Periclimenes alcocki, Kemp, 1922

Li, Xinzheng & Bruce, Alexander J., 2006, Further Indo-West Pacific palaemonoid shrimps (Crustacea: Decapoda: Palaemonoidea), principally from the New Caledonian region, Journal of Natural History 40 (11 - 12), pp. 611-738 : 719-720

Key to the species of Periclimenes alcocki species group

1. Telson with seven pairs of dorsolateral spines; rostrum overreaching scaphocerite; third pereiopod with dactyl truncate subdistally, propod without spinules on flexor margin........... P. albatrossae Chace and Bruce, 1993

– Telson with three to five pairs of dorsolateral spines......... 2.

2. Telson with three pairs of dorsolateral spines; rostrum not overreaching scaphocerite; corneal diameter about 0.125 of carapace length, eye stalk not distinctly narrower than cornea; dorsal rostral margin concave; third pereiopod with propod with spinules on flexor margin, and transverse setal rows distally and spines; R. 1+7/3.............. P. paralcocki sp. n.

– Telson with four to five pairs of dorsolateral spines......... 3

3. Rostrum overreaching scaphocerite; corneal diameter about 0.16 of carapace length, eye stalk distinctly narrower than cornea lateral view; dorsal rostral margin concave; third pereiopod with propod with spinules on flexor margin, and transverse setal rows distally and spines; R. 1+7+1/4.... P. paraleator sp. n.

– Rostrum not overreaching scaphocerite............. 4

4. Cornea markedly reduced, diameter about 0.1 of carapace length..... 5

– Cornea not markedly reduced, diameter more than 0.13 of carapace length; dorsal telson spines not minute................. 7

5. Ambulatory pereiopods with propod without distoventral or ventral spines, dactyl with accessory tooth minute, at most 0.11 of unguis length; rostrum relatively deep, distally with a strong upward curve; dorsal telson spines relatively large, 0.045 of telson length; R. 1+7/2......... P. pseudalcocki sp. n.

– Ambulatory pereiopods with propod with distoventral and ventral spines... 6

6. Corneal diameter about 0.075 of carapace length; hepatic spine at about same level of posterior rostral series (epigastric) tooth; third pereiopod dactyl 0.17 of propod length, accessory tooth about 0.2 of unguis length; dorsal telson spines minute, about 0.03 telson length; R. 2+628/224 (1+9/3). P. alcocki Kemp, 1922

– Corneal diameter about 0.1 of carapace length; hepatic spine anterior to level of posterior rostral series (epigastric) tooth; third pereiopod dactyl about 0.28 of propod length, accessory tooth about 0.07 of unguis length; dorsal telson spines minute, about 0.04 telson length; R. 1+7/1.... P. tangeroa Bruce, 2005

7. Ambulatory dactyl with accessory tooth almost as long as unguis, laterally twisted; R. 1+729/2–3............. P. poupini Bruce, 1990

– Ambulatory dactyl with accessory tooth not unusually long or twisted.... 8

8. Rostrum distinctly exceeding antennular peduncle......... 9

– Rostrum not reaching end of antennal peduncle; pigmented cornea large, diameter about 0.16–0.18 of carapace length............. 10

9. Hepatic spine distinctly lower than antennal spine; R. 1–2+529/324...................... P. aleator Bruce, 1991

– Hepatic spine very slightly lower than, almost at same level of antennal spine; R. 2+6/3................. P. loyautensis sp. n.

10. Rostrum deeper, proximally not elevated over orbital region, upturned in female, ventral margin convex, with two teeth; ambulatory dactyl with accessory tooth about 0.3 of unguis length; R. 1+526/2..... P. brevirostris Bruce, 1991

– Rostrum shallower, proximally elevated over orbital region, tapered distally, ventral margin straight, with one tooth; ambulatory dactyl with accessory tooth reaching about proximal 0.4 of unguis length; R. 1+627/1... P. forgesi sp. n.