Endecous (Ramalhoecous) spelaeus, Carvalho & Ferreira, 2025

Carvalho, Pedro Henrique Mendes & Ferreira, Rodrigo Lopes, 2025, No need to jump in the darkness: A new troglobitic species of Endecous Saussure, 1878 (Orthoptera: Grylloidea: Phalangopsidae) from the Brazilian Semiarid region, Zootaxa 5642 (4), pp. 317-330 : 320-326

publication ID	https://doi.org/10.11646/zootaxa.5642.4.2
publication LSID	lsid:zoobank.org:pub:8D8C07B5-CB0D-44A2-9450-0423FBBF16DC
DOI	https://doi.org/10.5281/zenodo.15563884
persistent identifier	https://treatment.plazi.org/id/03D287F6-5879-FFBE-3CCA-27C354D4D105
treatment provided by	Plazi
scientific name	Endecous (Ramalhoecous) spelaeus
status	sp. nov.

Treatment

Endecous (Ramalhoecous) spelaeus sp. nov.

( Figures 4–10 View FIGURES 4–10 , 11–24 View FIGURES 11–24 , 25–32 View FIGURES 25–32 , 33–38 View FIGURES 33–38 , 39–43 View FIGURES 39–43 ; Table 1)

Diagnosis —Combination of the following characteristics: reduced tympanum on the outer surface of the fore tibiae; partial loss of subapical spurs on the hind tibiae; a single rounded protuberance on the metanotum; apex of the pseudepiphallic dorsal branches triangular; shallow, basket-like pseudepiphallic inner bars; pseudepiphallic parameres with a rounded outline; parallel ectophallic median projections; rami short and truncated; endophallic sclerite elongated, rectangular, without an apodeme.

Etymology —The specific epithet spelaeus is derived from the Latin word “ spelaeus ”, meaning “cave”. It references the troglobitic nature of the species. The epithet should be treated as a noun in apposition.

Material examined — Holotype (ISLA 144228), ♂, Brazil, Bahia, Feira da Mata, Gruta Boca da Lapa cave (13°56’46.76”S, 44°11’8.91”W), 19.VII.2024, R. L. Ferreira; condition: genitalia dissected, left legs and right tegmen detached and store alongside the holotype GoogleMaps . Allotype ( ISLA 144229), ♀, same data as the holotype; condition: genitalia dissected, left legs detached and stored alongside the allotype GoogleMaps .

Male genitalia (holotype ISLA 144228, Figs 4–9 View FIGURES 4–10 )— Phallic complex broadened, roughly quadrangular in contour, typical of Endecous (Ramalhoecous) . Pseudepiphallus: A sclerites (Ps.a) elongated, parallel and fused to the pseudepiphallic dorsal branches throughout almost all of their extension, apex triangular, slightly curving inward, and reaching the dorsolateral portion of the pseudepiphallic parameres in lateral view; dorsal branches (Ps. db) broad, elongated, distal half highly sclerotized, dorsally projected, and abruptly bending inward, apex tapered in posterior view; inner bars (Ps.ib) concave, forming two shallow, horizontally aligned, basket-like structures in dorsal view, connected through a thin membrane; rami ( R) short, truncated, with an indefinite contour; parameres (Ps.p) concave, turned inward, internally membranous, projecting past the pseudepiphallic dorsal branches in dorsal and lateral views, distal portion broad, highly sclerotized and rounded ventrally, proximal portion thin and less sclerotized, forming a scythe-like structure adjacent to the ectophallic median projections. Ectophallic invagination: apodemes (Ect.ap) slightly longer than the endophallic sclerite, broad and laterally oriented; arc (Ect.arc): conical, elongated, apex visible in dorsal view, central axis highly sclerotized; lateral projections (Ect.lp) elongated, reaching the base of the pseudepiphallic parameres, curving outward, slightly sinuous, apex tapered, inner side highly sclerotized; median projections (Ect.mp) elongated, straight, parallel to the endophallic sclerite duct. Endophallus : posterior portion (End.p) membranous, rounded; duct (End.d) short, but longer than the ectophallic median projections, sclerotized at the junction with the endophallic sclerite; sclerite (End.s) elongated, approximately rectangular, with a central groove and lacking any apodeme, apex slightly tapered.

Female genitalia (allotype ISLA 144229, Fig. 10 View FIGURES 4–10 )— Copulatory papilla sclerotized, membranous posteriorly; roughly oval in dorsal and ventral views, longer than wide; anterior half ventrally open, concave; dorsal surface with a medial slender depression (visible in dorsolateral view).

Male body morphology (holotype ISLA 144228, Figs 11–24 View FIGURES 11–24 , 25–32 View FIGURES 25–32 )— Head ( Figs 11–13, 15, 16 View FIGURES 11–24 ): elongated dorsoventrally, pubescent; fastigium and frons covered with a few elongated setae; antennae and mouthparts also pubescent; antennal scape well-developed, longer than wide; maxillary palpomeres I and II short, palpomeres III and IV of intermediate length, and palpomere V elongated and clavate, its apex slightly curved upwards in lateral view; labial palpomeres I, II, and III short, but progressively longer, palpomere III clavate; ocelli absent, compound eyes greatly reduced. Thorax ( Figs 14, 17, 18, 20 View FIGURES 11–24 ): pronotum wider than long; anteriorly and posteriorly arched; lateral lobes rounded; anterior margin covered with long and thick setae; dorsal surface pubescent; metanotum featuring a well-developed, central, rounded protuberance. Right tegmen ( Figs 17, 18 View FIGURES 11–24 ): approximately oval in shape, covering tergites I and II; slightly sclerotized; basal field with a secondary crossvein connecting 1A to the stridulatory file; stridulatory file with 62 teeth; harp with two complete crossveins; mirror with one complete and one incomplete arched crossvein, anterior margin triangular; lateral field with two well-marked longitudinal veins and several interconnected transverse veins. Legs ( Figs 25–28 View FIGURES 25–32 ): pubescent; tympana oval, located on the proximal portion of the tibiae I, outer tympanum reduced; tibiae I and II with two ventral distal spurs; proximal tarsomeres of legs I and II ventrally serrated; femur III underdeveloped; left tibia III with one subapical spur on the inner side (k) and three on the outer side (x, y, z), distal subapical spurs shorter than the rest; right tibia III with one subapical spur on the inner side and two on the outer side, proximal subapical spur longer than the rest; both tibiae III with three (d, e, f— spur d the longest, spur f the shortest) apical spurs on the inner side and three (a, b, c— spur a the longest, spur c the shortest) on the outer side; proximal tarsomere of legs III with two dorsal apical spines, the inner spine longer than the outer one. Abdomen ( Figs 19, 21–24 View FIGURES 11–24 ): pubescent; tergite III with a small posterior central bump, tergites IV, V, VI and VII with less conspicuous posterior humps; supra-anal plate approximately trapezoidal, anterior margin straight, wider than the posterior margin, which is rounded and covered with elongated setae, lateral margins featuring a small medial projection; paraprocts as long as the supra-anal plate; subgenital plate elongated, longer than the supra-anal plate, posterior margin trapezoidal, wide, with a small central dent, and covered with elongated setae; cerci pubescent, covered with elongated setae, short, broader at the base, which has globose setae internally. Body color: color of the different parts of the head varying from light yellow to brown; vertex light brown, fastigium brown with a dark brown spot on each side of the epicranial sulcus near the antennae bases; gena light yellow with irregular, faded brown marks; subgena light yellow; frons light yellow with a central reddish-brown spotted mark extending over the base of the clypeus; area directly beneath the eyes featuring a brown spot; clypeus and labrum yellow at the base and whitish at the apex; mandibles and laciniae yellow with dark brown sclerotized edges and apexes, mandibles’ anterior and posterior articulations also dark brown due to sclerotization; labium whitish-yellow; galea, maxillary and labial palps light yellow with white apexes; scape, pedicel and flagellum yellowish-brown; circumantennal sulcus and neck membrane white; pronotum medially light yellow, lateral lobes also yellow, the remainder of the pronotum brown; tegmina light brown; legs yellowish-brown; tympana white, translucent; tergites yellow, tergites III, IV and V distally dark brown due to the presence of wide fusiform sclerotized “plates”; thoracic sternites whitish-yellow; abdominal sternites translucent yellow; supra-anal plate withish to yellowish-brown; subgenital plate translucent yellow with a central translucent white spot extending toward the posterior margin; cerci yellowish-brown at the base, transitioning to translucent light yellow toward the apex.

Female body morphology (allotype ISLA 144229, Figs 29–32 View FIGURES 25–32 , 33–38 View FIGURES 33–38 )—Apterous; legs similar to the holotype, tibiae I with outer and inner tympana, tibiae III also bearing fewer subapical spurs when compared to other Endecous species; supra-anal plate subtriangular; subgenital plate wider than long, posterior margin W-shaped; ovipositor elongated, spear-shaped, yellowish-brown, with a dark line throughout its extension, apex acute; body color similar to the holotype .

Ecological remarks— The Gruta Boca da Lapa cave is a large system with around 3km of extension, with a single entrance that marks the resurgence point of the river running through its main passage ( Fig. 39 View FIGURES 39–43 ). The river is autogenic, formed by infiltration waters that drain into the cave. This drainage traverses the entire length of the cavity, from its deepest point, which functions as a spring, to its emergence at the resurgence.

Throughout most of the cave, the stream occupies the lower portion of the passage ( Fig. 40 View FIGURES 39–43 ). Emergent areas are limited to regions closer to the entrance (approximately the first 400 meters) where clastic sediment banks of varying configurations are found ( Fig. 41 View FIGURES 39–43 ). Specimens of E. (R.) spelaeus sp. nov. were primarily observed on these sediment banks. The population density of this species was notably low, contrasting with other Endecous species and even with the only other known species in the subgenus, E. (R.) infernalis , which also displays low population densities. Only a few individuals were recorded throughout the cave ( Figs 42 and 43 View FIGURES 39–43 ), and just one adult male was located ( Fig. 42 View FIGURES 39–43 ), identified by its stridulation.

A remarkable characteristic of E. (R.) spelaeus sp. nov. is its sluggish movement and apparent inability to jump. Even when disturbed, individuals fled by running rather than leaping, a typical escape behavior in other Endecous species. The morphology of its hind legs differs significantly from those of its congeners, and their slender form aligns with the species’ apparent inability (or low propensity) to jump.

Available organic matter, in the form of plant debris, potentially serving as food for these crickets, is scarce, likely due to the autogenic nature of the drainage. The primary source of nutrition appears to be bat guano, especially from hematophagous species, which is deposited along the cave passage over sediment banks. Although other caves in the Serra do Ramalho region have been surveyed during biological inventories, E. (R.) spelaeus sp. nov. has, to date, been recorded exclusively in this cave.