Fish dissection.

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Living things are similar to and different from each other. When we look at the inside of a fish, we will learn that certain organs and systems in fish are similar to those in humans; and other organs and systems are not. Stomach contents can tell us much about a fish's habit. The external anatomical features (outside body parts) of fish can also tell us a lot about a species--where it lives in the water, how it finds food, and how it protects itself from predators.

Vocabulary

• Anal Fin - fin located near the anal opening; used for balance and steering.
• Caudal or Tail Fin - fin at the tail of a fish; used for propulsion.
• Circulatory System - delivers blood and oxygen throughout the body via the heart.
• Digestive System - breaks down and processes proteins, carbohydrates and fats.
• Dorsal Fin - backside (top) fin on a fish; used for balance and protection.
• External Anatomy - the outside body parts, such as, fins, scales, mouth.
• Gills - organ used to obtain oxygen from the water and rid carbon dioxide.
• Gill Rakers - filter feed tiny prey; appendages along the front edge of the gill arch.
• Gonads - the sex organs; males have testes, females have ovaries. Some fish are hermaphroditic, meaning having both sets of gonads (male & female) in one fish.
• Lateral Line - organ of microscopic pores that sense low vibrations and water pressure.
• Nares - organ to smell; similar to nostrils.
• Nervous System - organs receiving and interpreting stimuli for nares, eyes, lateral line, muscles, and other tissues.
• Pectoral Fin - fins on the sides; used for balance and assist turning.
• Pelvic Fin - belly fins on a fish; used for balance and steering.
• Pyloric Caece - "finger-like" organ that aids in digestion, using bile from the liver.
• Reproductive System - the organs and tissues involved in reproduction, including gonads, eggs, sperm.
• Respiratory System - organs and tissues involved in the oxygen & carbon dioxide gas exchange, including gills, gill rakers, and gill filaments.
• Scales - protective cover on a fish; similar to skin.
• Slime - slippery covering on scales, protecting fish from bacteria, parasites, etc.
• Swim bladder - found only in "ray-finned" fish; a double sac used to assist in buoyancy.
• Urinary System - the kidneys remove nitrogen (ammonia) from the blood and regulate water balance in the blood and tissues.
• Vertebrate - an organism with a backbone or spine.