Different sea urchin species have different spawning seasons. When Biol 101L is held in person, the labs involving sea urchins happen in early September for the fall semester, and early February for the spring semester. Using the information given on Virtual Urchin, which species is best for each semester? Banded urchin (Lytechinus pictus) Purple urchin (Strongylocentrotus purpuratus) > >

Sea urchins are the globular and spiny echinoderms belonging to the class Echinoidea. Approximately 950 species of sea urchins are found in the seabed. The hard shells of these animals are known as tests and are spiny and round. The length of tests is generally 1-4 inches. Sea urchins use tube feet to crawl or move slowly. They also sometimes use their spines to push themselves. Sea urchins primarily feed on algae and also on some sessile or slow-moving animals. The predators of sea urchins include humans, triggerfish, wolf eels, starfish, and sea otters.