In “The Nutmeg of Consolation” by Patrick O’Brian, the 14th in his series of maritime novels, the good Dr. Stephen Maturin’s unabashed joy at finally seeing a platypus in Australia is almost immediately tempered by the incapacitating pain he experiences when he is stung by poisonous spurs on the animal’s rear legs.

Dr. Maturin could be forgiven if he didn’t know that the platypus is among the few mammals that produce venom (and with platypuses, only the male does). Even those who know about platypus venom do not really know much about it.

They know a little more now. Researchers in Japan have identified some of the constituents of the venom that may help make it so painful.

Using high-performance liquid chromatography and other techniques, Masaki Kita of the University of Tsukuba, Daisuke Uemura of the Nagoya University and colleagues analyzed venom samples and identified about a dozen peptides, small chains of amino acids that are the building blocks of proteins. Their findings are reported in The Journal of the American Chemical Society.