Epeorus (Epeorus) unicornutus Braasch, 2006a

Vasanth, M., Selvakumar, C., Subramanian, K. A., Sivaramakrishnan, K. G. & Sinha, Bikramjit, 2021, Contribution to the study of Epeorus Eaton, 1881 (Ephemeroptera: Heptageniidae) from India, Zootaxa 4991 (3), pp. 499-522 : 503-508

publication ID

https://doi.org/ 10.11646/zootaxa.4991.3.4

publication LSID

lsid:zoobank.org:pub:842EA450-A680-4D5D-9723-C1D7CCE13E5D

DOI

https://doi.org/10.5281/zenodo.5042550

persistent identifier

https://treatment.plazi.org/id/039D87CC-FFA1-FF89-FF56-F931FD166E4F

treatment provided by

Plazi

scientific name

Epeorus (Epeorus) unicornutus Braasch, 2006a
status

 

Epeorus (Epeorus) unicornutus Braasch, 2006a View in CoL

( Figs 35–49 View FIGURES 35–42 View FIGURES 43–49 )

Material examined: 2 larvae, INDIA, Arunachal Pradesh, Lower Subansiri district, Pa stream 27.74791 N, 94.0346 E, 284.2 m, 14.vi.2017, colls. K. A. Subramanian and M. Vasanth [ZSI/ SRC-I / E 287 ] GoogleMaps ; 2 larvae, INDIA, Arunachal Pradesh, West Kameng district, Dirang, Showda village , Dirang river , 27.3267528 N, 92.231802 E, 1877 m, 13.iii.2018, coll. Bikramjit Sinha [ZSI/ SRC-I / E 296 ] GoogleMaps ; 2 larvae, INDIA, Arunachal Pradesh, Lower Dibang valley district, Roing, Iphipani river , 28.18728 N, 95.84094 E, 488 m, 04.iv.2016, coll. Santabala & Party [ZSI/ SRC-I / E 309 ] GoogleMaps .

Description: Mature larva: Body length 11.8 mm; length of cerci 12 mm. Body generally pale brown. ( Fig. 35 View FIGURES 35–42 ).

Head: Length 1.9 mm, width 2.8 mm; pale brown ( Fig. 35 View FIGURES 35–42 ); subrectangular; anterior and lateral margins convex, with rows of dense hair-like setae directed anteriorly; posterior margin slightly concave. Compound eyes blackish, antennal scape, pedicels and flagellum pale brown. Labrum wide, dark brown, anterior margin with 11–12 denticles, long hair-like setae laterally ( Fig. 39 View FIGURES 35–42 ). Hypopharynx as in Fig. 40 View FIGURES 35–42 . Mandible brown with scattered setae along the molar area; incisor serrated; outer incisor longer than inner incisor ( Figs 41– 42 View FIGURES 35–42 ). Maxilla as in Fig. 43 View FIGURES 43–49 . Labium: glossae broad with V-shaped separation, subtriangular; paraglossae slightly expanded laterally; apical segment of palp pointed, dorsal surface with dense row of comb setae ( Fig. 44 View FIGURES 43–49 ).

Thorax: Pronotum pale brown; mesonotum light brown ( Fig. 35 View FIGURES 35–42 ). Femora light brown with distinct patches; dorsal surface of all femora with two brown maculae medially ( Fig. 45 View FIGURES 43–49 ) and stout setae ( Fig. 45A View FIGURES 43–49 ); femora of distal end with a prominent pointed spine on all legs ( Fig. 45 View FIGURES 43–49 ). Claw with 4 denticles ( Fig. 46 View FIGURES 43–49 ).

Abdomen: Abdominal terga pale brown without special marks ( Fig. 35 View FIGURES 35–42 ); posterior margin of abdominal terga I–X each with a row of spines ( Figs 37– 38 View FIGURES 35–42 ); terga II–X with a single acute median and medially prominent pointed spine ( Fig. 35 View FIGURES 35–42 ); tergum X with short spines with minute hair-like setae on posterior margin ( Fig. 38 View FIGURES 35–42 ); terga II–VII with long posterolateral extensions ( Fig. 36 View FIGURES 35–42 ); sterna pale with brown markings of oblique stripes medially and medio-lateral stripes laterally. Lamellae of gill I somewhat extended beneath of abdomen ( Fig. 47 View FIGURES 43–49 ). Gills II–VII with anal rib straight ( Figs 48–49 View FIGURES 43–49 ); gill faces with exception of marginal parts brownish tinged with black. Cerci with row of small hair-like setae dorsally.

Diagnosis: The larva of Epeorus (E.) unicornutus can be distinguished from other species of this genus by the following combination of characters: (i) posterior margin of abdominal terga I–X each with a row of spines ( Fig. 35 View FIGURES 35–42 ); (ii) terga II–IX each with acute median and medially prominent pointed spine ( Figs 35–38 View FIGURES 35–42 ); (iii) tergum X with short spines with minute hair-like setae on posterior margin ( Fig. 38 View FIGURES 35–42 ) and (iv) anterior margin of labrum with 11–12 denticles ( Fig. 39 View FIGURES 35–42 ).

Distribution: Nepal, Thailand and India (Arunachal Pradesh).

Remarks: The larva of this species was described from Nepal by Braasch (2006a) and reported from Thailand by Boonsoong and Braasch (2013); we provide a supplementary larval description based on our material, which represents the first record of the species for India.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Ephemeroptera

Family

Heptageniidae

Genus

Epeorus

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