Serious answer: why does it matter? Are you an organization promoting veganism? Maybe direct your limited awareness raising funds at less ambiguous examples.

Serious answer: why does it matter? Are you an organization promoting veganism? Maybe direct your limited awareness raising funds at less ambiguous examples. Are you looking to score points against a self-professed vegan acquaintance? Maybe don't offer guidance on what other people eat unless they ask for input. Are you a conflicted vegan? If you're feeling inner turmoil about consumption of scallops/oysters then maybe abstain to be safe. Are you (as I suspect) merely concerned about definitions? Define "vegan" sufficiently and the answer should follow from that. Different self-professed vegans will use different definitions, some seek to avoid "animal products", others "animal suffering". In the latter case, an organism without a nervous system cannot "suffer" as the term is commonly defined, in the former "animal" is typically used synonymously with the kingdom Animalia.