DECAPOD CRUSTACEANS OF THE WEST INDIES 45 



of the pool, and all of the occupants, including the previously dom- 

 inant M. carcinus gave wide clearance to the newcomer. A short 

 time after the shrimp with the worm had found cover and presum- 

 ably had devoured it, the crab crawled back into its lair, the large 

 M. carcinus moved into crevices, and the remainder of the population 

 returned to its original state. A second worm introduced into the pool 

 resulted in a similar turmoil, but this worm was successfully acquired 

 by one of the young M. crenulatum, which quickly swam to the shal- 

 low down-stream end of the pool and crawled beneath a stone. Re- 

 peated introductions of worms into the pool elicited comparable 

 responses. 



Similar observations were made in other pools on several occasions, 

 and it seems highly probable that all of the shrimps respect the 

 crab, that the dominant shrimp in the pool is the largest M. carcinus 

 inhabiting it, and that the size of the individual M. carcinus deter- 

 mines its rank in the hierarchy. Even the largest M. crenulatum 

 with heavier chelipeds gives way to M. carcinus that are scarcely 

 larger. In turn, the smaller M, crenulatum and A. innocous respect 

 the larger M. crenulatum but join with X. elongata in hesitantly 

 approaching the more dominant members of the pool, darting away 

 when challenged. Xiphocaris elongata, A. innocous, and juvenile M. 

 crenulatum seem able to vie with one another although X. elongata 

 backs away from all except the smallest M. crenulatum and^. innocous. 



Local Importance of Dominican Species 



Of the freshwater and terrestrial decapod crustaceans utilized 

 directly for food, perhaps none are so generally exploited as the two 

 species of the genus Gecarcinus. Since most of the Dominicans make 

 no distinction between them, they are equally acceptable for recipes 

 ranging from "crab-back" to "calilou soup." Both G. lateralis and 

 G. ruricola seem definitely to be preferred to Cardisoma guanhumi 

 and apparently are more widely available than the latter. 



While probably fewer freshwater shrimps, Macrohrachium, are used 

 for food than Gecarcinus, all five species are eaten. Chiefly, we suspect, 

 because of its larger size, Macrohrachium carcinus is favored, but 

 M. heterochirus and M. crenulatum along with either species of Atya 

 are eaten. Macrohrachium does provide one advantage over the crabs 

 in that apparently its availability is not seasonal. 



Following a dry spell (during the latter part of March and early 

 April), when the rains first begin to fall or, better still, on the first 

 evening after a good rain, the crabs emerge from their burrows and 

 wander up and down hill. On such an evening, groups of children and 

 adults of both sexes carry gunny sacks and torches and walk through 

 cleared areas searching for crabs; especially productive are the road- 

 side ditches along the coast. In a single evening, dozens of crabs 



