Spotted Porcelain Crab

Porcellana sayana (Leach, 1820)

Porcellana sayana.—Coêlho and Ramos, 1972:175.—Werding, 1977:174, 176, 212, fig. 29.

MATERIAL EXAMINED.—PANAMA, Atlantic, Limón Bay, Fort Sherman, Devil's Beach (sta 127-1), 1 cheliped.

DISTRIBUTION.—Cape Hatteras, North Carolina to near the Brazialian-Uruguayan border; littoral to 92 m, and doubtfully to 713 m off Puerto Rico (Haig, 1956, 1966; Williams, 1965).

Discussion

The porcellanid crab fauna in the West Indian and Eastern Pacific faunal regions is becoming increasingly well known. Prior to this report, 35 species in 11 genera were recognized in the West Indian region, an area extending from about Cape Hatteras, North Carolina, to the northern coast of South America. As was noted, Petrolisthes cessacii (A. Milne-Edwards, 1878), was erroneously thought to occur in the Caribbean Sea (e.g., Gore, 1974), but individuals previously assigned to that taxon belong instead to Petrolisthes marginatus Stimpson, 1859 (Manning, in litt.). The specimens previously attributed by many authors to P. marginatus are now recognized to constitute a new species. An additional eight species, most of which have been recently described, occur in several faunal provinces along the eastern coast of South America southward to Brazil (see, e.g., Rodrigues da Costa, 1968). With the exception of Pisidia brasiliensis Haig, 1968, which was reported from Caribbean Colombia by Werding (1978b), the remaining seven have not been collected to date in Caribbean or West Indian waters. The total number of species in the western Atlantic now stands at 44, including the as yet undescribed new species. In addition, I have seen material of what probably is yet another new species of Petrolisthes.

At present, 65 species in 13 genera have been recorded in the eastern Pacific within the Panamic Province, extending from the Gulf of California and outer Baja Peninsula southward to about Guayaquil, Ecuador. Here, too, one new species will be described (Haig, in litt.), so that 66 species are known within the Panamic Province. Of the 89 species in 15 genera found in the eastern Pacific region, five species in two genera are presently considered to be conspecific across the Middle American land mass, with another species based on a questionable record of a juvenile specimen of an otherwise Atlantic form allegedly occurring off Ecuador.

The porcellanid fauna is exceptionally rich in the waters adjacent to the Republic of Panama, undoubtedly reflecting intense collecting efforts. Prior to this report, 43 species in 12 genera were recorded from Panamanian Pacific waters, with another five species having ranges encompassing the Pacific coast of Panama from north to south (Gore and Abele, 1976). The present study has confirmed the presence of Megalobrachium festae in Panama, previously recorded from north and south of the country, and established Polyonyx confinis as a new member of the Panamanian component. Thus, 45 species are known to occur within the Pacific waters of the Republic of Panama.

Similarly, 21 species in eight genera have been collected from Caribbean Panama, and the present study added two species recently described from Colombia, Petrolisthes magdalenensis and P. rosariensis, as well as confirming P. marginatus, previously misidentified as P. cessacii. These totals include four of the five known species presently considered conspecific across the isthmus. The only trans-Panamanian conspecific not yet recorded from that country is Petrolisthes tonsorius, an eastern Pacific species with representatives found in Colombian waters (Werding, 1977). Thus, the 24 species now recorded from Caribbean Panama, plus the 45 species from Pacific Panama (including the conspecifics), bring the total porcellanid crab fauna to 64 species in 12 genera for this country. Regrettably, collecting efforts for other central American countries are not so complete, so little can be said at this time in regard to comparison of Pacific and Atlantic faunas.

Two Panamic species, Pachycheles trichotus and Petrolisthes artifrons, were of particular interest. The former is an extremely rare form previously known from four specimens, and the latter (although known from a large type series) had not been recollected since its original description by Haig in 1960. These two forms reaffirm the fact that, although our knowledge of the Middle American porcellanids is extensive (see, e.g., Carvacho, 1980), it remains incomplete. It should also be pointed out that several genera known to occur along the Pacific coast were not represented in the collections reported herein. These included Euceramus, Minyocerus, and Orthochela, all cryptic, burrowing, or commensal forms that could be easily overlooked during the sampling periods. And though the porcellanid fauna from Pacific Mexican waters is reasonably well known (van der Heiden and Hendrickx, 1979; Carvacho, 1980), that of the Atlantic side is not. Nor are the faunas of other Central American areas. Collections are especially needed along the Pacific coasts of El Salvador, Honduras, Nicaragua and, Costa Rica, and in the Atlantic from the Yucatan Peninsula southward to the northern coast of Colombia. The numerous offshore islands and the extensive barrier reef system off Honduras may well harbor many new and interesting species. Much of the aforementioned area is extremely rugged terrain, sparsely populated and with difficult access. But as civilization continues to encroach on these regions, further collections may yet be facilitated, particularly (it is hoped) before total development and concomitant habitat destruction occurs.

Porcellana sayana is a species of porcelain crab that lives in the western Atlantic Ocean, often as a commensal of hermit crabs. It is red with white spots, and has a characteristic bulge behind each claw.

Shallow to deep-waters (e.g. 10-190 m)

Hard bottom (rock and rubbles)