Pectenoniscus montalvaniensis, Ferreira, 2020
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publication ID |
https://doi.org/10.1590/2358-2936e2020039 |
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https://treatment.plazi.org/id/875F1C5E-FFD0-FFC9-FC18-FCCCFAE1FECC |
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treatment provided by |
Felipe (2025-01-16 04:47:50, last updated 2025-01-16 06:08:17) |
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scientific name |
Pectenoniscus montalvaniensis |
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sp. nov. |
Pectenoniscus montalvaniensis View in CoL n. sp.
( Figs. 1–4 View Figure 1 View Figure 2 View Figure 3 View Figure 4 , 21 View Figure 21 , 22A View Figure 22 )
Zoobank: urn:lsid:zoobank.org:act:E4E34FDD-8225-4F0A-A863-F90691934E57
Type material. Holotype: male (ISLA 77524), Brazil, Minas Gerais, Montalvânia, Abrigo da Ema ( WGS84 - 14.286846 ° -44.392976°), 25 November 2016, leg. R. L. Ferreira . Paratypes: 2 males, 19 females ( ISLA 77525) ; 3 males, 6 females ( ISLA 77526), same data as holotype .
Diagnosis. Triangular shape of antennal lobes; male pleopod 1 exopod triangular; pleopod 2 exopod trapezoidal, and pleopod 2 endopod apex with lobe directed inward and subapical denticles projected outward.
Description. Maximum length: male, 2.5 mm. Colorless, eyes absent ( Figs. 1A View Figure 1 , 3A View Figure 3 , 4C View Figure 4 ). Dorsal scale-setae tricorn-shaped ( Fig. 3B, C View Figure 3 ). Dorsal granulations disposed randomly on cephalon, in three rows on pereonite 1, two rows on pereonites 2–7 ( Figs. 1A View Figure 1 , 3A–C View Figure 3 ), smooth pleon ( Fig. 3D View Figure 3 ).Cephalon with triangular antennal lobes obliquely directed and grooved dorsally; supra-antennal line bent in middle ( Fig. 3A View Figure 3 ). Pereonite 1 with margin projected forward, not surpassing median portion of cephalon; pereonites 3–7 posterior margin progressively more concave; pleonites 3–5 epimera posterior points developed pleon narrower than pereon ( Fig. 1A View Figure 1 ). Pleotelson with concave sides and round apex ( Figs. 1B View Figure 1 , 3C View Figure 3 ). Antennula with three articles, distal article with eight aesthetascs ( Fig. 1C View Figure 1 ). Antenna reaches pereonite 1 when extended backward, fifth article of peduncle shorter than flagellum with one seta longer than first f lagellum article; f lagellum with three articles ( Fig. 1D View Figure 1 ). Left mandible with two penicils ( Fig. 1E View Figure 1 ); right mandible with one penicil, lacinia mobilis leaf-shaped ( Fig. 1F View Figure 1 ). Maxillula outer branch with 4+4 teeth,apically entire, and one plumose seta; inner branch with three penicils ( Fig. 1G View Figure 1 ). Maxilla with bilobate apex, inner lobe wider than outer lobe with several setae on distal margin ( Fig. 1H View Figure 1 ). Maxilliped basis enlarged on distal portion; palp with two setae; endite triangular, apex with one triangular penicil and one lateral spine ( Fig. 1I View Figure 1 ). Pereopod 1 antennal grooming brush composed of serrated scale setae longitudinally on propodus and on sternal margin of carpus ( Fig. 2A View Figure 2 ); dactylar seta bifid with thin setule. Uropod protopod longer than wide, longer than distal margin of pleotelson; exopod longer than endopod, inserted distally ( Figs. 1B View Figure 1 , 3C View Figure 3 ).
Male: Pereopods 6 and 7 ( Figs. 2B, C View Figure 2 ) propodus with tufts of setae on tergal margin; and water conducting system; pereopod 7 ischium with convex sternal margin ( Figs. 2C View Figure 2 , 3D View Figure 3 ). Genital papilla ( Fig. 2D View Figure 2 ) enlarged on medial portion, apical portion narrow. Pleopod 1 ( Fig. 2E View Figure 2 ) protopod rectangular, three times wider than long; exopod triangular, apex round, lateral margin straight; endopod twice longer than exopod. Pleopod 2 ( Fig. 2F View Figure 2 ) protopod rectangular; exopod trapezoidal, wider than long; endopod with distal article almost three times longer than proximal article, apex with lobe directed inward and subapical denticles projected outward. Pleopod 3 exopod ( Fig. 2G View Figure 2 ) trapezoidal; pleopod 4 exopod ( Fig. 2H View Figure 2 ) rectangular, and pleopod 5 exopod ( Fig. 2I View Figure 2 ) rectangular with dorsal lobe.
Etymology. The specific epithet montalvaniensis refers to the city of Montalvânia, where the new species was collected.
Remarks. Pectenoniscus montalvaniensis n. sp. differs from P. angulatus by the number of articles in the antenna flagellum (3 versus 5 in P. angulatus ), and by the shape of male pleopod 2 endopod (apex with lobe directed inwards versus apex with plate-like appendage in P. angulatus ) and exopod (triangular versus rectangular in P. angulatus ). In relation to P. liliae , P. montalvaniensis n. sp. differs by the triangular shape of antennal lobes (versus quadrangular in P. liliae ), by the number of aesthetascs in the antennula distal article (8 versus P. liliae : 9) and the shape of male pleopod 2 endopod (apical portion chela-shaped with two triangular lobes in P. liliae ) and exopod (ovoid in P. liliae ).
Habitat and ecological remarks. Pectenoniscus montalvaniensis n. sp. was collected in a cave associated with an isolated limestone outcrop( Fig.4A View Figure 4 ) in relation to the main massif occurring in the area. Although there are many caves in the region, only a few were sampled, suggesting that new populations of P. montalvaniensis n. sp. potentially can be discovered in the future in this region. The original name of the cave where this species was found (Abrigo da Ema - “Ema shelter” - in Portuguese) was attributed by archaeologists due to the ancient rock engravings on the cave wall ( Fig. 4B View Figure 4 ). The cave presents aphotic conduits, the specimens were found concentrated on the cave floor (around 20 specimens), close to moist areas, where the humidity came from dripping speleothems. The main cave conduit seems to be trespassed by water f lows during strong rains, which brings organic matter to the cave interior (especially vegetal debris). A few bat guano piles were observed in the cave, but no isopod specimens were found associated with them. Indeed, several individuals of P. montalvaniensis n. sp. were found close to roots, which were frequent on the cave floor ( Fig. 4C View Figure 4 ). The dark gut content observed in the living specimens indicate they were feeding on dark brown organic debris, as plant material or eventually dead root masses. The external environment surrounding the cave is altered, especially by the replacement of native vegetation by pastures ( Figs. 21 View Figure 21 , 22A View Figure 22 ). However, considering that this cave seems not to be frequently visited by humans, no direct impact for the species was detected.
Figure 1. Pectenoniscus montalvaniensis n. sp. Male paratype: A, habitus, dorsal view; B, pleotelson and uropod, dorsal view; C, antennula; D, antenna; E, left mandible; F, right mandible; G, maxillula; H, maxilla; I, maxilliped. Scale bars: 0.2 mm.
Figure 2. Pectenoniscus montalvaniensis n. sp. Male paratype: A, pereopod 1; B, pereopod 6; C, pereopod 7; D, genital papilla; E, pleopod 1; F, pleopod 2; G, pleopod 3 exopod; H, pleopod 4 exopod; I, pleopod 5 exopod. Scale bar: 0.2 mm.
Figure 3. Pectenoniscus montalvaniensis n. sp. Male paratype:A, cephalon, frontal view; B, dorsal scaled setae; C, epimeron2, dotted line indicating the lines of tubercles, dorsal view; D, pleonite 5, pleotelson and uropod, dorsal view; D, pereopod 7. Scale bars: A, D,E: 300µm; B: 40µm; C: 50µm.
Figure 4. Pectenoniscus montalvaniensis n. sp.A, entrance of Abrigo da Ema cave, outside view; B, ancient rock engravings on the cave wall; C, specimen of Pectenoniscus montalvaniensis n. sp., approximately 2 mm.
Figure 21. Map of South America highlighting Brazil and the states of Bahia (BA), Minas Gerais (MG), and Santa Catarina (SC), where the species of Pectenoniscus are recorded. Brown and green colors indicate the elevation of the terrain, with brown for higher levels, green for lower levels; gray indicates karstic areas.
Figure 22. Satellite images of localities: A, Abrigo da Ema (Montalvânia municipality); B, Gruta do Tabuleirinho (Juvenilia municipality); C, Baixa da Fortuna cave (Iuiu municipality); D, Gruna da Água Clara Cave, Gruna dos Índios cave and Gruna dos Peixes II, from top to bottom (Carinhanha municipality); E, Gruta do Padre cave (Santana municipality); F, Gruta dos Brejões (Morro do Chapéu municipality).
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Departamento de Geologia, Universidad de Chile |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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