Embedded Files
Hermit crabs can be found in a variety of shells that are actually produced by other organisms. Photo by J. Cutter.
In addition to some of the "normal" species interactions we commonly focus on, organisms also interact in less common (or less studied) ways. This session focuses on a recently discovered (and coined) interaction known as "lethal eviction". This occurs when a species kills another organism to acquire a resource and is somewhere between predation (organism is killed, but not for food) and competition (an extreme form of contest competition).
This interaction has been observed in thin stripe hermit crabs, Clibanarius vittatus. Unlike bivalves (like oysters and mussels), snails, turtles, and many other "shelled" organisms, hermit crabs do not produce their own shells. Instead, they acquire shells that have been produced and vacated by other organisms. Shell availablity is a actually a limiting factor for populatin growth in crabs, which have been frequently observed competing over new shells.
It turns out that crabs not only compete for empty shells. Recent work by Cutter has shown that crabs "evict" crown conchs, Melongena corona, a large snail that commonly occurs in their habitat, in order to obtain their shell. For recitation this week, learn more about this work by reading the first few pages of Cutter's recently published thesis and a recent presentation she gave on her work. Her finding about "lethal eviction" were a part of her graduate work at Florida Atlantic University. Graduate students conduct original research to grow the body of science and publish their finding in theses and dissertation to complete their degrees. These projects also often result in academic articles such as you seen this semester.
Cutter Thesis Presentation.pdfReview Questions
Review Questions
What was the most interesting part of the article to you? Why?
Find one “ecological term” in the paper that we have used in class. Define it in your own words using course material (no citation needed) and state its relevance to the topic.
Why might crabs have developed the ability to evict conchs?
Jargon is both useful to scientists (we need a detailed language) and cumbersome (it makes communication outside and among fields difficult). For those reasons the development of new terms should be scutinized. Why does Cutter argue a new term is needed for this species interaction? Do you agree?
Why is it important that Cutter used field and lab methods to study this new interaction? What are the differences between these types of studies?
Google Sites
Report abuse