Bdelloidea

Part of speech: noun

Definitions

1. A subclass of microscopic freshwater rotifers known for their asexual reproduction and ability to survive desiccation and other extreme conditions
2. Small aquatic invertebrates belonging to a group distinguished by reproducing without males and enduring harsh environments through dormancy
3. Tiny wheel animals characterized by their parthenogenetic life cycle and resilience to drying and environmental stressors in freshwater habitats

Etymology: Bdelloidea is a taxonomic name, coined in the 19th century from Greek "bdello," meaning "leech," and the suffix "-oidea," the standard zoological ending for a superfamily. The name was given to rotifers because their bodies have a leech-like, contracting and extending motion as they crawl, and the group was classed as a superfamily within the rotifers, a phylum of microscopic animals named for the wheel-like crown of cilia used for swimming and feeding. Rotifers themselves take their name from Latin "rota," "wheel." What makes the group remarkable is less its name than its biology. Bdelloid rotifers have reproduced without males for tens of millions of years, a supposed evolutionary dead end, and they survive desiccation by drying into a dormant state and reviving when water returns. Their name reflects an observation about movement, while the science that made them famous concerns how they persist without sex.

Synonyms: rotifer group, bdelloid rotifers