Parapenaeopsis, Alcock, 1901

Hsu, Yen-Cheng & Chan, Tin-Yam, 2023, On the penaeid shrimps of the genus Parapenaeopsis Alcock, 1901 (Crustacea, Decapoda) from Taiwan, Zootaxa 5361 (2), pp. 221-236 : 234

Key to the species of Parapenaeopsis in Taiwan

1. Pereiopods I and II without epipod....................................................................... 2

- Pereiopods I and II with epipod.......................................................................... 3

2. Epigastric tooth present......................................................................... P. venusta

- Epigastric tooth absent........................................................................... P. tenella

3. Rostrum either very long or very short, far overreaching antennular peduncle or not exceeding second segment of antennular peduncle; longitudinal suture long, extending near to posterior carapace............................... .. P. hardwickii

- Rostrum extending to distal segment of antennular peduncle; longitudinal suture short, extending to about level of epigastric tooth............................................................................................... 4

4. Male endopod of pleopod II strongly modified and sock-like; petasma with tip of distolateral projection only protruded at outer side; thelycum with posterior plate bearing median boss; tuft of setae behind thelycum thick and long, bluish in color.................................................................................................. P. cornuta

- Male endopod of pleopod II normal in shape, not modified; petasma with tip of distolateral projection protruded on both sides; thelycum with posterior plate lacking median boss; tuft of setae behind thelycum thin and short, colorless........ P. amicus