Animal Encyclopedia Category: Corals and Other Invertebrates

Shallow-water populations are known to have symbiotic algae living within their cells, providing the corals with excess energy that they make via photosynthesis (the use of sunlight to convert carbon dioxide into food/energy). Nearly all species of shallow-water corals and several other groups of reef invertebrates have symbiotic relationships with these algae. On deep reefs, however, there … Read more

Like most sea cucumbers, the edible sea cucumber is a scavenger. It crawls along soft bottoms near coral reefs and seagrass beds ingesting sand and mud in its path. It separates out and digests any plant or animal matter and passes the sand, leaving a trail of clean sand behind. The edible sea cucumber feeds throughout the day and … Read more

The yellow tube sponge is a relatively large sponge (to over 3 feet/1 m) that lives on coral reefs around the Caribbean Sea and its adjacent waters. The common name is an accurate description of the species, with individuals typically having a yellowish color (sometimes almost iridescent yellow-blue at deeper depths) and consisting of one … Read more

Though this species spends most of its time crawling along the reef surface, it will swim when threatened, violently flapping its external gills and other appendages and displaying its brightest warning colors. This behavior reminded some observers of a flamenco dancer, earning the Spanish dancer its common name. Spanish dancers are specialized predators that prefer to … Read more

Using these stinging cells, the sea wasp hunts small fishes and pelagic invertebrates like swimming crabs or prawns. The cnidocytes are also the source of the powerful sting, and the stories of deaths caused by the sea wasp almost always involve a person being wrapped in multiple tentacles, with stings covering much of the body. There … Read more

Though it has “yellow” in its name, some yellow cup black corals can be a beautiful lime green color. The general name “black coral” refers to the color of the naked skeleton, not to the color of the live animal. Black corals are closely related to stony corals and anemones. Unlike shallow-water corals, most black corals … Read more

The eccentric sand dollar is a relatively small species (reaching sizes of only a few inches in diameter) that lives off the west coast of North America, from Alaska to Baja California. Though they are totally flat, these sand dollars are often observed buried in the sand on an edge with half of their bodies under … Read more

The lobe coral is a common reef-building coral that grows very large and builds large coral reefs throughout its range. This species is one of relatively few that live throughout the tropics, across the entire Indo-Pacific Ocean basin, from the Red Sea to the tropical eastern Pacific, where it is one of the most important … Read more

Since the giant kelp is not a plant, it does not have roots. Instead, it obtains all of the necessary nutrients directly from the water and is attached to the rocky bottom by a structure known as a holdfast. Like plants, however, the giant kelp harvests the sun’s energy through photosynthesis and does not feed on other … Read more

The cushion star, like all sea stars, moves on a system of tube feet, so called because they are operated by a hydraulic system controlled by the main body. They are known to prey on corals and other sedentary animals, as well as decaying organic matter. They feed by inverting their entire stomach, through the mouth, and … Read more