The common names for the four major kinds of echinoderms are
sea star, sea urchin, sea cucumber, and flowery sea lilies
What is the common name of echinoderms?
Echinodermata –
Sea urchins
, Sand dollars, Sea cucumbers, Seastars, Cushion stars, Brittle-stars, Basket-stars, Sea lilies, Feather stars — Discover Life mobile. Click on images to enlarge. The phylum Echinodermata, which means “spiny skin”, has about 20,000 species.
What are the four major kinds of echinoderms?
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 is the most common echinoderm?
Perhaps the most common echinoderm is
the sea star
. Although more well known as the star fish, sea stars are not actually fish.
What are the major classes of echinoderms?
In traditional taxonomy, there are five classes of living echinoderms:
Crinoidea (sea lilies)
, Asteroidea (starfish), Ophiuroidea (brittle stars or snake stars), Echinoidea (sea urchins and sand dollars), and Holothuroidea (sea cucumbers).
What are the 2 types of echinoderms?
- Eleutherozoa are the echinoderms that can move. This group includes the starfish and most other echinoderms.
- Pelmatozoa are the immobile echinoderms. This group includes crinoids, such as the feather stars.
What shape are echinoderms?
The general shape of the echinoderm may be that of a star with arms extended from a central disk or with branched and feathery arms extended from a body often attached to a stalk, or it may be
round to cylindrical
.
What do echinoderms have instead of brains?
Echinoderms do not have brains, they
have nerves running from the mouth into each arm or along the body
. They have tiny eyespots at the end of each arm which only detect light or dark. Some of their tube feet, are also sensitive to chemicals and this allows them to find the source of smells, such as food.
What is unique about echinoderms?
Echinoderms possess a unique
ambulacral or water vascular system
, consisting of a central ring canal and radial canals that extend along each arm. Water circulates through these structures and facilitates gaseous exchange as well as nutrition, predation, and locomotion.
Which organ is absent in echinoderm?
Echinoderms lack
specialized excretory (waste disposal) organs
and so nitrogenous waste, chiefly in the form of ammonia, diffuses out through the respiratory surfaces.
Do sea stars have hearts?
Sea stars have a very unusual
circulatory system
. They do not pump blood around their bodies. Instead, they use seawater and a complex water vascular system to keep things moving. Their tube feet, also used for movement, are an important part of this circulatory system.
Is a jellyfish an echinoderm?
Cnidarians
are invertebrates with stinging cells called nematocysts. Included in the cnidarian group are anemones, corals, and jellyfish.
What does echinoderm mean in English?
: any of a phylum (Echinodermata)
of radially symmetrical coelomate marine animals including
the starfishes, sea urchins, and related forms.
What are the 6 classes of echinoderms?
six classes: (1) Asteroidea, sea stars; (2) Ophiuroidea, brittle stars and basket stars;
(3) Echinoidea, sea urchins and sand dollars
; (4) Holothuroidea, sea cucumbers; (5) Crinoidea, sea lilies and feather stars; and (6) Concentricycloidea, sea daisies.
What is the largest echinoderm class?
The largest class in phylum Echinodermata with the most number of species is
Ophiuroidea
with the more popular class Asteroida a near second.
Which echinoderms have arms?
Sea stars
have thick arms called ambulacra that are used for gripping surfaces and grabbing hold of prey. Brittle stars have thin arms that wrap around prey or objects to pull themselves forward.
