The biologist is a vegetarian who grows various plants in his kitchen, such as tomato and seaweed. He never eats meat, especially fish meat. It's possible that he suffered a lot of phycological issues from the experiments he's been tasked with.
worldbuilding: https://aidelank.notion.site/The-Fish-Bone-da011a69d4f94067a5a941c25767de37?pvs=74