A new species of Isonychia Eaton, 1871 (Ephemeroptera: Isonychiidae) from Kapila River, Central Western Ghats, India

Abstract

Isonychia (Isonychia) radhae n. sp. is described based on larvae and imagoes from Kapila River, Dakshina Kannada, Karnataka State, India. The imagoes of I. radhae n. sp. can be distinguished from the other known Oriental species by the following combination of characters: (i) absence of rusty brown maculae in the costal, subcostal, and median areas of forewing; (ii) forelegs dark brown except coxae; (iii) Scattered barbs present in penis; (iv) Second segment of gonostylus long and slender; and (v) sterna of abdominal segment X in female not deeply cleft. Isonychia radhae n. sp. can be distinguished in the larval stage from other known Oriental species by the following combination of characters: (i) tergites II–IV without distinct stripe medially, tergites V–X with a pair vague oblique stripe; (ii) abdominal terga II–IX with median dark brown maculae progressively larger with dark brown slanting streaks in lateral margins; (iii) gills I and II small, tracheae of abdominal gills I–VII unbranched; (iv) postero-lateral projection on anterior segments of abdomen blunt and small, acute on segments VIII–IX and large at on segment IX; (v) median terminal filament slightly shorter than 1/3 length of cerci; (vi) distal segments of cerci dark, basal ¾ of mesal margin of cerci and lateral margin of terminal filament with long thin setae. Revised keys to the known larvae and male imagoes of Oriental species of Isonychia are also provided.

A preliminary review of Isonychia Eaton, 1871 from Chinese mainland with a re-description of I. kiangsinensis Hsu, 1936 (Insecta, Ephemeroptera, Isonychiidae)

“… Isonychia kiangsinensis : Gui 1985 : 80; You and Su 1987 : 334 (nymph); You and Gui 1995 : 23; Su and Zhou 1998 : 28; Gui et al 1999 : 326; Zhou et al 2015 : 118 (adult, nymph); Tiunova et al 2004 : 2; Vasanth et al 2019 : 169; Muthukatturaja et al 2021 : 284). …”

“… vshivkovae vshivkovae Tiunova et al, 2004 (see below), I. radhae Muthukatturaja et al, 2021 , forewings of I. kiangsinensis are transparent, without clear markings (Fig.…”

“…7A–D ), which was missing in the description of You and Su (1987) . However, Vasanth et al (2019) and Muthukatturaja et al (2021) reported wrongly that I. kiangsinensis has projections on terga I–IX.…”

Nuevo registro del género Isonychia (Ephemeroptera: Isonychiidae) en México y datos de parámetros del agua

“…El género Isonychia Eaton (1871) es el único de la familia Isonychiidae. Este grupo es conocido como efemerópteros pisciformes de patas cepilludas (Saito et al 2016, Muthukatturaja et al 2021. El género ha sido reportado como Holártico y en el continente americano se encuentra en la zona Neotropical como en la Neártica (Sartori y Brittain 2015).…”

“…Tiene una distribución amplia, desde el sur en Costa Rica hasta Canadá en el norte (Vasanth et al 2019). No obstante, en la región Neártica es donde se distribuye de manera más abundante (Vasanth et al 2019, Sartori y Brittain 2015, Muthukatturaja et al 2021) y esencialmente al este de los Estados Unidos posee mayor cantidad de registros (GBIF 2023).…”