Study

A pharmacological and biochemical investigation of the venom from the platypus (Ornithorhynchus anatinus)

de Plater, G.; Martin, R. L.; Milburn, P. J.

Toxicon, 1995

Peer-reviewedcontrolled laboratory experimentlaboratory

What they did

Venom collected from the crural spur of male platypuses was separated into fractions and each assayed for biological activity, characterising the components responsible for its effects.

Studied in: Ornithorhynchus anatinus
Sample size: venom fractions assayed pharmacologically

The venom is a complex mixture including defensin-like peptides, and produces severe and unusually persistent pain along with local swelling. It is not lethal to humans. Venom production is seasonal, rising sharply in the breeding season, and only males possess a functional spur.

What it means

The authors' reading, and ours. Where they differ, that difference is the point.

How the authors put it

Platypus venom is adapted for use in male–male competition rather than for prey capture or defence against large predators.

How NatureHQ reads it

The seasonality is the detail that explains the whole system, and it is usually left out. A venom used to subdue prey would be produced all year; this one peaks when males are competing for mates, and only males have the apparatus. So the platypus is venomous in a genuinely narrow sense — half the animals, part of the year, in a fight with each other. The pain is reportedly extreme and resistant to conventional analgesia, which is medically notable and is not the same as dangerous.

Limitations

Human effects are documented from a small number of case reports rather than from any controlled study, for obvious reasons.
Assays are of isolated fractions; the interaction between components in whole venom is less well characterised.
Later genomic work identified the evolutionary origin of the components, which this study predates.