This document discusses fishery, fish cultivation, kinds of fish, and the external and internal parts of fish and their functions. Fishery involves catching, handling, marketing, and preserving fish or aquatic products. Fish cultivation is the raising of aquatic products under controlled environments and is a good source of income, especially for export. There are two main kinds of fish - fin fish which have fins and scales, and shellfish which have outer shells like oysters, shrimps, crabs, crayfish, scallops, lobsters, and prawns. The document then lists the external and internal parts of fish and their functions.