Wild Eggs Revitalize Aquarium Cuttlefish Genetics

The Tennessee Aquarium is always seeking ways to minimize its impact on the environment and wild populations of animals.

To maintain the health of species that reproduce in human care, however, zoos and aquariums occasionally bring in new wild individuals to increase the genetic diversity of their populations and minimize the chances of inbreeding-related health conditions. Some institutions refer to these wild genetic ambassadors as “founder animals.”

On April 13, the Aquarium received a shipment of wild-collected Pharaoh Cuttlefish eggs. Three bunches of these pale, white eggs — also known as “sea grapes” — are currently developing off-exhibit . Once hatched, these babies will delight visitors and serve an important purpose within the aquarium community, says Aquarist II Rachel Thayer.

“It’s a common species that’s exhibited and fairly easily cultured in-house, so you don’t have to get eggs from the wild,” says Aquarist II Rachel Thayer. “The trick is, though, that after several generations, you need an influx of wild individuals to ensure the populations in human care are robust and healthy.”

The Aquarium has exhibited Pharaoh Cuttlefish (Sepia pharaonis) before, but in recent months, the Boneless Beauties gallery primarily has housed Common Cuttlefish. Unlike Commons, which are native to the East Atlantic and Mediterranean, the Pharaoh Cuttlefish is found on the opposite side of the planet in Indo-Pacific waters.  Males are typically larger than females.

Note: If you visit the Quarantine Room as part of a Backstage Pass Tour and look closely at the eggs, you can see tiny embryos developing. The eggs are expected to hatch in a couple of weeks, with the resultant baby Cuttles on track to reach exhibit size several months later.