Procerobaetis leptobranchius Kaltenbach & Garces & Gattolliat 2020, gen. et sp. nov.
Creators: name: Kaltenbach, Thomas
name: Garces, Jhoana M.
name: Gattolliat, Jean-Luc
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Ephemeroptera
Baetidae
Procerobaetis
Procerobaetis leptobranchius

description: Procerobaetis leptobranchius Kaltenbach & Gattolliat gen. et sp. nov.
urn:lsid:zoobank.org:act: B05740B0-8BC1-4F5B-9F32-6852C54B9EB1
Figs 1–4, 12 A–B, 14B
Diagnosis: larva
The diagnostic characters of all species are summarized in Table 3.
Etymology
Procerobaetis leptobranchius gen. et sp. nov. is a combination of lepto – derived from the Greek word ʻleptosʼ, meaning ʻfineʼ, ʻthinʼ, ʻslenderʼ – and branchius, derived from the Latin word branchiae, meaning ʻgillsʼ, in reference to the remarkably elongate and long-pointed gills I and II, which are typical for the genus. It is also in reference to Leptophlebiidae, where this type of gill partly exists as well.
Material examined
Holotype
INDONESIA • larva; Sumatra, volcano Singgalang, Caruak River; 00°23.06′ S, 100°21.41′ E; 1640 m a.s.l.; 23 Mar. 2014; M. Gueuning leg.; on slide; voucher: GBIFCH 00421984; MZL.
Paratypes
INDONESIA • 4 larvae; same collection data as for holotype; on slides; vouchers: GBIFCH 00422019, GBIFCH 00422023, GBIFCH 00421977, GBIFCH 00421989; MZL • 5 larvae; same collection data as for holotype; in alcohol; vouchers: GBIFCH 00421983, GBIFCH 00422974 (3 larvae), GBIFCH 00421986; MZL • 1 larva; Sumatra, volcano Singgalang, Pagu Pagu River; 00°23.54′ S, 100°21.46′ E; 1785 m a.s.l.; 22 Mar. 2014; M. Gueuning leg.; on slide; voucher: GBIFCH 00421957; MZL.
Description: larva (Figs 1–4, 12 A–B)
BODY LENGTH. 4.6–5.5 mm.
COLOURATION (Fig. 12A). Head, thorax and abdomen dorsally dark brown, head and thorax with bright median dorsal suture. Head and thorax ventrally brown, abdomen ventrally dark brown. Legs light brown, caudal filaments light brown without darker band or pattern.
Head
ANTENNA (Fig. 3A). Approximately 2× as long as head length; flagellum with lanceolate spines at apex of each segment, longer at inner lateral margin, increasing in length distally until segment IX and decreasing thereafter.
LABRUM (Fig. 1A). Rectangular, length 0.7× maximum width. Distal margin with medial emargination and a small process. Dorsally with long, fine, simple setae scattered over surface in proximal area; many long, stout, simple setae in anteromedial area, erratically distributed, not arranged in an arc. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid setae; ventral surface with about ten short, spine-like setae near lateral and anterolateral margins.
RIGHT MANDIBLE (Fig. 1 B–C). Outer and inner set of denticles with 4+3 denticles. Margin between prostheca and mola straight, with a row of long, stout setae. Tuft of setae at apex of mola present.
LEFT MANDIBLE (Fig. 1 D–E). Outer and inner set of denticles with 4+3 denticles. Subtriangular process long and slender, above level of area between prostheca and mola. Denticles of mola apically constricted. Setae at apex of mola absent. Both mandibles with lateral margins slightly convex. Basal half with fine, simple setae scattered over dorsal surface.
HYPOPHARYNX (Fig. 1F). Lingua shorter than superlingua, about as broad as long, with medial tuft of long, stout setae. Superlingua distally almost straight, lateral margin rounded, with fine, long, simple setae along distal and distolateral margin.
MAXILLA (Fig. 1G). Galea-lacinia with two simple, robust apical setae under crown. Medially with one pectinate, spine-like seta and a row of 6–8 medium to long, simple setae. Maxillary palp 2× as long as length of galea-lacinia; palp segment II 0.7× length of segment I, palp segment III 0.6× length of segment II; setae on maxillary palp fine, simple, scattered over surface of segments I, II and III; apex of last segment rounded.
LABIUM (Fig. 1H). Glossae basally broad, narrowing toward apex, slightly shorter than paraglossae; inner margin with 13–15 spine-like setae; apex with two long, robust, pectinate setae and one medium, robust, pectinate seta; outer margin with eight spine-like setae, increasing in length distally; ventral surface with medium, fine, simple, scattered setae. Paraglossae sub-rectangular, apically curved inward; apex rounded, with three rows of long, robust setae; ventrally four medium, simple setae in anteromedial area; dorsally with a row of 6–7 long, spine-like setae near inner margin and several medium, fine, simple setae at outer margin. Labial palp with segment I 0.9× length of segments II and III combined, ventrally with scattered short, fine, simple setae; segment II with small distolateral expansion, ventrally with scattered short, fine, simple setae, dorsally with a row of 4–5 long, spine-like setae; segment III subquadrangular, apex rounded, ventrally covered with short and medium spine-like, simple setae and short, fine, simple setae. Mentum medially and distally with scattered fine, simple setae.
Thorax
FORELEG (Figs 2 A–F, 4A). Ratio of foreleg segments 1.3:1.0:0.9:0.3. Femur. Length 4.2–4.7× maximum width; dorsal margin with a row of 7–9 curved, spine-like setae; length of setae 0.3× maximum width of femur; apex rounded, with one pair of laterally slightly pectinate, spine-like setae; many stout, lanceolate, laterally pectinate setae scattered along ventral margin; femoral patch absent. Tibia. Dorsal margin bare; ventral margin with a row of curved, laterally pectinate, spine-like setae, on apex some longer, laterally pectinate, spine-like setae; anterior surface with scattered stout, lanceolate, laterally pectinate setae; patellotibial suture present on basal ⅓. Tarsus. Dorsal margin bare; ventral margin with a row of curved, laterally pectinate, spine-like setae; tarsal claw elongate, slender, apically pointed, with one row of 7–8 larger denticles and many minute denticles, ventral margin at apex undulated, with many stripes.
MIDDLE LEG (Fig. 4B). As foreleg, but dorsal margin of femur slightly concave, tibia at dorsal margin with a row of stout setae, and tarsal claw with one row of 5–11 larger denticles and many minute denticles.
HIND LEG (Fig. 4C). As foreleg, but dorsal margin of femur slightly concave, and tarsal claw with one row of 7–11 larger denticles and many minute denticles.
Abdomen
TERGITES (Fig. 2G). Surface with scattered scales and U-shaped scale bases. Posterior margin of tergites I–VIII without spines, tergite IX with triangular spines.
GILLS (Fig. 3 B–H). Present on segments I–VII; elongate with pronounced points; gills I and II extremely slender and with very long, extended points; margin with very small denticles intercalating fine, simple setae; tracheae limited to main trunk. Gill I as long as length of segments II and ¾ of III combined, gill II as long as length of segments III and IV combined, gill III as long as length of segments IV and ¾ of V combined, gill IV as long as length of segments V and VI combined, gill V as long as length of segments VI and VII combined, gill VI as long as length of segments VII to ½ of IX combined, gill VII as long as length of segments VIII to X combined.
PARAPROCT (Fig. 2H). Posterior margin with 5–9 stout spines; surface with scattered U-shaped scale bases, micropores and a few fine, simple setae; posterolateral extension (cercotractor) with numerous small, marginal spines.
CAUDAL FILAMENTS (Fig. 12A). Cerci ca 0.4× body length.
Distribution
Indonesia: Sumatra (Fig. 14B).
Remarks
The specimens were collected at altitudes from 1600 to 1800 m a.s.l. in two small, shallow, slow and rather cool forest streams (width ca 1 m, depth 5–30 cm, velocity 0.15–0.2 m /s, temperature 15.5–17°C, pH 6–7) with partly to completely closed canopy. The substrate in both streams was dominated by boulders, stones and gravel with some sandy patches and with or without patches of leaf litter or dead wood.
description: Published as part of Kaltenbach, Thomas, Garces, Jhoana M. & Gattolliat, Jean-Luc, 2020, A new genus of Baetidae (Insecta, Ephemeroptera) from Southeast Asia, pp. 1-32 in European Journal of Taxonomy 612 on pages 6-11, DOI: 10.5852/ejt.2020.612, http://zenodo.org/record/3702176