Amphibians exhibit a diverse array of life cycles; some go through a free-swimming larval stage, while some hatch as miniature copies of their parents. While not the language a scientist would use, the term "baby" applies to both tadpoles and newly metamorphosed "toadlets" equally well. While fire belly tadpoles look nothing like the adults, the toadlets resemble the adults in most respects. The biggest differences between young and mature fire belly toads are their colors and sizes.
Fire belly toads begin life shortly after the adults mate. Termed amplexus, the male grasps the female by the waist and fertilizes the eggs as they enter the water. The females usually deposit about 30 eggs per mating, and usually group them in loose clusters near the top of the water. Within 48 hours, the pea-sized, jelly-like eggs begin visibly changing, and in 5 to 7 days, the tadpoles hatch and begin swimming around.
The tadpoles are completely aquatic and spend the next few months feeding, growing and developing. Fire belly tadpoles have two easily identifiable features. Most obviously, their intestines are visible through their abdominal walls, appearing like coiled worms inside their bellies. Additionally, the tadpoles possess a spiracle on their ventral surface, which functions as a gill. As they progress, the toads begin to develop rear, then front, legs. At the end of the process, they will begin inhabiting very shallow water near shore, as their tails begin to disappear.
Shortly after absorbing their tails, the small “toadlets” will take to the land. At this point, the youngsters display the same basic body plan as the adults. The biggest difference between the two groups is the size discrepancy: While adult fire belly toads are about 2 to 3 inches long, the young toadlets are only about one-quarter to one-half of an inch in total length. The young frogs are generally brown dorsally and white to yellow on their ventral surfaces – if they are to change colors, they will do so over the next several months.
Complications of Color
Fire belly toads naturally occur in several different color varieties. While some have bold green dorsal surfaces, infused with bold black markings, others display dark brown colors on their backs. Additionally, the ventral colors of these frogs vary, and while some have the bright red bellies deserving of their common name, others display pale yellow or orange ventral surfaces – some even have dark brown bellies. These color patterns do not always breed true, meaning that green looking adults can produce brown juveniles. Additionally, some aspects of captivity – including, but not limited to their diet -- appear to affect the colors of fire belly toads, as some captives lose their bold coloration over time.
- Animal Diversity Web: Bombina Orientalis
- Doctors Foster and Smith: Bombina Frogs: Characteristics, Husbandry, and Reproduction of Fire-bellied Toads
- Amphibian.co.uk: The Fire Bellied Toad (Bombina Species) FAQ
- Endangered Species Research: Breeding, Rearing and Raising the Red-Bellied Toad Bombina Bombina in the Laboratory
- Digital Vision/Photodisc/Getty Images