A recent paper in an important publication had the formulation " Alitta (=Neanthes) succinea" in the first lines of the abstract and introduction, and even in the running title!
No, no no! That is just silly. It offends my eye, and it will confuse the biologist public, and I dare say, informatics data algorithms will get it wrong when parsing the name.
What was really meant was " Alitta succinea [formerly Neanthes succinea] " Of course it was also formerly several other combinations, starting with Nereis. But we progress.
Too late now, but since how to handle this situation is still not clear to a few I raise the matter here again. It's quite straightforward. WE DO NOT PUT COMMENTS INTO SPECIES NAMES. A name with first letter in upper case that is interpolated in parenthesis between genus and species is solely for the intermediate category, subgenus. But Neanthes will never be a subgenus of Alitta. Likewise Neanthes and Alitta are not equivalent so why the equals sign? The formulation Alitta (=Neanthes) succinea is thus nonsensical.
How to formulate correctly is covered by Recommendation 6A of the current ICZN code.
" Recommendation 6A. Undesirable interpolation of certain genus-group names in binomina or trinomina. No genus-group name other than a valid subgeneric name should be interpolated between a generic name and a specific name, even in square brackets or parentheses. An author who desires to refer to a former generic combination should do so in some explicit form such as "Branchiostoma lanceolatum [formerly in Amphioxus]".