Siphonophores: A Colonial Existence

Imagine a colony of ants: the worker ants, the soldier ants, and the queen. Each individual is a part of a larger whole, all working together towards a common goal. In biology, the (simple) definition of a colony is a group of organisms that live together for a joint purpose. In the case of our ant example, each individual has a task that helps ensure its colony’s survival and promote its growth. Colonies are not uncommon in the animal kingdom—can you think of any others? How about any in the ocean? Ever heard of a siphonophore?

At first glance, a siphonophore might be easily mistaken for a jelly. Although closely related to the sea jellies, siphonophores are in a category of their own—characterized by their unique body structure. They are a kind of super-organism. Again, at first glance, a siphonophore might look like one single animal. It’s not. In fact, it’s several smaller animals, called zooids, that work together to create one mega-animal. These zooids each play different, crucial roles that allow the siphonophore to thrive. For example, there are zooids called nectophores, or swimming bells, that can contract in unison to help the siphonophore swim. There are pneumatophore’s, gas filled sacs that help the siphonophore stay buoyant in the water. Gastrozooid’s that feed and digest. Some of these zooids have tentacles lined with stinging cells for defense.

Recently in Toyon Bay, a siphonophore was spotted at the sea’s surface by some scuba diver’s. It was identified as a hula skirt siphonophore (scientifically named Physophora hydrostatica). This deep-sea dweller spends its days a few thousand feet below the surface. How did it end up in the shallow’s of our bay? Most likely as a result of an upwelling event—although it can swim about a foot/minute, courtesy of its nectophores. Regardless, this fleeting visitor offers us a reminder of the incredible diversity of marine organisms—and the mystery of all that exists in the deep.

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