Question

what features do the sea urchins and sea cucumbers, sea brittle and sea stars have in common that identify them as a echinoderms​

Answer 1

Answer:

Whether you are a newly certified diver (if so, we offer our congratulations) or an old salt (good for you, too), odds are you are familiar with the animals known as echinoderms.The feet hold tight to the bottom as muscles within the feet contract, enabling the animal to propel itself. Repeating this process allows echinoderms to travel in a fashion that is “more turtle than hare.”One of the most remarkable traits about echinoderms is their ability to regenerate body parts that have been lost. Many tropical destinations have learned this lesson the hard way. A sea star known as the wnwn of thorns readily preys upon living corals, and a crown of thorns invasion poses a serious, but usually temporary threat, to coral reef ecosystems. A few decades ago, when crown of thorns showed up in big numbers, resort owners asked local divers to go into the water and chop them up. Bad idea. Like many sea stars and brittle stars, crown of thorns not only regenerated lost parts, but in some instances the lost part often regenerated an entirely new animal. The not-surprising lesson here, “Don’t mess around with Mother Nature.” The ability to regenerate is an important part of the survival strategy of many species as they readily sacrifice body parts to escape predation.Sexes are separate in most echinoderms, but they look very similar and distinguishing male from female is a task best left to specialists. Reproduction is most often achieved by spawning as males and females simultaneously release sperm and eggs into the water column where sexual union occurs. The resulting larval life-forms spend from a few days to a few weeks as part of the community of plankton before settling down to live their adult lives on the sea floor.