Download Echinodermata Webquest Visit the following web sites to answer the

Echinodermata Webquest
Visit the following web sites to answer the
questions and complete the paragraphs
given on this page. Your instructor may ask
you to copy the questions into a word
document and then complete them by filling
in the missing information.
http://mbgnet.mobot.org/salt/animals/echinod.htm
Echinoderms are __________ ____________ animals that are only found in the sea (there
are none on land or in fresh water). Echinoderms mean "_____________" in Greek. Many,
but not all, echinoderms have spiny skin. There are over 6,000 species. Echinoderms
usually have _____ _____________ (arms or rays), but there are some exceptions.
___________ symmetry means that the body is a hub, like a bicycle wheel, and tentacles are
spokes coming out of it (think of a starfish). As larvae, echinoderms are ____________
_____________. As they mature, they become radially symmetrical. Most adult echinoderms
live on the bottom of the ocean floor. Many echinoderms have ___________ on the ends of
their feet that are used to capture and hold _______, and to hold onto rocks in a swift
current. Each _______________ had hundreds of tiny feet on the bottom of each ray. These
are tube feet, or _______. These tiny feet can be filled with sea water. The __________
_________ of the sea star is also filled with sea water. By moving water from the vascular
system into the tiny feet, the sea star can make a foot move by expanding it. This is how
sea stars move around. Muscles within the feet are used to retract them. Each ray of a sea
star has a light sensitive organ called an __________. Though it can not see nearly as well
as we do, sea stars can detect light and its general direction. They have some idea of where
they are going. Sea urchins, heart urchins, cake urchins, and sand dollars belong to a subgroup of echinoderms called _______________. These creatures have many sharp spines
pointing out in all directions that offer protection from predators.
http://www.starfish.ch/reef/echinoderms.html
Reproduction is carried out by the release of ________ and ________ into the water. Most
species produce _________ (= free floating) planktonic larvae which feed on plankton.
These larvae are __________ -___________, unlike their parents (illustration of a larvae of a
sea star below). When they settle to the bottom they change to the typical echinoderm
features.
Starfish have no hard mouth parts to help them capture prey. The ____________ is extruded
over the prey, thus surrounding the soft parts with the digestive organs. ___________
___________ are secreted and the tissue of the prey liquefied. The digested food mass,
together with the stomach is then sucked back in. This method can be observed, if you turn
around a starfish, that sits on prey or sand - you will see the stomach retreating.
Starfish are well known for their powers of ________________. A complete new animal can
grow from a small fragment such as a arm. In some species one of the arms will virtually
pull itself away, regenerates and forms a new animal (____________ reproduction =
autotomy): Linckia multifora and Echinaster luzonicus. In others the body is broken into
unequal parts (= fission) then the missing limbs regenerate (Allostichaster polyplax and
Coscinasterias calamaria)
http://www.seasky.org/reeflife/sea2d.html
What is the size of the purple sea urchin and where is it typically found?
What is the common name for Psolus chitinoides?
What is the genus and species name for an orange starfish?
http://www.oceanicresearch.org/echinoderm.html
What class of organism is a cushion star and example of?
What class of organism is a basket star and example of?
What happened to the northern sea star photographed in Massachusetts?
Find the following information on sea cucumbers.
Many sea cucumbers are quite _____________. These cucumbers, if injured, can kill fish in
the same aquarium. The poison of some sea cucumbers has shown promise as an inhibitor
in the growth of _________ ___________.
The sea cucumber has another interesting (if not slightly disgusting) habit, called ______ __________. When a sea cucumber is attacked, it may expel some of its internal organs.
This could either satisfy a predator, or scare it off. The cucumber will then proceed to
___________ another set of organs.
http://www.cyhaus.com/marine/Echinoderm.htm
List the 5 classes of Echinoderms with examples
http://animaldiversity.ummz.umich.edu/site/accounts/classification/Echinodermata.html
Look for information on subclass Orphiuroidea
The rays differ from those of asteroids and crinoids in being long and _________, and
nearly solid. They are very flexible and enable the animals to make snake-like movements
(which is the source of the class name: G. ophis = ____________) -- an ophiuroid locomotes
by using two rays to produce a _____________ motion.
_______________ are carnivores, filter feeders, and scavengers; those of some species use
more then one method to obtain food. Mucus on the tube feet can trap phytoplankton,
bacteria, and even medusae from the water or particles from sediment that are moved by
the tube feet to the mouth; some ophiuroids capture small ___________ ____ __________
by looping the organisms with their rays. The mouth is surrounded by five _______ and
leads to an ____________ that connects to the sac-like stomach. The stomach fills much
of the disc, but does not extend into the arms, and ends blindly (that is, it has no ________).
Digestion occurs within 10 pouches or infolds of the stomach.
http://www.ucmp.berkeley.edu/echinodermata/echinomm.html
All echinoderms have a ______________________, a set of water-filled canals branching
from a ring canal that encircles the gut. The canals lead to _________, or tube feet, which
are sucker-like appendages that the echinoderm can use to move, grip the substrate, or
manipulate objects. These tube feet are extended and retracted by hydraulic pressure in the
water-vascular system.
Echinoderms also have a spacious ____________ (an open, fluid-filled body cavity lined
with tissue), large _______, and (usually) a complete gut. Many starfish have the peculiar
ability to feed by turning the stomach inside out through the mouth; sea urchins scrape
algae from rocks with five large teeth arranged in a structure known as "_________
__________." Echinoderms (except holothurians) generally lack respiratory systems, and
many have only rudimentary circulatory systems; the water-vascular system takes over
some of the functions of these systems. Nervous and sensory systems are generally poorly
developed in echinoderms.
http://www.floridasmart.com/subjects/ocean/animals_ocean_echin.htm
A water _____________system
A system of endoskeletal elements (arising from mesoderm) composed of a calcareous
meshwork called ____________
Basic 5-part symmetry (often modified later in ontogeny) expressed in the development of 5
primary lobes in the hydrocoel of the rudiment
Construction of ambulacra by the addition of new plates adjacent to the terminal (or ocular)
plate that marks the ends of the radial canals
A diffuse ______-______________ nervous system
Sea cucumber is a ocean creature found in the wild. A traditionally treatured nutritious sea
delicacy enjoys by most Asians as a healthy products. Known to be free of
______________, sea cucumber is also good for blood purification, enhacing kidney
performace, lowering ________ _______________.
http://tolweb.org/tree?group=Echinodermata&contgroup=Metazoa
List the Synapomorphies of the Echinodermata
list the Plesiomorphies and other features