This afternoon I engaged in a Twitter conversation with some colleagues regarding the use of the term dreissenid in the context of “dreissenid mussels”. Colleague A wanted to know if dreissenid should be italicized. I assured her that it indeed does not, because Dreissenidae is a family of mussels containing 3 genera and is not a single genus (to which she obliged). Colleague B then questioned this and asked what to do if using the term when only referring to the genus Dreissena, whereby I suggested using a more specific term (i.e., Dreissena spp.). Colleague A then responded that she originally wanted to use the term to describe only the genus Dreissena, and that this was common practice. Then I got annoyed (again) at common names in general…
So which is it – does dreissenid refer to the family Dreissenidae or the genus Dreissena?
The answer is that it’s commonly used for both. Although many scientists may not care about or acknowledge this, the interchangeability of common names across different taxonomic resolutions can be problematic for a number of reasons.
Let’s first look at a relatively simple example. Say I published a paper on “dreissenid mussels” in the Journal of Crappy Nomenclature, and in the introduction made the claim that there are 16 species of dreissenid mussels. Without context, the reader has no idea as to whether there are 16 species within the family Dreissenidae or 16 species within the genus Dreissena unless they search this information themselves (there are 16 species in the family Dreissenidae; Figure 1).
Likewise, let’s say that in the same paper I was to claim that dreissenid mussels reside in supraterranean (above ground) freshwater systems. While that is true for the genus Dreissena, there exists a subterraneous genus of Dreissenidae (Congeria; resides solely in cave river systems). Again, without context, the reader would be left searching such information. Unfortunately, many readers would not recognize the need to search for this information and would likely apply the information obtained from the two statements outlined above in the context of how they interpret the term “dreissenid mussels”, which may be correct or incorrect depending on my definition of “dreissenid mussels”. Thus, in subsequent publications obtaining information from my hypothetical paper on dreissenid mussels, information may be incorrect, but nonetheless become “common knowledge”.
While the above examples may appear extreme, particularly for those who study these mussels, the points still stand – and for many more taxa than the example herein. Researchers conducting work on species new to them must learn as much about their new study species and related taxa as possible. In this way, using common names interchangeably across levels of taxonomic resolution can easily create problems for these researchers and the propagation of incorrect biological information may result. Furthermore, other problems with common names arise when even more generic terminology is used, like “cushion stars”.
Ultimately, there are two ways to solve the problems outlined above: either define the range of taxa (up front) that a common name being used encompasses, or stop using common names all together. If we are to follow the biological writing rules of Dr. Pechenik (i.e., more concise = better), scientific works would benefit from the elimination of common names (for example, “Dreissena spp.” consumes less space than “dreissenid mussels”, and the former would not require a formal definition). Not only does the use of precise taxonomic nomenclature reduce verbiage, but it would remove the potential for misinterpretation with respect to the breadth of biological processes across various levels of taxonomic resolution. That, and we would negate complex Twitter conversations regarding how to use common nomenclature and have more time to spend on writing our actual papers…
So, in conclusion, just stop using common names. They suck.