Metretopodidae

Definition

A family of cleft-footed minnow mayflies in the order Ephemeroptera, characterized by larvae with distinctive cleft tarsi adapted for clinging in fast-flowing streams. The family comprises at least three genera and more than 20 described species, with nymphs typically inhabiting cool, well-oxygenated running waters where they graze on periphyton.

Etymology

From Greek metretos (measurable) + pous, podos (foot), referring to the distinctive tarsal structure of the larvae.

Example

Metretopus and Siphloplecton are representative genera in Metretopodidae; their nymphs are collected by kick-sampling in riffle habitats and are indicators of high-quality lotic ecosystems.

Related Terms

• Ephemeroptera
• Baetidae
• Heptageniidae
• Siphlonuridae
• lotic
• periphyton
• kick sampling

Usage Notes

Specialists distinguish Metretopodidae nymphs from other heptagenioid mayflies by the deeply cleft fore tarsus with a single claw; adults have reduced mouthparts and do not feed. The family has a Holarctic distribution with greatest diversity in North America and northern Eurasia.