Unformatted text preview:

Phylum EchinodermataCharacteristics of the EchinodermataSlide 3Classes of EchinodermsClass AsteroideaSlide 6Slide 7Slide 8Slide 9Water vascular systemSlide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Feeding and digestionSlide 22Slide 23Slide 24Slide 25Slide 26Slide 27Reproduction and developmentSlide 29Slide 30Slide 31Slide 32Slide 33Slide 34RegenerationClass OphiuroideaSlide 37Slide 38Slide 39Slide 40Slide 41Class EchinoideaSlide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Aristotle’s LanternSlide 51Slide 52Class HolothuroideaSlide 54Slide 55Slide 56Slide 57Slide 58Slide 59Slide 60Class CrinoideaSlide 62Slide 63Slide 64Slide 65Phylum HemichordataSlide 67Acorn wormsSlide 69Slide 70Slide 71PterobranchiaSlide 73Taxonomy of hemichordatesSlide 75Slide 76Phylum EchinodermataPhylum EchinodermataThe echinoderms (“hedgehog skin”) are a very The echinoderms (“hedgehog skin”) are a very unusual group that includes about 7000 living unusual group that includes about 7000 living species.species.Members include: starfish, brittle stars, sea urchins, Members include: starfish, brittle stars, sea urchins, sea cucumbers, and sea lilies or feather stars.sea cucumbers, and sea lilies or feather stars.They are deuterostomes (as are chordates), but They are deuterostomes (as are chordates), but have secondarily evolved radial symmetry from have secondarily evolved radial symmetry from bilateral symmetry (they still have bilaterally bilateral symmetry (they still have bilaterally symmetrical larvae).symmetrical larvae).Characteristics of the Characteristics of the EchinodermataEchinodermataExclusively a marine group. They cannot Exclusively a marine group. They cannot osmoregulate so rarely occur even in osmoregulate so rarely occur even in brackish water. brackish water. The body is not segmented, but shows The body is not segmented, but shows pentaradial symmetry.pentaradial symmetry.There is no head or brain and the nervous There is no head or brain and the nervous system is relatively simple.system is relatively simple.Characteristics of the Characteristics of the EchinodermataEchinodermataThey possess an endoskeleton of dermal They possess an endoskeleton of dermal calcareous ossicles, which are connected together calcareous ossicles, which are connected together by connective tissue.by connective tissue.Possess a unique water vascular system that Possess a unique water vascular system that consists of a series of canals that extend from the consists of a series of canals that extend from the body surface as tube feet. body surface as tube feet. These tube feet are tentacle-like and enable the These tube feet are tentacle-like and enable the animal to move. In some species movement of the animal to move. In some species movement of the arms or spines contributes to locomotion too.arms or spines contributes to locomotion too.Classes of EchinodermsClasses of EchinodermsThere are a total of five classes of There are a total of five classes of echinoderms and about 7300 species.echinoderms and about 7300 species.Class Asteroidea: sea stars or starfishesClass Asteroidea: sea stars or starfishesClass Ophiuroidea: Brittle starsClass Ophiuroidea: Brittle starsClass Echinoidea: Sea Urchins, Sand Class Echinoidea: Sea Urchins, Sand dollarsdollarsClass Holothuroidea: Sea cucumbersClass Holothuroidea: Sea cucumbersClass Crinoidea: Sea Lilies and Feather Class Crinoidea: Sea Lilies and Feather stars.stars.Class AsteroideaClass AsteroideaStar fish are the most familiar of the Star fish are the most familiar of the echinoderms and demonstrate the echinoderms and demonstrate the characteristics of the group well.characteristics of the group well.Typically, they have 5 tapering arms, which Typically, they have 5 tapering arms, which merge gradually with the central disc.merge gradually with the central disc.The mouth is found on the oral surface, the The mouth is found on the oral surface, the opposite side of the animal being referred to as opposite side of the animal being referred to as the aboral surface.the aboral surface.Cushion seastar (Asteroidea)Class AsteroideaClass AsteroideaThe aboral surface of starfish is usually rough to The aboral surface of starfish is usually rough to the touch and has spines (although these may the touch and has spines (although these may be flattened so the animal appears smooth.).be flattened so the animal appears smooth.).Around the base of the spines are small Around the base of the spines are small pincerlike structures called pedicellariae, which pincerlike structures called pedicellariae, which are under muscular control and help to remove are under muscular control and help to remove debris and protect the animals papulae (skin debris and protect the animals papulae (skin gills) projections of the coelomic cavity that gills) projections of the coelomic cavity that increase the surface area for gas exchange.increase the surface area for gas exchange.Figure 22.01Figure 22.04fPedicellariaeWater vascular systemWater vascular systemGrooves called ambulacral grooves Grooves called ambulacral grooves radiate out from the mouth on the oral radiate out from the mouth on the oral surface. Tube feet project from the surface. Tube feet project from the grooves.grooves.These tube feet are connected to the These tube feet are connected to the water vascular system, which is a unique water vascular system, which is a unique invention of the echinoderms.invention of the echinoderms.Figure 22.02bWater vascular systemWater vascular systemThe water vascular system is a The water vascular system is a compartment of the coelom and is a compartment of the coelom and is a system of canals and tube feet. system of canals and tube feet. The water vascular system uses hydraulic The water vascular system uses hydraulic pressure to extend, move and contract the pressure to extend, move and contract the tube feet enabling the starfish to move and tube feet enabling the starfish to move and feed.feed.Water vascular systemWater vascular systemThe water vascular system opens to the The water vascular system opens to the outside via small pores in a structure outside via small pores in a structure called the madreporite on the aboral called the madreporite on the aboral surface.surface.The madreporite connects to a ring canal The madreporite connects to a ring canal


View Full Document

SUNY Plattsburgh BIO 323 - Phylum Echinodermata

Documents in this Course
Load more
Download Phylum Echinodermata
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Phylum Echinodermata and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Phylum Echinodermata 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?