Bioluminescence in deep sea starfish

Main area:Marine biology
Target group:Biology
Educational level:Masters, Bachelor
Project description:

Figure 1. The deep sea starfish Hymenodiscus coronata

Light is scattered by water and below 400-800 meters in the ocean there is no detectable sunlight left. Still there is lots of light – bioluminescence. Bioluminescence is the phenomenon that many organisms are able to produce light through biochemical processes. Studies have shown that up to 80% of deep sea animals are bioluminescent using the light for a number of functions including camouflage, predator avoidance, luring prey, and intraspecific communication.

              One of the dominate animal groups in the deep sea benthic animals are starfish. More than 100 species of starfish are found in the deep sea and the deepest record so far is 8100 meters. Especially the order Brisinga (see figure 1) is common in the deep sea. They resemble feather stars (crinoids) and many of them are also filter feeders forming a filter basket with their many arms. An interesting feature of many brisingid starfish is that they are highly bioluminescent, but little is currently known about how this light is produced and what function it serves in these animals.

              In the project, the bioluminescent tissue of brisingid starfish will be examined in order to localize and describe the light producing cells. There will be a focus on the North Atlantic species Hymenodiscus coronata (figure 1) but other species will also be included. Several different microscopical techniques will be applied to characterize the tissue including high-resolution light microscopy, transmission electron microscopy and confocal laser scanning microscopy. Besides characterization of the light producing cells, the project will also map the nervous system in the bioluminescent tissue, since there is evidence that light emission is under nervous control. This will be done through anti-body labelling of the neurons and confocal microscopy followed by 3D reconstruction of the nervous system.    

Methods used:electron microscopy, confocal microscopy, 3d reconstruction of nervous system
Keywords:deep sea, starfish, bioluminescence, nervous system
Supervisor(s):  Anders Garm