This curious critter is a worm like no other: The pigbutt worm

Bobbing along in ocean currents a half mile below the surface is a worm like no other. Our team first spotted the unusual pigbutt worm (Chaetopterus pugaporcinus) in 2001 and had a tough time determining how to categorize such a curious critter. Working closely with our collaborators, DNA analysis eventually confirmed we had encountered a new species of bristle worm that drifts through the midwater instead of living on the seafloor. Over the last two decades, these worms have only been observed in Monterey Bay and a few near the Channel Islands off the southern California coast. This little worm is about the size of a hazelnut, and even using our high-resolution cameras, it took the eagle eyes of our expert biologists to spot these miniature orbs in the massive ocean. Our skilled submersible pilots were able to gently sample them and transport them back to the ship alive for detailed examination. Observing these animals up close in the lab also revealed more aspects about their natural history that we were unable to see in the wild. We learned that these incredible worms are bioluminescent, producing blue light in their body tissues as well as green glowing mucous secretions, an adaptation that may be used to deter predators. Chaetopterus pugaporcinus casts out a web of snot to capture bits of organic material called marine snow to eat. Mucus is a useful substance for snaring food in the deep sea where it may be sparse. Numerous other animals get their nutrition this way too. Animals of all shapes and sizes in the ocean perform an essential climate service by taking up excess carbon dioxide from the atmosphere and transporting it deep in the ocean. These assorted midwater mucous-feeders help repackage carbon to sink more rapidly to hungry seafloor communities. The pigbutt worm is just one of more than 200 new species described and named by our team and collaborators. We are working to catalog deep-sea animals and environments so we can predict how threats like climate change and mining will affect them. Learn more at our Animals of the Deep gallery: Script writers: Kyra Schlining, Raúl Nava Science advisor: Karen Osborn Editor: Ted Blanco Narrator: Kristine Walz Motion graphics: Madeline Go Production team: Heidi Cullen, Madeline Go, Larissa Lemon, Raúl Nava, Kyra Schlining, Nancy Jacobsen Stout, Susan von Thun Music: Dramatic Documentary Background by MoodMode Reference: Osborn, K.J., G.W. Rouse, S.K. Goffredi, and B.H. Robison (2007). Description and relationships of Chaetopterus pugaporcinus, an unusual pelagic polychaete (Annelida, Chaetopteridae). Biological Bulletin, 212: 40-54.