Thor

Komai, Tomoyuki, Okuno, Junji & Minemizu, Ryo, 2015, New records of two species of the coral reef shrimp genus Thor Kingsley, 1878 (Crustacea: Decapoda: Thoridae) from the Ryukyu Islands, Japan, Zootaxa 4013 (3), pp. 399-412 : 411

Key to the Indo-West Pacific species of Thor

1. Supraorbital tooth present............................................................................... 2

1. Supraorbital tooth absent................................................................................ 4

2 Antennular stylocerite with small erect tooth on dorsolateral margin proximally; chela of first pereopod stout, not markedly tapered.............................................................................................. 3

2 Antennular stylocerite without small erect tooth on dorsolateral margin proximally; chela of first pereopod slender, tapered....................................................................... T. leptochelus ( Xu & Li, 2015) n. comb.

3. Telson with posterior margin bearing 2 pairs of spines and 1 mesial pair of plumose spines or setae, but without median tooth; fourth and fifth pereopods with dactyl fully 3.0 times as long as wide.......................... T. spinipes Bruce, 1983

3. Telson with posterior margin bearing acute medial tooth, flanked by 2 pairs of spines and 2 mesial pairs of plumose setae; fourth and fifth pereopods with dactylus twice as long as wide............................... T. spinosus Boone, 1935

4. At least third maxilliped and first pereopod with strap-like epipods.............................................. 5

4. Third maxilliped and first pereopods without strap-like epipods................................................. 6

5. Second pereopod with strap-like epipod............................................... T. singularis Xu & Li, 2015

5. Second pereopod without strap-like epipod.......................................... T. hainanensis Xu & Li, 2014

6. Stylocerite of antennular peduncle with small erect tooth near proximal end....................................... 7

6. Stylocerite of antennular peduncle without small tooth near proximal end..................... T. paschalis ( Heller, 1862)

7. Telson with 1 pair of barely visible dorsolateral spines in posterior one-fourth of length....... T. intermedius Holthuis, 1947

7. Telson with 2–5 pairs of distinct dorsolateral spines.......................................................... 8

8. Rostral apex acuminate; telson bearing 4 pairs of posterior spines; first pereopod with chela not tapered or compressed.................................................................................. T. amboinensis (De Man, 1888)

8. Rostral apex typically subtruncate with 3 or 4 teeth; telson bearing 3 pairs of posterior spines; first pereopod with chela tapered and compressed................................................................... T. marguitae Bruce, 1978