Pseudironidae

Definition

A monotypic family of mayflies (Ephemeroptera) commonly called crabwalker mayflies, distinguished by their unusual sprawling leg posture and benthic habitat in sandy riverbeds. The family contains the single genus Pseudiron with one described species, Pseudiron centralis.

Etymology

From Pseudiron, the type genus, with the family suffix -idae.

Example

Pseudiron centralis, the sole member of Pseudironidae, inhabits shifting sand substrates of large rivers in North America, where its crab-like walking posture allows it to remain anchored in currents that would dislodge typical streamlined mayfly nymphs.

Related Terms

• Ephemeroptera
• Pseudiron
• Pseudiron centralis
• Spheniscidae (mayfly family)
• Baetidae
• benthic macroinvertebrate
• lotic habitat

Usage Notes

The family is notable for its highly derived morphology among mayflies; specialists distinguish Pseudironidae from other Ephemeroptera families by the nymph's flattened body, raptorial forelegs, and posteriorly directed gills. The common name "crabwalker" refers to the lateral, sprawled leg position unique among mayfly nymphs.