Following is a summery of common names for crabs in the genus Uca. See individual species for more information on the common names of a particular species.
There is a sort of small Land-Crab, which we call a Fiddler, that runs into a Hole when any thing pursues him.and again (p. 162):
Fidlars are a sort of small Crabs, that lie in Holes in the Marshes. The Raccoons eat them very much. I never knew any one try, whether they were good Meat or no.
This is the animal so well known to the inhabitants of the sea coast under the name of “Fiddler,” an appellation almost universal, and probably derived from a supposed similitude between the large hand of the male and the fiddler or violin.Note that he associates the name with the large claw, but without the motion—a half-correct answer we will see again. Gould (1841) has a similar explanation when discussing the crab Gelasimus vocans (likely both Uca pugilator and U. pugnax) in Massachusetts (p. 325):
It is well distinguished by its large claw, which is sometimes on the right side and sometimes on the left, and has gained for it the name of the “Fiddler Crab.”
The movable finger is curved, and extends somewhat beyond the tip of the other, which is almost straight ; from this results a figure somewhat resembling the bow of a violin, and has probably suggested its popular name of Fiddler Crab.His explanation of the origin of the name is unusual: that the curving dactyl on the large claws looks like the bow over the violin (the pollex and manus).
These are the swimming Crabs, of which there are numerous species. These differ materially from the kinds we have described, in habits, appearance, and structure. By the use of their powerful oar-like legs they are enabled to propel themselves through the water with great rapidity and precision, and by darting among the meshes of the fishing-nets they becomes so helplessly entangled, that a “Fiddler Crab” (as it is sometimes called from the rapidity with which it works its elbows) in a transel net, is often used by fishermen as a standard with which to compare the cases of the most utter bewilderment.
The drainage-ditches were everywhere alive with little crabs—‘fiddlers.’ One saw them scampering sidewise in every direction whenever they heard a disturbing noise. Expensive pests, these crabs; for they bore into the levees, and ruin them.
When these crabs are disturbed their claws are brandished in an amusing manner, strikingly suggestive of the motions of a violinist, whence these forms have received the common name of “Fiddler Crabs.”Angelo Heilprin makes an even more confusing explanation in his 1888 book The Animal Life of Our Sea-Shore (p. 82).
When provoked, the animal brandishes this claw in a somewhat threatening manner, which has been likened to the pulling of a violin-bow—hence the name of 'fiddler'—and by others to the action of beckoning or calling (hence 'calling crabs').And again in Johnson and Snook's book, Seashore Animals of the Pacific Cost (1927), p. 400:
The males are frequently seen to brandish the large claw in a peculiar way. First, they reach out with it as far as it will go, then they bring it toward the body with a sudden movement. This motion which has probably suggested the name “fiddler” crab is carried on during the breeding season and is persecuted more vigorously when a female crab is nearby.Similar confusing claims are made by Boyce (1924), while Boone (1927) returns to the resemblance of the large claw (without associated motion) (see quotes under “Calling Crab” below).
When you draw near the beach where these crabs are abundant, no matter how cautiously you have approached, there is a hurried rush of myraids of these crabs, each scuttling away as fast as four pairs of legs will carry it, to a a place of safety. At such a time the appropriateness of the common name is seen. In every direction are the fiddlers, each playing its small claw across the enormous fellow in the most amusing manner. No matter how often seen, one cannot help thinking of the musician—usually bald-headed—away down to the left of the orchestra, who so vigorously saws the bass notes from the viol. Let the latter scamper away, viol and all, as rapidly as does the crab, and the simile would be complete.
These three species are commonly known as “fiddlers”; for, when running over the beach with the large claw held out in front of them and the small one sawing in front of it, they ludicrously resemble a man carrying a bass viol.
At this time it is seen to be pierced with innumerable little holes; and hundres of a tiny Calling-crab (Gelasimus vocans) are running over its surface, the males of which hold up their enormous claws in front, as if in defiance. At the approach of an intruder, every one hastens into his burrow, and in a moment the muddy bank, that was alive with the moving atoms, is perfectly still…The little Crabs are very swift and wary, so that it is difficult to capture them, except by making a sudden rush from a distance among them.or Tennent (1861) in Sri Lanka (p. 477-478):
...the nimble little Calling Crabs scamper over moist sands, carrying aloft the enormous hand (sometimes larger than the rest of the body), which is their peculiar characteristic, and which, from its beckoning gesture has suggested their popular name.or Paulmier (1905) in New York (p. 148):
The old specific name vocans was given them because, when the tide was out, they appeared to stand on the beach and wave their great claws, calling it back again.
The enlarged chela is constantly being waived in the air as if beckoning or calling, and this has suggested the term Calling Crab. The alternate name, Fiddler Crab, is less appropriate, for the movement is really not suggestive of the action of a violinist drawing the bow across the strings.
The odd aspect of this group of crabs, resulting from the strikingly disproportionate size attained by one of the claws in the male and the curious manner in which the little creatures handle the claw, has been a source of comment among the peoples of many lands, which has found expression in a series of quaint common names. Among English-speaking folk, it is known as the “calling crab” because it seems to be forever beckoning with its huge claws. Another name, and the one by the way, most widely used among the coasts of the southern United States is “fiddler” crab, from the fancied resemblance of the great claw to this musical instrument.
The Japanese have woven a legend around the species of Uca common in Japan, and give it the name Siho maneki, which means “beckoning for the return of the tide.”Ricketts & Calvin copy this in their book Between Pacific Tides (probably in the original 1939 edition, but definitely by the revised edition of 1948). For example, in the fifth edition (1985), on p. 356:
The Japanese call the fiddler crab siho maneki, which translates as “beckoning for the return of the tide.” It is too picturesque a name to quibble over, but one might reasonably ask why Mahomet does not go to the mountain, for the presumably free-willed fiddler digs its burrow as far away from the tide as it can get without abandoning the sea entirely.
To the Peruvians these crabs are known as “maestro-sastre,” (master-tailor). Long before the coming of Columbus to the New World, these little crabs were woven in the folk-lore of the Indians who dwelt along the coast.
Locally the Gelasimi are known as “dhobi crabs,” doubtless from the resemblance of their beckoning movement to the manner in which the native washerman swings the clothes over his head in the act of pounding them against a flat stone.