Choroterpes ( Dilatognathus ) klugei Kubendran, Vasanth & Subramanian, 2025

Vasanth, M., Kubendran, T. & Subramanian, K. A., 2025, Three new species of the subgenus Dilatognathus Kluge, 2012 (Ephemeroptera: Leptophlebiidae: Atalophlebiinae) from Western Himalaya, India, Records of the Zoological Survey of India 125 (1), pp. 1-17 : 2-6

publication ID	https://doi.org/10.26515/rzsi/v125/i1/2025/172818
persistent identifier	https://treatment.plazi.org/id/863C3C63-8A6A-BE5E-227A-2B649B3983B9
treatment provided by	Felipe
scientific name	Choroterpes ( Dilatognathus ) klugei Kubendran, Vasanth & Subramanian
status	sp. nov.

Treatment

Choroterpes ( Dilatognathus) klugei Kubendran, Vasanth & Subramanian sp. nov.

( Figs. 1, 4 View Figs , 7, 10 View Figs , 13-36 View Figs View Figs )

Materials examined: Holotype: 1 mature larva, India, Jammu and Kashmir, Udhampur district, Tawi River, Chenani , 33.03122° N, 75.20751° E, 1011 m, 14.xi.2018, Coll. T. Kubendran and Akhil Nair. I /E 873 Paratype: 12 larvae, same data as holotype I/E 869. GoogleMaps

Description: Mature larva ( Fig. 1 View Figs ): body brownish with black markings; length 6.5-7 mm; caudal filament 6-6.5 mm; median caudal filament 9-9.5 mm; antennae 2.3-2.5 mm ( Fig. 35 View Figs ).

Head: Head prognathous, brownish with pale white markings; three distinct black ocelli with slightly white colour markings. The upper layer of the head is slightly shallow. Eyes with pale reddish and lateral black ( Fig. 7 View Figs ). Labrum wide, (3:1=width and length of middle) median shallow and lateral width small and long dense hair-like setae, anteriorly with a row of long numerous hair-like and small simple setae on the dorsal surface ( Fig. 13 View Figs ); ventral surface with small hair-like setae. Hypopharynx with well-developed lateral process, lingua non-curved laterally, superlingua rounded anterior and hands wide laterally ( Fig. 14 View Figs ). Mandibles curved smooth laterally with dense hair-like setae; left mandible incisors fused; outer and inner incisors with 3+2 teeth; inner incisor wide compared to outer; inner incisor almost same as outer incisor; inner incisor upper teeth longer than lower ( Fig. 15 View Figs ); prostheca narrow with hair-like setae; the margin between prostheca and mola convex; dorsal margin without setae under mola; mola with 5 wide chambers with small setae; right mandible incisors fused; outer and inner incisors with 3+2 teeth; inner incisor slightly smaller than outer incisor; prostheca long and hair-like setae; the margin between prostheca and mola concave and gradually increase the mola convex; dorsal margin with 5-6 long setae under mola; outer margin with the convex triangular and closely large chamber with medially stout setae ( Fig. 16 View Figs ). Maxillae long with palps III segmented; maxilla with inner-apical angle produced as long as a tusk-like process; palp elongated and bears long filtering simple setae; galea-lacinia outer margin deeply convex with long and small simple hair-like setae; inner margin with dense hair-like setae; crown inner and outer long hair-like setae; segment I with smooth excavation distally and outer margin with 7-8 simple setae; segment II narrow, inner side concave with 4 long, simple setae, outer side with 3-4 small setae; segment III apically blunt with a dorsal transverse row of long setae proximally, on inner side with a row of numerous long, simple setae, outer side with apically long simple setae ( Figs. 17-18 View Figs ). Labium; glossae wide rounded laterally (bean shaped), anteriorly covered with small stout setae; paraglossae wide and laterally without blunt excavation, dorsal surface with medium dense hair-like, small stout setae and anterior margin with rows of dense hair-like setae; palps elongated, III segmented, with long and wide filtering and longitudinal setae; segment I wide with outer margin a row of numerous simple setae; segment II outer margin with rows of long, simple hair-like setae and dorsal surface with rows of numerous long, simple hair-like setae, ventral surface with three rows of long setae; segment III apically narrow with inner and outer margin long simple setae and dorsal surface small simple setae ( Fig. 19 View Figs ).

Thorax: Notum yellowish with diffuse black marking on lateral ( Fig. 1 View Figs ); humeral setae on prothorax with small and long setae ( Figs. 16-27 View Figs ), ventral surface of pro-notum black markings medially, mid-notum with light black circular marking and pale white marking entire area ( Fig. 4 View Figs ). Legs yellowish black; each femur with black markings on middle and apex; mid and hind tibia with black colour marking on basal and fore tibia with black marking on base and apex. Foreleg ( Figs. 20, 21 View Figs ): proximal and middle region of femur wide, narrow distally; dorsal surface without any setae on proximal part; middle and distal with black marking and a few simple rounded setae apically, anterior margin with long simple rounded setae apically; posterior margin with small simple and feathered setae; tibia inner margin with a row of long feathered, simple setae, dorsal surface with a row of irregular small setae; outer margin with long hair-like setae; inner margin of tarsi without setae, dorsal surface with small simple setae, outer surface hair-like setae; claw sharp apically with 12- 13 denticles, basally 4 denticles, another denticle larger towards apex. Middle leg ( Figs. 22, 23 View Figs ): dorsal surface of femora with small simple setae and long simple rounded setae near apex; anterior margin with long hair-like setae and irregular simple rounded setae in various lengths of apically; posterior margin with long simple, irregular rounded and small stout setae apically; inner margin of tibia with 8-9 spine-like irregular setae, outer margin with long hair-like setae, dorsal surface with small stout setae; outer and inner margin of tarsi with hair-like and small stout setae on dorsal. Hind leg ( Fig. 24 View Figs ): dorsal surface of the femur with simple, rounded setae on apical in various lengths, small stout setae, anterior margin with long dense simple, apically rounded setae and hair-like setae, posterior margin with numerous simple apically rounded setae; tibiae inner and outer margin with rows of simple, apically rounded and hair-like setae, proximal of dorsal surface with few simple apically rounded setae and mixed with small hair-like setae; inner and outer margin of tarsi with hair-like and small stout setae on dorsal surface; claw with 13-14 denticles, basally 4 denticles and other denticles increasing size towards apex ( Fig. 25 View Figs ). Hind wing pad present.

Abdomen: Dorsal surface of terga I-IX yellowish, posterior region brown, tergum X dark brownish; posterolateral margin of abdominal terga I-VII with blunt spines and terga VII-IX pointed denticles ( Fig. 1 View Figs ). Posterior margins of abdominal terga I-X with a row of regular, sharp denticles ( Fig. 28 View Figs ); sterna medially pale white, laterally blackish ( Figs. 4 View Figs , 10 View Figs ). Gills present on terga II-VII, black colour; each gill two lamellae, gill II-V with 6 apical processes, gill VI smaller, gill VII smallest ( Figs. 29-34 View Figs ). Caudal filament, yellow colour, each segment surrounding with stout setae and inner and outer margin with simple setae on each segment; setae smaller than the length of the corresponding segment ( Fig. 36 View Figs ).

Adult: Unknown.

Etymology: The species is named in honour of Dr. Nikita Kluge in recognition of his significant contributions to the study of the subfamily Atalophlebiinae and his pivotal role in establishing the subgenus Dilatognathus .

Distribution: Jammu Kashmir (UT), India.

Diagnosis: Choroterpes ( D.) klugei sp.nov. is closely related to Ch. ( D.) triapicalis sp. nov. it can be differentiated from all other known species of the subgenus by the following combination of characters: (i) labrum wide, median shallow and lateral width small compared to C. triapicalis ( Fig. 13 View Figs ); (ii) lingua slightly wide compare to C. triapicalis ( Fig. 14 View Figs ); (iii) segment I of maxillary palp distally with smooth excavation; segment II narrow ( Figs. 17-18 View Figs ); (iv) paraglossae wide and without blunt excavation laterally, glossae wide compared to C. triapicalis ( Fig. 19 View Figs ); (v) Three new species of the subgenus Dilatognathus Kluge, 2012 ( Ephemeroptera : Leptophlebiidae : Atalophlebiinae )... inner incisor of left mandible wide with 2 teeth, upper one longer than lower one, mola with 5 wide chamber with small setae ( Fig. 15 View Figs ); (vi) posterior margin spines on each terga sharp and narrow ( Fig. 28 View Figs ); (vii) femora with median and distal black markings, forefemur plain without any setae compare to C. triapicalis ( Figs. 20, 22, 24 View Figs ); (ix) claw with 13-14 denticles, basally 4 denticles, and other denticles increasing size towards apex ( Fig. 25 View Figs ).

Ecology: The type-locality, Tawi River is located 37 km far from the Patnitop towards the Udhampur district ( Fig. 96 View Figure 96 ). The riverbed is mostly composed of boulders, gravel, sand and silt. The Tawi River is 2-2.5 m wide and 20 cm depth and medium water current (1.0 m/sec.) on the eastern part of Western Himalaya. The water temperature ranged between 12-14°C (seasonal variations). The larvae were collected at the stony bottom found at the edge of the Tawi River.