The bizarre Surinam toad needs little introduction to amphibian enthusiasts…their unique strategy of brooding the eggs below the skin of the female’s back has rendered the species quite well-known. Yet, when I received a group of adults in 1986, I found that little had been published on their husbandry, and the last recorded captive breeding seemed to have occurred in the 1950’s.
Courtship and Fertilization of the Eggs
One female was in breeding condition, as evidenced by the circular, swollen ring about her cloaca and the dark brood patch on her back. Several males were giving forth their metallic, clicking breeding calls, so I chose the most robust of the group and placed him with the female.
Surinam toads swim in a series of circular loops, from the bottom to the top of the aquarium, when in amplexus, and will rarely be successful in fertilizing the eggs unless provided with a tank of at least 48 inches in depth. As the pair reaches the top of their loop, the female lays an egg, which is (on the next loop) fertilized and manipulated by the male onto her back’s spongy brood patch.
My Observations of Amplexus and Birth
Amplexus in the frogs I observed lasted for nearly 3 days, which I have subsequently found is the norm. The pair “shivered” in unison on many occasions, but I was not able to see the “bobbing” motions described by others. The photo accompanying this article shows what might be the first captive breeding (this while I was working at the Bronx Zoo) in many years. Within 24 hours of this photo, the skin on the female’s back swelled and completely covered the eggs.
After egg-laying, I removed the male. The female fed as usual. I did not offer blackworms, as these voracious little beasts burrowed into the soft skin of her brood patch at one point…talk about a horrid sight (I was able to wash them away easily)!
The young began to pop their heads out (the sight of 74 pointed little heads protruding from their mother’s back was yet another vision not for the squeamish!) in 100 days, and swam off on their own within a day or so. They averaged ½ to ¾ inches long, and fed readily upon chopped blackworms, brine shrimp and guppy fry. Sexual maturity was reached in 3 years.
Amazing Healing Abilities
The females back appeared “healed” within 24 hours of giving birth, but remained roughened in appearance for several weeks. Amphibians are increasingly being found to produce compounds of great medicinal value…I wouldn’t be surprised if the incredible skin trauma undergone by female Surinam toads is somehow tempered by a chemical that could be of use to people.
A wonderful video of baby Surinam toads emerging from their mother’s back is posted below:
Baby Surinam Toads emerging from their mother’s back