98 U.S. NATIONAL MUSEUM BULLETIN 292 



the more than 400 females taken during the remaining six months 

 carried eggs. 



During the second author's visits to Dominica M. carcinus was 

 spied upon, fished for, purchased, and consumed on numerous occa- 

 sions, but two specific encounters with this largest species of American 

 shrimps are frequently recalled as highlights of the study. Early in 

 the course of the field work, inquiry had been made as to how large 

 specimens of M. carcinus might best be obtained, and a demonstra- 

 tion had been provided by a local police officer, Mr. Courette, in the 

 Sari Sari River north of La Plaine. The technique, described on 

 page 46, had been tried unsuccessfully in many likely looking crevices 

 and beneath rocks along Mannet's Gutter, and one small specimen had 

 finally been taken in the large pool mentioned above. 



Upstream from this pool the creek flowed sluggishly around and 

 under a tremendous rock. As this rock was approached one day, the 

 largest Macrobrachium heretofore encountered was seen partially 

 exposed. As it quickly retreated under the rock, the baited hook was 

 thrust gently after it and, within seconds, the shrimp had taken the 

 bait and in minutes was being pulled from beneath the rock, its long 

 chelipeds and walking legs widely braced against the sandy bottom 

 of the pool. Under water, the animal appeared at least twice as large 

 as it actually is — even so, it is a fine specimen with a carapace length 

 of 64 mm, a total body length of 191 mm, and a leg span of nearly 

 20 inches (about 500 mm). After pulling the animal to shore, the 

 highly excited fisherman was faced with the problem of removing the 

 hook. The wild thrashing of the huge chelipeds and four additional 

 pairs of legs and the violent flexing of the abdomen seemed to offer 

 no safe way of accomplishing this. Finally, by covering the entire 

 shrimp with a plastic bag and grasping all of the appendages firmly, 

 the fisherman extricated the pin, and the shrimp, uninjured, was 

 consigned to a container. This is the specimen shown in figure 21. 



The other memorable encounter with the species occurred at the 

 mouth of the Layou after nine o'clock in the evening, when Dr. R. B. 

 Manning and the same author were searching from a dugout canoe 

 for signs of penaeid shrimps in the lower reaches of the river. The 

 eyes of literally thousands of Xiphocaris elongata and Macrobrachium 

 acanthurus (perhaps also Jonga serrei) shone in the rays of our lantern 

 in the extreme littoral areas. As the boat moved away from the shore 

 and over a clump of submerged tree limbs resting on the bottom, a 

 large M. carcinus came into view. It was not too wary; however, 

 equipment was not available to work with ease in more than three 

 feet of water, and attempts to catch the animal were unsuccessful. 

 Later, three additional and apparently gigantic individuals, alerted 

 by the light from our lantern and headlamp, crawled rapidly away; 



