Benthanoides tarzan Cardoso & Ferreira 2023, n. sp.
Creators: name: Cardoso, Giovanna Monticelli
name: Ferreira, Rodrigo Lopes
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Philosciidae
Benthanoides
Benthanoides tarzan

description: Benthanoides tarzan n. sp.
(Figures 2G, 3D, 8 and 9)
Type material. Holotype: male (ISLA 96768 in slide), Brazil, Pará state, municipality of Parauapebas, cave ST_ 0005 (-6.3297º -50.1067º), 11.viii.2016, leg. F.M.B Silva. Paratypes: 2 males, 3 juvenile (ISLA 96407), same data as holotype; 1 male (ISLA 96452), same data as holotype; 1 male (ISLA 96371), 21.i.2016, same data as holotype; 1 female (ISLA 44237), 21.i.2016, same location as holotype, leg. R.B. Pereira.
Additional material: Brazil, Pará state, municipality of Parauapebas. Cave ST_0003 (-6.327461° -50.114125°): 1 female (ISLA 96370), 28.i.2016, leg. F.M.B Silva. Cave ST_0022 (-6.319868° -50.132135°): 1 female (ISLA 44236), 10.viii.2016, R. B. Pereira leg.; 1 male (ISLA 96367), 2.ii.2016, leg. F.M.B Silva; 2 males (ISLA 96443), 10.viii.2016, F.M.B Silva leg.; 1 male, 2 females (ISLA 96429), 10.viii.2016, leg. F.M.B Silva. Cave ST_0023 (- 6.319160° -50.130079°): 2 females (ISLA 96451), 09.viii.2016, F.M.B Silva leg.; 2 females (ISLA 96461), 26.i.2016, leg. F.M.B Silva. Cave ST_0030 (-6.3164º -50.1205º): 2 females (ISLA 96432), 04.ii.2016, leg. F.M.B Silva; 1 female (ISLA 96379), 04.ii.2016, leg. F.M.B Silva. Cave ST_0034 (-6.3201º -50.1128º): 1 female (ISLA 96428), 18.viii.2016, leg. F.M.B Silva. Cave ST_0043 (-6.3131º -50.0927º): 1 male, 1 female (ISLA 96389), 19.vii.2016, leg. F.M.B Silva. Cave ST_0050 (-6.3174º -50.1284º): 1 female (ISLA 96454), 26.i.2016, leg. F.M.B Silva. 1 female (ISLA 96459), 26.i.2016, leg. F.M.B Silva; 2 females (ISLA 96347), 26.i.2016, leg. F.M.B Silva. Cave ST_0054 (- 6.3213º -50.1392º): 4 females (ISLA 96383), 20.viii.2016, leg. F.M.B Silva; 6 females (ISLA 96396), 29.i.2016, leg. F.M.B Silva; 1 male (ISLA 96414), 20.viii.2016, leg. F.M.B Silva; 1 male (ISLA 96444), 20.viii.2016, leg. F.M.B Silva. Cave ST_0062 (-6.3232º -50.1428º): 2 males, 1 female (ISLA 96416), 05.viii.2016, leg. F.M.B Silva; 1 male (ISLA 96447), 5.i.2016, leg. F.M.B Silva.
Diagnosis. Eyes with 5–6 ommatidia; antennula with 12+2 aesthetascs; male pleopod 1 exopod as long as wide, distal part triangular slightly developed; uropod exopod twice longer than endopod.
Description. Maximum body length: male and female with 4 mm. Colourless, some specimens with dots of pigmentation. Body convex, outline as in Fig. 8A. Dorsal surface smooth bearing long triangular scale-setae (Fig. 8B); noduli laterales long, one line per side with d/c coordinates reaching maximum on pereonite 4; b/c coordinates gradually decreasing (Fig. 8C, D). Cephalon (Fig. 8E) with suprantennal line straight, no frontal line and lateral lobes; eyes composed of 5–6 ommatidia arranged in two rows. Pereonites 5–7 with postero-lateral corners gradually more acute; pleon narrower than pereon, pleonites 3–5 with posterior point not developed (Fig. 8A). Telson (Fig. 8F) triangular, lateral sides straight. Antennula (Fig. 8G) of three articles, distal article longest bearing 12 lateral aesthetascs in four rows plus apical pair. Antenna (Fig. 8H) long, reaching pereonite 4 when extended backwards, distal article of peduncle longer than flagellum; flagellum of three articles, first and second articles subequal in length, distal article longest, apical organ short. Mandibles with molar penicil of 8 branches, left mandible (Fig. 8I) with 2+1 penicils, and right mandible (Fig. 8J) with 1+1 penicils. Maxillula (Fig. 8K) inner endite with two penicils; outer endite with 4+5 teeth (5 pectinate). Maxilla (Fig. 8L) outer lobe wider than inner lobe, covered with thick setae; outer lobe distal margin sinuous, covered with thin setae. Maxilliped (Fig. 8M) with rectangular basis; endite rectangular, medial seta surpassing distal margin, two hooks on distal margin, dorsal face with longitudinal ridge bearing dense setae plus one short triangular seta; proximal article of palp with two setae, one longer. Pereopods slender; carpus 1 with transverse antennal grooming brush, distal seta with hand-like apex; dactylus inner claw shorter than outer claw, dactylar and ungual setae simple, not surpassing outer claw. Uropod (Fig. 8F) protopod subquadrangular, protopod and exopod grooved on outer margin, with glandular pores, exopod longer than endopod, endopod inserted proximally.
Male. Pereopod 1 (Fig. 9A) merus and carpus with brushes of setae on sternal margin. Pereopod 7 (Fig. 9B) ischium proximal margin setose; merus with proximal lobe and thick setae on lateral margin. Genital papilla (Fig. 9C) with triangular ventral shield and two subapical orifices. Pleopod 1 (Fig. 9C) exopod rounded, as long as wide, distal part triangular slightly developed; endopod longer than exopod, stout and straight, distal portion tapering with line of short setae. Pleopod 2 (Fig. 9D) exopod triangular, outer margin concave with three setae; endopod slender, slightly longer than exopod. Pleopods 3 and 4 exopods as in Fig. 9E, F, respectively. Pleopod 5 exopod (Fig. 9G) as wide as long, outer margin with three setae and transverse plumose fringe.
Etymology. The epithet name refers to the location where the species was found, Serra do Tarzan.
Morphological remarks. Benthanoides tarzan n. sp. is similar to Benthanoides amazonicus n. sp. in the disposition of the aesthetascs on antennula, in the modifications on merus on pereopod 7, in the shape of male 1 endopod, and in the shape of male pleopod 2. They can be distinguished from each other by the shape of male pleopod 1 exopod, that is as wide as long in Benthanoides tarzan n. sp., and longer than wide in Benthanoides amazonicus n. sp.
Ecological remarks. Specimens of Benthanoides tarzan n. sp. were observed in some caves located in “Serra do Tarzan” (ST). This area presents 69 caves, distributed along the whole extension of the ferruginous outcrop. Individuals of Benthanoides tarzan n. sp. were found in 10 caves (Fig. 1), thus indicating the species is widely distributed along the outcrop. Differently from Benthana alba n. sp., which may eventually inhabit voids in the ferruginous outcrop, the distribution of Benthanoides tarzan n. sp. indicates that this species seems to be also closely related to the macrocave itself. However, as the caves in which the species was observed are widely distributed throughout the iron ore formation, along with the specimens’ small body size, it is plausible to assume that migrations between caves through the canaliculi network occur. Furthermore, Be. tarzan n. sp. has a lower number of ommatidia among all known species of Benthanoides, and may indicate an important troglomorphic trait, and that the species is troglobitic. However, unlike B. alba n. sp., which seems to be highly threatened, Be. tarzan n. sp. occurs in a region inserted within the limit of a conservation unit (Campos Ferruginosos National Park), which fully protects the caves and their surrounding area, preventing touristic and exploratory activities; in addition, the geographic isolation protects the area in its pristine state. Therefore, this species seems not to be currently under any threat.
description: Published as part of Cardoso, Giovanna Monticelli & Ferreira, Rodrigo Lopes, 2023, New troglobitic species of Benthana Budde-Lund, 1908 and Benthanoides Lemos de Castro, 1958 from iron-ore caves and their important record in the Amazon biome (Crustacea: Isopoda: Philosciidae), pp. 548-562 in Zootaxa 5319 (4) on pages 557-560, DOI: 10.11646/zootaxa.5319.4.5, http://zenodo.org/record/8203308