Download PDF as one large file - AToL Decapoda

410 Family Porcellanidae
Family Porcellanidae
Key to genera and species
[Based on Gore and Abele, 1976]
1. Carapace at least 1.5 times as long as broad; form elongate, "Hippa"-like; large
orbit-like concavity on hepatic margin, its outer angle marked by tooth
Euceramus praelongus
Carapace less than or nearly 1.5 times as long as broad; form not elongate, or
"Hippa"-like; no large orbit-like concavity on hepatic margin 2
2. (1) Basal segment of antennae short, not strongly produced forward to meet anterior
margin of carapace, movable segments with free access to orbit 3
Basal segment of antennae strongly produced forward and broadly in contact with
anterior margin of carapace, movable segments thus far removed from orbit 6
3. (2) Posterior portions of side walls of carapace lacking or consisting of one or more
small pieces, separated by membranous interspaces behind epibranchial regions ... 4
Posterior portions of side walls of carapace entire, without small pieces or
membranous areas behind epibranchial regions 5
4. (3) Side walls of carapace incomplete; portion posterior to epibranchial or
mesobranchial area occupied by membrane Neopisosoma angustifrons
Side walls of carapace consisting of one or more pieces separated by membranous
interspaces in epibranchial or mesobranchial area (front triangular or transverse in
dorsal view, never with projecting teeth; carapace more or less subquadrate;
chelipeds very robust and thick) Pachycheles
5. (3) Basal segment of antennule not laterally expanded; basal antennal segment neither
produced inward nor forming partial suborbital margin; front triangular, prominent;
carapace with distinct frontal, epibranchial and mesobranchial spinules; cheliped
with fingers distorted, gaping, deeply grooved along cutting edges, spooned and
truncate at tips; telson 7-plated Parapetrolisthes tortugensis
Basal antennular segment as above; basal antennal segment either not produced
inward or, if with distinct inward projection, forming only partial suborbital
margin; front triangular or trilobate, usually prominent; carapace without
mesobranchial spinules; cheliped fingers normal, not grooved along cutting edges
or spooned at tips; telson almost invariably 7-plated Petrolisthes
6. (2) Dactyli of walking legs ending in 2 or more large, strong, fixed spines; carapace
markedly broader than long, front nearly transverse in dorsal view
Polyonyx gibbesi
Dactyli of walking legs ending in single spines, usually with accessory movable
spinules on posterior margins 7