Euryleptid? A  
Photos 1-2: David Rolla, Pupukea, O`ahu. (3-4 mm / about 3/20ths of an inch)
Photo 3: David Prutow, Kawaihae, Hawai'i (4-5 mm)

In July 2014 David Rolla found this tiny worm at Pupukea, O`ahu. It was crawling on a cave wall at a depth of about 30 ft.

David writes "It was so small (est. 3-4 mm) that I could not make out any details with the naked eye…I just saw the tiny white body moving slowly. Thank goodness for macro lenses!"

The worm is white and covered with small, evenly distributed, faint gray blotches. About 8-10 irregular black spots are spaced more or less evenly along the margin. There is a narrow yellow rim. The two marginal tentacles are yellow with blackish bases. It is not clear, however, whether these are true tentacles (typical of family Euryleptidae) or pseudotentacles (family Pseudocerotidae). I am guessing the former, but the genus and family remain undetermined, and the worm could be something else entirely.

I looked through all my sources, online and off, and was unable to find a match for this worm. Being so small, it could be the juvenile form of a known species that has a different appearance when mature. Or it could be new.

August 2016: David writes: "I believe I found the same animal again ... about 50’ away from where the first one was located. It was about the same size (3-4mm), but moving fast enough that I was only able to get one decent shot before it disappeared into a puka." (see photo 2)

October 2021: David Prutow photographed another of these worms at Kawaihae, Hawai'i, on a rocky wall (photo 3). The tentacles in his photo appear to be true tentacles rather than pseudotentacles, supporting our provisional placement of the worm in the family Euryleptidae. Thanks, Dave!

BACK to spots or blotches

David Rolla