What are echinoderms and cnidarians?

What are echinoderms and cnidarians?

Echinoderms include animals such as sea stars and sea urchins. Most live on the ocean floor, and they have radial symmetry. Cnidarians include animals such as jellyfish, and they all have stinging cells in their tentacles called nematocysts.

What are two examples of echinoderms?

Echinodermata are exclusively marine organisms. Sea stars (Figure 1), sea cucumbers, sea urchins, sand dollars, and brittle stars are all examples of echinoderms. To date, no freshwater or terrestrial echinoderms are known. Figure 1.

What does echinoderm literally mean?

spiny skin

Is echinoderm a class?

The phylum echinoderms is divided into five extant classes: Asteroidea (sea stars), Ophiuroidea (brittle stars), Echinoidea (sea urchins and sand dollars), Crinoidea (sea lilies or feather stars), and Holothuroidea (sea cucumbers). The most well-known echinoderms are members of class Asteroidea, or sea stars.

What does the word echinoderm mean in Greek?

The word “echinoderm” is made up from Greek ἐχινόδερμα, “spiny skin”, cf. ἐχῖνος, “hedgehog; sea-urchin” and δέρμα, “skin”, echinodérmata being the Greek plural form. The echinoderms are important both biologically and geologically.

What does echinoderm mean in Latin?

1834, from Modern Latin Echinodermata, name of the phylum that includes starfish and sea urchins, from Latinized form of Greek ekhinos “sea urchin,” originally “porcupine, hedgehog” (see echidna) + derma (genitive dermatos) “skin,” from PIE root *der- “to split, flay, peel,” with derivatives referring to skin and …

What does echinoderm mean in Greek quizlet?

What does echinoderm mean in Greek? Why is this a good name for this group? Spiny Skin, the osicles make sea stars spiny. Name 2 classes of echinoderms & a member of each class. Asteroidea – True Sea Stars and Sun Stars.

What does the word benthic mean?

1 : of, relating to, or occurring at the bottom of a body of water. 2 : of, relating to, or occurring in the depths of the ocean.

Is jellyfish a Benthos?

Jellyfish are usually thought of as drifting organism there are in fact some forms of medusae and ctenophores that are benthic, with the adult sexual stage spending their entire life on the seafloor. As tiny polyps they are stuck to rocks, shells or algae on the floor of the sea, the benthic zone.

What animals are considered benthos?

Animals that live on the sea floor are called benthos. Most of these animals lack a backbone and are called invertebrates. Typical benthic invertebrates include sea anemones, sponges, corals, sea stars, sea urchins, worms, bivalves, crabs, and many more.