A new species of Amolops from Thailand (Amphibia, Anura, Ranidae).

We describe a new species of torrent-dwelling ranid frog of the genus Amolops from western to peninsular Thailand. Amolops panhai, new species, differs from its congeners by the combination of: small body, males 31-34 mm, females 48-58 mm in snout-vent length; head narrower than long; tympanum distinct; vomerine teeth in short, oblique patches; first finger subequal to second; disc of first finger smaller than that of second, with circummarginal groove; no wide fringe of skin on third finger; toes fully webbed; outer metatarsal tubercle present; supratympanic fold present; dorsolateral fold indistinct; axillary gland present; horny spines on back, side of head and body, and chest absent; large tubercles on side of anus absent; glandular fold on ventral surface of tarsus absent; nuptial pad and paired gular pouches present in male; white band along the upper jaw extending to shoulder absent; larval dental formula 7(4-7)/3(1). This new species is the second anuran discovered which has a disjunct distribution around the Isthmus of Kra.

A new Ansonia from the Isthmus of Kra, Thailand (Amphibia, Anura, Bufonidae).

A new species of torrent-dwelling bufonid frog of the genus Ansonia is described from the Isthmus of Kra, Thailand. Ansonia kraensis is morphologically similar to Malaysian A. malayana, but differs from it in ventral coloration and larval morphology. Occurrence of A. kraensis in this region suggests a heterogeneous nature of the anuran fauna between northern and southern regions of the Malay Peninsula.

Biologically active substances from amphibians: preliminary studies on anurans from twenty-one genera of Thailand.

Amphibian skin has been the source of a wide variety of biologically active substances, but less than one-third of the known genera of amphibians have been probed for such active substances. Skins of 21 genera of anurans from Thailand have now been investigated for noxious secretions, toxic substances, and alkaloids. Four genera of bufonid toads (Bufo, Ansonia, Leptophryne, Pedostipes) were toxic due to the presence of bufadienolides or bufadienolide-like compounds. Two species of ranid frogs (Rana raniceps, Rana signata) were toxic, perhaps due to the presence of toxic peptide(s). Two species of rhacophorid frogs (Polypedates) were slightly noxious/toxic. One species of microhylid frog (Kaloula pulchra) was noxious. Trace amounts of pumiliotoxin alkaloids were detected in a ranid frog (Limnonectes kuhli). A further 18 species did not exhibit noxious or toxic properties to a significant extent.