Article

Mini Creatures

By Joe Levit
From the October/November 2021 Issue

Steven Kovacs/Biosphoto/Minden Pictures (Lionfish, Moray Eel); Doug Perrine/NPL/Minden Pictures (Cusk Eel)

Actual size of larva: up to 5 millimeters

Left: Cusk Eel
This creature is a larva, or young form, of an eel-like fish called a cusk eel. Its frills are thought to ward off predators by resembling stingers.  

 

Top Right: Lionfish
When this larva grows up, don’t get too close! The sharp spines of an adult lionfish pack a painful sting.

 

Bottom Right: Moray Eel
This eel larva is transparent. Its body is made of a thin layer of muscle over a jelly-like pouch.

These creatures may look ghostly, but they’re actually young forms of fish, called larvae. In real life, they’re just a few millimeters long! Scientists often study these and other zooplankton, or tiny ocean animals, by catching them in nets. But a modern technology called blackwater photography gives a clearer picture of zooplankton in the wild. 

To capture these eye-catching images, photographers dive into the ocean at night. That’s when many zooplankton swim up to the top ocean layer to find food. During the day, they retreat to the darker layer below to escape predators (see “Daily Migration,” below). 

Blackwater photographers use cameras that can light up the dark and zoom in on small objects. The pictures reveal how zooplankton behave in their natural habitat, says Ai Nonaka, a researcher at the National Museum of Natural History. That makes the images important to scientists.

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