Hi James,

well, although I am neither a biologist nor terminological expert, I came across similar questions during my work as knowledge engineer. I have written two book chapters about related questions, since it seems that even the research in knowledge representation hasn't adressed the underlying issues yet properly. Unfortunately for you, both chapters are written in German. So I try to briefly summarize the issues:

In general the use of natural language isn't normative, that means authors of information often use different terms to describe the concept they have in mind (even if they are experts) than the information seekers. Because of the same reason the later also use improper terms.

Although classification systems are intended to solve the problem by defining a controlled, normative language system for different objects (in your case animals), even these systems evolve over time (especially taxonomies in biology). As a biologist pointed out to me: "it seems that every biologist once in her lifetime tries to name a species with her own name", so renamings of species and restructuring of the taxonomy are quite common. It seems that even Lesueur 1819 has used both names (https://www.itis.gov/servlet/SingleRpt/RefRpt?search_type=author&search_id=author_id&search_id_value=5559) and probably "Ictalurus natalis" was considered invalid only afterwards.

Searching for the invalid term in the Internet shows 1) that references to the invalid name occur still often, 2) that other disciplines (such as medicine) use the invalid term (Article Chemical Communication in Social Behavior of a Fish, the Yel...

So, it seems reasonable to me that an author searching for the latin name of the concept "yellow bullhead" comes across the invalid name and uses it without noticing that from the viewpoint of a biologist/terminologist it is invalid.

If you transfer these toughts to the pre-internet area, where the printed books in libraries are updated even less frequently, it seems to me even more reasonable that researchers came across and used the nowadays considered invalid term from a taxonomy of an outdated book.

I hope my thoughts answer your question to some degree.

Have good new year

Thomas

Thomas:

I received your reply and found it quite refreshing. I too was in that pre-internet era when I wrote my first paper. The literature that was available to me at that time referred to the Yellow Cat/Bullhead as Ictalurus natalis. I understand that the Ameiurus was considered to be a sub-genus at one time. You have given me a lot of information to get and go through and I do appreciate it very much.

Thank you for your information,

James