Pacific Portholefish (Diplophos taenia) and ventral photophores

The Pacific Portholefish (Diplophos taenia) has a worldwide distribution in tropical and subtropical waters. They are found down to 850m depth and are members of the deep scattering layer – the group of organisms that migrate to shallower surface waters to feed each evening. They employ counterillumination as their ventral photophores (light producing organs) produce light and shine that light downward – effectively eliminating the silhouette from the fish to predators looking upward from deeper depths (see bottom image in composite). This is part of the DEEPEND-RESTORE Project (www.deependconsortium.org). All the work has been done out on the RV Point Sur with an amazing captain and crew. A big thanks to CSA and Gray Lawson for management of the MOCNESS system. My participation is by way of the Center for Conservation & Research, San Antonio Zoo.