Hyla arborea

Hyla arborea and other hylid frogs are distributed in wide parts of the Old World, the New World and Asia. Low molecular compounds isolated from their skin secretions are serotonin, bufotenin, and histamin. 

Hyla arborea moreover contains a hemolytic active peptide of unknown structure, still active in solutions of 1 200.000, while from Hyla caerulea a small peptide, caerulein, has been obtained (ref. 7) ... 

Concerning rog larvae, Pfeiffer (1963, 1966) tested alarm responses in tadpoles of Rana esculenta, R. temporaria, R. pipiens, Hyla arborea, and Xenopus laevis to skin extracts of conspecifics, and concluded that fright reactions were not present in these species. Skin extract of R. temporaria was also negative in tests with toad Bufo bufo) tadpoles, and R. temporaria tadpoles did not respond to skin extract of toad tadpoles. These results made him suggest that non-bufonids lack both the alarm substance and the ability to respond to the alarm substance. 

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