This document discusses fish and shellfish, describing them as two types of water animals eaten as food. It defines fish as having fins and backbones, living in fresh or salt water, while shellfish have shells instead of backbones. Shellfish are further divided into mollusks like oysters and clams, and crustaceans like shrimp and lobster. The document outlines the nutrients found in fish and shellfish, how to purchase and store them properly, and how to cook them for a short time due to their tender nature.