Perch ‒ Anatomy

The body of a fish is divided into three main regions: the head, trunk, and tail. On the head, there is a mouth equipped with sharp teeth for capturing prey, as well as a pair of nostrils and eyes. The trunk features two sets of paired fins (the pectoral fins and the pelvic fins) as well as four unpaired fins: the cranial and caudal dorsal fins, the anal fin, and the caudal fin. The perch's skeleton is composed of both bone and cartilage. Its respiratory system includes four gills for breathing. The digestive system comprises a large liver, a stomach, a small intestine that empties into a large intestine, and an anus for expelling waste. The spleen is also present, functioning to filter blood, produce white blood cells, and contribute to the immune system. Perch have a two-chambered heart with an atrium and a ventricle. The primary reproductive organs differ by sex: males have a pair of testes, while females have a single large ovary located in the same position. The nervous system is divided into the central nervous system, which includes the brain and spinal cord, and the peripheral nervous system, which consists of nerves outside the brain and spinal cord. The primary excretory organs are a pair of elongated kidneys.