ANY sentient being has an interest in continuing to live simply by virtue of being sentient.
I have noticed a number of animal people making comments on Facebook about fish
being "less sentient" than other animals.
That is the exact WRONG way to think about sentience. If a being is
sentient, or subjectively aware, that is ALL we need to know. We
should never ask whether, for example, a fish is more or less
sentient than a chicken or cow or whether a chicken is more or less
sentient than a cow or a pig.
If a being is sentient, that being is subjectively aware. That being
has interests, and can suffer. That being has an interest in
continuing to live. In these regards, all sentient beings are the
same. We should not buy into the nonsense that some beings are less
sentient than others so that it morally acceptable, or less morally
wrong, to kill them. Sentience is a yes/no matter; not a matter of
degree. If a being is sentient, then that being is equal to every
other sentient being in that all sentient beings have the moral
right not to be used exclusively as a resource.
Closely related to the idea of "degrees" of sentience is the ideas
of "degrees" of cognitive sophistication. For example, Peter Singer
claims that only animals who are rational and self-aware in a
humanlike way have an interest in continuing to live. I reject that
view.
ANY sentient being has an interest in continuing to live simply by virtue of being sentient. To say that a being can be sentient but not have an interest in continuing to live is to ignore what it means to be sentient.