Nihonotrypaea petalura

Kornienko, Elena S., Korn, Olga M. & Golubinskaya, Darya D., 2015, The number of zoeal stages in larval development of Nihonotrypaea petalura (Stimpson, 1860) (Decapoda: Axiidea: Callianassidae) from Russian waters of the Sea of Japan, Zootaxa 3919 (2), pp. 343-361 : 355-356

Key to the identification of zoeal stages of Nihonotrypaea petalura

1. Uropod absent; antennule uniramous; pleon with five somites.................................................. 2

- Uropod present; antennule biramous; pleon with six somites................................................... 3

2. Eyes sessile; posterior margin of telson with 7+1+7 processes; pereiopods absent............................... zoea I

- Eyes stalked; posterior margin of telson with 8+1+8 processes; pereiopods 1 and 2 present...................... zoea II

3. Endopod of uropod unarmed; pleopod buds absent; height of telson nearly equal posterior margin.................zoea III

- Endopod of uropod with plumose setae; pleopod buds present; height of telson longer than posterior margin............. 4

4. Endopod of uropod with 6–8 plumose setae; distal segment of antennular peduncle with 4 plumose setae; endopod of antenna equal half of scaphocerite without setae.............................................................. zoea IV

- Endopod of uropod with 10–18 plumose setae; distal segment of antennular peduncle with 5–8 plumose setae; endopod of antenna longer than half of scaphocerite without setae......................................................... 5

5. Endopod of antennule shorter than exopod; distal segment of antennular peduncle with 5–6 plumose setae; height of telson 1.5 times longer than posterior margin................................................................... zoea V

- Endopod of antennule longer than exopod; distal segment of antennular peduncle with 7–8 plumose setae; height of telson nearly 2 times longer than posterior margin................................................................. 6

6. Endopod of antenna equal scaphocerite without setae; scaphocerite of antenna with 15 inner plumose setae; CL about 2.7 mm...............................................................................................zoea VI

- Endopod of antenna longer than scaphocerite without setae; scaphocerite of antenna with 16–18 inner plumose setae; CL about 3 mm ......................................................................................... zoea VII