Tadpole Behavior: A Unique Sanitation Strategy

Some tadpoles go without pooping for weeks, maintaining clean environments in their small puddles, writes Science News. Eiffinger’s tree frogs (Kurixalus eiffingeri), specifically, utilize an interesting strategy by storing waste in an intestinal pouch until metamorphosis.

Eiffinger’s tree frogs are small amphibians found in Taiwan and the Japanese islands of Ishigaki and Iriomote. They lay eggs in diminutive puddles, often found in plant stems, tree hollows, and bamboo stumps. Once tadpoles hatch, they live in these limited water sources, which have low ammonia dilution. Ammonia, a harmful chemical, is released through feces and urine.

Biologists Bun Ito and Yasukazu Okada from Nagoya University discovered this tadpole's unique cleaning method — self-induced constipation. The tadpoles postpone releasing waste until they prepare to become frogs. To understand this phenomenon, Ito and Okada raised tadpoles from four frog species in small, controlled environments. They moved the tadpoles to tiny containers with just over a tablespoon of water, measuring ammonia released and stored by each species.

Eiffinger’s tree frog tadpoles emitted less than half the average ammonia of the other species in the study and retained more ammonia in their guts. This contrasts with frogs that lay eggs in larger ponds, where ammonia easily dilutes. Ito noted that their strategy protects small water bodies from contamination, despite some ammonia still seeping through their urination.

Additionally, Eiffinger's tree frog tadpoles exhibit resilience by surviving in higher ammonia levels than the Japanese tree frog (Dryophytes japonicus), a finding that might seem paradoxical. Their waste-free period allows them to share habitats with other creatures like mosquito larvae, which also produce ammonia.

Ito posits that this development represents a tolerance to ammonia. It could serve as a defense against ammonia from both internal production and neighboring organisms.

Earlier, SSP reported that scientists discover a fascinating third state of life beyond death.