Final answer:
Hendrickson mayfly nymphs are known as Ephemerella subvaria. They represent the aquatic larvae stage of the Hendrickson Mayfly life cycle and are crucial in indicating the health of aquatic ecosystems.
Step-by-step explanation:
Hendrickson mayfly nymphs are called Ephemerella subvaria. This term refers to the aquatic larvae stage of the Hendrickson Mayfly, an insect species found primarily in North America. The Hendrickson Mayfly life cycle is divided into several stages, with the nymph stage being one of the most crucial periods. During this time, the nymphs live underwater and are a major food source for fish.
Their name, Ephemerella subvaria, is derived from the genus 'Ephemerella' and the species 'subvaria'. Notably, they prefer clean, fast-moving rivers or streams, and their presence often indicates a healthy aquatic ecosystem due to their inability to tolerate polluted waters.
The primary distinguishing characteristics of these nymphs include a robust, worm-like body, three tails, and feathery gills along the sides of their abdomen. Once they have matured, they come to the water surface, their skin splits open, and an adult mayfly emerges, leaving the nymph stage behind and entering the next stage of its life cycle - adulthood.
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