Leviticus 11:9-12 ESV
These you may eat, of all that are in the waters. Everything in the waters that has fins and scales, whether in the seas or in the rivers, you may eat.
But anything in the seas or the rivers that does not have fins and scales, of the swarming creatures in the waters and of the living creatures that are in the waters, is detestable to you.
You shall regard them as detestable; you shall not eat any of their flesh, and you shall detest their carcasses.
Everything in the waters that does not have fins and scales is detestable to you.
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Life According to the Bible, and the Scientific Evidence
So one may observe that the definition of a nervous system must not be thought of in terms of its basic function (response to stimuli), but in terms of its makeup (specialized cells).
answersingenesis.org