Evidence of regenerative ability inMyxicola infundibulum(Annelida, Sabellida): evolutionary and systematic implications

Abstract

AbstractMembers of only a few species of annelids are reported as being incapable of regeneration; of these,Myxicola infundibulumis the only example in the family Sabellidae. Interestingly, its congenerMyxicola aestheticaexhibits noteworthy regenerative ability. Unambiguously identifying non‐regenerating species is critical to reconstructing how regenerative abilities evolved within the phylum. However, studies designed specifically to assess the regenerative potential ofM. infundibulumhave never been performed. In this study, we aimed to confirm the lack of regeneration ability ofM. infundibulum, reported previously for Atlantic specimens, or to determine the extent to which regeneration occurs. Our results showed that individuals from the Mediterranean Sea (Adriatic Sea) do undergo regeneration of lost body parts, although to a lesser extent than do other sabellids. Therefore,M. infundibulumshould no longer be considered a non‐regenerating species. At present, uncertainties regarding phylogenetic relationships of Sabellidae prevent inferences about the polarity of change inM. infundibulum. Since our findings are counter to those of previous studies which describe Atlantic specimens as non‐regenerating, more extensive analysis is required to ascertain if they could actually belong to a different species than MediterraneanM. infundibulum, accounting for these differences in reported regenerative capacity.