Ctenorillo araguaia Cardoso & Ferreira, 2024

Cardoso, Giovanna Monticelli, M, Diego de, Bento, edeiros & Ferreira, Rodrigo Lopes, 2024, Unveiling a hidden diversity: descriptions of nine new species of Ctenorillo Verhoeff, 1942 (Isopoda, Armadillidae) discovered in Brazilian caves and their importance for conservation, Zoosystema 46 (5), pp. 95-132 : 104-107

publication ID	https://doi.org/ 10.5252/zoosystema2024v46a5
publication LSID	lsid:zoobank.org:pub:1B0779F3-FAE4-4105-8130-A26DE519721E
DOI	https://doi.org/10.5281/zenodo.10813628
persistent identifier	https://treatment.plazi.org/id/4F19B81C-879D-43EC-A3BF-0AFBB1D908EF
taxon LSID	lsid:zoobank.org:act:4F19B81C-879D-43EC-A3BF-0AFBB1D908EF
treatment provided by	Plazi
scientific name	Ctenorillo araguaia Cardoso & Ferreira
status	sp. nov.

Treatment

Ctenorillo araguaia Cardoso & Ferreira , n. sp.

( Figs 5-7 View FIG View FIG View FIG ; 27C View FIG ; 28E View FIG )

urn:lsid:zoobank.org:act:4F19B81C-879D-43EC-A3BF-0AFBB1D908EF

TYPE MATERIAL. — Holotype. Brazil • 1 ♂ (5 mm); Pará state; São Geraldo do Araguaia municipality; Serra das Andorinhas cave; 6°16’55”S, 48°32’34”W; sector 4; 17-20.II.2018; V. F. Sperandei leg.; ISLA 96775. GoogleMaps

Paratypes. Brazil • 1 ♂ in slide; same data as holotype; ISLA96784 • 6 ♀; sector 1; same data as holotype; ISLA96776 GoogleMaps • 1 ♀; sector 1; same data as holotype; ISLA96777 GoogleMaps • 1 ♀; sector 3; same data as holotype; ISLA96778 GoogleMaps • 3 ♂, 8 ♀; sector 4; same data as holotype; ISLA96779 GoogleMaps • 5♂; sector 5; same data as holotype; ISLA96780 GoogleMaps • 3 ♂, 5♀ sector 6; same data as holotype; ISLA96781 GoogleMaps • 1 ♂; sector 7; same data as holotype; ISLA96782 GoogleMaps • 1♂, 3 ♀; same data as holotype; ISLA96783 GoogleMaps .

OTHER MATERIAL. — Brazil • 4 ♂; Pará state; São Geraldo do Araguaia municipality; Remanso dos Botos cave; 6°22’6”S, 48°23’38”W; V. F. Sperandei leg.; 20.II.2018; ISLA 96785 GoogleMaps .

ETYMOLOGY. — The new species name is a noun in apposition that refers to the Araguaia River, a Brazilian environmental heritage: the type locality is within the hydrographic basin of the Araguaia river. The word Araguaia comes from the indigenous Amazonian language term arauay (or araguaí), which designates a type of macaw species.

DIAGNOSIS. — Dorsum covered with conical tubercles and lateral ribs with three rows on cephalon (6, 2, 6); four rows on pereonite 1 (4, 7, 10, 6); two rows on pereonites 2-6 (10 + 8) and on pereonite 7 (6 + 8); one row of four tubercles on pleonites 3-5; and two paramedian tubercles on telson. Pleopod 1 exopod distal portion round, outer margin straight; endopod with distal portion slightly bent outward, slightly swollen, four times longer than exopod.

DISTRIBUTION.— Serra dos Martírios/Andorinhas State Park in São Geraldo do Araguaia municipality, Pará state.

DESCRIPTION

Maximum size: ♂, 5 mm, ♀, 6 mm. Color grey with lateral margins depigmented ( Fig. 27C View FIG ). Dorsum covered with conical tubercles and lateral ribs ( Figs 5A, B View FIG ; 28E View FIG ): cephalon with three rows (6, 2, and 6 from front to back of vertex); pereonite 1 with 27 in four rows (4, 7, 10 and 6); pereonites 2-6 with 18 (10 + 8); pereonite 7 with 14 (6 + 8); pleonites 3-5 with one row of four tubercles; telson with two paramedian tubercles. Dorsal cuticle ( Fig. 28E View FIG ) with short triangular scale setae; pereonites 1-7 bearing one line of noduli lateralis per side on outer surface of posterior tubercle of second line of tubercle. Cephalon with frontal shield directed upward; eye consisting of 16 ommatidia ( Fig. 5C, D View FIG ). Pereonite 1 with posterior margin sinuous at sides; inner lobe of schisma rounded, extending beyond posterior margin of outer lobe; pereonite 2 with triangular ventral tooth reaching epimeron posterior margin ( Fig. 5E View FIG ). Pereonites 2-7 ( Fig. 5A View FIG ) with wide quadrangular epimera slightly bent outwards.Telson ( Fig. 5F View FIG ) hourglass-shaped, proximal portion broader than distal portion. Antennula ( Fig. 5G View FIG ) of three articles, second article shorter than first and third, third article with six apical and one subapical aesthetascs. Antenna ( Fig. 5H View FIG ) short and stout, flagellum shorter than fifth article of peduncle; second article of flagellum about four times as long as first. Buccal pieces as C. pelado Cardoso & Ferreira , n. sp. ( Fig. 5 View FIG I-L). All pleopod exopods with monospiracular covered lungs. Uropod ( Fig. 6A View FIG ) protopod flattened, enlarged on basal portion; exopod very short, inserted dorsally close to medial margin of protopod.

Male

Pereopods without particular modifications ( Fig. 6B, C View FIG ). Pleopod 1 exopod ( Fig. 6D View FIG ) wider than long, distal portion round, outer margin straight; endopod four times longer than exopod, distal portion slightly bent outwards, slightly swollen. Pleopod 2 endopod longer than exopod ( Fig. 6E View FIG ). Pleopods 3-5 exopods as in Figure 6 View FIG F-H.

HABITAT

Specimens of C. araguaia Cardoso & Ferreira , n. sp. were found in the Andorinhas cave and in Remanso dos Botos cave which are quartzite caves located in the Serra das Andorinhas Mountain Range (also known as Serra dos Martírios). The regional climate is classified, according to Köppen, as Aw5 (Tropical climate with dry season or Humid Equatorial), with annual rainfall between 1000 mm and 1500 mm and an average annual temperature of 26°C (22°-32°C). The relative humidity is high and varies from 25% to 90% with an average of 78% ( Alvares et al. 2013).

The Andorinhas cave is 1 km long, featuring entrances on both the side cliffs covered by Amazonian Forest and the mountaintop covered by savannah vegetation ( Fig. 7A, B View FIG ). During the rainy season, an intermittent drainage flows through the cave. A large colony of insectivorous bats ( Pteronotus sp. ) inhabits some inner and isolated parts of the cave, producing a massive guano piles that cover the floor of several conduits and chambers. In upper areas of the cave conduit ( Fig. 7C View FIG ) away from the bat colony, specimens of C. araguaia Cardoso & Ferreira , n. sp. were found under rocks ( Fig. 7D View FIG ). Given the lack of bat guano in that part of the cave, it is probable that the new species feeds on plant debris carried by floods and deposited along this conduit. In contrast, the Remanso dos Botos cave is smaller (125 m) and located at a lower altimetric level of the hill. The main organic deposits in this cave are guano produced by bats with distinct feeding habits, such as frugivory ( Carolia sp. ) and insectivory ( Peropteryx sp. and Natalus sp. ). Moreover, seeds transported by the bats germinate, resulting in sprouts that were also consumed by some invertebrates. Specimens of C. araguaia Cardoso & Ferreira , n. sp. were observed on the cave floor in deeper areas of the cave, as in the Andorinhas cave.

The caves are located in the Serra dos Martírios/Andorinhas State Park, which preserves the mountain top and cliffs. However, the surrounding landscape has been significantly impacted, particularly by deforestation for agriculture. The Andorinhas cave receives sporadic visitors, likely due to the difficult access to the cave. It is worth noting that the occurrence of C. araguaia Cardoso & Ferreira , n. sp. in these caves does not imply that the species is restricted to this habitat, especially considering the absence of any obvious troglomorphic traits. Therefore, further studies, including external samplings, are needed to better understand the distribution of the species.

REMARK

Ctenorillo araguaia Cardoso & Ferreira , n. sp. is similar to C. pelado Cardoso & Ferreira , n. sp., presenting two tubercles on pereonite 1 and lateral ribs from pereonites 2 to 7, but differs in the number of tubercles on pereonite 1 (27 vs 24 in C. pelado Cardoso & Ferreira , n. sp.), in the number of tubercles on pereonites 2 to 7 (18 tubercles on pereonites 2 to 6 and 14 on pereonite 7 vs C. pelado Cardoso & Ferreira , n. sp. with 12 tubercles on pereonites 2 to 7).