BI 340 Phylum Echinodermata

Pentaradial

Most Echinoderms have secondarily derived _____ symmetry

6000

Amount of species of Echinoderms

Oral aboral

Symmetry of Echinoderms is based on their ____ _____ axis

Endoskeleton

Echinoderms have a mesodermally derived ______

Complete

What kind of digestive tract do Echinoderms have

Hemal system

Echinoderms have a circulatory system (if present) known as the ____ _____ which is derived from coelomic sinuses

Excretory

Echinoderms do not have a specialized ______ system

Decentralized

The nervous system of echinoderms can be described as

Hydrocoel

What is the water vascular system derived from

adults

Five-fold symmetry in echinoderms is only present in

nerve ring or nerve net

The decentralized nervous system of Echinoderms is present in the form of a ___ ____ or ____ ____

Bilateral symmetry

Symmetry of echinoderm larva

Sea urchins and sea cucumbers

Some echinoderms such as ____ ________ develop secondary bilateral symmetry

Mutable collagenous tissue

Connective tissues of echinoderms that can change viscosity from very rigid to soft and flexible and back

Ionic environment

While the WVS is not completely understood it is believed that changes in the ____ _____ alters interactions between molecules to allow for alterations in tissue

Autotomize

The water vascular system can be used to ______ arms and other parts, especially in brittle stars or used to reposition the organism (in sea lillies)

Water vascular system

Despite having no muscles in their stalk, sea lillies are able to reposition themselves due to their

Coelom

The water vascular system is derived from the

Madreporite

External connection of the WVS

Polian vesicles

These store fluids in the WVS

Tiedmans bodies

These regulate turgor pressure in the WVS

Hydrostatic pressure

In many echinoderms tube feet are operated by ___ ____ generated by the WVS

Ampulla

Pressure is applied to the bulb of the tube foot known as the _______

Locomotion, attachment, feeding, gas exchange, and sensory reception

What are the functions of tube feet

Class Asteroidea

Class of Echinoderms which contains sea stars and sea daisies

2000

Amount of species of Class Asteroidea

Intertidal and subtidal habitats

Where is organisms within Class Asteroidea found

Predators or scavengers

What is the feeding methods of Class Asteroidea

Class Ophiuroidea

Class of Echinoderms which contains brittle stars and basket stars

2000

Amount of species of Class Ophiuroidea

Benthic

Class Ophiuroidea vary in where they are found but all are at least _____

Most deposit feeding but others suspension feeding, scavenging, or predaotry

Describe the feeding methods of Class Ophiruoidea

Mulitple madreporites, brooding, lacking anus, tube feet without ampullae, and branched arms

What are some distinctive features of Class Ophiuroidea

respiratory cavities (bursae)

In brittle stars, young are brood where

Ampullae

In brittle stars, tube feet lack

Branched

In basket stars, the arms are

Class Echinoidea

Class of Echinoderms which contains sea urchins and sand dollars

1000

How many species of Class Echinoidea are there

Describe the feeding methods of

herbivores or detrivores

Most echinoderms are grazing ______ or _____ but some are suspension feeders or predators

Soft

sea biscuts and sand dollars live in ____ sediments

Detrius

Sea biscuts and sand dollars primarily feed on

Irregular

______ Echinoids which are secondarily bilateral and include sea biscuits and sand dollars

Class Crinoidea

Class of Echninoids which include feather stars and sea lillies

600

Amount of species of Class Crinoidea

Suspension feeders

Class Crinoidea are primarily sessile _____ _____ in the deep sea

Class Crinoidea

What are the only extact echinoderm with an upward facing oral surface

U shaped

What is the shape of the Class Crinoidea gut

Class holothuroidea

What class of Echinoderms includes sea cucumbers

Oral aboral

Sea cucumbers are elongated along their ___ ____axis

Reduced

Ossicles in sea cucumbers are _____ and not linked together

1700

How many species of Class Holothuroidea are there

Bilateral

Class holothuroidea has a tendancy for what kind of symmetry

Tube feet

Tentacles around the mouth of Class Holothuroidea are derived from

Selective deposit feeding or suspension feeding

Sea cucumbers feed via

Tentacles

Sea cucumbers use _______ to sort particles (selective deposit feeding) or to trap food particles (suspension feeding)

CaCO3 ossicles

The endoskeleton of Echinoderms are composed of _____ _____ derived from mesoderm

Thin cuticle and epidermis

A ___ ____ and ____ covers the external surface of echinoderms T

Papulae

Outward external extensions of the coelom

Spines

Extensions of endoskeleton which may be flattended to protect papulae

Pedicellaria

Extensions from the epidermis in Echinoderms

Test

In Sea urchins, ossicles are fused into a rigid

Fleshy dermis

In Sea Cucumbers, microscopic occicles seperate into ___ ____

Cardiac and pyloric stomach

In Echinoderms, the digestive tract is divided into multiple structures known as

Digestion absorbance and storage

In sea stars, the cardiac stomach is the site of _____ while the pyloric stomach and caeca are the site of ____ and ____ nutrients

Cardiac stomach

Some sea stars evert their ____ _____ to feed

Body wall

Crinoids use thin areas of their ___ ____ for respriation

Tube feet and tentacles

All echinoderms utilize modied ___ ___ and _____ for respiration

Bursae

Infoldings of body wall near base of the arm in brittle stars for respiration

Respiratory trees

Out-pocketing of rectum in sea cucumbers for respiration

Dermal gill (Papulae)

Respiratory structure in Asteroidea; extensions of the coelom filled with coelomic fluids

Tube feet and respiratory surfaces

Echinoderms do not have any specialized excretory structures and rely on diffusion across ____ and ______

Hemal system

Consists of spongy tissues and canals; circulatory like system in echinoderms but not a true circulatory system

Water vascular system

While in close proximity, the Hemal system does not have a direct connections to the

Supporting and production fo coelomocytes, transport nutrients, transport O2, immune functions, collagen synthesis, and would repair function

What are the proposed functions of the hemal system (not truly certain)

Brain and ganglia

Echinoderms do not have a ____ and only some have _____

Chemical and tactile

Senses in Echinoderms are primarily facilitated through tube feet and are primarily ____ and ____ reception

Tube feet

Some echnioderms also have ocelli found on their

Dorsal shield ossicles

In some brittle stars, ___ ____ ____ have tiny bumps that function as microlenses to focus light onto nerve cells beneath for visual senses

Asexual reproduction

Some sea stars, brittle stars, and sea cucumbers can use their regenerative ability as a form of

Dioecious and hermaphroditic

Most echinoderms are sexually _______ with a few being _______

Broadcast spawners

The main reproductive method of echinoderms is

Indirect

Most echinoderms have what kind of development

External fertilization

Fertilization in most echinoderms is typically

Sea daisies and brittle stars

In some species of ____ ____ and _____ ____ fertilization is internal as females release phermones to attract sperm inside of them

Brooded and direct

In echinoderm species (sea daiseis and some brittle stars) which use internal fertilization eggs are ________ and have _____ development

Dipleurula

This is the most basic form of Echinoderm larva which can develop into many various forms

U shaped

Dipleurula larval have a complete gut and has a ___ ____ gut

Mouth and anus

Dipleurula larva have a cilliated band around their