Choroterpes (Choroterpes) girigangaensis Kubendran and Vasanth, 2022

Kubendran, T., Vasanth, M., Subramanian, K. A., Selvakumar, C., Jabeen, Fatima & Sivaramakrishnan, K. G., 2022, A new species of Choroterpes Eaton, 1881 (Ephemeroptera: Leptophlebiidae: Atalophlebiinae) from Western Himalaya, India, Records of the Zoological Survey of India 122 (3), pp. 237-245 : 238

Material examined: Holotype: Mature larva, INDIA, Himachal Pradesh, Sirmour, Giri Ganga River , Giripul 31. 11872 N, 77. 53689 E, 1600 m, 09.vi.2018, Coll. T. Kubendran (Reg. No. HARC/I-6181 ) . Paratypes: 4 larvae, same data as holotype (Reg. No. HARC/I-6182 ) . Type specimens are deposited in the ZSI, Solan, Himachal Pradesh.

Choroterpes (Choroterpes) girigangaensis Kubendran and Vasanth sp. nov.

( Figures 1–22 )

Length: body, 5.0– 5.2 mm; antennae, 3.0– 3.5 mm; cerci, 5.5–5.7 mm; terminal filament, 5.8–6.2 mm. General coloration dark brownish yellow ( Figures 1–2 ).

Head: Head prognathous. Dark brown washed with yellow. Upper portion of the male compound eye is reddish black, lower portion is black. Antenna whitish yellow. Labrum ( Figures 3–5 ) dark brown, anteromedian emargination with broad five unequal denticles; laterally rounded with dense hair-like setae. Hypopharynx ( Figure 6 ) lingua well developed; lateral process with anterior margin cleft, superlingua ‘V’ shaped marking medially. Mandibles (Figsures 7–8) translucent, dark brown, incisors and molars reddish, inner incisor slightly longer than outer one; prostheca long and branched; outer margin curved with scattered long setae. Maxilla ( Figure 9 ) palp 3 segmented; segment II subequal in the length of segment I, segment III approximately ¾ length of segment II. Labium ( Figure 10 ) glossa with plate-like thick setae on the ventral surface and dense row of fewer setae on the dorsal surface; paraglossa with denser setae but thinner setae on the dorsal surface; segment I of labial palp with thick long setae on outer margins, segment II with hair-like setae on outer margin, the apical segment with thick and fine setae and small tufts; segment I length, subequal to segment II length, segment III approximately ¾ length of segment II.

Thorax: Yellowish brown, irregularly washed with dark brown; pronotum dark yellowish brown with diffuse black markings laterally. Meso and metathorax light brown tinged with dark brown or black laterally. Legs ( Figures 11–13 ) pale yellowish brown; each femur with a brown macula on middle and distal region; fore femur proximally ca. 3–4 feathered setae on dorsal surface, mid and hind femur moderately developed; each femur with thick and thin setae on outer margin; tibiae with fine and thick setae on inner margin, and very sparse and thin setae on inner margin, and very sparse and thin setae on outer margin, but hind tibiae mixed with thick and few feathered setae on surface; tarsi of all legs with several thin setae on inner margin and sparse setae on outer margins ( Figures 15–16 ). Tarsal claw apically hooked with a row of 13–14 denticles ( Figure 14 ).

Abdomen: Terga I–IV light yellowish brown with diffuse black markings; terga V–IX dark brown with light yellow; terga X yellowish; I–IX with posterior marginal spines; posterolateral margins of abdominal terga I–V blunt denticles and VI–IX with pointed denticles, size of denticles progressively larger posteriorly ( Figure 1 ). Gills present on segments I–VII; gill I single, slender, lanceolate and hair like setae present on the inner and outer margin of half of the gill ( Figure 17 ); gills II–VII broad, alike with 3 apical processes ( Figures 18–21 ). Sterna I–X yellowish, sternum VII with one spot on middle ( Figure 2 ). Sternum IX of male with a deep apical cleft, sternum IX of female with apex entire and without emargination ( Figure 22 ). Caudal filaments yellowish brown; with a whorl of setae on alternate segments; setae shorter than the length of the corresponding segment. Hind wings present.

Adult: Unknown.

Distribution: Giri Ganga River, Himachal Pradesh ( Figure 23 ).

Etymology: This species is named after the type locality of Giri Ganga River, Sirmour district, Himachal Pradesh, India.

Diagnosis: Choroterpes (C.) girigangaensis Kubendran and Vasanth sp. nov. can be differentiated from all other known Oriental species of the subgenus by the following combination of characters: (i) femur with a dark brown macula middle and apex ( Figures 11-13 ); (ii) anteromedian emargination of the labrum with five broad unequal denticles ( Figures 3–5 ); (iii) hind tibiae with a row of the dense medium, long, feathered setae ( Figure 15 ); (iv) upper and lower lamellae of gills II–VII broad, alike with 3 apical processes ( Figures 18–21 ); and (v) tarsal claw apically hooked with a row of 13-14 denticles ( Figure 14 ).

Figures

Figure 23. Distribution of Choroterpes (Choroterpes) species of India.

Figures 1-8. Larvae of Choroperpes (Choroterpes) girigangaensis sp. nov. 1. Dorsal view; 2. Ventral view; 3. Labrum; 4. Labrum emargination; 5. Labrum emargination with unequal denticles 6. Hypopharynx; 7. Left mandible; 8. Right mandible.

Figures 9-16. Larvae of Choroperpes (Choroterpes) girigangaensis sp. nov. 9. Maxilla; 10. Labium; 11. Foreleg; 12. Midleg; 13. Hindleg; 14. Hind tibia; 15. Hind tarsi. 16. Claw.

Figures 17-22. Larvae of Choroperpes (Choroterpes) girigangaensis sp. nov. 17. Gill I; 18. Gill II; 19. Gill V; 20. Gill VI; 21. Gill VII; 22. Ventral view of segment VIII–X.