In the biblical context, the dietary laws concerning permissible sea creatures are primarily found in the Old Testament, specifically within the books of Leviticus and Deuteronomy. These laws were given to the Israelites as part of the Mosaic Law, which outlined various aspects of religious, moral, and dietary conduct. The primary passages that address permissible sea creatures are Leviticus 11:9-12 and Deuteronomy 14:9-10.

Leviticus 11:9-12 :
"Of all the creatures that live in the water, whether in the seas or the streams, you may eat anything with fins and scales. But anything in the seas or streams that does not have fins and scales, among all the swarming things and other living creatures in the water, is detestable to you. They shall be an abomination to you; you must not eat their meat, and you must detest their carcasses. Everything in the water that does not have fins and scales shall be detestable to you."

Deuteronomy 14:9-10 :
"Of all the creatures that live in the water, you may eat anything with fins and scales, but you may not eat anything that does not have fins and scales; it is unclean for you."

The criteria for permissible sea creatures are clear: they must have both fins and scales. This requirement excludes a variety of aquatic life, including shellfish (such as shrimp, crabs, and lobsters), mollusks (such as clams, oysters, and squid), and other sea creatures like catfish and eels, which do not possess both fins and scales.

The rationale behind these dietary laws has been the subject of much theological and scholarly discussion. Some suggest that these laws were given for health reasons, as certain sea creatures without fins and scales can be more prone to carrying toxins or parasites. Others propose that the dietary restrictions served as a means of setting the Israelites apart from surrounding nations, emphasizing their unique covenant relationship with God.

In the New Testament, the dietary laws, including those concerning sea creatures, are revisited. In Acts 10, Peter receives a vision in which he is told, "Do not call anything impure that God has made clean" (Acts 10:15). This vision is often interpreted as a sign that the dietary restrictions of the Old Testament were no longer binding on Christians, symbolizing the inclusion of Gentiles into the faith and the new covenant established through Christ.

Despite this New Testament perspective, some Christian denominations and individuals choose to adhere to the Old Testament dietary laws, viewing them as beneficial guidelines for health and spiritual discipline. The discussion of permissible sea creatures thus remains a topic of interest and debate within the broader Christian community.