Echinoderms - Spiny Skin

>Phylum: Echinodermata

General

• Ancient Greek “Echinos” meaning “spiny” and “dermos” meaning “skin"
• Approximately 7,000 species
• Includes starfish, sea urchins, sand dollars, sea cucumbers, sea lillies

 Distribution

• Exclusively marine animals, no freshwater

Habitat

• Benthic animals
• Found usually on the sea floor in every marine habitat from the intertidal zone to ocean depths

 Body

• They are triploblastic.
• Larval form show bilateral symmetry and adult forms show radial symmetry
• Body is unsegmented without a head
• The body is uniquely shaped. It can be star like, elongated or spherical

 Reproduction

• Sexes are dimorphic, Echinoderms are either male or female
• Become sexually mature after about two to three years
• Most release their eggs and sperm into the water where they are fertilized externally
• A female can release one hundred million eggs at once

> Phylum Echinodermata can be divided into:

 >- Subphylum:  Asterozoa

  >> Class  Asteroidea            Sea Stars & starfishes 

  >> Class  Ophiuroidea         Brittle Stars

 >- Subphylum:  Crinozoa

  >> Class  Crinoidea              Sea Lilies & Feather Stars

 >- Subphylum:  Echinozoa

  >> Class  Echinoidea           Sea Urchins and Sand Dollar

  >> Class  Holothuroidea      Sea Cucumbers

>>Class:   Asteroidea          Sea Stars & starfishes

>>>Order:   Forcipulatida 

>>>>Family:   Asteriidae          Asteriid Sea Stars

Asterias amurensis _ Northern Pacific Sea Star              Coscinasterias muricata _ Eleven-armed Sea Star          Marthasterias Africana _ Spiny Seastar

Photo taken Frankston Pier, Victoria on 18.09.2023                                   Photo taken Mornington Pier, Victoria on 01.10.2020                                   Photo taken False Bay, South Africa on 31.10.2006

>>>>Family:   Stichasteridae          Reef Sea Stars

 Uniophora sp._Granular Sea Star                                 Uniophora granifera_Granular Sea Star

Photo taken Second Valley, South Australia on 13.02.2022                        Photo taken Mornington Pier, Victoria on 01.10.2020

Order:   Spinulosida

Family:     Echinasteridae          Spiny Star

Echinaster sp._ Luzon Sea Star                               Echinaster luzonicus _ Luzon Sea Star                         Henricia ornata _ Reticulated Sea Star

Photo taken North Stradbroke Island, Queensland on 17.02.2024     Photo taken Amed, Indonesia on 20.07.2022                                            Photo taken False Bay, Indonesia on 31.10.2006  

Plectaster decanus  _ Mosiac Sea Star

Photo taken Bare Island, New South Wales on 30.08.2008

>>>Order:   Paxillosida

>>>>Family:   Astropectinidae

Astropecten sp._ Spiny Sand Star                                   Astropecten irregularis _ Sand Sea Star 

Photo taken Isabela Island, Gaalpagos on 24.06.2023                                Photo taken False Bay, South Africa on 31.10.2006

>>>Order: Valvatida

>>>>Family:   Acanthasteridae

Acanthaste sp._Crown of Thorns Sea Star                                  Acanthaster planci_Longed Spined Crown of Thorns Sea Star

Photo taken Puerto Galera, Philippines on 29.10.2018                                Photo taken Adaman Sea, Thailand on 17.02.2023        

>>>>Family:   Asterinidae

Callopatiria granifera_Red Sea Star                                  Asterinidae_sp.__Sea_Star                                        Meridiastra calcar_Carpet Sea Star

Photo taken False Bay, South Africa on 31.10.2006                         Photo taken Sorrento Pier, Victoria on 15.05.2023                Photo taken Frankston Pier, Victoria on 26.09.2023

Meridiastra gunni_Gunns Six Armed Star           Paranepanthia grandis_Seastar 

Photo taken Flinders Pier, Victoria on 19.09.2023          Photo taken Sorrento Pier, Victoria on 15.05.2024

>>>>Family:   Asteropseidae

>>Class:   Holothuroidea

>>-Subclass:     Actinopoda

>>>Order:     Dendrochirotida

>>>>Family:     Cucumariidae

Colochirus robustus _ Yellow Sea Cucumber            

Photo taken Puerto Galera_ Philippines on 22.09.2021       

>>>>Family:     Phyllophoridae             

Massinium magnum_Large Burrowing Sea Cucumber        Thyone_sp.___Burrowing_Sea_Cucumber

Photo taken Dauin_ Philippines on 02.05.2025                                                   Photo taken False Bay on 31.10.2006  

>>>Order:   Holothuriida

>>>>Family:   Holothuriidae

Bohadschia_argu_Leopard_Sea_Cucumber                  Holothuria (Halodeima) edulis_Pinkfish Sea Cucmuber                        

Photo taken Lady Musgrave Island, Queensland on 13.10.2017                 Photo taken Dauin, Philippines on 22.09.2016                                                                           

>>>Order:     Molpadida

>>>>Family:     Caudinidae

 Paracaudina_bacillis_Sea_Cucumber

Photo taken Rye Pier, Victoria on 03.06.2017

>>>Order:     Synallactida

>>>>Family:     Stichopodidae

Australostichopus mollis_Australiasian BrownSea Cucumber        Isostichopus fuscus_Brown Sea Cucumber               Notostichopus ludwigi_Ludwigs Sea Cucumber

Photo taken Sorrento Pier, Victoria on 15.05.2024                                                          Photo taken Kicker Island, Galapogos Islands on 27.06.2023                Photo taken Rapid Bay, South Australia on 13.03.2022

Stichopus chloronotus_Greenfish Sea Cucumber                            Thelenota ananas_Pineapple Sea Cucumber

Photo taken Dauin, Philippines on 19.09.2016                                                  Photo takenPalau, Micronesia on 08.12.2023  

>>-Subclass:     Paractinopoda

>>>Order:     Apodida

>>>>Family:     Chiridotidae

Chiridota sp. _ Chiridota

Photo taken Edithburgh Jetty, South Australia on 10.07.2025

>>>>Family:     Synaptidae

Synaptidae (Family) sp._Synaptidae                          

Photo taken Apo Island, Philippines on 23.09.2016