Paracloeodes prismatobranchus, Cruz & Salles & Hamada, 2018

Cruz, Paulo Vilela, Salles, Frederico Falcão & Hamada, Neusa, 2018, Contribution to the taxonomy of Paracloeode s Day 1955 (Ephemeroptera: Baetidae) from South America, Zootaxa 4403 (1), pp. 1-49 : 39-44

Paracloeodes prismatobranchus sp. n.

( Figures 25–28)

Diagnosis. Male imago. 1) stigmatic area of forewing opaque ( Fig. 25C); 2) hind wing present ( Fig. 25D); 3) abdominal terga II–VI light brown, segments VIII–X brown ( Fig. 25B); 4) posterior margin of styliger plate concave with rounded spine medially ( Fig. 25E).

Mature Nymph. 1) frons elevated forming keel ( Figs 26C and 26D); 2) distolateral margin of labrum with bifid and pectinate setae ( Fig. 27B); 3) right mandible incisors partially fused ( Fig. 27C); 4) distomedial projection of labial palp 1.6× width of segment III ( Fig. 27G); 5) hind wing pads present; 6) anterior surface of forefemur with one row of pectinate and stout setae near dorsal margin, and one row of pectinate and stout setae near ventral margin ( Fig. 28C); 7) anterior surface of foretibia with one row of stout setae near dorsal margin, and two rows of pectinate and stout setae near ventral margin ( Fig. 28C); 8) anterior and posterior surface of foretarsus with pectinate and stout setae ( Fig. 28C); 9) ventral margin of foretarsus with one row of pectinate and stout setae ( Fig. 28C); 10) cercus with long spines every two segments ( Fig. 28D); 11) paracercus with spines on all segments ( Fig. 28E); 12) body color pattern as in figures 26A and 26B.

Description. Male imago. Body 4.0 mm; forewing 4.36 mm; hind wing 0.80 mm (n=1). Head brown. Turbinate portion of compound eyes orange. Dorsal portion of turbinate eyes oval ( Fig. 25B); length 1.8× width; stalk height 1.4× height of dorsal portion; inner margins divergent anteriorly. Thorax brown. Anteronotal and metascutellar protuberance rounded. Legs light brown. Forewing ( Fig. 25C) hyaline; veins light brown; stigmatic area with five cross veins reaching subcostal vein and two veins not reaching subcostal vein; marginal intercalary veins paired between C and IMP2, single between IMP2 and ICA 1, absent between ICA 1 and A; length of each intercalary vein 0.7× distance between adjacent longitudinal veins; length of forewing about 2.5× width. Hind wing ( Fig. 25D) hyaline; costal process quadrangular, posteriorly projected, located on basal third. Abdomen with segments II–VI light brown, segments VIII–X brown ( Figs 25A and 25B). Genitalia ( Fig. 25E) with forceps segment I cylindrical; 0.3× length of segment II; distance between base of forceps 0.5× distance between lateral margins of forceps. Forceps segment II narrow basally. Posterior margin of styliger plate concave with rounded spine medially.

Mature Nymph. Length of body: 4.0–5.0 mm; cercus: 2.61 mm; paracercus: 2.55 mm; antennae: 2.69 mm (n=1). Head brown. Antenna light brown. Turbinate portion of male compound eyes light brown. Frons elevated forming one keel ( Figs 26C and 26D). Antenna with scape and pedicel subcylindrical; flagellum ( Fig. 27A) with blunt spines and thin setae. Labrum ( Fig. 27B) rectangular, broader than long; length about 0.7× maximum width; distal margin with shallow medial emargination; dorsally with thin setae scattered over surface; subapical pair of setae distinguishable from others; near anterolateral margin with two long setae distinguishable from others; ventrally with submarginal row of setae composed of bifid and pectinate setae; ventral surface with short and stout setae near lateral and distolateral margins. Right mandible ( Fig. 27C) with incisors partially fused. Inner and outer set of incisors respectively with 2 + 4 denticles. Prostheca slender, bifurcated at middle, inner lobe longer than outer, both pectinate. Margin between prostheca and mola concave; tuft of stout setae at base of mola present; tuft of setae at apex of mola present. Lateral margins almost straight. Left mandible ( Fig. 27D) with incisors partially fused. Inner and outer set of incisors respectively with 3 + 5 denticles. Prostheca robust, apex with three to five digitiform projections. Margin between prostheca and mola slightly convex; tuft of stout setae at base of mola present; subtriangular process narrow; denticles of mola apically constricted; tuft of setae at apex of mola absent. Lateral margins almost straight. Hypopharynx ( Fig. 27F) with lingua shorter than superlingua; distal margin convex; medial tuft of setae present. Superlingua rounded, lateral margin straight and with thin setae scattered over distal margin; distolateral margin with short spines. Maxilla ( Fig. 27E), medially, with 1 stout setae. Maxillary palp 1.5× length of galea-lacinia; setae on maxillary palp thin; palp segment II 1.3× length of segment I. Labium ( Fig. 27G) with glossa subequal in length to paraglossa, slightly narrowing toward apex; inner margin ventrally bare, inner margin dorsally with nine stout setae; apex dorsally with four robust setae; outer margin ventrally bare, outer margin dorsally with eight stout setae; dorsal surface bare; ventral surface scattered with short and thin setae. Paraglossa, subtriangular; outer margin ventrally bare, dorsally with one row of long and stout setae; dorsal surface with two longitudinal rows of setae, one near outer and other near inner margins; ventral surface with one row of five stout setae near inner margin. Labial palp with segment I 0.9× length of segments II and III combined; segment I with thin setae. Segment II with small distomedial protuberance 1.6× width of base of segment III; inner margin with few short and thin setae; outer margin covered with short and thin setae. Segment III inner margin with one row of stout setae ventrally and dorsally, length 1.0× width, covered with short and thin setae. Thorax light brown, with brown marks. Hind wing pads present. Foreleg ( Fig. 28C) whitish, with brown marks distally on femur, tibia and tarsus; ratio 1.3:(0.56mm):0.6:0.2. Forefemur with length about 3.6× maximum width; dorsal margin with row of blunt setae (in lateral view they look like stout setae); ventral margin with few short and thin setae; anterior surface with one row of pectinate and stout setae near dorsal margin, and one row of pectinate and stout setae near ventral margin. Ventral margin of tibia with one row of stout setae; anterior surface with one row of stout setae near dorsal margin, and two rows of small pectinate and stout setae near ventral margin; posterior surface with robust and pectinate and stout setae. Dorsal margin of tarsus with scarce short and thin setae; ventral margin with one row of pectinate and stout setae; posterior surface with one row pectinate and stout setae; anterior surface with irregular pectinate and stout setae. Abdominal segments II, III, V and IX ( Fig. 26A) with brown marks laterally, segments VI–VIII with same marks but lighter; medioanterior and medioposterior sigilla brown. Posterior margin of terga with regular spines ( Fig.28A). Gills ( Fig. 28B) hyaline; margin with spines intercalating short and thin setae. Tracheae restricted to base of main trunk. Gill I subequal in length to segment II; lanceolate. Gill IV as long as length of segment V to half VI combined; oblong, apically pointed. Gill VII as long as length of segments VIII to IX; oblong, apically rounded. Paraproct ( Fig. 28F) with 17–20 marginal spines; postero-lateral extension with marginal spines. Paracercus with short spines on each segment ( Fig. 28E). Cercus with long spines on every two segments ( Fig. 28D).

Etymology. The name is an arbitrary combination of two Greek words, prismato (something sawed) and branchus (gill), an allusion to the strongly serrated shape of the gill margins.

Comments. The male imago of P. prismatobranchus sp. n. is unique within the genus, in that it has the posterior margin of the styliger plate concave, with a rounded spine medially.

The nymph of P. prismatobranchus sp. n. possesses: gills with borders that are strongly serrated (which seems to be the costal and anal ribs fused); a distomedial projection of labial palp that is 1.6× width of segment III; incisors of both mandibles partially fused; the surface of femur, tibia and tarsi with rows of pectinate and stout setae; cercus with long spines every two segments; paracercus with spines on all segments; and a peculiar abdominal color pattern. This peculiar combination of characteristics makes P. prismatobranchus sp. n. unique. Moreover, the wide distribution of the species also is unique, having been collected from all Brazilian regions and three different biomes (Amazon, Atlantic Forest and Cerrado).

Material Examined. Holotype: One nymph, BRAZIL, Santa Catarina state, Campos Novos, Rio Leão , 03.x.2011, 27°10’54.0”S / 51° 19’ 21.4”W, 741m alt., P.V. Cruz and R. Boldrini cols., INPA . Paratypes: Six nymphs, same data as holotype. Additional material: One nymph, BRAZIL, Santa Catarina state, Paraiso ( São Miguel do Oeste ), River Peperiguaçu , border with Argentina , 26°36’49.9”S / 53°43’53.8”W, 367m alt., 15.ix.2011, A.O. Pes, P.V. Cruz, R. Boldrini and N. Hamada cols., INPA . One nymph, BRAZIL, Paraná state, Rio Ivaí (bridge Olaria ); 24°31’55.9” S / 52°27’02.8” W, 449 m alt., 12.ix.2011, A.O. Pes, P.V. Cruz, R. Boldrini and N. Hamada cols., INPA . One nymph, BRAZIL, Paraná state, Marquinhos, River Cobre , 25°08’25.6”S / 52°17’20.6”W, 595 m alt., 13.ix.2011, A. O. Pes, P.V. Cruz, R. Boldrini and N. Hamada cols., INPA . Four nymphs and two male imagoes reared, BRAZIL, Minas Gerais state, BR 267, from Caxambu to Juiz de Fora , bridge under river Furnas , 21°55’56.9” S / 44° 50’25.6” W, 26.x.2011, P.V. Cruz and M. R. De-Souza cols., INPA . One nymph, BRAZIL, Maranhão state, BR 0 10, river Farinha , 06°31’47.3”S / 47°28’11.4”W, 22.vii.2010, P. V. Cruz, R. Boldrini and N. Hamada cols., INPA . Thirty nymphs and ten male imago reared, BRAZIL, Rio de Janeiro state, Nova Friburgo, triburaty of river Cascatinha , opposite to small resort Ananais (brigde on road), 22°20’38.2”S / 42°33’26.2”W, 22.x.2011, P. V. Cruz and M. R. De-Souza cols., INPA . Eight nymphs, BRAZIL, Roraima state, Caroebe, ramal 37, river Caroebe , Cachoeirinha farm, 00°57’09.2”N / 59°37’00.5”W, 23.iii.2012, N. Hamada, P. V. Cruz, G. Dantas and R. Boldrini cols., INPA . One nymph, BRAZIL, Ceará state, Morajaú, Riacho dos Porcos , 03°23’21.3”S / 40°41’01.7”W, 05.vi.2011, P. V. Cruz and N. Hamada cols., INPA . Two nymphs, BRAZIL, Piauí state, border Cocal /PI and Padre Vieira /CE, river Piranji ( Cachoeira Pirapora ), 03°33’31.8”S / 041°21’56.9”W, 02.vi.2011, P. V. Cruz and N. Hamada cols., INPA . Three nymphs, BRAZIL, Espiríto Santo state, Sooretemana national park, river Barra seca, 18°57’50.4”S / 40°07’36.2”W, 05.xi.2011, P. V. Cruz col., INPA . Two nymphs, BRAZIL, Mato Grosso do Sul state, Bodoquena, Fazenda Califónia/ Fazenda Ouro Verde , 15 minutes walking to waterfall, 20°42’18.1”S / 56°51’14.6”W, 18.iii.2012, P. V. Cruz and N. Hamada cols., INPA . Two nymphs, BRAZIL, border between Goiás and Bahia states, Correntina , Comunidade do Val. Rio do Meio , 13°13’35.2”S / 44°35’37.3”W, 07.vi.2012, P. V. Cruz and N. Hamada cols., INPA .