Oiticicarcinia epikarstica, Cardoso & Bento & Ferreira, 2025

Cardoso, Giovanna Monticelli, Bento, Diego de Medeiros & Ferreira, Rodrigo Lopes, 2025, Remnants of an ancient world: three new genera and three new species of Calabozoidea isopods from Brazilian semi-arid caves (Crustacea: Isopoda), Tropical Zoology (trop. Zool.) 38 (1 - 2), pp. 1-25 : 5-8

publication ID	https://doi.org/10.4081/tz.2025.180
publication LSID	lsid:zoobank.org:pub:A3B5E8FB-4BEC-48E7-8F5F-AEEE16D194B9
DOI	https://doi.org/10.5281/zenodo.15801211
persistent identifier	https://treatment.plazi.org/id/B5213824-FFEC-FFA2-FE07-FEE3C02E0B41
treatment provided by	Felipe
scientific name	Oiticicarcinia epikarstica
status	sp. nov.

Treatment

Oiticicarcinia epikarstica n. sp.

Figures 2–4 View Figure 2 View Figure 3 View Figure 4 , 13A View Figure 13

urn:lsid:zoobank.org:act:F60DF0A9-814D-4107-B54D-DB0A5F82AB0D

Material examined

BRAZIL: Holotype ♂ ( ISLA 96917 ), Rio Grande do Norte state, Felipe Guerra municipality, Crotes cave (5.56051°S, 37.65860°W), 23.V.2023, leg. DMB GoogleMaps . Paratypes: 1 ♀, 1 ♂ in slide ( ISLA 96918 ), 21.VII.2017, same data as holotype GoogleMaps ; 1 ♀ ( ISLA 96919 ), 3.X.2021, same data as holotype GoogleMaps ; 1 ♂ in slide ( ISLA 96920 ), 09.XII.2022, same data as holotype GoogleMaps .

Description

Body approximately 1.3 mm, three times as long as wide ( Figures 2A View Figure 2 , 14A View Figure 14 ). Head shield with clypeus short; eyes absent. Pereonites rectangular, with round epimeral angles, three setae on lateral margins and four setae dorsally on pereonites I–IV and two on pereonites V – VII; pereonites I and III with similar width, wider than pereonite VII ( Figure 2A View Figure 2 ). Pleon about 40% of body length; pleonites I–II reduced, pleonites I and III about 20% and 90% of pereonite VII width, pleonites III – V with two setae laterally. Pleotelson ( Figures 2A View Figure 2 , 3D View Figure 3 ) approximately 20% of body length, and 50% of pleon length, slightly wider than long, with five setae on lateral margin, apex with two long setae plus four short setae. Antennula ( Figure 2B View Figure 2 ) longer than peduncle of antenna, flagellum of one article with one aesthetasc, twice longer than flagellum. Antenna ( Figure 2B View Figure 2 ) long, about 50% of body length, reaching pereonite V, flagellum with seven articles. Mandibles ( Figure 2C,D View Figure 2 ) lacinia mobilis with denticulate apex, one pappose robust seta, right and left incisor with three and four teeth. Maxillula ( Figure 2E View Figure 2 ) lateral lobe with five robust simple setae, three robust serrate setae and one trifid seta medially, mesial lobe with two robust pappose setae and one serrated seta. Maxilla ( Figure 2F View Figure 2 ) lateral and medial lobe with seven serrate setae each; mesial lobe with four plumose setae and three simple setae. Maxilliped ( Figure 2G View Figure 2 ) endite proximal lobe with five pappose setae apically, distal lobe with seven pappose setae; palp of five articles, first article fused with maxilliped body, articles with long simple setae, article 5 smallest, with tuft of setae distally. Pereopod I ( Figure 3A View Figure 3 ) ambulatory, carpus 1/3 of propodus length, propodus medial margin with three serrate setae, dactylus shorter than propodus, unguis shorter than dactylus; propodus and unguis medial margin with scales. Pereopod II ( Figure 3B View Figure 3 ) carpus as long as propodus, propodus distal lateral corner with one plumose seta, dactylus shorter than propodus, unguis medial margin with scales. Pereopods III –VII progressively growing in length. Pereopod VII ( Figure 3C View Figure 3 ) 1.5 times longer than pereopod I, propodus two times longer than carpus, unguis half dactylus length. Uropods ( Figures 2A View Figure 2 , 3D View Figure 3 ) longer than pleotelson apex, uniramous, styliform, with acute apex, about 20% of pleotelson length.

Immature male. Genital papilla ( Figure 3D,E View Figure 3 ) bilobed, apex round. Pleopod I ( Figure 3D,E View Figure 3 ) longer than wide with two plumose seta on distal margin. Pleopod II ( Figure 3D,E View Figure 3 ) protopodite trapezoidal, endopodite simple, longer than exopodite; exopodite ovoid with two distal plumose setae. Pleopods III and V exopodite with oval shape, similar in size, with two distal plumose setae; pleopod IV bigger than others ( Figure 3D View Figure 3 ).

Mature male. Genital papilla ( Figure 3F View Figure 3 ) bilobed, apex tapering. Pleopod I ( Figure 3F View Figure 3 ) simple, exopodite longer than protopodite, apex tapering. Pleopod II ( Figure 3G View Figure 3 ) protopodite rectangular, longer than wide, endopodite longer than exopodite, apex tapering; outer ramus short with seta on apex. Pleopods III exopod ( Figure 3H View Figure 3 ) oval shape with two distal plumose setae.

Etymology The species epithet “epikarstica ” refers to the species habitat.

Habitat, treats and conservation status

Specimens of O. epikarstica n. sp. were exclusively collected in Crotes cave, a limestone cave ( Figure 4A, B View Figure 4 ) that is part of a complex of 120 caves located within the outcrop locally known as “Lajedo do Rosário”, most of which lack perennial water bodies. Although several other caves with water bodies in the region have been investigated, no other specimens of O. epikarstica n. sp. were found. This increases the relevance and biological uniqueness of Crotes cave, as it is home to an exclusive stygobiotic fauna composed of flatworms ( Hausera hauseri Leal-Zanchet & Souza, 2014 ), amphipods, cirolanids ( Isopoda ) and earthworms (Oligochaeta) that have not yet been described ( Bento et al. 2021; Bento et al. 2024).

Formed by the expansion of a diaclasis (a diagenetic fracture in the rock) the main gallery of Crotes cave extends over a linear projection of 351.5 meters. The roof features several vertical openings through which external light enters, fostering the growth of vegetation, including trees ( Figure 4C View Figure 4 ). Despite predominantly dry substrates, a small perennial stream ( Figure 4D View Figure 4 ) drains water from the epikarstic system, traversing an upper small conduit. This stream boasts a series of travertine pools with depths ranging from a few centimeters to around 30 centimeters.

Despite several visits to the cave, only a few specimens of O. epikarstica n. sp. were observed, indicating the rarity of this species in this accessible part of its habitat. The specimens were found on the bottom of the drainage, often associated with small pieces of vegetal debris such as decomposed small branches and fragmented leaves. Their preference for decaying branches or leaves with darker coloration made them somewhat easier to detect amidst the calcium carbonate substrate.

The physical-chemical parameters of the drainage were assessed during nine visits to the cave between 6. III.2021 and 12.IX.2023, unveiling the following characteristics of this water body: water temperature: 27.14±1.01°C; pH: 7.72±0.58; conductivity: 0.28±0.05 µScm-1; dissolved oxygen: 6.29± 3.01mg /l; total dissolved solids: 0.18± 0.03 g /l; total phosphorus: 34.63±6.85μg/L; total nitrogen: 5.93± 5.54mg /l; total carbon: 14.37± 5.68 mg /l.

While tourists regularly visit the cave, access to the upper conduit containing the drainage is currently restricted. However, if this situation changes and the upper conduit becomes accessible to visitors, it poses a potential risk to the species. Additionally, visitation may disturb bats, leading to a decrease in guano deposition, which would likely further reduce the already limited supply of organic matter. Another potential impact is the future installation of mining projects in the region, as the area falls within mining polygons with research authorization. Given that Crotes cave is the sole known habitat of O. epikarstica n. sp., and considering these potential impacts, the new species could be classified as Vulnerable under criterion D2. Therefore, it is imperative to initiate monitoring programs to assess the conservation status of the cave and the remaining cave-restricted species it harbors.