[1] Mertens worked at the Senckenberg Museum in Frankfurt for many years, beginning as an assistant in 1919, and retiring as director emeritus in 1960.
Mertens died after being bitten while feeding his pet savanna twigsnake, Thelotornis capensis.
[1] He kept a diary of his deteriorating condition, noting that it was the "für einen Herpetologen einzig angemessene Ende" (the only appropriate demise for a herpetologist).
[1] The death of Robert Mertens parallels that of another well known herpetologist, Karl Patterson Schmidt, almost 20 years earlier.
Each was a herpetologist, each was bitten by a venomous colubrid native to Africa, and each documented his symptoms until his death.