Although not native to the Delmarva region, X. laevis is ideal for our research because it has been established as a model organism for identifying the effects of EDCs.

Brief description:

Scientific Name—Xenopus laevis

Common Name—African Clawed Frog

Habitat—These frogs reside primarily in southern Africa, but populations have been introduced in Chile, Great Britain, and California. X. laevis like to live in warm, stagnant grassland ponds or arid and semi-arid stream environments. They can tolerate wide variations in water pH, but metal ions may be toxic to these species. They thrive in temperatures from 15.5°C to 27°C. X. laevis is entirely aquatic, and will only migrate on to land when forced.

Physical Characteristics—X. laevis is unique because they lack tongues and visible ears. Adult males weigh around 60 grams, measure around 5 to 6 centimeters long, and lack the vocal sacs found in most other male frogs. Adult females weigh around 200 grams and measure around 10 to 12 centimeters long.

Reproduction and Lifespan—X. laevis sexually mature in 10 to 12 months. Mating generally occurs during the spring or summer. The females can release hundreds of sticky eggs during the three to four-hour mating events. The eggs grow into tadpoles, which filter feed. The tadpoles then undergo metamorphosis where their tails retract into their body. At this point, they are termed juvenile frogs. The juvenile frogs will continue to grow until they reach adult sizes. X. laevis can generally live up to 15 to 16 years in the wild.

For more information, visit the following websites:
Reptiles and Amphibians from Smithsonian
African Clawed Frog from National Geographic