Nigrobaetis plures, Kaltenbach & Gattolliat, 2023

Kaltenbach, Thomas & Gattolliat, Jean-Luc, 2023, New species of Nigrobaetis from Southeast Asia (Ephemeroptera, Baetidae), ZooKeys 1166, pp. 175-234 : 175

publication ID	https://dx.doi.org/10.3897/zookeys.1166.102941
publication LSID	lsid:zoobank.org:pub:29BC14B3-2F38-429C-B0E1-F877D1FE5A15
persistent identifier	https://treatment.plazi.org/id/88034E97-CBC0-4831-863C-F56104AC0004
taxon LSID	lsid:zoobank.org:act:88034E97-CBC0-4831-863C-F56104AC0004
treatment provided by	ZooKeys by Pensoft
scientific name	Nigrobaetis plures
status	sp. nov.

Treatment

Nigrobaetis plures sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8

Differential diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submedian seta and two long, simple setae in submarginal position (Fig. 2b View Figure 2 ); B) right mandible: incisor with four denticles, kinetodontium with four denticles (Fig. 2c View Figure 2 ); C) left mandible: incisor with four or five denticles, kinetodontium with three denticles; margin between prostheca and mola with row of minute denticles (Fig. 2d View Figure 2 ); D) fore femur length ca. 3 × maximum width, dorsal margin with 7-11 curved, spine-like setae (Fig. 5a View Figure 5 ); E) claw with 11 or 12 denticles (Fig. 5b View Figure 5 ); F) hind protoptera minute (Fig. 5d View Figure 5 ); G) tergalii on abdominal segments I-VII; H) paraproct with ca. six stout, large marginal spines (Fig. 6b View Figure 6 ); I) posterior margins of abdominal terga: I-III smooth, without spines; IV-V with rudimentary spines or smooth; VI-IX with triangular, sharply pointed spines (Fig. 6a View Figure 6 ).

Description.

Larva (Figs 1 View Figure 1 - 7 View Figure 7 ). Body length 3.3-4.9 mm. Cerci: ca. ½ of body length. Paracercus: ca. ⅔ of cerci length. Antennae broken.

Colouration (Fig. 1a-c View Figure 1 ). Head, thorax, and abdomen dorsally brown; abdominal terga VI and VII darker, abdominal terga VIII-X pale brown, except apex of tergum X brown. Head ventrally brown, thorax and abdomen ventrally pale brown, abdominal sterna VII and VIII darker. Legs pale brown, femur basomedially and distomedially with uncoloured areas. Caudalii brown.

Labrum (Fig. 2a, b View Figure 2 ). Slightly conical, length 0.76 × maximum width. Distal margin with medial emargination and a small process. Dorsally with medium, fine, simple setae scattered over surface; submedian seta and two long, simple, submarginal setae. Ventrally with marginal row of setae composed of anterolateral long, feathered setae and medial long, bifid, pectinate setae.

Right mandible (Fig. 2c View Figure 2 ). Incisor and kinetodontium fused. Incisor with four denticles; kinetodontium with four denticles, inner margin of innermost denticle with row of thin setae. Prostheca stick-like, apicolaterally denticulate. Margin between prostheca and mola straight, with row of setae-like processes. Tuft of setae at apex of mola present.

Left mandible (Fig. 2d View Figure 2 ). Incisor and kinetodontium fused. Incisor with four or five denticles; kinetodontium with three denticles. Prostheca robust, apically with small denticles and comb-shaped structure. Margin between prostheca and mola straight, with row of minute denticles. Tuft of setae at apex of mola absent.

Hypopharynx and superlinguae (Fig. 3a View Figure 3 ). Lingua approx. as long as superlinguae. Lingua longer than broad; medial tuft of stout setae poorly developed, broad; distal half laterally not expanded. Superlinguae distally straight; lateral margins rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 3b-d View Figure 3 ). Galea-lacinia ventrally with two simple, apical setae under canines. Medially with one spine-like seta and ca. four long, simple setae. Maxillary palp 1.3 × as long as length of galea-lacinia; 2-segmented; palp segment II approx. as long as segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II; apex of last segment pointed.

Labium (Fig. 4a-c View Figure 4 ). Glossa basally broad, narrowing toward apex; nearly as long as paraglossa; inner margin with ca. ten spine-like setae; apex with two long and one medium, robust setae; outer margin with ca. six spine-like setae; ventral surface with fine, simple, scattered setae. Paraglossa curved inward; apex rounded; with three rows of long, robust, distally pectinate setae in apical area and two medium, simple setae in inner anterolateral area; dorsally with row of three long, spine-like, simple setae near inner margin. Labial palp with segment I 1.2 × length of segments II and III combined. Segment I ventrally with short, fine, simple setae. Segment II without protuberance; ventral surface with short, fine, simple setae; dorsally with row of four long, spine-like setae. Segment III sub-quadrangular; inner apical margin slightly concave, with some setae-like processes; apex with rounded protrusion; length subequal to width; ventrally with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 5e View Figure 5 ) minute.

Foreleg (Fig. 5a-c View Figure 5 ). Ratio of foreleg segments 1.5:1.0:0.8:0.3. Femur. Length ca. 3 × maximum width. Dorsal margin with 7-11 curved, spine-like setae; length of setae 0.21 × maximum width of femur. Apex rounded, with pair of spine-like setae. Stout, lanceolate setae scattered along ventral margin; femoral patch absent. Tibia. Dorsal margin with 0-3 short, spine-like setae, and with row of fine, simple setae; on apex one stout, apically rounded seta. Ventral margin with row of short, curved, spine-like setae, on apex some longer, spine-like, pectinate setae. Anterior surface with row of stout, lanceolate setae near ventral margin. Patellatibial suture present on basal half. Tarsus. Dorsal margin with row of fine, simple setae. Ventral margin with row of curved, spine-like setae. Claw with one row of 11 or 12 denticles; distally pointed; subapical setae absent.

Middle and hind legs. As foreleg, but tibiae at dorsal margin with 4-6 spine-like setae.

Abdominal terga (Fig. 6a View Figure 6 ). Surface with irregular rows of U-shaped scale bases. Posterior margin of terga: I-III smooth, without spines; IV and V with rudimentary spines or smooth; VI-IX with triangular, sharply pointed spines.

Abdominal sterna. Posterior margins smooth, without spines.

Tergalii (Fig. 5d View Figure 5 ). Present on segments I-VII. Margin with small denticles intercalating fine simple setae. Tracheae extending from main trunk to inner and outer margins. Tergalius I ca. ½ length of segment II; Tergalius IV as long as length of segments V and ½ VI combined; Tergalius VII as long as length of segments VIII and ½ IX combined.

Paraproct (Fig. 6b View Figure 6 ). With 6-9 stout, marginal spines. Surface scattered with U-shaped scale bases. Cercotractor with numerous small, marginal spines.

Subimaginal gonostyli (Fig. 6c View Figure 6 ) developing under cuticle of male last instar larvae folded in Nigrobaetis -type ( Kluge 2004: fig. 29G).

Adult stages. Unknown.

Eggs (Fig. 7a, b View Figure 7 ). Ovoid; surface cone-like with numerous papillae-like structural elements (polygonal to rounded structure, centrally with a smaller, rounded, slightly elevated area surrounded by a round trench).

Etymology.

Plures in Latin meaning several, referring to the distribution of the species across several islands.

Distribution

(Fig. 8 View Figure 8 ). Philippines: Leyte, Mindanao, Camiguin.

Biological aspects.

The specimens were collected on altitudes of 30-660 m, mostly on bottom gravel in run or riffle, partly together with Labiobaetis camiguinensis Kaltenbach, Garces & Gattolliat, 2020 (Camiguin) or L. delocadoi Kaltenbach, Garces & Gattolliat, 2020 (Leyte).

Type-material.

Holotype. Philippines • larva; Leyte, Southern Leyte, Brgy. Malico, San Francisco, Taglibas River; 10°01'07"N, 125°12'35"E; 50 m; 19.-20. X. 2019; leg. Garces and Pelingen; on slide; GBIFCH00592356; PNM. Paratypes. Philippines • 4 larvae; same data as holotype; 3 on slides; GBIFCH00975650; AdMU; GBIFCH00515525, GBIFCH00975682; MZL; 1 in alcohol; GBIFCH00975649; AdMU • 1 larva; Mindanao, Surigao del Sur, Tandag, middle Tandag River; 09°03'33"N, 126°05'57"E; 30 m; 04.XII.2018; leg. Pangantihon; on slide; GBIFCH00592268; MZL • 1 larva; Mindanao, Agusan N, Cabadbaran, Del Pilar, Payas River; 09°11'34"N, 125°36'34"E; 660 m; 23. VI. 2018; leg. Pangantihon; on slide; GBIFCH00975656; AdMU • 2 larvae; Mindanao, Agusan N, Cabadbaran River; 09°10'15"N, 125°40'55"E; 240 m; 03. VI. 2018; leg. H. Freitag and Pangantihon; GBIFCH00975657, GBIFCH00975678; MZL • 6 larvae; Camiguin, Sagay, Bonbon, lower Binangawan River; 30 m, 09°06'39"N, 124°43'45"E; 30 m; 09.XII.2018; leg. H. Freitag; 4 on slides; GBIFCH00654914, GBIFCH00975652; MZL; GBIFCH00592248, GBIFCH00592249; AdMU; 2 in alcohol; GBIFCH00975651, GBIFCH00975653; AdMU.