Answers are grounded in this paper and cite their sources.
The female gastric brooding frog Rheobatrachus silus broods its young in its stomach. A substance that inhibits gastric acid secretion in a toad stomach preparation in vitro appears to be secreted by the developing young. This substance has been identified as prostaglandin E2. Rheobatrachus silus may thus have developed a mechanism whereby prostaglandin secreted by the larvae inhibits acid secretion in the stomach of the female until the larvae have completed development and emerged as juvenile frogs by way of the female's mouth.
No takes yet. Share an insight, caveat, or question.
Tyler et al. (1983) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: