Clypeocaenis kaveri Balasubramanian and Muthukatturaja, 2021

Srinivasan, Pandiarajan, Sivaruban, T., Barathy, S. & Isack, Rajasekaran, 2023, Contribution to the knowledge of family Caenidae (Insecta: Ephemeroptera) from Madurai District, Tamil Nadu, Zootaxa 5258 (1), pp. 39-75 : 70-71

Clypeocaenis kaveri Balasubramanian and Muthukatturaja, 2021

( Figs. 157–171 )

Materials examined. 1 L-S-IJ, 3 L-S-I ♀, 5 larvae, South India, Tamil Nadu, Madurai District, Vaigai river , 9°95′52′′N, 78°06′59′′E, 144 m, 8.VII.2022, colls. P. Srinivasan & R. Isack ( AMC /ZN/257). 10 larvae, South India, Tamil Nadu, Madurai District , Vaigai river , 10°08′32′′N, 77°93′22′′E, 192 m, 1.VIII.2022, colls. P. Srinivasan & R. Isack ( AMC /ZN/257) .

Additions to the description. Detailed imago and larval descriptions of Clypeocaenis kaveri are given by Balasubramanian and Muthukatturaja, 2021. However, several important diagnostic characters of the imago, subimago and larva were not included in the original description.

Female imago ( Fig. 157 ).

Coloration: Terga whitish (eggs under the body give the appearance of yellowish color to the tergum). Posterior half of terga I– IX with dark brownish transverse band ( Fig. 158 ). Prosternal sclerites trapezoid with concave lateral sides with a transverse blackish strip in the fore margin and with well-developed basolateral dark pigmentation ( Fig. 160 ).

Subimago. Legs. Cuticular coloration: Femora of all legs light brownish-ochre, with diffusive light and darker areas; tibiae and tarsi light brownish-ochre ( Fig. 161 ). In both sexes of all leg pairs, tibiae and tarsomeres are covered with microtrichia ( Figs. 162, 163 ).

Larva ( Fig. 159 ). Abdomen. Tergalius II with a well developed medial ridge, forming an elevated triangular keel ( Fig. 164 ). Ventral row of microtrichia ending far from the hind margin, consists of 2–3 irregular rows of cluster of 2–6 spines medially ( Fig. 165 ). Hind margin of sternum IX broadly rounded with numerous indentations ( Fig. 166 ); shagreen on dorsal side of sternum IX with 5–6 irregular rows of very small denticles parallel to the hind margin ( Fig. 167 ).

Egg. Length: 115–120 μm; width: 65–70 μm. Oval-shaped ( Fig. 168 ); chorion smooth ( Fig. 169 ) with a flat epithema forming a coil of fine threads with numerous small terminal knobs on one pole ( Fig. 170 ). Micropyle short, situated at the subequatorial plane with mouth slightly broadened ( Fig. 171 ).

Distribution. Kaveri river (Karnataka), Vaigai river (Madurai, Tamil Nadu).

Ecology. Larvae of Clypeocaenis kaveri were collected in the water temperature ranges between 24°C–26°C; pH 7.2–7.3. Substratum is mainly made of cobbles and pebbles. The larvae of Clypeocaenis kaveri shared their habitat with Choroterpes (Euthraulus) latus (Leptophlebiidae) , Tenuibaetis sp. (Baetidae) , Labiobaetis operosus (Baetidae) , Nigrobaetis klugei (Baetidae) , Cheleocloeon vaigaiensis (Baetidae) , Tricorythus meenakshi (Tricorythidae) , Caenis maduraiensis (Caenidae) , Caenis venkataramani sp. n. and Clypeocaenis kaveri (Caenidae) .

Figures

FIGURES 157–159. Clypeocaenis kaveri Balasubramanian and Muthukatturaja, 2021: (157) female imago; (158) abdominal terga of female imago; (159) larva.

FIGURES 160–163. Clypeocaenis kaveri Balasubramanian and Muthukatturaja, 2021: (160) prosternal triangle; (161) foreleg of female subimaginal exuvia; (162) microtichia in foretibia of female subimaginal exuvia; (163) microtichia in foretarsus of female subimaginal exuvia.

FIGURES 164–167. Larva of Clypeocaenis kaveri Balasubramanian and Muthukatturaja, 2021: (164) dorsal view of tergalius II; (165) SEM view of microtrichia in tergalius II; (166) shape of sternum IX; (167) detail of shagreen field in sternum IX.

FIGURES 168–171. SEM view of eggs of Clypeocaenis kaveri Balasubramanian and Muthukatturaja, 2021: (168) entire view; (169, 170) epithema; (171) micropyle.