Letter to the editor: Sarcocystis pinnipedi nomenclature?

I read with great interest the paper “Clinicopathologic, molecular, and ultrastructural features of Sarcocystis pinnipedi infection in 2 California sea lions with fatal necrotizing hepatitis,” by Chiu et al., published in JVDI ¹ for 2 reasons. First, the so-named S. pinnipedi is a molecular variant of Sarcocystis canis that we described. ⁴ My purpose for naming it S. canis was to draw attention to the fatal protozoal hepatitis in dogs, that was previously attributed to Toxoplasma gondii. ² The life cycle of S. canis is unknown, and the definitive and intermediate hosts have not been found. Second, I am revising the book Sarcocystosis in Animals and Humans, ³ and I need to address the discovery of the parasite so-named Sarcocystis pinnipedi. The article by Chiu et al. ¹ is an excellent description of the disease in sea lions. Another article ⁶ describes a parasite with the same genetic sequence that caused fatal hepatic sarcocystosis in 2 different pinniped species, which appears to be synonymous and appropriately was not speciated but referred to as an S. canis–like variant, which is appropriate. However, in the Chiu et al. ¹ paper, there is no formal description of the parasite, which is necessary to name it as a new species, Sarcocystis pinnipedi. This new species designation appears for the first time in a peer-reviewed journal: JVDI. It references an abstract for an oral presentation delivered at a conference in 2013. ⁵ Any taxon named at a conference in the absence of a previous publication in a peer-reviewed journal is nomen nudum according to the Rules of Zoological Nomenclature. In my view, a correction is needed by Chiu et al. ¹ in print. Until then, parasites causing hepatitis in marine mammals can simply be designated as a molecular variant of an S. canis–like parasite, as done by others. ⁶ In future, for formal description, the new organism needs to be morphologically and molecularly distinguished from S. canis.