They are all good, there is no difference. Release whatever you encounter.

Releasing animals is a fearless donation, and the reward is longevity and health; because the animals being released are bought with money, this is a donation of wealth, and the reward is abundant wealth; when releasing animals, follow the Buddhist release rituals, and This is Dharma giving, and the result is wisdom and intelligence. There are simple life-releasing rituals available online, but just follow them and recite them. There are also many life-release inspiration articles on the Internet by a senior brother named "Huashan Siguoya". Learning from them can increase your confidence in life-release.