‘Infinitesimally small’ odds: A deep-sea fish that lights up in the dark washed up on Cape Cod

The fish can be found about a mile deep in the ocean.

A couple of environmental researchers were walking along Coast Guard Beach in Eastham when one spotted something unusual: a small, silver fish no longer than an index finger, according to a Facebook post from the Center for Coastal Studies. 

Tasia Blough, a researcher and environmental educator, picked up the dead fish and realized it was a myctophid, which has light organs and can be found as deep as 1,500 meters below the ocean’s surface.

Additional research helped Blough and her partner, Owen Nichols, the research director at the Center for Coastal Studies Marine Fisheries, determine that it’s likely a pearlside or silvery lightfish. The two used a UV light to examine the fish in the dark, illuminating lines of what look like beads of light. 


“[The fish] approach the surface at night, and are a known prey of cod and pollock — keep an eye out for these tiny little fish in the bellies of bigger fish or along the beaches!” the center wrote.

The odds of finding one on Cape Cod are “infinitesimally small,” according to the center, though there are records of them being found on beaches in Nahant and Provincetown in the early- to mid-19th century.