Commentary on: "Unravelling the ultrastructure and mineralogical composition of fireworm stinging bristles" by Righi et al. 2020.

ABSTRACT

In a recent paper published in Zoology, Righi et al. (2020) investigated the chaetae of the venomous fireworm Hermodice carunculata (Amphinomida, Annelida) and revived the hypothesis of venom injection by hollow chaetae. This conclusion reached by Rigihi et al. (2020) contradicts previously published results, and in our opinion, it is also not supported by their data. We propose the idea that broken chaetae cause lesions and unprotected exposure to venomous epidermal mucous. Herein we also provide further data that show the artificial nature of the empty core of the calcareous bristles. We further emphasise that there is no evidence for venom storage within the chaetae. The idea that fireworm's chaetae are equipped with a venom delivery mechanism, analogous to hypodermic needles, must be considered as refuted. We hope our commentary may help future clarification of venom delivery in fireworms.