Waterdog Eggtravaganza!

Eggs are visible.

CREW’s aquatic salamander laboratory supports the only zoo-based captive assurance population of the endangered Black Warrior waterdog.  In the first year of the project, CREW scientists developed the life support and husbandry protocols necessary to maintain this species in captivity.  In the following two years, we’ve focused more on stimulating successful breeding and reproduction in the waterdogs by administering exogenous hormones and implementing seasonal changes in water temperature and lighting.

In 2012, we had a single black warrior waterdog ovulate and deposit over 50 eggs during three days in April.  This year, we had one Mudpuppy, one Black Warrior and two Gulf Coast waterdogs deposit eggs.  While some eggs were not fertile, eggs from two Gulf Coast waterdogs were fertilized and marks the first report of successful breeding of this species in a zoo setting.  A waterdog eggtravaganza!

Muffin Top with her eggs.
Muffin Top with her eggs.

Pat Story, Cincinnati Zoo’s Media Projects Manager, was able to capture Black Warrior waterdog ‘Scarlet’ in the process of laying her eggs.  As you can see from the video, female waterdogs deposit their eggs upside down on the underside of rocks or logs.  We offer either substrate to our female waterdogs, so they can choose their nest location.

In many amphibian species, there is little maternal investment after eggs are deposited.  However, a waterdog mom puts a lot into ensuring she has a successful brood.  It has been amazing to watch how devoted these females are not only to laying the eggs, but how intensively they guard and brood them (which involves keeping them clean and well aerated).  This process is also quite prolonged; the time from deposition to hatching is > 70 days.  We are excited to show you in upcoming blogs how the larvae have developed and hatched.