The endless expanse of the ocean’s midnight zone offers plenty of room to stretch out. Here, some animals can grow to great lengths. Siphonophores are gelatinous animals composed of specialized parts growing together in a chain. The woolly siphonophore (Apolemia lanosa) is a shaggy species we often encounter in Monterey Bay. We know they can reach at least five meters (16 feet) in length, but other siphonophores can be as long as a blue whale!

We often encounter the woolly siphonophore in a spiral coil dangling a curtain of tentacles. Specialized stinging cells stun any unfortunate animal that blunders into those sprawling tentacles. The woolly siphonophore is one of two new Apolemia species we discovered in Monterey Bay. Our team has worked with collaborators around the world to describe 11 previously unknown siphonophore species off the California coast.

Understanding and documenting deep-sea biodiversity is increasingly critical. Fishing pressure, pollution, and climate change all threaten the deep ocean. We urgently need to establish a baseline of what lives in the deep sea to monitor ongoing human impacts on this environment.