Adaptive Coloration: Marine Animals
We are interested in the adaptive coloration properties of the cuttlefish, Sepia officinalis and Sepia pharaonis. These mollusks, invertebrates closely related to the squid and octopus, display amazing color matching capabilities on a very short timescale.
While the anatomy of the animal has been known for decades, the molecular circuitry governing the rapid color change has not been elucidated.
We are starting to work on this problem using two approaches:
1) Using Hyperspectral Imagery Analysis to characterize the reflectance properties of the whole animal.
2) By studying the leucophore, a cell responsible for a very broad band of reflectance, or in other words, the cells functioning as a white coat of paint underneath the variety of chromatophore and iridophore cells responsible for the array of colors displayed by the animals.
By identifying the molecules responsible for the near-perfect reflectance character of these cells (the intensity of the reflected light is wavelength-independent) we can then overexpress these biological molecules in simple model organisms such as E coli in order to better analyze their optical properties.
The techniques we are using include basic animal husbandry, the chemical analysis of the water to ensure purity, behavioral assays, dissection, tissue staining, light microscopy, nucleic acids extraction, electrophoresis, PCR, and standard cloning procedures.
he identification of the molecules responsible for leucophore function is hampered because the genome hasn’t been determined. To remedy this drawback, we are entering into collaborative arrangements to harness the power of the high throughput sequencer the department received in 2008.
Flounder: not just a snazzy nickname from Animal House anymore. These animals display remarkable adaptive coloration in a variety of background. We are studying various species of flounder but focusing on Bothus lunatus, the peacock flounder. These animals have a very light biological load on our marine aquaculture system and are readily available 12 months out of the year thus freeing the group from spending time on maintenance to focus on experiments. The animals may also prove to be a source of leucophores for use in cell culture.
Between surface interference, some sand as cover, and the adaptive coloration abilities, it’s very difficult to spot the flounder in the photograph above or any of the four flounder in the photograph to the left.
Cuttlefish Links and Videos