Ctenorillo pelado 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 : 101-104

Ctenorillo pelado Cardoso & Ferreira , n. sp.

( Figs 2-4 ; 27B ; 28 A-D)

urn:lsid:zoobank.org:act:B55B71C4-84ED-4DF5-AF0E-6B8356376022

nec Ctenorillo ferrarai – Campos-Filho et al. 2023: 560, figs 22, 23. TYPE MATERIAL. — Holotype. Brazil. Pará state; Curionópolis municipality; Serra Leste plateau • ♂ (4.5 mm); SL_0001 cave; 5°57’58”S, 49°38’57”W; 14.I.2011; ISLA 96773. Paratypes. Brazil • 1 ♂ (parts in slide); same data as holotype; ISLA96774 • 4♂, 3 ♀; SL_0001 cave; same data as holotype; ISLA15135 • 2 juv.; same data as holotype; 4.VII.2010; ISLA15926 • 5 ♂, 5 ♀; same data as holotype; 4.VII.2010; ISLA15969 .

OTHER MATERIAL. — Brazil. Pará; Curionópolis municipality; Serra Leste plateau • 4 ♂, 5 ♀; SL_0002 cave; 5°52’57”S, 49°38’57”W; 13.I.2011; ISLA15136 • 8 ♂, 2 ♀; SL_0002 cave; 3.VII.2010; ISLA15970 • 2♂; SL_0003 cave; 3.VII.2010; ISLA15971 • 2 ♂, 5 ♀; SL_0004 cave; 5°57’49”S, 49°38’59”W; 13.I.2011; ISLA15137 • 2 ♂, 2 ♀; SL_0004 cave; 3.VII.2010; ISLA15972 • 1 ♂, 2 ♀; SL_0006 cave; 5°57’48”S, 49°38’59”W; 13.I.2011; ISLA15138 • 3 ♀; SL_0006 cave; 28.VI.2010; ISLA15902 • 1 ♂, 6 ♀; SL_0007 cave; 5°57’58”S, 49°38’58”W; 3. XII.-2011; ISLA15872 • 1♂, 2 ♀; SL_0007 cave; 4.VII.2010; ISLA15939 • 3 ♀, 3 juv.; SL_0008 cave; 5°58’3”S, 49°38’58”W; 14.I.2012; ISLA15139 • 4 ♂, 3 ♀; SL_0008 cave; 5.VII.2010; ISLA15973 • 1♀, 1 juv.; SL_0011 cave; 5°58’4”S, 49°38’59”W; 14.I.2011; ISLA15140 • 1 ♀; SL_0012 cave; 5°57’52”S, 49°38’59”W; 4.VII.2016; ISLA15974 • 2 ♀; SL_0013 cave; 5°57’47”S, 49°38’59”W; 13.I.2011; ISLA15141 • 1 ♀; SL_0014 cave; 5°57’46”S, 49°39’0”W; 13.I.2011; ISLA15878 • 1 ♀; SL_0015 cave; 5°57’44”S, 49°39’0”W; 2.II.2011; ISLA15142 • 1 ♂; SL_0016 cave; 5°58’12”S, 49°38’51”W; 12.I.2011; ISLA6211 • 2 ♂, 6 ♀; SL_0016 cave; 12.I.2011; ISLA15143 • 1 ♀; SL_0016 cave; 6.VI.2010; ISLA16588 • 1 ♂; SL_0017 cave; 5°58’16”S, 49°38’48”W; 8.I.2011; ISLA15144 • 3♀; SL_0019 cave; 5°58’15”S, 49°38’47”W; 12.I.2011; ISLA15145 • 1 juv.; SL_0020 cave; 5°58’15”S, 49°38’47”W; 12.I.2011; ISLA15146 • 2 ♀; SL_0022 cave; 5°58’17”S, 49°38’46”W; 29.I.2011; ISLA15147 • 1 ♀, 3 juv.; SL_0023 cave; 5°58’18”S, 49°38’46”W; 12.I.2011; ISLA15985 • 3♂, 6 ♀; SL_0024 cave; 5°58’19”S, 49°38’41”W; 9.VI.2010; ISLA15929 • 2♂, 4 ♀; SL_0026 cave; 5°58’21”S, 49°38’41”W; 12.I.2011; ISLA15976 • 2 ♂, 1 ♀; SL_0026 cave; 9.VI.2010; ISLA16589 • 2 ♂; SL_0030 cave; 5°58’20”S, 49°38’37”W; 8.VI.2010; ISLA15954 • 1♀; SL_0032 cave; 5°58’7”S, 49°38’40”W; 27.VII.2010; ISLA15942 • 1 ♂, 3 ♀; SL_0035 cave; 5°58’32”S, 49°38’16”W; 31.I.2011; ISLA15148 • 1 ♂, 2 ♀; SL_0036 cave; 5°58’31”S, 49°38’15”W; 23.VII.2010; ISLA15931 • 1 ♀; SL_0037 cave; 5°58’40”S, 49°37’54”W; 27.I.2011; ISLA15855 • 1♀; SL_0037 cave; 8.VII.2010; ISLA15935 • 1 ♂; SL_0042 cave; 5°58’14”S, 49°38’47”W; 2.II.2011; ISLA15149 • 2♂; SL_0042 cave; 8.VII.2010; ISLA16590 • 1 ♀; SL_0047; 30.VI.2010; ISLA16591 • 1♀; SL_0048 cave; 5°58’58”S, 49°37’52”W; 29.I.2011; ISLA15860 • 2 ♂, 1 ♀; SL_0049 cave; 5°58’58”S, 49°37’51”W; 29.I.2011; ISLA15980 • 2 ♂, 1 ♀; SL_0049; 27.VI.2010; ISLA16592 • 1 ♂, 2 ♀; SL_0057 cave; 5°58’36”S, 49°37’32”W; 11.I.2011; ISLA15151 • 1♀; SL_0058 cave; 5°58’34”S, 49°37’28”W; 29.I.2011; ISLA15150 • 1 ♂, 3 ♀; SL_0058 cave; 27.VI.2010; ISLA16593 • 3 ♂, 5 ♀; SL_0060 cave; 5°58’46”S, 49°37’22”W; 10.I.2011; ISLA15152 • 4 ♂, 5 ♀; SL_0060 cave; 10.VI.2010; ISLA16594 • 1 ♂; SL_0064 cave; 5°58’44”S, 49°37’17”W; 10.VI.2010; ISLA15924 • 1 ♀; SL_0065 cave; 5°58’53”S, 49°37’11”W; 2. XII.-2011; ISLA15154 • 2 ♂, 1♀; SL_0065; 2. XII.-2011; ISLA15155 • 2 ♂, 8 ♀; SL_0065 cave; 5.VI.2010; ISLA16595 • 1♀; SL_0066 cave; 5°58’52”S, 49°37’12”W; 2. XII.-2011; ISLA15153 • 1 ♀; SL_0066; 8.VII.2010; ISLA16596 • 1 ♂, 1 ♀; SL_0067 cave; 5°58’51”S, 49°37’12”W; 5.VI.2010; ISLA16597 • 1♂, 3 ♀; SL_0067 cave; 3.III.2011; ISLA15156 • 3♂, 5 ♀; SL_0069 cave; 5°59’2”S, 49°37’14”W; 3. XII.-2011; ISLA15157 • 1♂, 3♀; SL_0069 cave; 11.VI.2010; ISLA16598 • 1 juv.; SL_0072 cave; 7.I.2011; ISLA15158 • 2 ♂, 1 ♀; SL_0072 cave; 5°58’21”S, 49°37’28”W; 23.VII.2010; ISLA15909 • 3 ♂, 2♀; SL_0074 cave; 5°57’57”S, 49°37’55”W; 11.I.2010; ISLA15965 • 4♀; SL_0074 cave; 24.VI.2010; ISLA16599 • 1♂, 1 ♀; SL_0075 cave; 5°57’55”S, 49°37’56”W; 12.I.2011; ISLA15966 • 2♂, 1♀; SL_0076 cave; 5°58’0”S, 49°38’32”W; 31.I.2011; ISLA15110 • 2♀; SL_0077 cave; 5°58’0”S, 49°38’33”W; 29.VI.2010; ISLA16600 • 1 ♂, 1 ♀; SL_0082 cave; 5°57’30”S, 49°38’15”W; 7.VII.2010; ISLA15911 • 1 ♀; SL_0083 cave; 5°57’29”S, 49°38’11”W; 7.VII.2010; ISLA15945 • 2 ♀; SL_0085 cave; 5°57’30”S, 49°38’10”W; 18.I.2011; ISLA15099 • 1 ♀; SL_0085 cave; 21.VII.2010; ISLA15894 • 1 juv.; SL_0086 cave; 5°57’31”S, 49°38’10”W; 18.I.2011; ISLA15990 • 2 ♂, 2 ♀; SL_0087 cave; 5°57’31”S, 49°38’9”W; 2.II.2011; ISLA15111 • 5♂, 8 ♀; SL_0087 cave; 21.VII.2010; ISLA15913 • 1 ♀; SL_0088 cave; 5°57’31”S, 49°38’9”W; 22.VII.2010; ISLA21127 • 1 ♀; SL_0089 cave; 5°57’31”S, 49°38’8”W; 2.II.2011; ISLA15967 • 2♂; SL_0089 cave; 2.II.2011; ISLA21128 • 1 ♀; SL_0091 cave; 5°57’32”S, 49°38’7”W; 2.II.2011; ISLA15906 • 1♀; SL_0092 cave; 5°57’33”S, 49°38’7”W; 2.II.2011; ISLA15885 • 1♀; SL_0092 cave; ISLA15904 • 1 ♂, 2 ♀; SL_0099 cave; 5°58’33”S, 49°37’28”W; 7.I.2011; ISLA15968 • 2♂, 5 ♀; SL_0100 cave; 5°58’45”S, 49°37’21”W; 10.I.2011; ISLA15964 • 3 ♂, 2 ♀; SL_0100 cave; ISLA21129 • 3 ♂, 10 ♀; SL_0101 cave; ISLA6178 • 1 ♀; SL_0102; ISLA6182 • 1 ♀; SL_cm-t4b; 5°58’36”S, 49°37’33”W; 17.IV.2018; ISLA21130 • 1♂, 3 ♀; SL_cm-t4c; 5°58’35”S, 49°37’35”W; 17.IV.2017; ISLA21131 • 1 ♂, 1 ♀; SL_as-t4d; 5°58’34”S, 49°37’37”W; 26.IV.2018; ISLA21132 • 1♀; SL_as-t4b; 5°58’36”S, 49°37’33”W; 26.IV.2017; ISLA21133 • 1 ♀; SL_as-t4c; 5°58’35”S, 49°37’35”W; 26.IV.2017; ISLA21134 • 1 ♂; SL_as-t1b; 5°58’23”S, 49°38’32”W; 29.IV.2017; ISLA21135 • 1 ♀; SL_cm-t4d; 5°58’34”S, 49°37’37”W; 17.II.2017; ISLA21136 • 1 ♂, 1 ♀; SL_apl-t4c; 5°58’35”S, 49°37’35”W; 17.II.2017; ISLA21137.

ETYMOLOGY. — The new species name is a noun in apposition that refers to the region where the species was collected, also known as “Serra Pelada”, which means “naked mountains”, in reference to the presence of the metallophilic vegetation, that is considerably reduced (in size) when compared to the surrounding Amazon Forest.

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

DISTRIBUTION. — Carajás National Forest, Pará State.

DESCRIPTION

Maximum size: ♂, 4.5 mm, ♀, 6 mm. Color grey in nature, brownish in ethanol ( Figs 4B ; 27B ). Dorsum covered with conical tubercles and lateral ribs ( Figs 2 A-C; 28A, B): cephalon with three rows (4, 2, and 6 from front to back of vertex); pereonite 1 with 24 in three rows (6, 10 and 8); pereonites 2-7 with 12 (6+ 6); pleonites 3-5 with one row of four tubercles; telson with two paramedian tubercles. Dorsal cuticle ( Fig. 28B ) 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 tubercles. Cephalon with frontal shield slightly protruding above vertex; eye consisting of 11 ommatidia ( Figs 2C ; 28A ). Pereonite 1 with posterior margin distinctly 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 ( Figs 2A, D ; 28D ). Pereonites 2-7 ( Figs 2A ; 28B ) with wide quadrangular epimera slightly bent outwards. Telson ( Fig. 2E ) hourglass-shaped, proximal portion broader than distal portion. Antennula ( Fig. 2F ) of three articles, second article much shorter than first and third, third article with two apical and four subapical aesthetascs. Antenna ( Fig. 2G ) short and stout, flagellum shorter than fifth article of peduncle; second article of flagellum about three times as long as first. Mandibles ( Fig. 2H, I ) with molar penicil semidichotomised, consisting of several plumose setae from common stem; right mandible with 1+1 and left mandible with 2 +1 free penicils. Maxillula ( Fig. 2J ) with outer branch bearing 4 +5 simple teeth. Maxilla ( Fig. 2K ) distally setose and bilobate, with inner lobe narrower than outer lobe. Maxilliped ( Fig. 2L ) endite with subapical large seta and two triangular setae on apical margin; palp with two setae on basal article. All pleopod exopods with monospiracular covered lungs ( Fig. 28C ). Uropod ( Fig. 3A ) protopod flattened, enlarged on basal portion; exopod very short, inserted dorsally close to medial margin of protopod.

Male

Pereopods without particular modifications ( Fig. 3B, C ). Pleopod 1 exopod ( Fig. 3D ) wider than long, triangular with protruding distal portion, outer margin concave and crenulate; endopod four times longer than exopod, distal portion straight, slightly swollen. Pleopod 2 endopod longer than exopod ( Fig. 3E ). Pleopods 3-5 exopods as in Figure 3 F-H.

HABITAT

Specimens of C. pelado Cardoso & Ferreira , n. sp. were found in several caves in the Serra Leste Mountain Range (also known as Serra Pelada) which is part of the geological complex of the Carajás region, in the Carajás National Forest ( Fig. 4A ). The specimens were found in caves, and also in the external habitats, during external surveys ( Fig. 4B ). The regional climate is also classified as Aw according to the Köppen system, characterized by the same patterns of precipitation and temperature as described for the previous species ( C. ferrarai ). Nevertheless, given the regularity with which specimens have been observed within cave systems, it is plausible to classify this species as troglophilic. Of the approximately 120 iron ore caves surveyed in the region, C. pelado Cardoso & Ferreira , n. sp. was identified in 63 of these caves (roughly 52.5% of the total caves in the area), indicating an even broader distribution within Serra Leste than C. ferrarai within the Serra Norte complex ( Fig. 4C, D ). It should be noted that Serra Leste is primarily comprised of a single, extensive plateau, as opposed to the multiple plateaus present in the Serra Norte complex. As with C. ferrarai , the geological characteristics of caves inhabited by C. pelado Cardoso & Ferreira , n. sp. vary significantly, suggesting that this species is not strongly reliant on specific habitat traits. Despite the wide distribution of this species in the caves of the area, a large quarry is rapidly expanding in the region, posing a significant threat to the species. Therefore, monitoring plans should include C. pelado Cardoso & Ferreira , n. sp. to assess any potential changes to its distributional patterns and population characteristics.

REMARKS

As mentioned previously, the Ctenorillo species are distinguished mainly by the shape, number, and disposition of dorsal tubercles. The morphology of C. pelado Cardoso & Ferreira , n. sp. and C. ferrarai is very similar, the species differ in the number of tubercles on pereonite 1 with C. pelado Cardoso & Ferreira , n. sp. presenting 24 tubercles and C. ferrarai presenting 22; this seems to be related to the prominent lateral rib in C. ferrarai while in C. pelado Cardoso & Ferreira , n. sp. the lateral rib is present from pereonite 2 to 7 with two tubercules (instead of one rib) on pereonite 1. The disposition of tubercles on pereonite 1 differ with 6 + 10 + 8 on C. pelado Cardoso & Ferreira , n. sp. and 4 +12 + 6 on C. ferrarai . The specimen presented by Campos-Filho et al. (2023) were also collected in the Serra Leste plateau and resembles the morphology of C. pelado Cardoso & Ferreira , n. sp. presented here; therefore, we can consider them as the same species.

Comparing C. pelado Cardoso & Ferreira , n. sp. with other Ctenorillo species, on pleon, the presence of four tubercles on pleonites 3-5 is similar to C. guinensis ( Schmalfuss & Ferrara, 1983) , C. legai ( Arcangeli, 1941) , C. mineri and C. ferrarai from which it differs by the shape of male pleopod 1 exopod.

Figures

FIG. 2. — Ctenorillo pelado Cardoso & Ferreira, n. sp. paratype (male, 5 mm, ISLA96774): A, habitus, lateral view; B, disposition of dorsal tubercles; C, cephalon and pereonite 1, dorsal view; D, epimera 1-3 ventral view; E, pleonites 3-5, uropods and telson, dorsal view; F, antennula; G, antenna; H, right mandible; I, left mandible; J, maxillula; K, maxilla; L, maxilliped. Scale bar: 0.5 mm.

FIG. 3. — Ctenorillo pelado Cardoso & Ferreira, n. sp. paratype (male, 5 mm, ISLA96774): A, uropod, B, pereopod 1; C, pereopod 7; D, pleopod 1 and genital papilla; E, pleopod 2; F, pleopod 3 exopod; G, pleopod 4 exopod; H, pleopod 5 exopod.

FIG. 4. — Ctenorillo pelado Cardoso & Ferreira, n. sp.: A, Serra Leste Mountain range; B, habitus in natural condition; C, inner portion of an iron ore cave where specimens are found; D, entrance of an iron ore cave in the Serra Norte region where specimens are found.

FIG. 27. — Habitus of the species of the genus Ctenorillo Verhoeff, 1942 discussed in the present paper:A, Ctenorillo ferrarai Campos-Filho, Araujo & Taiti,2014; B, Ctenorillo pelado Cardoso & Ferreira, n. sp.; C, Ctenorillo araguaia Cardoso & Ferreira, n. sp.; D, Ctenorillo intertidalis Cardoso & Ferreira, n. sp.; E, Ctenorillo ubajarensis Cardoso & Ferreira,n. sp.; F, Ctenorillo cearensis Cardoso & Ferreira,n. sp.; G, Ctenorillo quiteriensis Cardoso & Ferreira,n. sp.; H, Ctenorillo potiguar Cardoso & Ferreira, n. sp.; I, Ctenorillo iuiuensis n. sp.; J, Ctenorillo jequitinhonha Cardoso & Ferreira, n. sp. Scale bars: 1 mm.

FIG. 28. — SEM images of Ctenorillo Verhoeff, 1942 new species: A-D, Ctenorillo pelado Cardoso & Ferreira, n. sp.: cephalon, dorsal view (A); epimera 1-3, lateral view (B); pleopod 3 exopod (C); epimera 1 and 2, ventral view (D); E, Ctenorillo araguaia Cardoso & Ferreira, n. sp.:, cephalon and epimera 1-3, lateral view; F, G, Ctenorillo intertidalis Cardoso & Ferreira, n. sp.: cephalon, frontal view (F); epimera 1-3, lateral view (G); H, Ctenorillo ubajarensis Cardoso & Ferreira,n. sp.: cephalon and epimera 1-3, lateral view;I, Ctenorillo potiguar Cardoso & Ferreira, n. sp.: cephalon and epimera 1 and 2, lateral view; J, K, Ctenorillo jequitinhonha Cardoso & Ferreira, n. sp.: cephalon, frontal view (J); cephalon and epimera 1 and 2, lateral view (K). Scale bars: A, B, D-K, 0.5 mm; C, 0.2 mm.