Cymothoa, Fabricius, 1793

Ravichandran, S., Vigneshwaran, P. & Rameshkumar, G., 2019, A taxonomic review of the fish parasitic isopod family Cymothoidae Leach, 1818 (Crustacea: Isopoda: Cymothooidea) of India, Zootaxa 4622 (1), pp. 1-99 : 18

Key to the Indian species of Cymothoa

1. Pereonite 1 anterolateral margins minute and not reaching the middle of the cephalon; uropods extending to pleotelson posterior margin.............................................................................................. 2

- Pereonite 1 anterolateral margins extending nearly half the length of cephalon; uropods not extending to pleotelson posterior margin.............................................................................................. 3

2. Coxae 2–7 posteroventral margins rounded, all are visible from dorsal view............ Cymothoa parupenei Avdeev, 1979

- Coxae 2–7 posteroventral margins subtruncate, only 4–7 visible from dorsal view................................................................................................... Cymothoa indica Schiöedte & Meinert, 1884

3. Pleonites not subequal in width; pereopod 7 merus with bulbous protrusion on inferior distal margin........................................................................................... Cymothoa eremita ( Brünnich, 1783)

- Pleonites subequal in width; pereopod 7 merus without bulbous protrusion on inferior distal margin.................... 4

4. Cephalon partially immersed in less developed amphicephalic process of pereonite 1; pereonite 1 anterolateral margins broad, with round or subtruncate projections..................................... Cymothoa frontalis Milne Edwards, 1840

- Cephalon immersed in well-developed amphicephalic process of pereonite 1; pereonite 1 anterolateral margins narrow, with minute projections........................................................ Cymothoa bychowskyi Avdeev, 1979