08/13/09 – Names
Most of us grew up with nicknames — Lizard's Gizzards, Little Mike, Zipper — names given to us by our friends and family. We also name objects such as boats (we are on the Seward Johnson) and even equipment (the Microlander is called the “Suil un Mara,” which means “Eye of the Ocean” in Gaelic). A recent New York Times article (Reviving the Lost Art of Naming the World, August 10, 2009) identifies the human need to name and organize items and discusses the decline in the scientific field called taxonomy.
Taxonomy is fundamental to our current mission. When we bring up organisms from the deep, whether by sub or by net, we identify and name them based on their physical characteristics. The names we use for these specimens are not common names or nicknames, which can vary depending on culture or language, but scientific names, which are used around the world by all scientific researchers. For example, many of the samples we collect are from Lophelia pertusa, a deepwater coral found worldwide. By using this coral's scientific name during our mission, we ensure that the rest of the world knows exactly which coral we are researching.
In addition to using physical characteristics to identify collected specimens, we use DNA analysis, a fairly new tool, to confirm our identifications and to help determine if minor differences in the appearances of individuals of the same species are significant. For example: “Are two animals that have a similar shape and size but different colors the same species or not?” If their DNA is not similar, then they are not the same species, despite their similar appearances. Also, DNA analysis is being used to help determine how closely related species are to one another, or, in other words, to create the “family trees” of living organisms.
When we collect a specimen, we usually take a photograph immediately, in order to document the color of the animal, which will change when the animal is preserved. We also take a DNA sample, which will go to a lab for testing and analysis. Then the specimen is preserved and stored with a label, which includes the date and location of collection. The specimen collections that we assemble during this mission will allow us (and future scientists) to document the ranges of deep sea organisms, analyze their habitats and monitor changes over time.
Taxonomists use scientific collections to gain an incredible amount of knowledge about the morphology (the form and structure) of specific groups of animals. Using the collections of various institutions such as the Smithsonian, which has collections that date back to the 1800s, and the North Carolina Museum of Natural Sciences, which has collections that date back to the early 1900s, taxonomists develop dichotomous keys that can be used to identify an individual organism collected by a research team or simply observed by a backyard naturalist. Dichotomous keys are a series of yes or no questions that help narrow down the range of possible choices that an animal could be. Keys start with broad questions, such as, “Does it have an internal skeleton?” and work their way down to more and more specific questions, such as, “Does it have eight spines on the posterior margin of the shell (carapace)?”
"We are lucky to have Dr. Martha Nizinski, a taxonomist with the NOAA National Marine Fisheries Service, on board with us. Martha's specialty is crabs, and we collect many unusual species out here. With Martha's instruction and the use of dichotomous keys, we have learned to recognize the differences between galatheid and brachyuran crabs, two types of crabs that, despiste their different appearances, are genetically related to one another. Generally, galatheid crabs have long narrow bodies, a pair of skinny claws that don’t appear to be very strong (but which must be effective at catching food), and four pairs of legs, the last of which is modified and tucked under the tail. The species of galatheid crab that we have collected most frequently is Eumunida picta, which is often called by its common name, Squat Lobster. The brachyuran crabs that we have collected so far look completely different from the galatheids: their shells (carapace) are wider than they are long, their two claws appear to be very powerful, and none of their four pairs of legs are hidden under any part of their bodies. The most frequently collected brachyuran crabs has been the Chaceon fenneri, commonly known as the Golden Crab.
For as many crabs that we collect each day during our mission, we collect many more animals for whom there are no experts in the world, much less on our vessel. For many of these organisms, dichotomous keys, which would help us identify them, have not yet been devised. Some of the deep sea animals that we collect may not have been seen since they were first described, which in some cases can be decades ago. To identify these organisms, we must search through museum collections, compare our specimens to those in the collections and hope that we can find matches for our unknowns.
We are honored to know that the data from the collections we make during this mission will add to the body of taxonomic knowledge of deep sea species.
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