Contribution to the knowledge of family Caenidae (Insecta: Ephemeroptera) from Madurai District, Tamil Nadu Author Srinivasan, Pandiarajan 0000-0001-8118-3256 PG & Research department of Zoology, The American College (affiliated to Madurai Kamaraj University), Madurai- 625002, India. Department of Zoology, Fatima College (affiliated to Madurai Kamaraj University), Madurai- 625018, India. barathyruban @ gmail. com; https: // orcid. org / 0000 - 0002 - 9464 - 6464 & srini 15.05.1996 @ gmail. com; https: // orcid. org / 0000 - 0001 - 8118 - 3256 srini15.05.1996@gmail.com Author Sivaruban, T. PG & Research department of Zoology, The American College (affiliated to Madurai Kamaraj University), Madurai- 625002, India. Department of Zoology, Fatima College (affiliated to Madurai Kamaraj University), Madurai- 625018, India. barathyruban @ gmail. com; https: // orcid. org / 0000 - 0002 - 9464 - 6464 Author Barathy, S. 0000-0002-9464-6464 barathyruban@gmail.com Author Isack, Rajasekaran 0000-0002-9952-4335 PG & Research department of Zoology, The American College (affiliated to Madurai Kamaraj University), Madurai- 625002, India. Department of Zoology, Fatima College (affiliated to Madurai Kamaraj University), Madurai- 625018, India. barathyruban @ gmail. com; https: // orcid. org / 0000 - 0002 - 9464 - 6464 & iceisack 143 @ gmail. com; https: // orcid. org / 0000 - 0002 - 9952 - 4335 iceisack143@gmail.com text Zootaxa 2023 2023-03-27 5258 1 39 75 http://dx.doi.org/10.11646/zootaxa.5258.1.2 journal article 10.11646/zootaxa.5258.1.2 1175-5326 7773275 D5B78BB6-E7AB-4CB8-B202-AA617E06F915 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. FIGURES 157–159. Clypeocaenis kaveri Balasubramanian and Muthukatturaja, 2021 : (157) female imago; (158) abdominal terga of female imago; (159) larva. 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 ). 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. 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 ).