Epeorus (Epeorus) petersi Sivaruban, Venkataraman & Sivaramakrishnan, 2013

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 : 513

publication ID	https://doi.org/ 10.11646/zootaxa.4991.3.4
publication LSID	lsid:zoobank.org:pub:842EA450-A680-4D5D-9723-C1D7CCE13E5D
persistent identifier	https://treatment.plazi.org/id/039D87CC-FFAB-FF8E-FF56-FE2DFBB468A8
treatment provided by	Plazi
scientific name	Epeorus (Epeorus) petersi Sivaruban, Venkataraman & Sivaramakrishnan, 2013
status

Treatment

( Figs 85–101 View FIGURES 85–91 View FIGURES 92–101 )

Material examined: 9 larvae, INDIA, Tamil Nadu, Tirunelveli, Karumandiyamman kovil, Kalakad range, 08.52969N, 77.46617 E, 1042 m, 03.iv.2017, coll. R. Venkitesan [ZSI/ SRC / I/E-210] GoogleMaps ; 3 larvae, Tamil Nadu, Kanniyakumari, Velachithodu, Kaliyal beat, KWLS, 08.53833 N 077.31174 E, 473 m, 04.iv.2017,coll. R. Venkitesan [ZSI/ SRC / I/E-221] GoogleMaps ; 9 larvae, Tamil Nadu, Nilgris, Avalanchi, Upper Bhavani , 11.26603 N, 76.56274 E, 2288 m, 13.xii.2016, coll. S. Prabakaran [ZSI/ SRC / I/E-233] GoogleMaps ; 20 larvae, Tamil Nadu, Nilgris, Iron bridge, Mukurthi range, Western chatment beat, 11.33476 N, 76.54975 E, 2302 m, 11.xii.2016, coll. S. Prabakaran [ZSI/ SRC / I/E-236] GoogleMaps ; 5 larvae, Tamil Nadu, Coimbatore, Udumalpet, Thirumoorthy falls , 10.451726 N, 77.151696 E, 23.iii.2016, coll. R. Babu [ZSI/ SRC / I/E-259] GoogleMaps ; 9 larvae, Tamil Nadu, Coimbatore, Periyakallar, Chinkona , Manampally , 10.451726 N, 76.969141 E, 1044 m, 23.iii.2016, coll. R. Babu [ZSI/ SRC / I/E-263] GoogleMaps ; 10 larvae, Tamil Nadu, Nilgiri, Singara range, Kallada river , 11.332405 N, 76.507539 E, 931 m, 02.iv.2016, coll. R. Babu [ZSI/ SRC / I/E-268] GoogleMaps .

Description: Mature larva: Body generally brown; body length 12 mm; length of caudal filaments 15 mm ( Fig. 85 View FIGURES 85–91 ).

Head: Length 2.2 mm, width 3.5 mm; yellowish brown; subquadrangular; anterior and lateral margins convex, with rows of dense hair-like setae directed anteriorly; posterior margin slightly concave. Compound eyes black. Antennae small, antennal scape, pedicels and flagellum yellowish brown. Labrum wide, dark brown, anterior margin with 11–12 denticles, middle of labrum slightly cleft with long hair-like setae laterally ( Fig. 88 View FIGURES 85–91 ). Hypopharynx as in Fig. 89 View FIGURES 85–91 . Mandibles with scattered setae along the molar area; inner incisors poorly developed; outer incisor longer than inner incisor ( Figs 90–91 View FIGURES 85–91 ). Maxilla as in Fig. 92 View FIGURES 92–101 . Labium broad; glossae with V-shaped separation, subtriangular; paraglossae slightly expanded laterally; apical segment of palp acutely pointed, dorsal surface with dense row of comb setae ( Fig. 93 View FIGURES 92–101 ).

Thorax: Pronotum yellowish brown; mesonotum yellowish brown with each a paramedian pair of brown dark- er spots anteriorly and a pair of of lateroparapsidal sutures inside curved streaks posteriorly ( Fig. 85 View FIGURES 85–91 ). Legs ( Figs 94–97 View FIGURES 92–101 ): yellowish brown; femora with distinct visible patches, hypodermal spot on dorsal surface; dense row of long setae on outer margin; scattered stout setae on dorsal surface ( Fig. 95 View FIGURES 92–101 ); outer margin of tibia with dense hairlike long setae. Claw with 4 denticles ( Fig. 98 View FIGURES 92–101 ).

Abdomen: Abdominal terga yellowish brown, a median dark brown line on segments III–IX, and a row of spines on posterior margin of segment I–X, terga III–X with pair of submedian larger spines on posterior margin medially ( Figs 85–86 View FIGURES 85–91 ); posterolateral spines on abdominal segment II–VII, progressively longer and curved inwards posteriorly ( Fig. 87 View FIGURES 85–91 ); sterna light yellowish without markings but partially visible muscle impressions. Lamellae of gills pale, posterior edge of the lamellate portion of gill 1 bluntly pointed ( Fig. 99 View FIGURES 92–101 ). Gills II–VII with anal ribs arched ( Figs 100–101 View FIGURES 92–101 ); gill faces with exception of marginal parts reddish tinged, tracheae of gills branched. Cerci long, dark brown, with row of hair-like setae dorsally.

Adult: Detailed description provided by Sivaruban et al. (2013).

Diagnosis: Epeorus (E.) petersi can be distinguished from other species of this genus by the following combination of characters: in larva: (i) median line on terga III–IX; (ii) a row of spines on posterior margin of segment I–X, terga III–X with two submedian large spines on posterior margin medially ( Figs 85–86 View FIGURES 85–91 ); (iii) posterolateral spines on abdominal segment II–VII, progressively longer and bent inwards posteriorly ( Fig. 87 View FIGURES 85–91 ); and (iv) anterior margin of labrum with 11–12 denticles ( Fig. 88 View FIGURES 85–91 ).

Distribution: India (Karnataka, Kerala and Tamil Nadu).

Remarks: The larva and adult of this species were described from Kumbakkarai (Tamil Nadu), India by Sivaruban et al. (2013); we provide a supplementary larval description based on our material.