Another issue would be that if we consider adding any group of invertebrates it is possible that someone would ask every time for a new group to be added, leading to eventually asking to add
every invertebrate
sensu lato (meaning every other animal but the
Vertebrata subphylum): needless to say it is a gargantuan amount of work.
It is already pretty difficult to keep up with vertebrate taxonomy, imagine having to add the remaining taxa: count subspecies, sensu lato entries,
genus entries (i.e.
Apis sp. for species difficult to identify without genetical or up-close analysis), hybrids, species complexes and so on so forth.
According to the Wikipedia page on
animals there's roughly 1.500.000 classfied
living animal species, with only 65.000 being vertebrates, and around 7.770.000 total estimated species - I imagine intended as living by the way it is phrased.
Now while it is true that not every animal species has been kept in captivity or will be kept (and that Wikipedia should not be trusted as the only source of information as Henry Cavill once said

) it can be debated that given the size of the average invertebrate it could also be the opposite.
And even if not every invertebrate is kept, the majority of kept species are insects, which make a crushing majority of the known taxa and the problem is not eased whatsoever.
There is also already cases of misidentification, the addition of all these taxa would add a hundredfold.