Procerobaetis petersorum Kaltenbach & Gattolliat, 2020

Kaltenbach, Thomas, Garces, Jhoana M. & Gattolliat, Jean-Luc, 2020, A new genus of Baetidae (Insecta, Ephemeroptera) from Southeast Asia, European Journal of Taxonomy 612, pp. 1-32 : 12-17

publication ID	https://doi.org/ 10.5852/ejt.2020.612
publication LSID	lsid:zoobank.org:pub:31157200-AF8E-4E67-93EC-37052672CC61
DOI	https://doi.org/10.5281/zenodo.3705897
persistent identifier	https://treatment.plazi.org/id/8E7DA59C-2AB6-4518-BE84-5C71C5A5BD03
taxon LSID	lsid:zoobank.org:act:8E7DA59C-2AB6-4518-BE84-5C71C5A5BD03
treatment provided by	Plazi
scientific name	Procerobaetis petersorum Kaltenbach & Gattolliat
status	gen. et sp. nov.

Treatment

Procerobaetis petersorum Kaltenbach & Gattolliat gen. et sp. nov.

urn:lsid:zoobank.org:act:8E7DA59C-2AB6-4518-BE84-5C71C5A5BD03

Figs 5–7 View Fig View Fig View Fig , 12 View Fig C–D, 14B

Diagnosis: larva

The diagnostic characters of all species are summarized in Table 3 View Table 3 .

Etymology

P. petersorum gen. et sp. nov. is dedicated to the well-known mayfly researchers Janice Peters and her late husband William L. Peters for their contribution to our knowledge of Leptophlebiidae in Southeast Asia. Specific reference is given to the remarkable gills of Procerobaetis gen. nov., which are similar to those of some species of Leptophlebiidae .

Material examined

Holotype

INDONESIA • larva; Sumatra, volcano Sago, Kobun River ; 00°22.55′ S, 100°39.55′ E; 1095 m a.s.l.; 19 Mar. 2014; M. Gueuning leg.; on slide; voucher no.: GBIFCH 00421980; MZL. GoogleMaps

Paratypes

INDONESIA • 1 larva; same collection data as for holotype; on slide; voucher: GBIFCH 00421975; MZL GoogleMaps • 3 larvae; same collection data as for holotype; in alcohol; vouchers: GBIFCH 00422930, GBIFCH 00422044, GBIFCH 00422751; MZL GoogleMaps • 1 larva; Sumatra, volcano Sago, Simbukan River , 00°17.40′ S, 100°40.84′ E; 955 m a.s.l.; 18 Mar. 2014; M. Gueuning leg.; on slide; voucher: GBIFCH 00422039; MZL GoogleMaps • 1 larva; Sumatra, volcano Sago, Simbukan River ; 00°17.13′ S, 100°41.23′ E; 880 m a.s.l.; 18 Mar. 2014; M. Gueuning leg.; in alcohol; voucher: GBIFCH 00422000; MZL GoogleMaps • 1 larva; Sumatra, volcano Sago, Tampo River ; 00°22.33′ S, 100°39.55′ E; 960 m a.s.l.; 20 Mar. 2014; M. Gueuning leg.; on slide; voucher: GBIFCH 00421968; MZL GoogleMaps • 4 larvae; same collection data as for preceding; in alcohol; vouchers: GBIFCH 00422045, GBIFCH 00421964, GBIFCH 00422002, GBIFCH 00422705; MZL GoogleMaps • 2 larvae; Sumatra, volcano Sago, Kaligain River ; 00°18.02′ S, 100°40.13′ E; 1040 m a.s.l.; 5 Apr. 2014; M. Gueuning leg.; on slides; vouchers: GBIFCH 00421988, GBIFCH 00422006; MZL GoogleMaps • 3 larvae; same collection data as for preceding; in alcohol; vouchers: GBIFCH 00422613, GBIFCH 00422043, GBIFCH 00422003; MZL GoogleMaps .

Description: larva ( Figs 5–7 View Fig View Fig View Fig , 12 View Fig C–D)

BODY LENGTH. 3.4–4.5 mm.

COLOURATION ( Fig. 12B View Fig ). Head, thorax and abdomen dorsally brown, head and thorax with bright median dorsal suture. Head and thorax ventrally light brown, abdomen ventrally brown. Legs light brown, caudal filaments light brown without darker band or pattern.

Head

ANTENNA ( Fig. 7A View Fig ). 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. 5A View Fig ). Rectangular, length 0.6× 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, pectinate setae; ventral surface with about five short, spine-like setae near lateral and anterolateral margin.

RIGHT MANDIBLE ( Fig. 5 View Fig 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. 5 View Fig 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 almost straight. Basal half with fine, simple setae scattered over dorsal surface.

HYPOPHARYNX ( Fig. 5F View Fig ). Lingua shorter than superlingua, longer than broad, with medial tuft of long, stout setae. Superlingua distally almost straight, lateral margin rounded, with fine, long, simple setae along distal margin.

MAXILLA ( Fig. 5G View Fig ). Galea-lacinia with two simple, robust apical setae under crown. Medially with one pectinate, spine-like seta and a row of 5–6 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 0.7× 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. 5H View Fig ). Glossae basally broad, narrowing toward apex, slightly shorter than paraglossae; inner margin with 9–10 spine-like setae; apex with two long and one medium-length, robust, pectinate setae; outer margin with 5–7 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 1–3 medium, simple setae in anteromedial area; dorsally with a row of 5 long, spine-like setae near inner margin and several medium, fine, simple setae at outer margin. Labial palp with segment I 0.6× 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 3–4 long, spine-like setae; segment III subquadrangular, apex rounded, ventrally covered with short, spine-like, simple setae and short, fine, simple setae. Mentum distally with scattered fine, simple setae.

Thorax

FORELEG ( Figs 6 View Fig A–H, 7B). Ratio of foreleg segments 1.4:1.0:1.0:0.3. Femur. Length 3.1–3.8× maximum width; dorsal margin with a row of 7–9 curved, spine-like setae; length of setae 0.26× 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, at 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 4–7 larger denticles and many minute denticles, ventral margin at apex undulated, with many stripes.

MIDDLE LEG ( Fig. 7C View Fig ). As foreleg, but dorsal margin of femur almost straight, tibia at dorsal margin with a row of stout setae, and tarsal claw with one row of 3–6 larger denticles and many minute denticles.

HIND LEG ( Fig. 7D View Fig ). As foreleg, but dorsal margin of femur almost straight, tarsal claw with one row of 4–7 larger denticles and many minute denticles.

Abdomen

TERGITES ( Fig. 6I View Fig ). Surface with scattered scales, U-shaped scale bases and micropores. Posterior margin of tergites I–VIII without spines, tergite IX with triangular spines.

GILLS ( Fig. 7 View Fig E–F). 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 II as long as length of segments III and ½ of IV combined, gill III as long as length of segments IV and ½ of V combined, gill IV as long as length of segments V and ½ of VI combined, gill V as long as length of segments VI and ⅔ of VII combined, gill VI as long as length of segments VII and VIII combined, gill VII as long as length of segments VIII and ⅔ of IX combined.

PARAPROCT ( Fig. 6 View Fig J–K). Posterior margin with 8–10 stout spines; surface with scattered U-shaped scale bases and micropores; posterolateral extension (cercotractor) with numerous small, marginal spines.

CAUDAL FILAMENTS ( Fig. 12C View Fig ). Cerci ca 0.5× body length.

Distribution

Indonesia: Sumatra ( Fig. 14B View Fig ).

Remarks

The specimens were collected at altitudes from 800 to 1100 m a.s.l. in medium to large, mainly shallow and slow to moderate fast streams (width 2–10 m, depth 20–150 cm, velocity 0.28–0.5 m /s, temperature 20–21°C, pH 7–7.5). The streams were mostly in forests with a partly closed canopy, the substrate was dominated by bedrock, boulders and stones with few patches of leaf litter or dead wood. One stream was in a more disturbed area (rice fields, waste and soap).