Oceanography – Perch Dissection
Our aspiring marine zoologists accomplished a perch dissection today! Perch are a type of bony fish and are fascinating because of many of their organs are analogous to our own (eyes, nose, jaw, bones, heart, stomach, liver, gonads, etc). Campers observed a variety of interesting adaptations unique to the perch, including a swim bladder which is a small, clear gas-filled sac inside the body of the perch which fills with air (or empties) allow the perch to have buoyancy in the water and gonads that take up so much room inside the perch that other structures are displaced!
Ask your camper: Why did the gonads of the fish occupy so much space inside the body of the perch? (fish carry out external fertilization, which requires production of a lot of gametes-hence, larger gonads – to increase the probability that at least some of the gametes become fertilized and turn into offspring, allowing those genes to pass into the next generation)