As mentioned on the Nutrition page, Photeros annecohenae is a victim of parasitism. It serves as a host for copepods, an ectoparasite in the family Nicothoidae, which reside in the valves of its carapace (Cohen and Morin 2010). These parasites are also crustaceans. The copepods consume the female ostracod's eggs in the brood pouch and replace them with their own. The female ostracod releases these eggs into the environment when it comes time for her to release what she thinks are her juveniles. The parasite is the most common cause of mortality in Photeros annecohenae (Gerrish Personal Communication).

      Ostracods are a component of marine plankton and are, therefore, prey for planktivorous fish and invertebrates. Because of this, they fall considerably low on the food chain with other "marine plankton species." Their main predator is the Cardinalfish. Ostracods do not interact with other species as fierce predators due to the fact that they are scavengers and feed off of dead and decaying organisms.

     Skogsbergia lerneri
, a nonbioluminescent ostracod that lives in the same habitat as Photeros annecohenae, is the bioluminescent ostracod's biggest competitor. This competition is indirect: the two species do not directly compete with each other, but they feed on the same material. Skogsbergia lerneri, forages during the day, while Photeros annecohenae does so at night. Other organisms that live in the same habitat as Photeros annecohenae include other bioluminescent organisms (the luminescent syllid polychaete worm and bioluminescent dinoflagellates) as  well as sea urchins (of the genus Diadema) and manatee and turtle grass. Photeros annecohenae does not directly interact with these species physiologically, but they can affect its life. Examples include the bioluminescent organisms acting as distractions to females during mating displays and the turtle grass (Thalassia testudinalis) providing a place for Photeros annecohenae to live.

     As scavengers, ostracods serve an important role in their environment: They decompose and recycle decaying animal matter. This means that the organic matter, and essential nutrients, are no longer "tied up" in the dead animals and can be recycled back to the soil for use by other organims. It can be assumed that Photeros annecohenae are able to find and consume plenty of food due to the large densities they may be found in.

     Although there are no known direct ties to medicinal use of bioluminescent ostracods, there has been discussion of using the bioluminescent chemicals, protein luciferin and enzyme luciferase, as DNA labels. Some of the researchers who first isolated GFP (green fluorescent protein) from a jellyfish, which is commonly used in scientific research, work on the ostracod luminescent system. In fact, the 2008 Nobel Peace Prize in Chemistry went to Shimomura Osamu, an organic chemist and marine biologist who first discovered GFP in jellyfish; his  work on bioluminescent ostracods is what actually spurred his research on green fluorescent proteins in jellyfish, and, therefore, lead to the isolation of GFP. Bioluminescent compounds have also been found to be strong antioxidants.

     There are not many known human uses for ostracods; however, there are stories of Asian explorers of the past who dried ostracods and put the organism in their salads (Gerrish Personal Communication)! Yum!

To read more interesting facts about ostracods, click here to be guided to a page dedicated to these fun facts!