Qualitative Research on the Primary Effect of Fish Pet Ownership Using the Bottleium, a Bottle-Type Aquarium, on Community-Dwelling Older Adults in Japan: A Potential Preventive Measure Towards Social Isolation.

Aging increases the risk of social isolation, which could lead to conditions such as depressive mood. Pet ownership is known to reduce social isolation. However, previous studies have mainly focused on mammals as pets, which could be difficult at old age. A small ornamental fish is relatively easy to culture and might be a suitable alternative. In this research, we aimed to elucidate the possible effects of fish ownership on the psychological state of community-dwelling older adults in Japan. A Bottleium, a bottle-type aquarium, was selected to lower the burden of fish ownership. A workshop was hosted in 2019 and participants brought home their own Bottleium, with fish and water snail inside. Nineteen participants gave consent to the follow-up interview a month later. Five themes, "observation of fish and water snail," "interaction between the fish and the owner," "taking care of the fish as pet owner," "facilitation of interpersonal interaction," and "development of support system," emerged from thematic analysis. The promotion of animal-to-human, and human-to-human interaction and development of responsibility could relate to a sense of social inclusion and ikigai-kan, a purpose of life. Fish ownership, when using equipment that suits the physical capability of older adults, could act as a positive stimulus.