Leptohyphes airuoca Nascimento, Molineri & Salles, 2014, sp. nov.
Creators: name: Nascimento, Jeane M. C.
name: Molineri, Carlos
name: Salles, Frederico F.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Ephemeroptera
Leptohyphidae
Leptohyphes
Leptohyphes airuoca

description: Leptohyphes airuoca sp. nov.
(Figs. 1–5 and 14)
Material examined. HOLOTYPE, female immature nymph, BRAZIL, Minas Gerais, Itamonte, Parque Nacional de Itatiaia, Rio Airuoca, 11/vii/2012, S 22˚ 18´31.3´´ / W 44 ˚ 42´07.3´´, 1420 m, Salles FF, Brito P, Pepinelli M cols. (INPA). Additional non-type material: very immature nymph (slide IBN608CM) from BRAZIL, Rio de Janeiro, 950 m, Nova Friburgo, municipal water supply, 20.iv.1977, C.M. & O.S. Flint cols. (IBN).
Immature nymph. Length of female: body, 6.2 mm; hind femur, 2.1 mm; caudal filaments, 5.8 mm. General coloration (Figs 1–3) yellowish brown, shaded with black. Head (Fig. 2 A) with two pairs of tubercles, a submedian smaller and sublateral longer and slightly pointed. Gena (Fig. 2 A) strongly projected. Clypeum fore margin with a row of whitish setae. Mouth parts (Fig. 4). Labrum (Fig. 4 A): with an anteromedial marked indentation on fore margin. Hypopharynx (Fig. 4 B): lingua with short and thick setae. Maxilla (Fig. 4 F): maxillary palp with setae at joints, suture on galea and lacinea complete; Mandibles (Figs. D, E): left mandible (Fig. 4 D) with fused and strong incisors; both mandibles with a dense row of setae on dorsolateral surface. Labium (Fig. 4 C): submentum with pointed and projected anterolateral corner; glossae and paraglossae equal in length; labial palp basal segment five times the length of segment two, apical segment subequal in length to segment two. Thorax. Pronotum subrectangular with one pair of sublateral and short and pointed tubercle near hind margin. Mesonotum with one pair of submedian tubercles at 1/2 from anterior margin. Mesonotum with small blunt anterolateral projection. Hind wing pad absent. Legs: yellowish brown, shaded with gray on coxae, trocanthers, femora and tibiae; coxae with blunt short projection. Fore leg (Fig. 5 A): femur ratio length/maximum width 1.7–2.0; transversal row of stout spines at 1/3 from base, with seven stout spines, three of the gaps between subsequent spines are larger than the others; fore margin bare, hind margin with five stout spines (on elevated sockets) distally to transversal row of stout spine; medial and dorsal projection on apex of femur small. Tibia subequal in length to femur with two, scattered blunt spines on apex of inner margin; dorsum with elevated ridge. Tarsus 1/3 the length of tibia with row of setae in inner margin; tarsal claw apically curved with four marginal denticles, without subapical, submarginal denticle (Fig. 5 D). Middle and hind legs (Figs. 5 B, C): middle femur ratio length/maximum width 2.1; dorsally with row of four short blunt spines at base, fore margin bare, hind margin with 11 stout spines on very elevated sockets, sockets increasing in size distally, dorsal surface without spine. Tibia 1.2x the length of femur, with dorsal ridge, inner margin with two minute stout spines; hind margin bare. Tarsus 0.5x the length of femur, inner margin with setae, tarsal claw as in fore leg. Hind femur ratio length/maximum width 1.8–2.2; with one short blunt spine at base, fore margin with two stout spines, hind margin with 7 stout spines on very elevated socket, dorsal surface without spine. Tibia 1.3x the length of femur, with dorsal ridge, inner margin with three minute stout spines; hind margin bare. Tarsus 0.4x the length of femur, inner margin with setae, tarsal claw as in fore leg. Abdomen (Figs. 3 A, B) with few strong spines on dorsum; with median tubercle on segments V–IX, VII and VIII longer. Lateral margins of segments III–II expanded forming flanges; posterior spines on segments VII–IX. Gills: operculate gill dark gray, distally paler, ventrally with strong and curved basal spine and two lamellae; other gills grayish, except for brownish ridge. Gill formula 3/9/9/7/6. Caudal filaments completely covered with pointed setae, and with a whorl of strong spines at the segment joint after every fourth segment.
Adults. Unknown.
Diagnosis (Table 1): i) two paired tubercles on head, 2 pairs on pronotum, and 1 pair on mesonotum, abdominal terga VI–IX with single medial tubercle on hind margin, very small on segment VI (Figs. 1–3); ii) fore femur length/maximum width, 1.7–2.0 (Fig. 5 A); iii) fore margin of middle and hind femora without spines, hind margin with five stout spines on elevated sockets (Figs. 5 B, C); iv) tarsal claws with four marginal denticles; subapical denticle absente (Fig. 5 D); v) middle coxa without acute projection on dorsum, only with a blunt short projection (Fig. 5 B); vi) hind wing pads absent in female; vii) operculate gill with yellowish-white distal macula, gill formula 3/9/9/7/6, gill V without ventral extension on dorsal lamella.
Etymology. Airuoca is the name of the stream, in Itatiaia National Park, where this new species was collected.
Distribution. Brazil (Minas Gerais, Rio de Janeiro).
Discussion. It is evident from the study of different nymphal stages of all the treated species that some characters show intraspecific variation when different instars from different samples are compared. Thus, the morphology of the nymphs varies noticeably during successive instars, mainly because the tubercles on the dorsum of thorax and the elevated sockets of femoral spines are larger on immature nymphs than in mature ones. Also, variations in number of tarsal claw denticles (only in the number of marginal denticles, subdistal denticles are more conservative, Molineri 2010) and leg ratios were found when comparing different stages of the same species. For this reason, it is expected that fully grown nymphs of L. airuoca, when known, may show somewhat different ratios in legs. Nevertheless, the presence of single median tubercles on abdominal terga, the absence of hind wing pads in females, the presence of two pairs of large tubercles on pronotum (anterior pair much smaller in the other species) and the absence of a submarginal subdistal denticle on tarsal claws are unique among the species of the genus.
description: Published as part of Nascimento, Jeane M. C., Molineri, Carlos & Salles, Frederico F., 2014, Redescription of Leptohyphes cornutus Allen, 1967 (Ephemeroptera: Leptohyphidae) and description of three related new species, pp. 397-415 in Zootaxa 3893 (3) on pages 398-400, DOI: 10.11646/zootaxa.3893.3.5, http://zenodo.org/record/250141