Anomura
Guides
Clibanarius
Clibanarius is a genus of hermit crabs in the family Diogenidae, comprising approximately 60 valid species as of 2025. Members possess soft, asymmetrical abdomens protected within scavenged gastropod shells. While predominantly marine, the genus includes C. fonticola, the only known hermit crab species to complete its entire life cycle in freshwater. The genus exhibits broad geographic distributions, with feeding rates documented to vary with temperature.
Euceramus
Euceramus is a genus of porcelain crabs (family Porcellanidae) described by Stimpson in 1860. At least one species, E. transversilineatus, has been documented as a commensal endosymbiont living within the mantle lobe of marine gastropods, specifically the Pacific crown conch Melongena patula in the Gulf of California. The genus belongs to the diverse anomuran crab radiation, characterized by a compressed body form adapted for inhabiting tight spaces.
Munididae
Munidid Squat Lobsters
Munididae is a family of squat lobsters (Decapoda: Anomura) taxonomically separated from Galatheidae in 2010. Members are predominantly deep-water taxa distinguished by a trispinose frontal edge to the carapace, a central rostrum, and two spines extending forward from above the eyes. The family exhibits substantial cryptic diversity, with species often distinguishable only by subtle morphological differences in telson shape and pereopod dactyli. Reproductive strategies vary, with Munididae typically producing numerous small eggs compared to related families.
Pachycheles
porcelain crabs
Pachycheles is a genus of porcelain crabs (family Porcellanidae) comprising more than 40 described species. These anomuran decapods are distributed across tropical and temperate marine regions, with origins in the Indo-Pacific and subsequent spread to the Americas. The genus is characterized by fragmented lateral carapace walls and exhibits considerable morphological diversity. Several species are subject to parasitism by rhizocephalan barnacles and bopyrid isopods, which can significantly affect host growth and reproduction.
Pagurus grainosinanus
Pagurus grainosinanus is a species of hermit crab in the family Paguridae. The species is documented within the genus Pagurus, a large and widespread group of marine hermit crabs characterized by asymmetrical abdomens adapted to occupy empty gastropod shells. Specific ecological and morphological details for this species remain poorly documented in available literature.
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.
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Polyonyx is a genus of porcelain crabs (family Porcellanidae) comprising at least 42 described species. Most species are obligate commensals of chaetopterid polychaete worms, living inside the tubes of their hosts. The genus exhibits a transversally cylindrical body form adapted for lateral movement within worm tubes. Several species frequently cohabit host tubes with other symbionts, including larger porcellanids, pinnotherid crabs, and nudibranchs.