Calcinus Dana, 1851

Poupin, Joseph & Bouchard, Jean Marie, 2006, The eastern Pacific species of the genus Calcinus Dana, 1851, with description of a new species from Clipperton Island (Decapoda, Anomura, Diogenidae), Zoosystema 28 (2), pp. 465-486 : 467-474

Genus Calcinus Dana, 1851

Calcinus californiensis Bouvier, 1898 ( Fig. 1 )

Calcinus californiensis Bouvier, 1898: 380 [type locality: San Jose I., Gulf of California]. — Glassell 1937: 252. —? Haig et al. 1970: 16 (see Remarks). — Ball & Haig 1974: 101 (?part, see Remarks). — Moran 1984: 74, fig. 6. — Villalobos Hiriart et al. 1989: 28. — Snyder- Conn 1980: 278. — Hernández Aguilera et al. 1986: 192. — Rodríguez de la Cruz 1987: 89. — Kerstitch 1989: 88, photograph 220. — Alvarez del Castillo et al. 1992: 5. — Hernández Aguilera & Martínez Guzmán 1992: 4, table 1. — Hendrickx 1993a: 7; 1993b: 282, 309; 1995: 550; 1996: 614. — Correa-Sandoval & Rodríguez-Cortés 1998: 1138, 1143. — García-Madrigal del Socorro 1999: 924, table 1. — Hendrickx & Harvey 1999: 368. — Boschi 2000: 71. —? Hernández Aguilera 2002: 312, table 1 (see Remarks). — Rodríguez Almaraz et al. 2002: 258.

TYPE MATERIAL. — Gulf of California. San José I., coll. L. Diguet, 5.VII.1898, 1 syntype ♂ 5.8 mm ; 1 syntype ♀ 2.2 mm (MNHN-Pg 632).

OTHER MATERIAL EXAMINED (see Remarks for meaning of asterisks). — Gulf of California. Espíritu Santo I., trawl, 15-25 m, coll. L. Diguet, 1.VIII.1897, 1 ♂ 6.0 mm ; 2 ♀♀ 4.2-4.7 mm (MNHN-Pg 633, labelled as “ type ” but not in Bouvier 1898). — Point Lobos , coll. & don. E. F. Ricketts, 20.III.1940, 3 ♂♂ 2.3-6.6 mm ; 2 ♀♀ 3.4-4.0 mm ( USNM 81950 ). — Pulmo Reef , coll. & don. E. F. Ricketts, 19.III.1940, 3 ♂♂ 1.7-3.0 mm ; 1 ♀ 2.9 mm ( USNM 81948 ) ; 2 ♂♂ 2.4-2.8 mm; 2 ♀♀ 2.2- 2.3 mm ( USNM 1076349 ). — San Josef, L. C. Gulf, coll. Albatross, 31.III.1911, 2 ♂♂ 4.6-4.7 mm ; 1 ovig. ♀ 2.1 mm; 1 ♀ 2.3 mm ( USNM 1076375 ). — “ Basse Californie ”, 2 ♂♂ 6.3-6.5 mm ; 2 ovig. ♀♀ 4.2-4.8 mm; 1 ♀ 5.9 mm (*MNHN-Pg 636).

Mexico. Sinaloa, Maztlán, Ola Atlas Bay , N of Derecke Point, 1 ovig. ♀ 4.2 mm ( USNM 1076386 ) ; Nayarit, Isabel I., shore, coll. S. A. Glassell, 2.VII.1938, 1 ♂ 5.3 mm ( USNM), 19.III.1933, 2 ♂♂ 2.3-3.6 mm ; 3 ovig. ♀♀ 2.0- 2.8 mm; 1 juvenile (* USNM 1076364 ). — Acapulco, Roqueta I., Jean-Louis Étienne Expedition, coll. J. Poupin, snorkeling 1-10 m, 8.III.2005, 5 ♂♂ 2.0-5.0 mm ; 3 ovig. ♀♀ 2.6-2.8 mm; 2 ♀♀ 2.0-3.0 mm (MNHN-Pg 7616). — Unknown locality, coll. “ Mexico, Sec. agricultura 1926”, det. W. L. Schmitt, 2 ♂♂ 6.1-7.8 mm (* USNM 62385 ) ; 1 ♂ 3.6 mm (* USNM 62415 ) ; 1 ♂ 4.0 mm; 2 ♀♀ 2.3-3.4 mm (* USNM 62436 ) .

DISTRIBUTION. — Gulf of California, mainland Mexico from Puerto Peñasco, Sonora (31°20’N) to Huatulco Bay, Oaxaca, and El Salvador (about 13°30’N). Insular records from Revillagigedo (Socorro I.) and tip of Baja California Sur, could be C. mclaughlinae n. sp. (see Remarks under that species).

HABITAT. — Lower intertidal, sometimes found in large aggregations ( Glassell 1937; Kerstitch 1989), and shallow water to 15-25 m, often on Pocillopora coral.

DIAGNOSIS

Ocular acicle terminating in two to five spines, or rarely one. Anterodorsal plate of branchiostegite smooth, at most with one to two spinules subproximally.Upper margin of right chela smooth ( Fig. 1D ). Outer face of left chela regularly convex ( Fig. 1C ). Dactyls of P2-P3 with similar setation consisting of sparse, widely-spaced tufts of setae ( Fig. 1E ). Propodus of P3 with dorsolateral margin weakly angled; upper half of outer face slightly concave, forming faint sulcus. Dactyl of P3 0.6-0.7 times length of propodus, with six to eight small spines on ventral margin.Telson with posterior lobes each with single terminal spine.

Coloration ( Fig. 1 )

In life, shield black with red orange margins, turning quickly to orange after few days in preservative. Ocular acicles with orange hue at bases. Ocular peduncles dark brown to black, with narrow white band close to corneas. Antennular peduncles and flagella orange. Antennal peduncles, flagella, and antennal acicles bright red, with white-tipped spines. Chelipeds black on meri, carpi, palm of chelae, margins bright red. Dactyl of left cheliped black on inner and outer faces, margins bright red; dactyl of right cheliped uniformly bright red; tip and cutting edges of fingers white. Ambulatory legs uniformly bright red; claws of dactyls black. Abdomen cream to white.

REMARKS

Calcinus californiensis is morphologically close to C. mclaughlinae n. sp. and, although this still must be proved by examination of living coloration,specimens of C. californiensis from west coast of Baja California ( Haig et al. 1970; Ball & Haig 1974) and Socorro I. ( Hernández Aguilera 2002) could belong in fact to C. mclaughlinae n. sp. Differences between the two are discussed under the latter species. The former is also morphologically close to C. explorator Boone, 1930 but the two can be easily separated by differences in coloration ( Figs 1 ; 3 ). In C. californiensis , the distal white ring on the ocular peduncle is larger than in C. explorator ; the chelipeds are black with bright red margins; the P2 and P3 are red. In C. explorator , the chelipeds are totally black, including the margins; the P2 and P3 meri, carpi, propodi are black; the dactyls are orange with a large black median ring, and a narrow black proximal ring. In the absence of coloration, the two species can usually be separated by the armature of the ocular acicles, with several spines in C. californiensis , whereas there is one in C. explorator ; the P3 propodus with an upper margin less angled and the upper half of the outer face less concave in C. explorator . However, because of intraspecific variations, identification of preserved museum specimens based exclusively on morphology is not always possible. For this reason, a few specimens (marked with an asterisk under Other material examined) are herein only tentatively attributed to C. californiensis .

Calcinus chilensis (H. Milne Edwards, 1836) ( Fig. 2 )

Pagurus chilensis H. Milne Edwards, 1836: 279 [type locality: “ Côte du Chili ”]; 1837: 230, pl. 22, figs 9, 10. — Nicolet 1849: 191.

Calcinus chilensis – Stimpson 1858: 234. — Rathbun 1910: 597. — Porter 1935: 136. — Haig 1955: 15.

TYPE MATERIAL. — Chile. 1 syntype ♂ 5.2 mm, in poor condition (missing left P3) (MNHN-Pg 635).

OTHER MATERIAL EXAMINED (see Remarks). — Peru. Callao, 2 ♂♂ 7.5-7.6 mm ( USNM 1024522).

DISTRIBUTION. — Chile (unknown locality),? Peru.

HABITAT. — Not known, probably intertidal.

DIAGNOSIS

Ocular acicle terminating in spine. Anterodorsal plate of branchiostegite smooth, with one or two spinules subproximally. Upper margin of right chela smooth. Outer face of left chela excavated on lower half, convex on upper half ( Fig. 2B ). Left P3 unknown. Ventrodistal pilosity of right P2 and P3 similar, sparse ( Fig. 2D ). Propodus of right P3 with upper margin and upper half of outer face rounded; dactyl 0.75 times length of propodus, with eight spines on ventral margin. Telson with posterior lobes each with single terminal spine.

Coloration

In life, unknown. The coloration illustrated by H. Milne Edwards (1837: pl. 22, fig. 9), herein reproduced ( Fig. 2A ), is probably based on a preserved specimen.

REMARKS

Calcinus chilensis is known only by the incomplete, poorly preserved type specimen (MNHN-Pg 635), for which the exact locality where it was collected is unknown. Haig (1955) was the last to mention this taxon for the Chilean fauna, and suggested that type locality, “ Chile ”, is possibly a labeling error. The taxon has not been listed in more recent reports of Chilean fauna ( Retamal 1981; Retamal & Jara 2002).

Calcinus chilensis can be distinguished from all other eastern Pacific species by the shape of the left chela, which is elongated and excavated on the lower half of the outer face ( Fig. 2B ). Unfortunately, with only one specimen, it is impossible to evaluate the variability, if any, of this character. In other morphological characters, C. chilensis is similar to C. explorator . These two could possibly be conspecific, but without live coloration data this is impossible to determine.

Two discoloured specimens from Peru are herein tentatively attributed to C. chilensis because of the similar left chela (see Fig. 2E ), the presence of only one spine on the ocular acicle, and collection locality (Callao, 12°S). A number of sibling species have been recognized in Calcinus recently, raising the possibility of the existence of new color variants along the eastern Pacific, especially in latitudes ranging from 10° to 25°S where scarce collections or observations have been made ( Fig. 7 ). Such is needed to make comparisons of any new variants with C. chilensis .

Calcinus explorator Boone, 1930 ( Fig. 3 )

Calcinus explorator Boone, 1930: 28 , pl. 3 [type locality: Española I. (= Hood I.), Galápagos]; 1932: 21, fig. 6. — Chace 1962: 624, figs 3, 4. — Haez et al. 1966: 29. — Snyder-Conn 1980: 278 (part, see Distribution). — Holthuis 1982: 320. — Hernández Aguilera et al. 1986: 192, 206. — Hendrickx 1992: 10; 1993b: 282, 309; 1995: 500. — Hernández Aguilera & Martínez Guzmán 1992: 4, table 1. — Correa-Sandoval & Rodríguez-Cortés 1998: 1138, 1143. — García-Madrigal del Socorro 1999: 924. — Hendrickx & Harvey 1999: 368. — Boschi 2000: 71. — Hickman & Zimmerman 2000: 58, photographs. — Hernández Aguilera 2002: 312, tab. 1. — Rodríguez Almaraz et al. 2002: 258.

Calcinus obscurus – Schmitt 1924: 170; 1939: 11, 25, 26. Non C. obscurus Stimpson, 1859 .

TYPE MATERIAL (not seen, see Remarks). — Galápagos. Española I. (= Hood I.), Gardner Bay, stn 54, 1925 Arcturus Oceanographic Expedition , coll. W. Beebe, diving 4.5 m, possible holotype 1 ♂ ( AMNH 12244), possible paratypes 8 specimens ( AMNH 12245).

Others AMNH lots labeled as paratypes are: Galápagos. Eden I., 4 specimens ( AMNH 12582), Genevosa I. (= Tower I.), 15 specimens ( AMNH 6312). — Cocos I. 1 specimen ( AMNH 6309), 2 specimens ( AMNH 6313), 8 specimens ( AMNH 12577).

MATERIAL EXAMINED (see Remarks for meaning of asterisks). — Galápagos. Santiago I. (= James I.), 1975, coll. H. Kühl, poor condition, 2 ♂♂ 3.0- 4.5 mm ; 3 ♀♀ 2.3-4.0 mm; 2 juveniles 2.0- 2.2 mm ( RMNH 31343 ). — Santa Fe I. (= Barrington I.), 10.I.1972, M. L. Azzaroli leg., don. B. Lanza, 3 ♂♂ 4.0-6.0 mm ( RMNH 31948 ). — Isabela I., Elizabeth Bay, 26.VII.1938, coll. W. L. Schmitt, 1 ♂ 2.3 mm ; 4 juveniles in shells

( USNM 77820). — Santa Cruz I., coll. Galápagos New York Expedition 1923, 2 ♂♂ 3.9-4.9 mm; 1 ♀ 4.4 mm ( USNM 57722 ). — Isabela I., Tagus Cove, 29.X.1961, coll. J. Joseph and E. Forsbergh, Swansong cruise Inter- AmericanTropical Fish Commission, 2 ♂♂ 4.9-5.0 mm ; 1 ♀ 2.2 mm; 8 specimens in shells ( USNM 1076311 ) ; 17.II.1933, 1 ♂ 3.8 mm (* USNM 1076330 ), 26.I.1933, 1 ♂ 1.6 mm (* USNM 1076328 ) ; 24.I.1933, 8 ♂♂ 3.0- 6.0 mm; 6 ovig. ♀♀ 3.0- 5.3 mm; 3 ♀♀ 2.6-4.6 mm; 6 juveniles (* USNM 1076325 ) ; 8.II.1933, 1 ♂ 2.0 mm; 1 juvenile (* USNM 1076329 ) ; 14.II.1933, 1 juvenile (* USNM 1076331 ). — Marchena I., 2.XII.1934, coll. W. L. Schmitt, poor condition, 5 ♂ 2.3-5.0 mm ; 14 ovig. ♀♀ 2.6-4.0 mm; 3 ♀♀ 3.0-4.0 mm; 3 juveniles ( USNM 1076327 ). — Santiago I. (= James I.), Sullivan Bay, stn 15, 24.VII.1938, coll. W. L. Schmitt, 1 ♂ 2.6 mm ( USNM 77830 ). — Fernandina I., coll. W. L. Schmitt, 25.VII.1938, 1 specimen in shell ( USNM 77824 ) ; 1 ♂ 4.6 mm ( USNM 1076324 ).— San Cristóbal (= Chathman I.), coll. W. H. Jones, VIII.1884, 1 ♂ 8.6 mm ( USNM 9332 ). — Pinzon I. (= Duncan I.), 13.IV.1888, coll. Albatross, 3 ♂♂ 4.2-6.5 mm ( USNM 1076326 ). — Santa Maria I. (= Charles I.), 6.XII.1934, coll. W. L. Schmitt, 1 ♀ 1.9 mm ; 1 juvenile (* USNM 1076332 ). — “Galápagos”, 4 ♂♂ 5.1-6.1 mm ( USNM 33504 ) Clipperton I. Side reef flat at low tide, depth 0-0.3 m (1 ft), 13.IX.1958, coll. C. Limbaugh, T. Chess, A. Hambly, 1♂ 2.8 mm ( USNM 110971 ) ; rocky intertidal, 7-26.VIII.1958, coll. E. S. Reese, 85 ♂♂ 1.7-6.8 mm; 56 ovig. ♀♀ 2.3-5.0 mm; 42 ♀♀ 1.6-3.5 mm ( USNM 110990 ) ; coll. Service de Santé des Armées , 4 ♂♂ 6.0- 7.6 mm (MNHN-Pg 564) ; 1966, coll. Le Chuiton, 1 ♂ 6.9 mm (MNHN-Pg 651); leg. Chace, Smithsonian, 10 specimens (MNHN-Pg 653).

Jean-Louis Étienne Expedition to Clipperton 2004- 2005, outer reef at low tide, I-II.2005, coll. J. Poupin, J. M. Bouchard, L. Albenga, 19 ♂♂ 1.9-8.5 mm ; 4 ovig. ♀♀ 2.3-3.0 mm; 1 ♀ 2.2 mm; 1 juvenile 1.1 mm; 22 specimens in shells (MNHN-Pg 7617). — Outer reef, low tide, stn 4, 10°18.11’N, 109°14’W, coll. L. Albenga, J. M. Bouchard, L. Dugrais, 9.I.2005, 3 specimens in shells (MNHN-Pg 7618). — Outer reef, low tide, stn 33, 10°18.27’N, 109°14’W, coll. L. Albenga, L. Dugrais, 25.I.2005, 5 ♂♂ 2.2-7.5 mm ; 1 ♀ 3.5 mm; 5 specimens in shells (MNHN-Pg 7619).

Clarión I. Stn 2, coll. A. W. Anthony, 3 ♂♂ 4.4-5.6 mm; 1 ♀ 5.3 mm (* USNM 42545 ). — Sulphur Bay, coll. W. L. Schmitt, stn 141-34, 1 ♂ 4.0 mm (* USNM 1076333 ) .

Socorro I. Braithwaite Bay, shore collecting at landing place, 20.VII.1938, coll. W. L. Schmitt, 3 specimens in shells ( USNM 78212 ). — Crayson Cove, intertidal zone, 7.III.1937, coll. W. Williams, “ M. S. Stranger ”, 5 ♂♂ 2.2-4.5 mm ( USNM 1076323 ). — Coll. Albatross, 8 ♂♂ 2.7-6.1 mm ; 2 ovig. ♀ 3.9-5.1 mm; 2 ♀♀ 2.8-3.4 mm ( USNM 33505 ) .

Mexico. Nayarit, Isabel I. shore, 2.VII.1938, coll. S. H. Glassell, “Isabel Is. Mex.”, 2 ♂♂ 4.0-6.0 mm ( USNM 1076312).

Cocos I. I.1902, coll. P. Biolley, 1 ♂ 5.8 mm (* USNM 33503).

DISTRIBUTION. — Revillagigedo (Socorro I., Clarión I.); Clipperton I.; Cocos I.; Galápagos (Española I., Fernandina I., Genovesa I., Isabela I., Marchena I., Santa Cruz I., Santa Maria I., Santa Fe I.); Gulf of California (Carmen I., Cabo Pulmo); Mexico (Tres Marías Is., Isabel I., Punta Mita, Chamela, Tenacatita). The species is also reported from Colombia by Snyder-Conn (1980: 278, undefined place) but it must have been confused here with C. obscurus .

HABITAT. — Collected at low tide in coral rubble; common in upper and median part of intertidal area, occasionally in lower part up to depth of few meters.

DIAGNOSIS

Ocular acicle terminating in one or rarely two spines, on one side only. Anterodorsal plate of branchiostegite smooth with one or two spinules subproximally. Upper margin of right chela smooth ( Fig. 3D ). Outer face of left chela regularly convex ( Fig. 3C ). Dactyls of P2 and P3 with similar setation consisting of sparse, widely-spaced tufts of setae ( Fig. 3E ). Propodus of P3 with dorsolateral margin rounded or weakly angled; upper half of outer face evenly convex or slightly depressed. Dactyl of P3 0.7-0.8 times length of propodus, with five to seven spines on ventral margin. Telson with posterior lobes each with single terminal spine.

Coloration ( Fig. 3 )

In life, shield black, paler on proximal half, fading quickly to orange after few days in preservative. Ocular acicles white on distal half, black at bases. Ocular peduncles black, with narrow white band close to corneas. Antennular peduncles black with distal half of terminal segments and flagella orange. Antennal peduncles black on first, to third segments, and orange on fourth and fifth segments, flagella, and antennal acicles. Chelipeds black on meri, carpi, and chelae, with white on cutting margins and tip of fingers ( Fig. 3D ). Ambulatory legs uniformly black on meri, carpi and propodi. Dactyls bright orange with large black median ring, and narrow black proximal ring (sometimes unclear); terminal claws black. Abdomen cream to white. Eggs red.

REMARKS

The type series of Calcinus explorator is defined by Boone (1932: 22) as: “The type, an adult male specimen and four additional specimens, one ovigerous”. This material was checked for us in AMNH collections by C. B. Boyko (pers. comm.). According to place of collection, one male ( AMNH 12244 ) labelled as “ Paratype ” must be the holotype. The paratypes are in AMNH 12245 but this lot includes eight specimens instead of four cited by Boone. Five others AMNH lots are labeled as “ Paratypes ”: Galápagos, Eden I., 6.IV.1923, 4 specimens ( AMNH 12582 ) ; Genovesa I. (= Tower I.), C. Hay leg., 15.IV.1930, 15 specimens ( AMNH 6312 ) ; Cocos I., J. Chapin leg., 17.IV.1930, 1 specimen ( AMNH 6309 ), 2 specimens ( AMNH 6313 ) ; 31.III-2.IV.1925, 8 specimens ( AMNH 12577 ). AMNH collection includes two additional uncataloged lots from the Vanderbilt Museum labeled as “ Pagurus explorator ”, probably those cited by Boone (1930: 28): Galápagos, Genovesa I. (= Tower I.), Darwin Bay, 13.III.1926 ; Española I. (= Hood I.), 5.II.1928.

The black coloration of Calcinus explorator is very similar to that of C. obscurus . Some authors have discussed their possible synonymy ( Chace 1962: 626; Hendrickx & Harvey 1999: 368). The two species, however, can be separated by the armature of the ocular acicles, one spine in C. explorator , and two to four spines in C. obscurus ; and by subtle colour differences. The chelae are totally black in C. explorator , whereas there are orange tints on the margins in C. obscurus ( Figs 3B ; 5A ); the dactyls of P2 and P3 are orange with a large median black ring and narrow proximal black ring in C. explorator , whereas this color pattern is variable in C. obscurus ( Fig. 6 ); the distal white band on the ocular peduncles is narrower in C. explorator than in C. obscurus . Calcinus explorator is also morphologically close to C. mclaughlinae n. sp. The two can be distinguished based on coloration ( Figs 3 ; 4 ), if still present on specimens. The specimens from Clarión I., Cocos I., and Galápagos, marked by an asterisk in Material examined, had lost coloration, and thus are

A

E assigned to C. explorator based on the morphological differences cited by Chace (1962: 628). The distal margin of palm of left chela is oblique and almost continuous with the upper margin of fixed finger in C. explorator , whereas the distal margin of the palm is nearly transverse and makes an angle with the upper margin of fixed finger in C. mclaughlinae n. sp. (see Chace 1962: figs 4, 6). The upper part of the outer surface of the propodus of P3 is less flattened and concave in C. explorator than in C. mclaughlinae n. sp. However, due to intraspecific variation these two characters are often difficult to use reliably.

Calcinus explorator has been frequently reported from eastern Pacific Oceanic Islands such as Revillagigedo, Clipperton, Cocos, and Galápagos. Snyder-Conn (1980: 278), based on J. Haig unpublished identifications (M. Hendrickx pers. comm.), listed other localities where C. explorator co-occurs with C. californiensis , such as Gulf of California (Cabo Pulmo), Mexican continental islands (Tres Maria Is., Isabel I.), and Mexican coast (Bay Tenacatita). The presence of C. explorator in the Gulf of California has been confirmed by Rodríguez Almaraz et al. 2002 (Carmen I.), and along the Mexican coast by Hernández Aguilera et al. 1986 (Tres Maria Is., Chamela Bay), and Hendrickx & Harvey 1999 (Punta Mita). Cooccurrence of Calcinus explorator and C. californiensis along the Mexican mainland is confirmed in this study. Both species were positively identified based on morphology and color, in material examined from Nayarit, Isabel I. (coll. Glassell, 2.VII.1938, USNM).

Figures

FIG. 1. — Calcinus californiensis Bouvier, 1898, Acapulco (MNHN-Pg 7616): A, live specimen in shell; B, dorsal aspect; C, left chela, outer face; D, right chela, outer face; E, left P2 and P3, outer face; A, ♂ 4.5 mm; B-E, recently preserved ♂ 5.0 mm. Scale bars: A, B, 5 mm; C-E, 2 mm.

FIG. 3. — Calcinus explorator Boone, 1930, Clipperton (MNHN-Pg 7617): A, live specimen in shell; B, dorsal aspect; C, left chela, outer face; D, right chela, outer face; E, left P2 and P3, outer face; A, ♂ 2.4 mm; B-E, recently preserved ♂ 8.5 mm. Scale bars: A, C-E, 2 mm; B, 5 mm.

FIG. 2.— Calcinus chilensis (H. Milne Edwards,1836),“Chile”,syntype ♂ 5.2 mm (MNHN-Pg 635):A, coloration (from H. Milne Edwards, 1837: 230, pl. 22, fig. 9); B, left chela, outer face; C, right chela, outer face; D, right P2 and P3 (on right and left, respectively), outer face; E, Calcinus?chilensis, Peru, Callao, ♂ 7.6 mm (USNM 1024522), left chela, outer face. Scale bars: A, 5 mm; B-E, 2 mm.

FIG. 7. — Geographic distribution of the eastern Pacific Calcinus species based on literature records, and material examined during this study. Shaded area represents “insular area” (see text);? indicates localities where specimens were identified without colour information.

FIG. 5. — Calcinus obscurus Stimpson, 1859: A, live specimen removed from shell, dorsal view (photograph D. L. Felder); B-E, coloration strongly altered by preservative; B, left chela, outer face; C, right chela, outer face; D, left P2 and P3; E, propodi and dactyls of P2 and P3, showing alternate color pattern on dactyls; A, Panama, ♀ approximately 6.8 mm (ULLZ 5940); B-D, El Salvador, ♂ 6.2 mm (RMNH 9399); E, ibidem, ♂ 6.5 mm. Scale bars: A, 5 mm; B-E, 2 mm.

FIG. 6. — A-D, Calcinus obscurus Stimpson, 1859, variation of color pattern on P3 dactyl (coloration adapted from photographs): A, ♂ 7.5 mm,La Libertad,El Salvador (USNM 96289);B, ♂ 4.5 mm,Máncora,Peru (RMNH 14833);C, ♂ 6.4 mm,Taboguilla I., Panama (USNM 267556); D, ♂ 4.9 mm, Máncora, Peru (RMNH 14833); E, Calcinus tibicen (Herbst, 1791), outer face of P3 propodus, arrow indicates sulcus,?♂ 7.0 mm, coll. Mus. Antilles 1978, Guadeloupe (MNHN). Scale bars: A-D, 1 mm; E, 2 mm.

FIG. 4. — Calcinus mclaughlinae n. sp., Clipperton: A, live specimen in shell; B, dorsal aspect; C, left chela, outer face; D, right chela, outer face; E, left P2 and P3, outer face; A, paratype, ovig. ♀ 2.0 mm (MNHN-Pg 7621); B-E, recently preserved holotype ♂ 4.4 mm (MNHN-Pg 7620). Scale bars: A, B, 5 mm; C-E, 2 mm.