Living an almost completely aquatic lifestyle, the Suriname toad is able to remain underwater for up to an hour without surfacing for air. As this species camouflages itself against the dark mud of its watery home, its small but upwardly positioned eyes are able to see in all directions, enabling the Suriname toad to detect and avoid predators (5).
The Suriname toad uses star-shaped sensory organs on the ends of its fingers to detect food (4) (10) (11), which it then scoops into its large, gaping mouth using its front feet (5) or by vacuuming in the prey (12). This species’ diet consists mostly of small fish and invertebrates (4) (8) (10).
One of the most remarkable features of the Suriname toad is its unusual and rather elaborate breeding system (3) (5) (7). Mating in this species begins soon after the onset of the rainy season, with the male toad uttering a series of metallic ticking calls before grasping the female in a position known as amplexus. If the female toad is not ready to mate, she indicates this by quivering (5).
Amplexus can last for as long as 12 hours or more (3), during which time the two toads perform a fascinating series of somersaults in the water (3) (5). At the point in the somersault when both toads are on their backs, the female lays between three and ten eggs, which then fall onto the belly of the male. As the male loosens its grip slightly, the eggs roll onto the female’s soft, spongy back, to which they adhere (5). At the same time, the male Suriname toad fertilises the eggs (5) (10). This process is repeated up to 18 times, with between 60 and 100 eggs being laid in total (5).
After the last egg has been laid, the male swims away, leaving the female remaining motionless (5). The skin on the female Suriname toad’s back gradually begins to swell (5) and grow around each egg, eventually completely engulfing the eggs (3) (5) (10) (13). Each egg lies in its own pocket, known as a brooding pouch, which is covered by a horny lid, giving the female Suriname toad a honeycomb-like appearance (5). Larval development of the young, which metamorphose from tadpoles into toadlets, occurs entirely within the pouch (5) (10). After incubating within the pouches for between three and four months (10), the young Suriname toads ‘hatch’ by erupting through the skin on the female’s back (3) (10) (14).
It is thought that the Suriname toad can live for between seven and ten years, or possibly longer (8).