Aschelminthes and Nematoda are often discussed in the context of invertebrate zoology, but they are not the same, although there are some connections between them.
Aschelminthes, a term historically used to refer to a group of pseudocoelomate animals, includes various phyla such as rotifers, acanthocephalans, and nematodes. Nematoda, on the other hand, is the phylum that specifically comprises roundworms, which are a significant component of the Aschelminthes group but also exist independently in classifications. Therefore, while all nematodes are considered part of the broader category of Aschelminthes, not all members of Aschelminthes are nematodes.
To summarize, Aschelminthes is a collective term that once included multiple phyla, one of which is Nematoda. Over time, the scientific community has moved towards more precise classifications that separate these groups. Understanding this distinction is valuable for studying the diversity of invertebrate life.