Activity 23: Activity 23: Phylum EchinodermataPhylum Echinodermata

GENERAL CHARACTERISTICSGENERAL CHARACTERISTICS

exclusively marineexclusively marinemostly mobile, slow-moving bottom mostly mobile, slow-moving bottom

dwellersdwellersCoelom subdivided into:Coelom subdivided into:

Perivisceral cavityPerivisceral cavityCavity of the ambulacral (hydrovascular) Cavity of the ambulacral (hydrovascular)

systemsystem

GENERAL CHARACTERISTICSGENERAL CHARACTERISTICS

Most exhibit pentamerous radial symmetryMost exhibit pentamerous radial symmetryOral surface contains the mouthOral surface contains the mouthAboral region indicates the side away or Aboral region indicates the side away or

opposite the mouthopposite the mouth (+) CaCO3 dermal endoskeleton(+) CaCO3 dermal endoskeleton

(+) thin epidermis or(+) thin epidermis or (+) embedded in a thick, tough body wall(+) embedded in a thick, tough body wallProject spines and tuberclesProject spines and tubercles

TAXONOMYTAXONOMY

SUBPHYLUM ASTEROZOASUBPHYLUM ASTEROZOAClass AsteroideaClass AsteroideaClass OphiroideaClass Ophiroidea

SUBPHYLUM ECHINOZOASUBPHYLUM ECHINOZOAClass EchinoideaClass EchinoideaClass HolothuroideaClass Holothuroidea

SUBPHYLUM CRINOZOASUBPHYLUM CRINOZOAClass CrinoideaClass Crinoidea

SUBPHYLUM ASTEROZOASUBPHYLUM ASTEROZOAClass AsteroideaClass AsteroideaClass OphiroideaClass Ophiroidea

SUBPHYLUM ECHINOZOASUBPHYLUM ECHINOZOAClass EchinoideaClass EchinoideaClass HolothuroideaClass Holothuroidea

SUBPHYLUM CRINOZOASUBPHYLUM CRINOZOAClass CrinoideaClass Crinoidea

SUBPHYLUM ASTEROZOASUBPHYLUM ASTEROZOA

Includes radially symmetrical, flattened Includes radially symmetrical, flattened echinodermsechinoderms

Mostly star-shapedMostly star-shapedNever stalked or attached to substratumNever stalked or attached to substratumBody made up of central disk with radiall Body made up of central disk with radiall

arranged armsarranged armsMouth centrally located at oral side of the Mouth centrally located at oral side of the

bodybody

Class AsteroideaClass Asteroidea

Sea stars or star fishesSea stars or star fishesTypically pentamerousTypically pentamerous (+) ambulacral grooves on the oral side(+) ambulacral grooves on the oral side

With tube feet that have suckersWith tube feet that have suckersAnus and madreporite on the aboral sideAnus and madreporite on the aboral sideMany Many pedicellariaepedicellariae present in many of the present in many of the

speciesspecies

Starfish AnatomyStarfish AnatomyORAL SIDETube feet are visible

Dissection of Asterias rubens 1 - Ambulacral ossicles and ampullae. 2 - Madreporite. 3 - Stone canal. 4 - Pyloric caecae. 5 - Rectal glands. 6 - Gonads.

Aboral side oral side

Asterias – Asterias – Subphylum Asterozoa;Subphylum Asterozoa;

Class AsteriodeaClass Asteriodea

A. rubensaboral surface

A. rubens feeding on mussel

Linckia – Linckia – Subphylum Asterozoa;Subphylum Asterozoa;

Class Asteriodea Class Asteriodea

L. laevigata

L. columbiae

L. multifloraL. multiflora

Protoreaster – Protoreaster – Subphylum Asterozoa;Subphylum Asterozoa;

Class Asteriodea Class Asteriodea

Culcita (cushion star) – Culcita (cushion star) – Subphylum Asterozoa;Subphylum Asterozoa;

Class AsteriodeaClass AsteriodeaCulcita novaguineae Culcita novaguineae

Culcita novaguineae

Class OphiuroideaClass Ophiuroidea

Basket stars and brittle starsBasket stars and brittle stars Typically pentamerousTypically pentamerous With elongated and movable arms sharpl With elongated and movable arms sharpl

marked off from the central diskmarked off from the central disk Anbulacral grooves are closed and covered by Anbulacral grooves are closed and covered by

ossiclesossicles Tube feet devoid of suckersTube feet devoid of suckers (-) anus(-) anus (+) madreporite on the oral side(+) madreporite on the oral side

Gorgonocephalus (Basket star) – Gorgonocephalus (Basket star) –

Subphylum Asterozoa;Subphylum Asterozoa;Class OphioroideaClass Ophioroidea

G. chilensisG. chilensis

Ophioplocus – Ophioplocus – Subphylum Asterozoa;Subphylum Asterozoa;

Class OphioroideaClass Ophioroidea

O. esmarkiEsmark’s brittle starO. esmarkiEsmark’s brittle star

Ophiocoma – Ophiocoma – Subphylum Asterozoa;Subphylum Asterozoa;

Class OphioroideaClass Ophioroidea

O. paucigranulata Ophiocoma erinaceus

Ophioderma – Ophioderma – Subphylum Asterozoa;Subphylum Asterozoa;

Class OphioroideaClass Ophioroidea

Ophioderma longicaudum

O. rubicundum O. rubicundum

SUBPHYLUM ECHINOZOASUBPHYLUM ECHINOZOA

Includes globoid, discoid, more or less Includes globoid, discoid, more or less cylindrical echinoderms without arms. cylindrical echinoderms without arms.

(+) tube feet with suckers(+) tube feet with suckersRestricted to the compact bodyRestricted to the compact body

Never stalked or attached to any Never stalked or attached to any substratumsubstratum

Diadema (sea urchin) – Diadema (sea urchin) – Subphylum Echinozoa;Subphylum Echinozoa;

Class EchinoideaClass Echinoidea

Echinocardium (heart urchin) – Echinocardium (heart urchin) – Subphylum Echinozoa;Subphylum Echinozoa;

Class EchinoideaClass EchinoideaE. cordatum

E. cordatum

Laganum (sea biscuit) – Laganum (sea biscuit) – Subphylum Echinozoa;Subphylum Echinozoa;

Class EchinoideaClass Echinoidea

L. depressumL. depressum

L. depressumLateral viewL. depressumLateral view

L. retinensL. retinens

Arachnioides (true sand dollar) – Arachnioides (true sand dollar) –

Subphylum Echinozoa;Subphylum Echinozoa;Class EchinoideaClass Echinoidea

A. placenta

A. placentaA. placenta

The end.The end.

Thank you.Thank you.

The end.The end.

Thank you.Thank you.