GENERAL HISTOLOGY

Detailed explanation-1: -Sea urchins are a vital part of our environment because they feed on dead organisms and help to recycle materials into usable energy for other organisms. It is dangerous if populations of echinoderms increases or decreases too drastically in an ecosystem; if a balance is not achieved the entire ecosystem can collapse.

Detailed explanation-2: -Echinoderms are an important part of the ocean food chain, keeping seaweed in check as grazers and serving as food sources for animals like otters. Echinoderms are used as food, medicine, and a source of lime for farmers.

Detailed explanation-3: -Although they may appear very different, echinoderms all have two major defining characteristics that set them apart from all other animals: a water vascular system and five-sided radial symmetry.

Detailed explanation-4: -Echinoderms feed on a variety of marine life in a variety of ways. Filter feeders, like brittle stars, absorb nutrients in marine water. Suspension feeders use their arms to capture floating food particles. Grazers, like sea urchins, feed on both plants and animals, making them omnivores.

Detailed explanation-5: -Food and feeding habits Crinoids are suspension feeders, capturing planktonic organisms in a network of mucus produced by soft appendages, called tube feet, contained in grooves on the tentacles, or arms.