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Interactions Between a Crustacean and an Alga: The First Marine Arthropod with Photobionts?

Award Period: 

Tuesday, April 1, 2014 to Friday, March 31, 2017

Award Amount: 

$9 654

Agency Name: 

Australian Museum

Award Number: 

SB14014

PI First Name: 

Celia

PI last name: 

Churchill

Co-PI: 

Todd Oakley

MSI Person: 

Area/s of Research: 

Abstract: 

Relationships between marine invertebrates and photobionts (photosynthetic endosymbionts) are not only fascinating biologically, they can comprise the energetic foundations of marine ecosystems (1, 2). Representatives of many invertebrate metazoan phyla house photobionts, yet while this evolutionary strategy appears successful over a wide taxonomic breadth, the number of times it has evolved is rare (3). Because of their often critical ecological roles and sensitivities to environmental perturbations, photosynthetic holobionts serve as ecosystem indicators (4).

               On a recent trip to Lizard Island Research Station, I found an undescribed philomedid ostracod (Ostracoda: Philomedidae) that appears to have photosynthetic endosymbionts (Fig. 1a). Upon initial examination, this species has an unusually colorless and translucent carapace, and a greenish hue is present both on the inner carapace membrane and on the ostracod’s body. Removing one of the shells reveals that each fossa of the carapace has an associated spot of green algae on the inner carapace membrane (Fig. 1b), and that the spots on the body are not in the gut, but around the gut (Fig. 1c) and in some of the limbs (Fig. 1d). To date, there are no known photosynthetic holobionts involving a marine arthropod.

A postdoctoral fellowship to conduct field work at LIRS so that I may charcterize the type of algae present in this remarkable ostracod, and test whether the ostracod sources nutrition from the alga.