You might think all the animals that live in the ocean are floating throughout the sea, but there are entire communities of benthic animals and plants that live in a two-dimensional way just like we do on land. ‘Benthos’ are animals and plants that live in or on the ocean floor. These benthic animals live by one of three strategies: 1) attachment to a firm surface, 2) free movement on the ocean floor, 3) burrowing in the sediment. Sometimes a species may live by more than one of these strategies.
Recently, a newly described benthic animal was discovered in the deep-sea off the coast of California. Here is a video produced by the Monterrey Bay Aquarium and Research Institute of the carnivorous sponge, known as the harp sponge (Chondrocladia lyra). It got the common name – harp – because the sponge has evolved up to 6 veins with structures fanning out from the spine to maximize ocean currents. The elaborate ribs have velcro-like hooks used to ensnare tiny prey and are also useful for distributing eggs. These animals use a rhizoid to anchor itself to the sea floor.
What a wonderful creature – and (for the dim layman) an object-lesson clear explanation with enough info & illustration but not too long / detailed. Would make a poor pet, though.