Pectenoniscus juveniliensis, Ferreira, 2020
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publication ID |
https://doi.org/10.1590/2358-2936e2020039 |
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persistent identifier |
https://treatment.plazi.org/id/875F1C5E-FFD4-FFC5-FC3E-FEFBFC40FE95 |
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treatment provided by |
Felipe |
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scientific name |
Pectenoniscus juveniliensis |
| status |
sp. nov. |
Pectenoniscus juveniliensis View in CoL n. sp.
( Figs. 5–7 View Figure 5 View Figure 6 View Figure 7 , 21 View Figure 21 , 22B View Figure 22 )
Zoobank: urn:lsid:zoobank.org:act:02D13338-26E0-410C-BE00-0D68F7831410
Type material. Holotype: male (ISLA 77527), Brazil, Minas Gerais, Juvenilia, Gruta do Tabuleirinho (also known as Lapa Grande) ( WGS84 , -14.37047° -44.288831°), 23 November 2016, leg. R. L. Ferreira . Paratypes: 6 females ( ISLA 77528) , 1 male (in slide) ( ISLA 77512) , 6 females ( ISLA 77529), same data as holotype .
Diagnosis. Male pleopod 1 exopod triangular with acute apex; male pleopod 2 exopod triangular, and pleopod 2 endopod apex distal margin rounded with two subapical lobes on inner margin.
Description. Maximum length: male, 3.5 mm. Colorless, eyes absent ( Figs. 5A View Figure 5 , 7D View Figure 7 ). Dorsal scale-setae tricorn-shaped. Dorsal granulations disposed in two rows on pereonites 1 to 7, smooth pleon ( Fig. 5B View Figure 5 ). Cephalon with round antennal lobes; supra-antennal line bent in middle ( Fig. 5A View Figure 5 ). 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. 5B View Figure 5 ). Pleotelson with concave margin and round apex ( Fig. 5B View Figure 5 ). Antennula with three articles, distal article with nine aesthetascs ( Fig. 5C View Figure 5 ). Antenna reaches pereonite2 when extended backward, fifth article of peduncle shorter than flagellum, with one seta longer than the first two flagellum articles; flagellum with three articles ( Fig. 5D View Figure 5 ). Left mandible with two penicils ( Fig. 5E View Figure 5 ); right mandible with one penicil, lacinia mobilis leaf-shaped ( Fig. 5F View Figure 5 ). Maxillula outer branch with 5+4 teeth, apically entire, and one plumose stalk; inner branch with three penicils ( Fig. 5G View Figure 5 ). Maxilla with bilobate apex, inner lobe wider than outer lobe with several setae on distal margin ( Fig. 5H View Figure 5 ). Maxilliped basis enlarged on distal portion; palp with two setae; endite triangular, apex with one triangular penicil and two small lateral spines ( Fig. 5I View Figure 5 ). Pereopod 1 antennal grooming brush composed of serrated scale setae longitudinally on propodus and on sternal margin of carpus ( Fig. 6A View Figure 6 ); dactylar seta bifid with thin setule. Uropod protopod rectangular, longer than distal margin of pleotelson; exopod longer than endopod, inserted distally ( Fig. 6A View Figure 6 ).
Male: Pereopods 6 and 7 ( Fig. 6B, C View Figure 6 ) propodus with tufts of setae on tergal margin, with water conducting system; pereopod 7 ischium with convex sternal margin. Genital papilla ( Fig. 6D View Figure 6 ) medial part enlarged, apex narrow. Pleopod 1 ( Fig. 6D View Figure 6 ) protopod rectangular, three times wider than long; exopod triangular with acute apex; endopod twice longer than exopod. Pleopod 2 ( Fig. 6E View Figure 6 ) protopod rectangular; exopod triangular, twice wider than long; endopod with distal threefold longer than proximal article, apex distal margin rounded, without apical lobe; two subapical lobes on inner margin. Pleopod 3 exopod
( Fig. 6F View Figure 6 ) trapezoidal. Pleopod 4 and 5 exopods ( Fig. View Figure 6
6G, H) subquadrangular, bearing four-five setae on outer margin, exopod 5 with dorsal lobe.
Etymology. The specific epithet juveniliensis refers to the municipality of Juvenilia, where the new species was collected.
Remarks. Pectenoniscus juveniliensis n. sp. differs from P.angulatus and P. liliae by the dorsal granulation pattern (two rows on all the pereonites versus three rows on the first pereonite and two on the others in P. angulatus and P. liliae ), the shape of male pleopod 1 exopod (apex acute versus round in P.angulatus and P. liliae ), and the shape of male pleopod 2 exopod (sub-triangular versus rectangular in P. angulatus and ovoid in P. liliae ). Moreover, P. juveniliensis n. sp. differs from P. montalvaniensis n. sp. by the dorsal granulation pattern, by the number of aesthetascs on antennula (9 versus 8 in P. montalvaniensis n. sp.), by the shape of male pleopod 1 exopod with acute apex (versus round apex), by the shape of male pleopod 2 exopod with triangular shape (versus trapezoid) and by the male pleopod 2 endopod apex distal margin rounded, without apical lobe; two subapical lobes on inner margin (versus apex with lobe directed inward and subapical denticles projected outward).
Habitat and ecological remarks. Specimens of P. juveniliensis n. sp. were found in Gruta do Tabuleirinho (also regionally known as “Lapa Grande” cave), which comprises the biggest known cave in the municipality ( Figs. 7A View Figure 7 , 21 View Figure 21 , 22B View Figure 22 ). This cave presents a single large entrance (40 m high) ( Fig. 7B View Figure 7 ). From the entrance onwards, the cave develops into a voluminous conduit ( Fig. 7C View Figure 7 ), which is mostly dry. In this conduit, although several bat guano piles were observed, no specimens of P. juveniliensis n. sp. were found associated. Considering that the visit to the cave occurred in the rainy season, many travertine pools were filled with water, but no specimens were found in this conduit. Near the end of this main conduit, a lateral ascent leads to an upper chamber, which is moister and warmer than the lower part of the cave. Furthermore, it is extremely oligotrophic, and the organic debris consisted of rare and old bat guano piles. All specimens of P. juveniliensis n. sp. were found in this upper chamber, especially walking on moistened speleothems, as stalagmitic f loors and flowstones ( Fig.7D View Figure 7 ). Despite the lack of visible organic matter (bat guano), the dark gut content observed in the living specimens indicate they are feeding on some organic resources occurring in this upper level. Since this cave is voluminous, it is difficult to find specimens, however thorough searches have revealed that they are not rare along the cavity (we observed at least 20 individuals in a single visit to the cave). Furthermore, other specimens of Pectenoniscus were found in two other caves in the area (Gruta do Zé Prefeito and Gruta do Fóssil caves), however, only females were found, and since male characters are important to define the species, we choose not to assign them to the herein described species. Another described troglobitic species found in this cave is the unusual hydrometrid hemipteran Spelaeometra gruta ( Polhemus and Ferreira, 2018) . Gruta do Tabuleirinho cave presents obvious signs of human visitation, but currently only a few visitors have been entering the cave, according to local residents. Regarding the external landscape, it is composed of secondary forest under regeneration (close to the outcrop), and pastures ( Fig. 22B View Figure 22 ).
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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.