This lecture is for BIOL 105 class at FCC. This is an introduction to Phylum Echinodermata.

1. Fall 2018

2. Spiny skinned
The entire aboral surface is covered
with numerous short, stout, blunt,
calcareous spines or tubercles.

3.  Echinodermata are part of Kingdom Animalia
 These are invertebrates
 Considered to be a link between invertebrates
and vertebrates
 Echinodermata are also called spiny skinned
animals
 e.g. starfish

4.  Habitat: Exclusively marine
 Grade of organization: organ system grade
 Germ layers: triploblastic
 Symmetry: Adults are radially symmetrical
while the larvae are bilaterally symmetrical.

5.  Body is without segmentation
 Shape of the body is flat, star like, spherical or
elongated.
 No head
 Tube feet for locomotion

6.  https://www.youtube.com/watch?v=f1ZBdOQ
nf-k
 https://www.youtube.com/watch?v=QBGccVA
fJV4

7.  Presence of water vascular system
 Mouth is present on ventral side while anus is
present on dorsal side
The madreporite is, thus, a
sieve-like porous plate and it
leads to the stone canal of water
vascular system.

9. Section of an arm (arm anatomy)

10.  Respiration: by papule, gills
 Nervous system: absent, no brain
 Circulatory system: is reduced, no heart
 Blood is present but has no pigment
 Digestive system: complete
 Excretory system: absent
The papulae are hollow evaginations of the body wall and
their lumen remains in continuation with the coelom. They are
internally lined by coelom. They have respiratory, as well as
excretory functions.

12.  Sexes: mostly dioecious (female and male
organisms are separate), rarely monocious
(female and male parts in same organism)
 Reproduction:
◦ Sexual: by gamatic fusion
◦ Asexual: regeneration
 Fertilization: external
 Development: indirect with characteristic
larvae

13. Questions??????