Endodermis develops into the gut tracts (GI Tract, Urinary Tract, Respiratory system, Auditory system, Endocrine glands)
What does the Mesoderm develop into?
Mesoderm develops into muscles and most other organs (bone, muscle, connective tissue)
What does the Ectoderm develop into?
Ectoderm develops into epidermis and nervous system
What are the three types of symmetry animals display?
Bilateral symmetry, Radial Symmetry, and Asymmetry
What are the two classes of animal embryos, what germ layers do they comprise of, and what type of symmetry is it associated with.
1. Diploblastic two germ layers (Ecto/Endo); Radial symmetry
2. Triploblastic three germ layers (Ecto/Meso/Endo); Bilateral symmetry
Which type of embryonic development will animals exhibit a body cavity?
What are the types of body cavities?
A body cavity can be pseduocoelomic (meso/endo) or a true coelom (meso only)
All animal are ________, representing a clade called _______.
Monophyletic ; Metazoa
What animal is considered paraphyletic?
Define a Coelom.
A fluid filled body cavity
Define what a True Coelom is.
A body cavity completely lined with mesoderm
What are animals with true coeloms called?
What are animals without coeloms called, and what does the body cavity contain instead of fluid?
Acoelomates; instead of fluid, the body cavity contains mesenchyme, a tissue derived from mesoderm.
What is a fluid-filled body cavity surrounded by muscles that supports the shape of the body of an organism?
When the body of an organism is divided into regions called segments
What animals exhibit segmentation?
chordates (to a lesser extent)
Give an example of an Acoelomate.
Give an example(s) of a Pseudocoelomate
Roundworms and Rotifers
Give an example of a Coelomate
What are the two large clades under Metazoa?
Deuterostomes and Protostomes
What are the two clades under Protostome?
Ecdysozoans and Lophotrochozoans
What does the term Ecdysis mean?
It means the process of shedding an old exoskeleton
What are two clades under Ecdysozoans
Nematoda and Arthropoda
What are the two features that Lophotrochozoa refers to?
1. Lophophore a crown of ciliated tentacles that function in feeding (exhibits in Brachiopods, Rotifers, and Bryozoans)
2. Trocophore Larvae a developmental stage that Annelids and Mollusks go through
What are the two clades of basal members of Eumetazoans? What type of embryonic development and symmetry do they exhibit?
Cnidaria and Ctenophora
Define cephalization. What type of animals exhibit it?
Localization of sensory organs at the anterior end of the organism
Give a brief description of sponges.
Sponges are sessile, with porous bodies and choanocytes
What do sponges have instead of nervous tissue?
Individual cells that react to the environment by detecting or retracting
What are the three lineages of sponges?
Hexactinella, Colcarea, Demospongia
Describe the spongocoel. What is it also know as?
Central cavity of the sponge
Describe the Osculum of sponges.
Larger excurrent opening of the spongocoel
Describe the Epidermis of sponges.
Single layer of flattened cells, forms out surface
Describe the Porocyte of sponges.
Cells which form pores; possess a hollow channel through the center which extends from the out surface (incurrent pore) to spongocoel
A synonym for Choanocytes is ______.
Describe the Choanocyte of sponges.
Collar cell, majority of cells which line the spongocoel, possesses a flagellum. Flagellar movement moves water and food particles which are trapped on the collar and later phagocytized
Describe the Mesohyl of sponges.
Gelatinous layer located between the two layers of the sponge body wall (epidermis and choanocytes)
Describe the Amoebocyte of sponges.
Wandering, pseudopod bearing cells in the mesohyl; function in food uptake from choanocytes, food digestion, nutrient distribution to other cells, formation of skeletal fibers, gamete formation
Describe the Spicule of sponges.
Sharp, calcium carbonate or silica structures in the mesohyl which form the skeletal fibers of many sponges
Flexible, proteinaceous skeletal fibers in the mesohyl of some sponges
Which specific sponges exhibit Siliceous spicules?
Euplectella (Venus flower basket)
Which specific sponges exhibit Calcareous (CaCO3) spicules?
What type of sex are sponges?
Sponges are hermaphroditic (monecious)
How do sponges reproduce?
Asexually and sexually
Give a brief description of the Cnidaria clade.
Exhibit radial symmetry, has a GVC, and has cnidocytes
True of false: Cnidarians are exclusively marine.
False: Cnidarians are mostly marine
What animals are included under the Cnidarians?
What two body forms can Cnidarians exhibit?
A sessile Poly form, and a motile Medusa form
Define the Gastrovascular Cavity (GVC).
a central digestive cavity with only one opening (functions as mouth and anus)
Cnidarians have photosensitive light organs know as ______.
True of False: All Cnidarians exhibit both body forms.
False: Some species exist only as polyps, some only as medusa, others are dimorphic (both polyp and medusa stages in their life cycles)
Describe the Polyp form.
cylindrical form which adheres to the substratum by the aboral end of the body stalk and extends tentacles around the oral end to contact prey
Describe the Medusa form.
flattened, oral opening down, bell-shaped form: moves freely in water by passive drifting and weak ell contractions; tentacles dangle from the oral surface which points downward.
True of False: Cnidarians exhibit the simplest forms of muscle/nervous systems.
What does the GVC in Cnidarians act as when filled with water?
acts as a hydrostatic skeleton
What coordinates movement in Cnidarians?
What are the 3 lineages of Cnidaria?
Hydra (small jellyfish, Obelia and the Portuguese man-of-war)
Scyphozoa (large jellyfish)
Anthozoa (sea anemones and coral)
True or false: Hydrozoans exhibit the medusa stage only.
False: Most alternate polyp and medusa forms in their life cycle
Hydrozoans are dominant in which form?
True of False: Hydrozoans have Cnidocytes.
Give an example of a colonial, and a solitary Hydrozoan.
Colonial = Obelia
Solitary = Hydra
Give an example of a Hydrozoan that exhibits only the Poly stage.
How do Hydrozoans usually reproduce?
reproduce asexually (by budding), however, in unfavorable conditions will reproduce sexually.
What animals are included in the Schyphozoan clade?
Which life stage is dominant in Scyphozoans?
How has varying environments effected the Polyp stage of Scyphozoans?
Coastal species usually pass through a small poly stage while open ocean species have eliminated the polyp stage completely
Name an organism under Scyphozoa.
Aurelia (moon jellyfish)
What is a young/immature medusa called?
What animals are in the clade Anthozoa?
sea anemones and coral animals
True of False: Anthozoans occur only as the medusa stage.
False; they occur only as Polyps
What substance are the external skeletons of coral animals made of?
calcium carbonate (CaCO3)
True of False: Ctenophores have a complete gut (mouth and anus).
The clade Ctenophora has which animal?
True of False: Ctenophores are found in both marine and freshwater
False; Ctenophores are exclusively marine
Ctenophores have a pair of long retractable tentacles (instead of Cnidocysts) called _____.
The sensory organ of Ctenophores is called a _______.
How many rows of fused cilia do Ctenophores have?
Define a Lophophore.
Horseshoe-shaped (ectocarp) or circular fold of the body wall bearing ciliated tentacles that surround the mouth at the anterior end.
What three groups of animals exhibit a Lophophore?
Name a freshwater Bryozoan.
What animals are under the Bryozoan clade?
True of False: Bryozoans are exclusively marine
False: Bryozoans are mostly marine
What animals are under the Brachiopod clade?
True of False: Brachiopods are exclusively marine
The body of a Brachiopod is enclosed by _______ and _______ shell halves.
Dorsal and Ventral
Brachiopods attach to the _______ by a fleshy stalk called a _________)
What type of Coelom do Brachiopods and Bryozoans possess?
a True Coelom
What animals are under the Phoronid clade?
Tube-dwelling marine worms
Phoronids live buried in sand in _______ tubes with the ______ extended from the tube when feeding
What animals are under the Platyhelminthes clade?
True or False: Flatworms are true coelomates.
False: Flatworms are acoelomates
True of False: Planarians exhibit gas exchange through diffusion.
What are the 4 lineages of Platyhelminthes?
Give a brief description of Planarians.
Carnivorous, they feed on small animals and carrion(dead animals). Lack specialized organs for gas exchange or circulation
What animals are included under the Turbellarian clade?
Give an example of a Turbellarian (specific genus/species).
Dugesiatigrina (brown planarian)
In Tubellarians, a ____ _____ excretory apparatus (called a ______) is present, which maintains osmotic balance.
Flame Cell ; protonephritia
What type of brain do Tubellarians possess?
A rudimentary brain (cerebral ganglia) capable of simple learning
Through what methods do Tubellarians reproduce?
asexually or sexually
How do Tubellarians reproduce sexually?
Sexually by cross-fertilization of the hermaphroditic forms
What are the two methods of movement Planarians utilize?
1. Use cilia on the ventral dermis to glide along with a film of mucus
2. Muscular contractions to produce undulations
How do Tubellarians reproduce asexually?
Asexually by regeneration; mid-body constriction separates the parent into two halves, each of which regenerates the missing portion
Which environments can Turbellarians be found?
Mostly marine, a few species in fresh water and moist terrestrial habitats
What type of animals are included in Monogenea and Trematoda? (think dietary habit)
What are the eyespots that detect light in Turbellarians called?
Ocelli (or Ocelus)
Flukes are members of Monogenea or Trematoda?
Ectoparasites of fish are members of Trematoda or Monogenea?
In Trematodas, the primary organ system is the ______ system; majority are _______
Reproductive ; hermaphroditic
Give an example of a specific Trematoda.
Clonorchissinensis (Chinese liver fluke)
What is the final (definitive), and intermediate host of the Chinese liver fluke?
Final (definitive) = Sheep
Intermediate - Snails
True of False: Trematodes have a fixed sex.
False: Life cycles include alternations of sexual and asexual stages with asexual development taking place in an intermediate host
Name the common parasitic Trematoda that infects humans.
Schistosoma (blood fluke)
Monogenea has structures (called ________) with large and small hooks are used for attaching to the host animal
_______ is a Monogenea found in the bladder of frogs and toads.
True of False: All Monogenea are hermaphroditic and reproduce asexually
True: All are hermaphroditic and reproduce asexually
What organisms are under the clade Cestoda, and give an example of one.
How can Cestodas reproduce?
Can be self/cross fertilizing hermaphrodites
Describe what a Proglottid is.
Posterior to the scolex is a long ribbon of nits called proglottids
proglottid is filled with reproductive organs
True or False: Cestodas exhibit a digestive system.
False: No digestive system is present
True or False: Rotifers are solely found in fresh water.
False: mainly freshwater though some are marine and others are found in damp soil
The body cavity of Rotifers acts as a ______ ______.
What type of body cavity do Rotifers exhibit?
What type of digestive system is present in Rotifers?
Complete digestive system is present
Rotifers have a jaw-like organ (called a ______) posterior to the mouth that grinds up food.
Rotifers contain a certain and consistent number of cells as adults. This phenomenon is know as _______. What other organism exhibits this phenomenon?
Eutely ; nematodes
True of False: Most animals of Nemertea are found in marine water.
True: Most are marine with a few in fresh water and damp soil
The lineage Nemertea has which organisms?
proboscis worms or ribbon worms
Nemertea posses a long retractable hollow tube called a ________ that is used for locomotion, defense, and to capture prey.
List 3 systems Nemertea have in common with Planarians.
Like flatworms, Nemertea are structurally _______.
What are 2 major differences between Nemertea and Platyhelminthes?
1. Nemertea has a closed Circ. Sys (consists of blood vessels). Some species have RBCs containing a form of hemoglobin (transports oxygen). No heart is present, body muscle contractions move the blood through the vessels.
2. Nemertea possess a complete digestive system (mouth and anus)
Give a genus/species of a Nemertean.
Lineus longissimus boot-lace worm found in the North sea
What where the two important evolutionary adaptions of Annelids?
Presence of a true coelom + segmentation
What function does the coelom serve in Annelids?
Serves as a hydrostatic skeleton
permits development of complex organ systems
protects internal structures
permits the internal organs to function separately from the body wall muscles
What environments can Annelids be found in?
marine, freshwater, and terrestrial (damp soil)
Annelids have a coelom partitioned by _____. The ______ tract, longitudinal ______ _____, and ______ ______ penetrate the ______ and extend the length of the animal
Septa ; digestive ; blood vessels ; nerve ; septa
Describe the digestive system of Annelids (in order).
All Annelids except the leeches have chitinous bristles called ______ on each segment.
What circulatory system do Annelids have?
Closed circulatory system
In Annelids, the excretory system of paired ________ is found in each segment; each of which has a _________ (which removes wastes from the coelomic fluid and blood) and exits the body through an exterior pore, called a __________.
Metanephridia ; nephrostome ; nephridiophore
The annelid Nervous System is composed of a pair of _____ _______ lying above and anterior to the _______.
Cerebral ganglia ; pharynx
A synonym for Cerebral Ganglia is?
In Annelids, a special organ called a ______ secretes a mucous cocoon which slides along the worm, picking up eggs and stores sperm during sexual reproduction.
A _____ _______ around the pharynx connects these ganglia to a subpharyngeal ganglion, from which a fused pair of _______ ________ runs posteriorly
Nerve ring ; nerve cords
Do Annelids have only one sex, and how do they reproduce?
Annelids are hermaphroditic (Monecious)
cross-fertilize during sexual reproduction, or asexually reproduce by fragmentation followed by regeneration
What two types of muscles do Annelids possess?
Circular and longitudinal
What are the three lineages of Annelids?
Oligochaeta, Polychaeta, Hirudinea
Oligochaeta has which species? Give an example of a specific organism.
Contains earthworms and a variety of aquatic species
Lumbricusterrestris (common earth worm)
Which environments can Polychaeta be found? Give an example of a specific organism.
Contains mostly marine species. A few drift and swim in the plankton, some crawl along the sea floor, and many live in tubes they construct by mixing sand and shell bits with mucus.
Nereis: clamworm or sandworm
In Polychaeta, each segment has a pair of _______ which are highly vascularized paddle-like structures that function in _____ ________ and ________
Parapodia ; gas exchange ; locomotion
How is the traction for locomotion in Polychaeta provided?
Traction for locomotion is provided by several chitinous setae present on each parapodium
Hirudinea contains which species?
Contains the leeches (have no setea, and seasonal clitellum)
True of False: Hirudinea are found solely in fresh water.
False: A majority of species are freshwater but some are terrestrial in moist vegetation
True of False: Leeches has a clitellum
True, but it is seasonal
Leeches also secrete _______ which prevents blood coagulation during feeding.
Name two specific organisms of the Hirudinea clade.
Hirudomedicinalis (European medicinal leech)
Haementariaghiliantii (giant amazon leech)
List the 3 parts that make up the Molluscan.
a muscular foot (locomotion)
visceral mass (house organs)
and a mantle (which secretes the shell)
What types of animals are included in the Mollusca clade?
octopuses and squids
Which environments can Mollusca be found?
Mainly marine, though some inhabit fresh water and many snails and slugs are terrestrial
A______ is present in many Mollusca and functions as a rasping tongue to scrape food from surfaces
True of False: All Mollusca are monecious.
False: Some species are monecious while most are dioecious
What are the 4 lineages of Mollusca?
The clade Polyplacophora contains which species?
Polyplacophora have an _____ shape with the shell divided into _____ dorsal planes
Oval ; 8
The clade Gastropoda contains which animals?
Contains snails and slugs
Only mollusks to undergo what embryonic developmental defect?
During embryonic development, it is a distinct characteristic
Uneven growth in the visceral mass causes the visceral mass to rotate 180degrees placing the anus above the head in adults
Gastropoda are found in which environments?
Mostly marine, many are freshwater or terrestrial
In Gastropodians, the shell is absent for which organism(s)?
absent in slugs and nudibranches “Sea-Slugs”
What type of diet do Gastropods exhibit?
Most gastropods are herbivorous, using radula to graze on plant material. Other groups are predatory and possess modified radula (ConusSnail)
How do aquatic and terrestrial Gastropods exhibit gas exchange?
Most aquatic gastropods exchange gas via gills
Terrestrial forms have lost gills and utilize a vascularized lining of the mantle cavity for gas exchange
______ snails = land snails
The Bivalvia clade contains which animals?
mussels and scallops
Bivalvians have no ____
Have no radula
Explain the two shell halves of Bivalvians
The shell halves are hinged at the mid-dorsal line and are drawn together by two adductor muscles to protect the animal
Bivalves may extend the foot for motility or anchorage when the shell is open
The mantle cavity (between shells) contains gills which function in gas exchange and feeding
What type of feeders are most Bivalvians?
Most are suspension feeders and they trap small food particles in the mucus coating of the gills and then use cilia to move the particles to the mouth
True of False: All Bivalvians are sessile.
False: Not all Bivalves lead sedentary lives (scallops can be motile). The sessile ones use the foot as an achor in sand or mud. Sessile mussels secrete threads that anchor them to rocks, docks or other hard surfaces
How do scallops (Bivalvians) propel themselves?
Scallops can propel themselves along the sea floor by flapping their shells
Give a genus/species of a Bivalvian.
Tridacnagigas (Giant clam)
The clade Cephalopoda contains which animals?
Contains squids and octopuses and chambered nautilus’
What is special about the mantle and shell of Cephalopods?
A mantle covers the visceral mass, but the shell is either reduced and internal (pen) as in squids, or totally absent as in octopuses
Name the only living cephalopod today.
The ChamberedNautilus is the only shelled cephalopod alive today
Name three genus/species of Cephalopoda.
Loglio - common Atlantic squid
Architeuthisdux – giant squid
Mesoychoteuthishamiltoni – colossal squid
What type of circulatory system do Cephalopods have?
Cephalopods are the only mollusks with a closed circulatory system (blood is contained in blood vessels)
Nematoda includes which type of worm?
True of False: Nematodes are segmented worms.
False: Nematodes are unsegmented, and cylindrical with tapered ends
Which environments can Nematoda be found?
Found in fresh water, marine, moist soil, tissues of plants, and tissues and body fluids of animals
What type of digestive system do Nematodes have?
A complete digestive tract is present (mouth+anus) and nutrients are transported through the body in the pseduocoelomic fluid
What forms the outer body covering of Nematodes?
A tough, transparent cuticle (typically made of collagen) forms the outer body covering
True or False: Nematodes are monoecious
False: They are dioecious and sexually dimorphic (M and F look different) with females larger than males
Through what method of reproduction do nematodes exhibit?
Sexual reproduction only, with internal fertilization
What is a similar characteristic of Nematodes and Rotifers?
Both exhibit Eutely (fixed number of cells as adults)
List the 8 parasitic nematodes
Loaloa (African eye-worm)
Dracunculusmedinensis (fiery serpent)
DiroFilariaimmitis (heartworm; vector is mosquito)
Wuchereriabancrofti (causes Elephantiasis; lives in the lymphatic system; has microfilaria)
Name the species of Nematode that is cultured to use as a model species.
Briefly describe Arthopodian's bodies.
Have regional segmentation, jointed appendages, and exoskeletons
List the 4 lineages of Arthropoda.
Trilobites (all extinct)
The arthropod body is completely covered by the ______, an exoskeleton constructed of _____ and ______ (an insoluble polysaccharide)
What type of circulatory system do Arthropods have?
Open circulatory system, containing hemolymph
Arthropods show extensive _______.
In Arthropods, the blood sinuses comprise the ______, and though it is the main body cavity, it is not part of the ______.
Describe the Spiders bodies.
The Spider's (chelicerae) body is divided into an anterior cephalothorax (head+thorax) and a posterior abdomen
How do Chelicerates get their name?
Chelicerates are named for their feeding appendages, the chelicerae
Where are the bulk of modern Chelicerates found?
The bulk of modern Chelicerates are found on land in lineage Arachnida.
Chelicerates includes which organisms?
Includes terrestrial spiders, scorpions, ticks, and mites
List the gas exchange structures of Arthropods, and give an example organism for each.
Feathery gills in aquatic species (e.g. Crayfish)
Tracheal systems in insects (e.g. Grasshopper)
Book lungs in other terrestrial forms (e.g. Spiders)
Name a specific animal that has book gills.
Limuluspolyphemus (Horseshoe crab)
List the 4 structures of the Arthropod tracheal system
Trilobites had extensive _____, but little appendage ______.
Give an example of an early Chelicerate.
Eurypterids (sea scorpions)
Describe how the Chelicerate body is divided
Anterior cephalothorax (head+thorax)
Chelicerates are named for their feeding appendages called ______.
How many modern species of Chelicerates remain? Name one specific organism alive today
What animals does Chelicerates include?
Describe the Arachnid body
Cephalothorax with sex pairs of appendages
Chelicerae pedipalps (used in sensing and feeding)
Four pairs of walking legs
In Chelicera, gas exchange occurs via ____ _____.
Millipedes and Centipedes are collectively know as _____.
The lineage Diplopoda includes the ______.
Give three descriptions of Millipedes.
Wormlike with a large number of walking legs (two pairs per segment)
Eat decaying eaves and other plant matter
Probably among the earliest land animals
The lineage Chilopoda includes the ______.
Give 4 descriptors of Centipedes.
They are carnivorous
One pair of antennae and three pairs of appendages modified as mouthparts (including mandibles) are located on the head
Each trunk segment has one pair of walking legs
Poison claws on the most anterior trunk segment are used to paralyze prey and for defense
Insects are also known as “______”
Insects inhabit where?
They inhabit terrestrial and freshwater environments, but only a few marine forms exist
______ = the study of insects
What was the key to the success of insects?
Flight is the key to the success of insects, enabling them to escape predators, find food and mates, and disperse more easily than nonflying forms
What type of digestive system do Insects have?
Complete digestive system with specialized regions
What are the excretory organs of Insects called?
Excretory organs are the Malpighiantubules, which are out-pocketing of the gut
How do Insects exhibit gas exchange?
Gas exchange is by a tracheal system, which opens to the outside cilia spiracles that can open or close to regulate air and limit water loss
What is the Insect nervous system comprised of?
Nervous system is composed of a pair of ventral nerve cords (with several segmental ganglia aka Metameric ganglia) which meet in the head where the anterior ganglia are fused into a dorsal brain close to the sense organs
Many insects undergo _______ during their development.
Are insects Monecious or Dioecious? How do the reproduce?
Insects are dioecious and usually reproduce sexually with internal fertilization.
Where are Crustaceans found?
Marine and freshwater
Explain the specialization of Crustacean appendages.
Two pairs of antennae, three or more pairs of mouthparts including mandibles, walking legs on the thorax appendages are present on the abdomen
Lost appendages can be regenerated
List the 4 characteristics of Crustacean physiology.
Gas exchange may take place across thin areas of the cuticle (small forms) (Daphnia is an example organism) or by gills (large forms)
An open circulatory system is present with hemolymph
Nitrogenous wastes are excreted by diffusion across thin areas of the cuticle
Salt balance of the hemolymph is regulated by a pair of specialized antennal or maxillary glands
True or False: Crustaceans are monecious.
False: Most are dioecious and some males (lobsters) have a specialized pair of appendages to transfer sperm to the females reproductive pore during copulation
The _______ are relatively large crustaceans that have a _______ (_____ _____ hardened exoskeleton over the __________)
Give examples of Crustaceans
Marine lobsters, crabs and shrimp
Tropical land crabs
The _______ are mostly small marine crustaceans but include terrestrial sow bugs and pill bugs.
Copepods are numerous small marine and freshwater planktonic crustaceans
True of False: Barnacles are crustaceans
True of False: Barnacles shells are Siliceous.
False: Barnacles shells are made of calcium carbonate (CaCO3)
How do barnacles feed?
Barnacles feed by directing suspended particles toward the mouth with specialized appendages (Cirri)
Echinodermata have what kind of vascular system, and what symmetry?
Have water vascular systems and secondary radial symmetry
True or False: All echinoderms are sessile.
False: Most echinoderms are sessile or sedentary marine forms with radial symmetry as adults
Give three descriptors of the echinoderms body.
Internal external parts radiate from the center, often as five spokes
A think skin covers a hard calcareous plate-like endoskeleton
Most have bumps and spines which serve various functions
Describe the uniqueness of the Echinoderms vascular system.
A unique feature of echinoderms is the water vascular system, a network of hydraulic canals which branch into extensions called tube feet that function for locomotion, feeding, and gas exchange
True or False: Echinoderms are diecious
True: Echinoderms are dioecious with sexual reproduction and external fertilization
True or False: Echinoderms are found in marine and freshwater.
False: All are marine
List the 6 lineages of Echinoderms.
The clade Asteroidea includes what animals.
Includes the sea stars or starfish which have five or more arms extending from a central disc (pentamerous radial symmetry)
Give a genus of an Asteroidea
Asterias – common starfish
The clade Ophiuroidea contains which animal.
How do Brittle Stars differ from sea stars? (5 ways)
Smaller central discs than sea stars
Longer, more flexible arms than sea stars
No suckers on their tube feet
Locomotion is by serpentine lashing of flexible arms
Varying feeding mechanisms
The voluntary release of appendages to avoid predators
The clade Echinoidea contains which animals?
Contains the sea urchins and sand dollars
Echinoideans lack arms but have what?
Five rows of tube feet present that provided slow movement
Muscles that pivot their spines to aid in locomotion
Describe the jaw-like structure of Echinoideans.
Echinoideans have a complex jaw-like structure (Aristotle’s Lantern) present around the mouth which is used for feeding on seaweeds and other foods
True or False: Most sea lilies are sessile.
True: Most sea lilies are sessile, living attached to substratum by stalks
The Crinoidea clade contains which animal(s)?
Contains the sea lilies
The Holothuroidea clade contains which animals?
Contains the sea cucumbers
How do sea cucumbers differ from other echinoderms?
They lack spines
The hard endoskeleton is reduced
The body is elongated in the oral-aboral axis
Species in the ________ do possess five rows of tube feet, a part of the unique water vascular system
What makes the Concentricycloidea controversial?
The controversial Concentricycloidea may not be a separate lineage but unusual Asteroidea. The group is know as the Sea Daisies. They have a water vascular system with tube feet on the body surface around the edge of the disk. Deep oceanic form.