Deep-Sea Fish Has Hair—Oh Wait, Those Are Giant Parasites

Behold, the latest in deep-sea fashion: An unfortunate fish sporting parasitic copepods as pigtails. Though the parasites’ presence might trigger your gag reflex, they’re actually a sign that the underwater ecosystem is functioning just the way it should. A Schmidt Ocean Institute release noted that parasites keep the ecosystem population in check, regulate the food web, and increase the ocean’s biodiversity. With so little known about this isolated part of the deep sea, every slimy copepod and wriggly fish becomes a clue into how biodiversity changes across underwater borders. The parasites topping this fish are more than a hair-do—they’re an indicator of a thriving ecosystem, shaped by the unique conditions of the deep sea.