Echinodermata Classification.pptx

Classe ,order

1. SUBMITTED BY GIRJA PRASAD PATEL

2. PHYLLUM :- ECHINODERMATA General Characters :- They are marine animals. Tribloblastic animals. True coelom is present. Their space is generally pentamerous. The exoskeleton is formed of calcareous plates or ossicles. Generally, spine are found over the body and calcareous plate below the skin. In Adult condition Body :- Radially symmetrical, but their larvae are Bilaterally symmetrical. Tube feet are present which are organ of locomotion and also helpful in food catching & respiration.

3. 9. A water vascular system is found in them. Respiration take place by branchiae. Excretory organs are absent. Sexes are separate. CLASSIFICATION Phylum has been classified into four sub- phylum. (Marshall & Williams) SUB-PHYLUM :- ECHINOZOA Globoid and cylindrical echinoderm which do not develop arms. Hydrocael forms a ring about the giving rise to meriodional water vessels.

4. Class 1 – Helicoplacodea Free living, fusiform placoid echinozoans. Plates of the body form the test. Anal & Oral aperture at opposite poles. Example :- Helicoplacus. Class 2 – Holothuroidea. Body elongated in oral – aboral axis. Skin leathery. Body is long and cylindrical or pentamerous. Mouth and anus are present on opposite surfaces. Mouth surrounded by tentacles. Tube feet are found & helpful in locomotion. Sexes are separated.

5. Sub-Class 1 – Dendrochioracea Respiratory tree present. Introvert presents or pharyngeal refractor muscles present. ORDER 1 – Dactylochirotida Digitate and feebly branched tentacles. Example :- Ypsilothuridae. ORDER 2 – Dendrochirotida Tentacles are elongated, branched to form tree like structure. Example :- Cucumaria. Sub-Class 2 – Aspidochiroatcea Tentacles 10-20 shield shaped. Test vestigial . Tube feet present on ventral side.

6. ORDER 1 – Aspidochiroatida Large branched respiratory tree. Example :- Holothuria. ORDER 2 – Elasipodida Respiratory tree absent. Example :- Elpidia, Pelagothuria. Sub-Class 3 – Apodacea Holothurian with simple digitate tentacles. Tube feet reduced or absent. No spicules in the skin, no refractor muscle.

7. Class 3 – Edriosteroidea Free swimming placoid echinozoan with mouth and anus on the upper side of the test. Five ambulacra radiate from the mouth. Hinged ambulacral ossicles border the ambulacra, which carry food groove. Body discoidal, dorsovantrally flattened . Extinct forms. Example :- Edrioaster. Class 4 – Exhinoidea Body is oval round or heart shaped without arms but with ambulacral areas. Body enclosed in a test made up of calcareous plates. Pedicilarie are stalked & tree – jawed. Introvert or lantern present. Example :- Sea urchin.

8. Sub-Class 1 – Perischoechinoidea ORDER 1 – Exhinocytitoida , Example :- Eothuria. ORDER 2 – Bothricidaroida , Example :- Bothriocidaris. ORDER 3 – Palaechinoidea , Example :- Palaechinus. ORDER 4 – Cidaroida , Example :- Miocidaris. Sub-Class 2 – Euechinodea Super Order 1 – Diaematacea ORDER 1 – Echibothuroida ORDER 2 – Diadamatoida ORDER 3 – Padinoida ORDER 4 – Pygasteroida

9. Super Order 2 – Echinancea ORDER 1 – Salenioida ORDER 2 – Hemidaroida ORDER 3 – Phymosomatoida ORDER 4 – Arbacioida ORDER 5 – Temnopkuroida. ORDER 6 – Schinoida. Super Order 3 – Gnathostomata ORDER 1 – Holectypoida ORDER 2 – Clypeasteroida Super Order 4 – Atelostomata ORDER 1 – Classiduloida ORDER 2 – Holastaoida ORDER 3 – Spatangoida

10. Class 5 – Sub – Phylum 1 – Hc Includes extinct, dorsovantrally flattened echinoderms, with no signs of radial symmetry . Sub – Phylum 2 – Cri Body aboral, cup shaped. Ambulacra are restricted to the adoral surface. Sessile, atleast in any part of their life. Mouth and anus both are situated on the upper side. Most of the member are now extinct. Example :- Antedon. Sub – Phylum 3 – Homalozoa Sub – Phylum 4 – Crinozoa Sub – Phylum 5 – Asterozoa

11. ANTEDON General Characters :- Commonly known as – “Feather star” or “Sea lily”. The pentamerous body is disc-shaped with flower-like appearance. The body is divisible into a central disc or calyx and a series of 10 radiating arms. The central disc is differentiated into convax and upwardly directed oral & flat ventrally directed aboral surfaces. The animals are highly coloured and may be green, purple, yellow & red.

12. 6. The oral surface is covered by soft, leathery skin the oral membranes are the tegmen in which are embedded minute calcareous plates in the form of a continuous sheet. 7. The mouth is the situated in the central of the oral disc and is surrounded by five small triangular oral valve. 8. In the between of oral valves radiate five narrow, open and ciliated food grooves. 9. The anus is situated near the mouth in one inner ambulacrum on a prominence. A series of five movable long slender arms often branched and bearing small alternating branches , the pinnules originated from central body. Ambulacral groove ciliated, open runs from mouth on the oral surface of arms & pinnules their tips. Tube feet reduced generally tentacle like present along the edge of ambulacral groove.

13. Madreporite is absent. The aboral surface is partly covered by tagmen and partly by a large flat, pentagonal central sketelal plate , the centro -dorsal ossicles. On the aboral surface are slender curved and cylidrical appendages known as cirri meant for gripping the substratum. The sexes are separate but there is no sexual dimorphism . The development is indirect with pentacrinoid larva with jointed stalk. They have the power of regeneration .

14. ASTERIAS General Characters :- It is commonly known as ‘stare fish’. Dorsoventrally flattened star –shaped , pentagonal body . Body is divisible into a central disc and five radiating arms. The animal are usually bright coloured yellow, brown or orange. The body is divisible into a flat , downwardly directed and light coloured oral surface and a convex, upwardly directed and light coloured oral surface and a convex , upwardly directed and much darker aboral surface.

15. 6. The pentagonal mouth lies in the centre of oral surface and surrounded by oral spines. 7. The narrow ambulacral grooves arise from the five corners of mouth and extend through the middle of each arm upto the tip. 8. Each ambulacral groove bears four rows (two double rows ) of soft thin walled tubular retractile tube – feet with sucker – like extremities.

16. OPHIOTHRIX General Characters :- It is commonly known as ‘ spiny brittles star’. Brilliantly coloured with phosphorocence . The body is divisible into a small rounded central disc and five greatly developed fragile and flexible arms sharply marked off from the disc. The arms are covered by plates or shields fringed with spines on all sides. The mouth is on the oral surface and is with five movable plates serving as jaws.

17. 6. Only the madreporite is present near the mouth on the oral surface. 7. The oral surface also bears five shields and podial pores. 8. Ambulacral grooves and pedicellariae are absent. 9. The tube feet without suckers are present on the lower plates of arms. 10. When distributed it readily breaks of one or more arms , which are later regenerated. 11. The anus is absent. 12. The sexes are separate. 13. The development is indirect with pelagic ophiopluteus larva. 14. The genital bursac are present at the base of each arm. 15. They have great power of regeneration or autotomy.

18. ECHINUS General Characters :- It is commonly known as ‘sea urchin.’ The hared and prickly body is globular in shape, slightly pentagonal in equatorial outline with rounded angles . The body is more or less flattened at the two poles, forming distinct oral . The colour of the body may be brown, black , purple, green, white or red. The body is enclosed in a shell or corons formed of closely fitting firmly united calcaeous plates.

19. 6. Body surface is covered by numerous cylindrical , solid , spines. 7. Among spines are found stalked pedicellarise with three jaws and tube feet arranged in five double rows. 8. The more flattened oral surface bear rounded central mouth surrounded by thin, soft flexible peris tome . 9. Through mouth project ten hard , white calcareous teeth from Aristotle’s lantern. 10. At the outer edge of peristome lie ten little boshy , thin walled and branching gills one pair opposite to each inter ambulacral area. 11. The aboral, end is somewhat dome-shaped and lie opposite to oral end. 12. At the aboral end lies a much smaller aperture , the anus , surrounded by periproct. 13. The sexes are separate and there is no sexual dimorphism. 14. Fertilization is external.

20. HOLOTHURIA General Characters :- It is commonly known as ‘ cucumber’. Body is large , cylindrical , elongated , vermiform and bilaterally symmetrical with mouth and anus at opposite ends. The colour of the animal is brown or yellowish and often reddish blue. The animal rests on ground with its long axis parallel to the surface. The anus is placed at the extreme aboral end.

21. 6. The retractile and locomotory podia are distributed all over the body 7. The surface of the animal is divided into five ambulacral and five interambulacral zones which are not recognizable externally. 8. Body wall leathery and muscular with exoskeleton in the form of calcareous ossicles. 9. The mouth is at the oral end and is surrounded by peristome and 20 or 30 pellate tentacles. 10. The respiratory tree is well developed . 11. The Cuvierian organ present. 12. Water vascular system is well developed. 13. The madreporite is internal. 14. The sexes are separate 15. The development is indirect with curricular larva.

22. CUCUMARIA General Characters :- It is commonly known as ‘ sea cucumber’. Body is elongated and cylindrical with terminal mouth and anus opening at opposite ends. The anterior oral end is somewhat thicker that the posterior aboral end. The oral and aboral axis greatly elongated. Body is pentamerous , having five longitudinal bands or ambulacra, each is provided with double row of locomotary podia.

23. 6. Three of these ambulacral areas are ventral and provided with numerous tube feet with suckers. 7. The other ambulacral are dorsal and are with smaller tube feet lacking sucker. 8. Mouth is surrounded by a lip thin, darkly pigmented peristomial membrane and a circlet of ten dendritic , tree-like tentacles , two belonging to each ambulacrum. 9. Each tentacle is enlarged, specially modified tube – feet of highly sensitive and contractile nature. 10. The smooth , thin and collar like body at the base of tentacles is known as introvert. 11. Two respiratory trees are present. 12. Water vascular system is well developed.