| |
If unknown species live here, imagine what remains to be discovered in the farthest depths of the oceans, or the remotest ponds and pools. |
|
|
| |
Todd Oakley |
|
| |
Stearn’s Wharf, the landmark wooden pier that effectively extends Santa Barbara’s main drag of State Street 1900 feet into the Pacific, is usually crowded with sightseers, diners, and fishermen --- locals and tourists alike. Yet, unless they enter the Sea Center, probably very few of the visitors to the wharf stop and consider what is living just meters below the wooden pier where they walk. The ostracod crustacean species Euphilomedes morini is one of these denizens of the not-so-deep, and because of its distinctive eyes, it is an object of scientific study within the Cheadle Center for Biodiversity and Ecological Restoration at the University of California, Santa Barbara. Euphilomedes morini males have compound eyes that would make proud Apollo, the Greek God of light. But females lack these eyes, nixed not by the Goddess of night (Nyx), but by evolution and development.
 |
The next time you walk on Stearn’s Wharf or Goleta Pier realize that many amazing creatures
are living just meters below your feet. Photo courtesy of Todd Oakley. |
Class Ostracoda
Before discussing E. morini and its eyes, I will first introduce the class of animals to which the species belongs, Ostracoda, the ostracod crustaceans. Ostracods are small and ancient crustaceans, usually the size of sesame seeds or smaller. Sometimes known as “seed shrimp,” they make their debut in the fossil record in deposits of Ordovician Age, rocks that are some 450 million years old. Following this ancient appearance, ostracods are notoriously abundant in the fossil record. In some places, ostracod density can reach up to several thousand individuals per 100 g (3.5 oz) rock mass!
In addition to the estimated 30,000 different fossil ostracod species, some 15,000 species are alive today. But only roughly half of these living ostracods are known to science (have official scientific names). On one research expedition to a marine lab in Puerto Rico, I dipped a bucket in the ocean and chanced to find an unknown species, which we later named Euphilomedes chupacabra. This was on the pier of the marine lab, where hundreds of marine biologists have walked, and where their boats are docked. If unknown species live here, imagine what remains to be discovered in the farthest depths of the oceans, or the remotest ponds and pools. Even the subject of this piece, E. morini, was first named as recently as 1997, after Jim Morin, an ostracodologist who has contributed much to our knowledge of the “fireflies of the sea,” a family of ostracods whose males produce brilliant blue light flashes to attract females (those females have eyes).
Ostracods are not confined to oceans. They live almost anywhere there is water. The small temporary ponds (vernal pools) that fill with California’s winter rains are home to hundreds of ostracod species. Life stages are resistant to drying over California’s long and often rainless summers. On a hike in the foothills above Montecito one winter, I once found a crevice in a boulder that had filled with rain water. To my surprise, that tiny bit of water teemed with ostracods. These animals also live in the water filled cups of bromeliad flowers, and some species even live without standing water, for example, in the damp leaf litter of Australian rainforests, and just above the tides in the United Kingdom. |
|
|
