Isopods
Guides
Armadillidae
Tropical Pill Woodlice, Pill Bugs
Armadillidae is the largest family of terrestrial isopods (woodlice), comprising approximately 80 genera and 700 species. Members are characterized by their ability to enroll into a complete sphere (conglobation), a defensive behavior that distinguishes them from most other woodlice families. The family exhibits a strongly convex body form adapted for this rolling behavior, with antennae fully enclosed within the sphere when enrolled—a key difference from the superficially similar family Armadillidiidae. Armadillids occupy diverse habitats across tropical and subtropical regions worldwide, with some species adapted to arid environments and others to cave systems.
Crustacea
crustaceans
Crustacea is a major subphylum of arthropods encompassing approximately 67,000 described species, with estimates suggesting this represents only 1-10% of actual diversity. The group includes familiar aquatic forms such as crabs, lobsters, shrimp, krill, and barnacles, as well as terrestrial representatives like woodlice. Crustaceans are united by biramous (two-parted) limbs and characteristic larval development, often involving a nauplius stage. Current phylogenetic understanding places Crustacea as paraphyletic with respect to Hexapoda (insects and allies), with both groups now combined in the clade Pancrustacea. The subphylum exhibits extraordinary morphological diversity, ranging from the 100-micrometer Stygotantulus stocki to the Japanese spider crab with a 3.8-meter leg span.
Detonidae
woodlice
Detonidae is a family of terrestrial isopods (woodlice) in the order Isopoda, containing at least 3 genera and more than 30 described species. Members of this family are primarily coastal, inhabiting upper intertidal and supratidal zones of rocky shores. The genus Deto includes species with complex taxonomic histories and documented cases of cryptic diversity, such as Deto echinata in southern Africa.
Haplophthalmus
Haplophthalmus is a genus of small terrestrial isopods (woodlice) in the family Trichoniscidae. The genus contains 47 described species, with several showing restricted geographic ranges that have led to conservation concerns. Two species, H. abbreviatus and H. rhinoceros, are listed as vulnerable on the IUCN Red List due to their limited distributions in the Balkans.
Oniscidae
sow bugs, woodlice
Oniscidae is a family of terrestrial isopods (woodlice) within the suborder Oniscidea. The family includes the common woodlouse Oniscus asellus and at least six confirmed genera: Oniscus, Oroniscus, Phalloniscus, Rabdoniscus, Rodoniscus, and Sardoniscus. Members are detritivores that contribute to decomposition and nutrient cycling in terrestrial ecosystems. Some species exhibit behavioral sensitivity to environmental contaminants, suggesting potential use as bioindicators.
Porcellio
woodlice
Porcellio is a large genus of terrestrial isopods (woodlice) in the family Porcellionidae, containing approximately 191 described species with a near-cosmopolitan distribution. The genus includes the well-studied common rough woodlouse (Porcellio scaber), which has served as a model organism for research on behavioral ecology, personality traits in invertebrates, and physiological processes such as ecdysis. Most species were described by 1950, though new species continue to be discovered. Members of this genus cannot conglobate (roll into a ball), distinguishing them from pill bugs in related genera.