Bigclaw Snapping Shrimp

Alpheus heterochaelis Say

Alpheus heterochaelis Say, 1818:243.—Williams 1965b:66, fig. 54.

TYPE-LOCALITY.—Amelia Island, Nassau County, Florida.

DISTRIBUTION.—North Carolina to Surinam; sublittoral. The true range of this species is not yet well defined. It is common along the southeastern and Gulf coasts of the United States from North Carolina to Texas (including Key West, Florida), but I have seen only two lots from the West Indies—one from Cuba and one from Curaçao—that could be assigned to A. heterochaelis with confidence. The specimens recorded by Holthuis (1959) from Surinam undoubtedly belong to this species. There is some question, however, about those recorded by the same author (1956) from Cananeia, Estado de São Paulo, Brazil, because the males of that series do not have the dactyl of the minor first chela “balaeniceps”-shaped. At least some of the lots recorded by Rathbun (1900) from between Estado do Rio Grande do Norte and Estado de Alagoas, Brazil, are assignable to A. armillatus and A. nuttingi, and some of the material recorded by the same author (1901) from Puerto Rico is A. armillatus and A. viridari. The two specimens from Isla de Providencia listed by Schmitt (1939) belong to A. nuttingi.

*128. Alpheus intrinsecus Bate

Alpheus intrinsecus Bate, 1888:557, pl. 100: fig. 1.—Crosnier and Forest 1966:286, fig. 26.

MATERIAL.—Tobago (Sta. 6–59: 1 ).

HABITAT.—The single specimen was found on or in the interstices of coral rock covered with algae.

TYPE-LOCALITY.—Off Salvador, Estado da Bahia, Brazil.

DISTRIBUTION.—Puerto Rico to Estado de São Paulo, Brazil; eastern Atlantic from Senegal to Congo; to a depth of 30 meters.

*129. Alpheus malleator Dana

Alpheus malleator Dana, 1852:557.—Crosnier and Forest 1966:240, fig. 10.

MATERIAL.—Grenada (Sta. 8–56: 1 ).

HABITAT.—The single specimen was concealed in an intertidal conglomerate rock and coral ledge.

TYPE-LOCALITY.—Rio de Janeiro, Brazil?

DISTRIBUTION.—Puerto Rico to Estado de São Paulo, Brazil; eastern Atlantic from Senegal to Congo; eastern Pacific from the Gulf of California, Ecuador, and the Galapagos Islands; littoral and upper sublittoral.

*130. Alpheus normanni Kingsley

Alpheus normanni Kingsley, 1878a:93.—Williams 1965b: 65, fig. 53.

Crangon normanni.—Chace 1937:122.

MATERIAL.—Tortola (Sta. 117–56: 1 )-—Barbuda (Sta. 85–56: 1 ; Sta. 108–58: 1 ).—Saint Christopher (Sta. 103–56: 2 ovig. ).—Antigua Island (Sta. 74–56: 1 ; Sta. 109–59: 8 , 2 ovig. ; Sta. 112–59: 1 , 2 ovig.).—Dominica (Sta. 75–59: 1 juv.).—Carriacou Island (Sta. 17–56: 1 ovig. ).—Tobago (Sta. 4–59: 1 , 1 ovig. ; Sta. 8–59: 1 , 2 ovig. ; Sta. 31–59: 5 , 2 [1 ovig.]).—Isla de Cozumel (Sta. 100–60: 1 spec.).—Bahía de la Ascensión (Sta. 91–60: 1 ).

HABITAT.—This species was found most frequently on sand and mud flats covered with turtle-grass and Porites. Some specimens were taken on a mud bottom under rocks and oysters and some occurred in and among reef corals.

TYPE-LOCALITY.—Pacific coast of Panama.

DISTRIBUTION.—Virginia and Bermudas to Tobago and westward to the Yucatan Peninsula; eastern Pacific in the Gulf of California and at Panama; to a depth of 73 meters.

*131. Alpheus nuttingi (Schmitt)

Crangon nuttingi Schmitt, 1924c: 78, pl. 2: figs. 4–6.

MATERIAL.—Barbuda (Sta. 111–58: 2 )—Antigua Island (Sta. 110–59: 2 ).—Guadeloupe (Sta. 68–56: 1 ; Sta. 69–56: 17 10 [9 ovig.]).—Saint Lucia Island (Sta. 60–59: 1 , 1 ovig. ).—Tobago Cays (Sta. 21–56: 6 7 [6 ovig.]).

HABITAT.—Most of the specimens listed above were cracked from coral and coral rock, but a few were found on sandy mud flats studded with boulders or Porites.

TYPE-LOCALITY.—Pelican Island, Barbados.

DISTRIBUTION.—Florida Keys to Estado de Alagoas, Brazil, and westward to Isla de Providencia and Panama; sublittoral.

DISTRIBUTION.—Virtually pantropical; to a depth of 18 meters. In the western Atlantic, from the Bermudas and the northeastern Gulf of Mexico to Tobago.

*133. Alpheus peasei (Armstrong)

Alpheus (Dicnesia) candei.—Verrill 1922:68, fig. 56, pl. 19: figs. 3a–d, pl. 20: fig. 1, pl. 21: figs. 6, 6a, pl. 24: figs. 2–4, pl. 29: figs. 1a—t. [Not A. candei Guérin-Méneville, 1855.]

Crangon peasei Armstrong, 1940:1.

MATERIAL.—Anguilla (Sta. 55–58: 2 , 2 [1 ovig.]).—Barbuda (Sta. 112a–58: 4 , 2 ).—Saint Christopher (Sta. 103–56: 1 , 3 [2 ovig.]).—Antigua Island (Sta. 73–56: 2 , 3 ovig. ).—Dominica (Sta. 62–56: ly : Sta. 75–59: 1 , 2 ovig., 5 juv.).—Saint Lucia Island (Sta. 65–59: 1 , 1 ovig. ).—Tobago Cays (Sta. 23–56: 1 , 1 ovig.).—Tobago (Sta. 8–59: 5 [3 ovig.]).—Isla de Cozumel (Sta. 34–60: 1 ; Sta. 115–60: 2 , 3 ovig.).—Bahía de la Ascensión (Sta. 52–60: 1 , 1 ovig., 2 juv.; Sta. 67–60: 1 , 1 ; Sta. 85–60: 1 ovig. ; Sta. 95–60: 1 , 1 ovig. , 1 juv.).—Bahía del Espíritu Santo (Sta. 41–60: 1 spec).

HABITAT.—Most of the specimens listed above were found on, under, or in the interstices of rocks and dead coral from the intertidal zone to a depth of 7 meters. One pair was extracted from a sponge in 3 feet of water.

TYPE-LOCALITY.—Castle Harbour, Bermudas.

DISTRIBUTION.—Bermudas and Florida Keys to Tobago and westward to Isla de Providencia and the Yucatan Peninsula; littoral and sublittoral.

*134. Alpheus ridleyi Pocock

Alpheus Ridleyi Pocock, 1890:518.

Alpheus nigrospinatus Rankin, 1898:249, pl. 30: fig. 6.

Alpheus ridleyi.—Crosnier and Forest 1966:230, 232, 233, 236, 237.

MATERIAL.—Anguilla (Sta. 55–58: 1 ).—Antigua Island (Sta. 73–56: 1 , 3 [2 ovig.]).—Saint Lucia Island (Sta. 47–56: 1y ; Sta. 60–59: 1 ).—Tobago Cays (Sta. 22–56: 1 ).—Tobago (Sta. 8–59: 2 , 1 ovig. ).—Isla de Cozumel (Sta. 115–60: 1 )—Bahía de la Ascensión (Sta. 67–60: 1 juv.).

HABITAT.—This species seems to have been collected most frequently under boulders and pieces of coral on sandy beaches, but it was also found in coral rock at depths of 4 feet or more.

TYPE-LOCALITY.—Arquipélago de Fernando de Noronha, Brazil.

DISTRIBUTION.—Bahamas to Fernando de Noronha, Brazil, and westward to the Yucatan Peninsula; littoral and sublittoral.

MATERIAL.—Antigua Island (Sta. 110–59: 2 ovig. ).—Grenada (Sta. 8–56: 1 holotype, USNM 135361).—Tobago (Sta. 15–59: 4 , 3 [2 ovig.]; Sta. 26–59: 1 ).

In addition to the above, I have seen a small male that seems to belong to this species from Cape Florida, Key Biscayne, Florida; it was collected 22 August 1969 by Gary Hendrix.

DESCRIPTION.—Rostrum (Figures 21a, b) small, triangular, reaching little beyond margins of ocular hoods, marked dorsally by low carina extending posteriorly about as far as posterior margins of ocular hoods. Ocular hoods strongly produced anteriorly, unarmed, bounded mesially by shallow but distinct adrostral depressions and laterally by similarly distinct grooves. Anterolateral margin of carapace nearly vertical for short distance below ocular hood, slanting posteroventrally near lateral midline of basal segment of antennal peduncle. Posterior margin of carapace with cardiac notch.

Pleura of 5 anterior abdominal somites broadly rounded. Sixth somite sharply acute ventral to insertion of uropod, bluntly acute dorsal to insertion. Telson (Figure 21c) nearly three-fourths as broad as long, posterior margin slightly more than half as wide as anterior margin; 2 pairs of rather stout dorsal spines, anterior pair inserted slightly anterior to midlength of telson, posterior pair slightly nearer to posterior margin than to anterior pair; posterior margin convex, armed with 2 pairs of stout lateral spines, mesial pair twice, or more than twice, as long as lateral pair, space between spines bearing double row of long setae.

Eyes entirely concealed by ocular hoods.

Antennular peduncle (Figure 21d) with stylocerite short, not nearly reaching distal margin of basal segment. Second segment subequal in length to first, about twice as long as third.

Antennal scale (Figure 21e) about three times as long as wide; outer margin strongly concave proximally, faintly convex distally, distal spine very stout, considerably wider than distal portion of blade, not reaching as far as end of antennular peduncle; blade narrowing abruptly with sinuous margin in distal half, falling far short of tip of spine. Antennal peduncle slightly overreaching antennular peduncle; basal segment with sharp slender lateral tooth below base of antennal scale.

Mouth parts as figured (Figures 21f–k). Mandible with 9 marginal teeth and vestige of tenth on incisor process. Third maxilliped overreaching antennal scale by two-thirds of terminal segment, exopod barely overreaching antepenultimate segment.

Major first pereiopod (Figure 21l) overreaching antennal scale by chela and carpus. Chela (Figure 21m) compressed, notched dorsally and ventrally, and grooved on both lateral surfaces. Movable finger opening and closing somewhat obliquely, rather strongly arched, truncately rounded distally, usually with distinct groove in distal part of each lateral surface; opposable margin with large, hooked, blunttipped tooth fitting into socket in fixed finger. Palm with well-defined depression on lateral surface spreading from dorsal notch to narrowly acute apex ventrally and continuing proximally as broad groove with subparallel margins disappearing proximal to oblique suture; depression bounded ventrally by rounded ridge delimited ventrally by longitudinal sinuous depression extending distally to near base of movable finger and obscurely joining similar depression on fixed finger; continuation of ventral notch sharply defined proximally, trending distally into depression on fixed finger. Mesial surface of palm with deep, sharply defined, elongate, triangular depression spreading from dorsal notch and bounded ventrally by strong, anteriorly acute boss accentuated by sinuous longitudinal depression extending proximally from articulation with movable finger nearly to midlength of chela; narrow oblique groove running ventrally and proximally from dorsal margin opposite articulation with finger and joining longitudinal depression at apex of boss; ventral notch continued on mesial surface as well-defined, obliquely U-shaped depression. Notches in dorsal and ventral margins distinct and slightly overhung proximally. Merus of major cheliped with flexor margins unarmed distally. Minor first cheliped (Figure 21n) overreaching antennal scale by chela and carpus. Movable finger rounded, usually slightly more than half as long as palm in males, often less than half as long as palm in females. Palm not noticeably compressed, without grooves or depressions, distal angle on mesial side of articulation with finger rounded, subrectangular. Merus with flexor margins unarmed distally. Second pereiopod (Figure 22a) overreaching antennal scale by chela, carpus, and most of merus. Movable finger considerably shorter than palm (Figure 22b). Carpus about three times as long as chela, subdivided into 5 articles decreasing in length as follows: 2, 1, 5, 4, 3. Merus slightly longer than 3 proximal articles of carpus and distinctly longer than ischium. Third pereiopod (Figure 22c) overreaching antennal scale by dactyl, propodus, and half of carpus; dactyl (Figure 22d) simple and unarmed, somewhat less than half as long as propodus; propodus with row of 6 strong spines on flexor margin and about 4 similar spines in adjacent discontinuous row. Carpus about as long as propodus; merus as long as carpus and fully half of propodus, slightly less than three times as long as wide, with small blunt tooth at distal end of flexor margin; ischium unarmed. Fourth pereiopod (Figures 22e, f) overreaching antennal scale by dactyl, propodus, and one-third of carpus, very similar to third pereiopod, but distal tooth on flexor margin of merus usually less distinct or absent. Fifth pereiopod (Figure 22g) much smaller than third and fourth, reaching only to midlength of antennal scale; dactyl (Figure 22h) not much more than one-third as long as propodus; propodus with spines on flexor margin clustered in distal third of length; carpus slightly longer than propodus; merus very slightly longer than carpus and without tooth at distal end of flexor margin.

Second pleopod of male (Figure 22i) with appendix masculina (Figure 22j) distinctly overreaching appendix interna. Uropod (Figure 21c) with lateral margin of lateral branch terminating in 2 widely separated teeth flanking long, uncolored movable spine; mesial branch of uropod with series of inconspicuous spines, in addition to setae, on distal margin.

Eggs numerous and small, measuring about 0.5 by 0.7 mm.

COLOR.—Color notes on the small male (carapace length 4.0 mm) from Key Biscayne, Florida, have been kindly contributed by the collector, Gary Hendrix: Carapace and abdomen mostly translucent and colorless. Carapace with band of bluish chromatophores on rostrum and anterior margin of carapace; hepatopancreas green; cluster of bluish chromatophores in dorsal midline near posterior margin of carapace. Abdomen with bluish-gray to greenish transverse bands (formed by numerous small blue chromatophores surrounding expanded and much sparser red chromatophores) near anterior margin of first somite and along posterior margins of 5 posterior somites; telson with 3 characteristic longitudinal stripes of grayish green. Antennules and antennal scale transparent. Antennal peduncle with scattered blue chromatophores. Major first pereiopod with chela marked by broad, brownish to chocolate-brown band covering most of extensor margin of palm and extending obliquely to distal half of flexor margin of propodus; chela white elsewhere; carpus and merus with few brown spots on white background. Minor first pereiopod with chela mostly brown, except for white proximal half of movable finger; carpus and merus as in major cheliped. Second pereiopods very conspicuously colored with bright blue. Three posterior pairs of pereiopods translucent and colorless. Lateral branch of uropod with subdistal, transverse, grayish-green band; mesial branch with similar oblique or nearly longitudinal band.

POSTURE.—Gary Hendrix noted that this species maintains a rather unusual posture about 90 percent of the time. The major first chela is directed upward at an angle of 45 degrees, the second pereiopods are held high and flexed in an arc, the third and fourth pereiopods are held together and angled forward in a partially flexed attitude, the fifth pereiopods are similarly flexed but lean posteriorly, and the abdomen is flexed under the thorax.

SIZE.—Males with carapace lengths, to base of rostrum, of 3.6–6.8 mm (holotype 6.0 mm); females, 5.2–7.0 mm; ovigerous females, 5.8–7.0 mm.

HABITAT.—In coral and conglomerate rock in the intertidal zone, sometimes exposed at low tide.

TYPE-LOCALITY.—Grand Anse Bay outside Saint Georges Harbour, Grenada, in partially exposed conglomerate rock and coral ledge along shore.

DISTRIBUTION.—Known only from the type-series from the Florida Keys, Antigua Island, Grenada, and Tobago.

Alpheus heterochaelis, the bigclaw snapping shrimp, is a snapper or pistol shrimp in the family Alpheidae. It is found in the western Atlantic Ocean and the Gulf of Mexico.

Shallow-waters (0-100 m)

Distribution of subprovince extends northward of the Carolinian subprovince of Cape Hatteras through Florida

Hard bottom (rock and rubbles)