Eastern-pacific
Guides
Loxorhynchus
masking crabs, moss crabs, sheep crabs
Loxorhynchus is a genus of spider crabs in the family Epialtidae, found in the eastern Pacific Ocean. The genus includes three described species: L. crispatus (masking crab or moss crab), L. grandis (sheep crab), and L. guinotae. Members of this genus are known for decorating behavior, in which they attach materials from their environment to their carapace.
Paralithodes rathbuni
spiny king crab, California king crab
Paralithodes rathbuni is a deep-sea king crab in the family Lithodidae, commonly known as the spiny king crab or California king crab. It inhabits the continental shelf and slope off the coast of California and Baja California at depths of 86–380 meters. The species is closely related to P. californiensis, with which it shares the common name "California king crab," and some authorities have suggested the two may be conspecific.
Petrolisthes armatus
Green Porcelain Crab
Petrolisthes armatus, commonly known as the green porcelain crab, is a small porcellanid crab native to the southwestern Atlantic, particularly Brazil. The species has established invasive populations along the southeastern United States coast, where densities can exceed 30,000 individuals per square meter. Genetic studies confirm it as a single monophyletic species with exceptional geographic range spanning the Atlantic and eastern Pacific. It is frequently parasitized by the bopyrid isopod Aporobopyrus curtatus, which causes parasitic castration.
invasive-speciesfilter-feederparasite-hostintertidalporcelain-craboyster-reefsymbiosisplanktonic-larvaevisual-ecologycrustaceandecapodanomuraporcellanidaesouthwestern-atlanticeastern-pacificsoutheastern-united-statesbopyrid-parasiteAporobopyrus-curtatusestuarinemangrovesponge-symbiosisgaze-stabilizationachromatic-visionlarval-transportoyster-bedballast-wateraquaculturemonophyleticcryptic-species-complexparasitic-castrationzoeamegalopapleopodspermatophorechellipedcarapacegranulatedolive-greenblue-colorationFarol-IslandBrazilGeorgiaSouth-CarolinaFloridaPanamaCosta-RicaEcuadorPeruBaja-CaliforniaCaribbeanGulf-of-MexicoWest-IndiesAscension-IslandBermudaBahamasWest-Africarock-rubblesoft-sedimentshallow-subtidallower-intertidaldensity-30000-per-square-meter6-8-mm0.5-gorange-spotfour-segmented-chelipedantennae-outside-eyesvestigial-fourth-leg-pairfeathery-mouthpartszooplanktonscavengerpheromone-settlement-cue3-mm-sexual-maturity17%-parasite-prevalencebranchial-chamber-parasitesynchronous-growth-parasite-hostcastrationvisual-noisecaustic-flickerpolarization-sensitivityoptomotor-assaytidal-creekspectrally-narrow-environmentmitochondrial-DNAgenetic-variabilityexceptional-rangepre-Canal-Panama18591930s-Floridalineagewarm-temperate-Atlanticspecies-complexhalf-crabsquat-lobster-relativetrue-crabfalse-crabDecapodaMalacostracaArthropodaCrustaceaGibbes-1850Porcellana-armatagreen-porcelain-crabPetrolisthes-armatusPetrolisthes eriomerus
flattop crab
Petrolisthes eriomerus, commonly called the flattop crab, is a small porcelain crab inhabiting the eastern Pacific coast of North America. It reaches 20 mm in carapace width and exhibits a distinctly flattened, rounded body form adapted for life under rocks and in crevices. The species employs filter feeding and deposit sweeping to consume diatoms and organic material. It displays notable social behavior, including aggregations and ritualized agonistic interactions between individuals.
Pleuroncodes
red crab, tuna crab, squat lobster, múnida
Pleuroncodes is a genus of anomuran crustaceans (squat lobsters) in the family Munididae, found in the eastern Pacific Ocean. Species occupy both pelagic and benthic habitats depending on life stage, with larvae and small individuals in pelagic waters and larger adults on the seafloor. The genus includes commercially and ecologically important species that form dense aggregations and serve as prey for large marine predators.
Pleuroncodes planipes
pelagic red crab, tuna crab, squat lobster, langostilla, benthic anomuran red crab
Pleuroncodes planipes is a pelagic and benthic anomuran red crab distributed across the eastern Pacific Ocean, from California to Panama. The species exhibits a complex life cycle with both pelagic and benthic phases: larvae and small individuals occupy open waters, while larger adults become exclusively benthic. It forms exceptionally dense aggregations on seamounts, with recorded densities up to 78 crabs/m² at depths of 355–385 m. The species tolerates hypoxic conditions (0.04 ml/l oxygen) and serves as a major prey item for large pelagic predators including yellowfin and skipjack tuna.