Cucullus: Cucullus broadened laterally, wider than long (Table 1); ventrolateral margins rounded (Figs. 2B, 3B); ventral margin predominantly linear in anterior aspect, with shallow median concavity in ventral aspect.
Chelicerae: Movable finger longer than fixed finger, not widened; mucron apex acute; tooth row comprising approximately seven small teeth and one markedly larger, proximal tooth. Fixed finger tooth row comprising approximately five small to medium-sized teeth.
Coxosternal region: Tritosternum large, forming diamond-shaped shield, abutting coxae of legs I; coxae of legs II–IV each abutting one another medially along entire length, except for coxae of legs II, separated anteriorly by tritosternum; coxae of legs II, anterior and posterior margins perpendicular to median axis, not forming angle medially; coxae of legs II–IV progressively decreasing in length (Table 1); suture between coxae of legs III shorter than suture between coxae of legs II and, to lesser extent, coxae of legs IV.
Opisthosoma: Opisthosoma elongate oval, longer than wide (Table 1), broadest at tergite XII (Figs. 2C, 3C). Tergites X–XIII each comprising median and lateral sclerites; median sclerites of tergites XI–XIII each with paired, shallow submedian depressions, lateral margins subparallel on XI, subparallel (♂) or slightly converging posteriorly (♀) on XII and XIII; of tergites XI and XII longer than wide (♂) or slightly wider than long (♀); of XIII longer than wide (Table 1). Sternites XI–XIII each with paired submedian depressions as tergites (Figs. 2E, 3D). Pygidium basal segment, posterior margin with small V-shaped notch ventrally, slightly emarginate dorsally (Figs. 2C–E, 3C, D).
Pedipalps: Femur robust (Table 1), dorsal surface convex (Fig. 4A). Tibia longer than femur (Table 1), entirely linear, slightly to moderately swollen proximally, rest of segment narrower in dorsal aspect and, to lesser extent, lateral aspect (Fig. 4A, B). Movable finger longer than fixed finger.
Legs: All legs very long and narrow (Fig. 4C–F); leg II longest (Table 1); legs I–IV similar in width, no segments swollen (Table 1). Legs unmodified except in association with male copulatory apparatus. Leg III (♂) metatarsus with moderate concavity dorsodistally (Fig. 5A); retrodorsal margin markedly angular submedially (Fig. 5B); metatarsal process situated proximally near tibia, tapering, apex dorsoventrally compressed and curving retrolaterally; lamina cyathiformis slightly deeper than long, with rounded apex (Fig. 5C).
Male copulatory apparatus: Fixed process, distal half prominent ventrally in lateral aspect (Figs. 6A, B, 7A, E); apex deeply incised longitudinally, forming pro- (L 2) and retrolateral (L 1) lobes (Figs. 6E, F, 7C–E), each on opposite sides of fixed process (relative to dorsal longitudinal sulcus). Movable process slightly shorter than fixed process, robust, rigid, and linear, margins parallel (Figs. 6A–C, E, G, 7A, B, F–H); apex bifurcate, producing dorsally curved, hook-shaped lobe (L′); apex with obliquely oriented, leaflike projection prodorsally, adjacent to termination of sperm transfer groove into distal opening.
Female spermathecae: Spermathecae heavily sclerotized, approximately as deep as wide (Fig. 7I); adjacent but separated; external morphology bilaterally symmetric, internal cavity not visible. Anterior genital lip subtrapezoidal; posterior genital lip missing.
Distribution. Cryptocellus armasi is known only from the type locality in the Municipio of Machiques de Perijá in the state of Zulia, northwestern Venezuela (Fig. 1).
Natural history. Cueva de Toromo is situated in the Parque Ecoturístico Cueva de Toromo, on a tributary of the Río Atapsi (a.k.a., Río Negro), its entrance located at 10°03’20”N 72°40’00”W (Botosaneanu & Viloria 1993). The cave is 1120 m in length (horizontal, accessible portion), its length traversed by a stream, and contains labyrinths, waterholes, and waterfalls (Botosaneanu & Viloria 1993; SVE 1993; FAA 2024). It develops in limestones of the Cogollo Group (Early Cretaceous), its soils comprising gravel, sand and compact rock (SVE 1993). A stygobite isopod, a styglophile crab, a depigmented micro-/anophthalmus fish, and another stygoxene fish have been recorded in the cave (Botosaneanu & Viloria 1993).
The habitat and habitus of C. armasi are consistent with the troglobitic ecomorphotype. Considering that C. armasi is known only from inside a cave (it is unknown whether the ecosystem outside the cave has been sampled for ricinuleids), the marked elongation of its appendages is presumed to be the result of adaptation to life in the subterranean environment.
The fact that the new species was collected in bat guano is noteworthy because, according to A. Pérez González (pers. comm.), troglophilic ricinuleids are more frequently associated with that substrate than troglobitic ricinuleids. This raises the possibility that C. armasi could be a troglophile rather than a troglobite. New collections are needed to shed light on this question.
Conservation status. The type material of C. armasi was collected almost three decades ago and no other material of this species is known to exist in biological collections. Based on satellite images from Google Earth Pro (2024) and its historical imagery functionality, the area where the cave is located seems to have aridified in recent years. The conservation status of Cueva de Toromo is unknown, as is the status of C. armasi. However, the stygobite isopod described from this cave, Zulialana coalescens Botosaneanu & Viloria, 1993, is considered vulnerable (Viloria 2015). Therefore, considering the restricted geographical distribution of the troglobite ricinuleid, C. armasi, the inherent sensitivity of troglobites to habitat transformation, and the fact that Cueva de Toromo to which this species appears to be endemic, is exposed to ecotourism (FAA 2024), this species may also be threatened. Efforts dedicated to determining whether C. armasi remains extant and, if so, to protect its population and habitat, should be prioritized.
description: Published as part of Botero-Trujillo, Ricardo & Prendini, Lorenzo, 2025, Cryptocellus armasi, a new troglomorphic hooded tick-spider from Venezuela (Arachnida: Ricinulei), pp. 96-108 in Zootaxa 5563 (1) on pages 98-105, DOI: 10.11646/zootaxa.5563.1.10, http://zenodo.org/record/14595768