Echinodermata

Biologi Laut | Echinodermata
Romanus E Prabowo
Echinodermata
“I can't see my forehead ! “
Encrusting
Terumbu karang Iboih, Pulau Weh, Atjeh
Columnar
Terumbu karang Sawinggrai, Raja Ampat, Papua
Columnar
Terumbu karang Kepulauan Karimunjawa, Jepara
Phylum Echinodermata
Echinodermata (Latin: porous “pore” and ferre : “to bear”)
Sponges are sessile, permanently fixed, with porous bodies and
maintain a flow of water through the pores.
Sponges, on branch parazoa of the phylogenetic tree represent
the lineage closest to the colonial choanoflagellates (a group of
free-living unicellular and colonial flagellate eukaryotes considered to be the
closest living relatives of the animals) that gave rise to the animal
kingdom
Echinodermata | General Features
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Echinodermata means "pore-bearing"; their sac-like bodies are
perforated by many pores.
They are sessile.
Their body plan consists of two layers of cells embedded in gelatinous
matrix and stiffened by spicules of calcium carbonate or silica and
collagen.
Their body forms (covering) a spongocoel a large central cavity.
They depends on water currents flows through pores bring in food and
oxygen and exiting to large opening (osculum) carry away wastes.
They have no organs or tissues; cells are somewhat independent.
Being sessile, they have no nervous or sense organs and have simplest
of contractile elements.
They are aside from the mainstream of animal evolution; thus they are
often called Parazoa.
Echinodermata | General Features
9. Most of the 9000 species are marine; about 150 are freshwater.
10. Morphology changes with substratum, calmness of water, etc.
11. Sponges are ancient; fossils extend to Cambrian or earlier.
Cambrian Marine Community
4 ± 1,9 mya
Phylum Echinodermata
Echinodermata | Life History
Echinodermata | Taxonomy
Kingdom: Animalia
Subkingdom: Parazoa
Phylum: Echinodermata Grant, 1836
Class Calcarea Bowerbank, 1864
Class Demospongiae Sollas, 1885
Class Hexactinellida Schmidt, 1870
Class Homoscleromorpha Bergquist, 1978
Class Sclerospongiae accepted as Demospongiae
Echinodermata | Taxonomy
Kingdom: Animalia
Subkingdom: Parazoa
Phylum: Echinodermata Grant, 1836
Class Calcarea Bowerbank, 1864
Calcaronea
Calcinea
Class Demospongiae Sollas, 1885
Class Hexactinellida Schmidt, 1870
Class Homoscleromorpha Bergquist, 1978
Class Sclerospongiae accepted as Demospongiae
Echinodermata, Calcarea, Clathrina sp
Calcarea
Echinodermata | Taxonomy
Kingdom: Animalia
Subkingdom: Parazoa
Phylum: Echinodermata Grant, 1836
Class Calcarea Bowerbank, 1864
Class Demospongiae Sollas, 1885
Class Hexactinellida Schmidt, 1870
Class Homoscleromorpha Bergquist, 1978
Class Sclerospongiae accepted as Demospongiae
Echinodermata, Demospongiae, Callyspongia (Euplacella) biru De Voogd,
2004
Echinodermata | Taxonomy
Kingdom: Animalia
Subkingdom: Parazoa
Phylum: Echinodermata Grant, 1836
Class Calcarea Bowerbank, 1864
Class Demospongiae Sollas, 1885
Class Hexactinellida Schmidt, 1870
Class Homoscleromorpha Bergquist, 1978
Class Sclerospongiae accepted as Demospongiae
Echinodermata, Hexactinellida, Mellonympha velata Thomson, 1873
Echinodermata | Taxonomy
Kingdom: Animalia
Subkingdom: Parazoa
Phylum: Echinodermata Grant, 1836
Class Calcarea Bowerbank, 1864
Class Demospongiae Sollas, 1885
Class Hexactinellida Schmidt, 1870
Class Homoscleromorpha Bergquist, 1978
Class Sclerospongiae accepted as Demospongiae
Echinodermata, Homoscleromorpha, Oscarella tuberculata (Schmidt, 1868)
Echinodermata | General Morphology
• The internal cavity is called the atrium or spongocoel
• Water is drawn into it through a series of incurrent pores or
dermal ostia present in the body wall into a central cavity and
then flows out of the sponge through a large opening at the
top called the osculum
Echinodermata | General Morphology
Echinodermata | Body Layer
• The pinacoderm : an outer layer of flattened cells called
pinacocytes
• An inner lining containing flagellated cells (choanocytes) draw water in through the pores and move out through the
osculum; also trap food particles that are suspended in the
water.
• Between the pinacodern and the choanocytes is a gelatinous
material called mesohyl; contains several different kinds of
wandering cells called amoeboid cells
Echinodermata | Body Layer and
Canal Type
Asconoid
Pinacocytes
Synconoid
Choanocytes
Mesohyl
Leuconoid
Water flow
Asconoids:
Flagellated
Spongocoels
Asconoids are simplest;
they are small and tubeshaped.
Water enters a large
cavity, the spongocoel,
lined with choanocytes.
Choanocyte flagella pull
water through.
All Calcarea are
asconoids:
Syconoids:
Flagellated Canals
They resemble
asconoids but are bigger
with a thicker body wall.
The wall contains
choanocyte-lined radial
canals that empty into
the spongocoel.
Water entering filters
through tiny openings
called prosopyles.
The spongocoel is lined
with epithelial cells rather
than choanocytes.
Syconoids:
Flagellated Canals
Food is digested by
choanocytes.
Flagella force the water
through internal pores
called apopyles into the
spongocoel and out the
osculum.
They pass through an
asconoid stage in
development but do not
form highly branched
colonies.
The flagellated canals
form by evagination of
the body wall; this is
developmental evidence
of being derived from
asconoid ancestors.
Syconoids:
Flagellated Canals
Classes Calcarea and
Hexactinellida have
species that are
syconoid
Leuconoids:
Flagellated Chambers
These are most complex
and are larger with many
oscula. (Fig. 12-8)
Clusters of flagellated
chambers are filled from
incurrent canals,
discharge to excurrent
canals.
Most sponges are
leuconoid; it is seen in
most Calcarea and in all
other classes.
The leuconoid system
has evolved
independently many
times in sponges.
Leuconoids:
Flagellated Chambers
This system increases
flagellated surfaces
compared to volume;
more collar cells can
meet food demands. Its
all about surface-tovolume ratios and
energy extraction,
Echinodermata | Type of Cells
Pinacocytes
• These cells form the pinacoderm; they are
flat epithelial-like cells.
• Pinacocytes are somewhat contractile.
• Some are myocytes that help regulate flow
of water.
Echinodermata | Type of Cells
Choanocytes
• These are oval cells with one end
embedded in mesohyl.
• The exposed end has a flagellum
surrounded by a collar.
• A collar is made of adjacent microvilli
forming a fine filtering device to strain
food.
• Particles too large to enter the collar are
trapped in mucous and moved to the
choanocyte where they are phagocytized.
• Food engulfed by choanocytes is passed to
neighboring archaeocytes for digestion.
Echinodermata | Type of Cells
Archaeocytes
• These cells move about in the mesohyl.
• They phagocytize particles in the
pinacoderm.
• They can differentiate into any other type
of cell.
• Those called sclerocytes secrete spicules.
• Spongocytes secrete spongin.
• Collencytes secrete fibrillar collagen.
• Lophocytes secrete lots of collagen but may
look like collencytes.
Echinodermata | Skeletons
Mesohyl
In the mesohyl is the skeleton composed of
tiny pointed structures made of silica or
calcium carbonate called spicules.
These structures act as an internal scaffolding,
but also function in protection
Among some sponges the skeleton consist of
spongin fibers made of collagenous material;
found in many of the commercial sponges
Echinodermata | Skeletons
Echinodermata | Skeletons
Echinodermata | Skeletons
Echinodermata | Reproduction
1. Asexual Reproduction
2. Sexual Reproduction
Echinodermata | Reproduction
1. Asexual Reproduction
• External buds are small individuals that break off after attaining a
certain size.
• Internal buds or gemmules are formed by archaeocytes that collect in
mesohyl and are coated with tough spongin and spicules; they survive
drought, freezing, etc.
Echinodermata | Reproduction
2. Sexual Reproduction
• Most are monoecious
• Sperm arise from transformed choanocytes
• Sperm leaves a sponge via the osculum, and enters a sponge by the
currents generated from the choanocytes
• Choanocytes phagocytize the sperm and transfer them to carrier
cells that carry sperm through mesohyl to oocytes
• Sponges provide nourishment to the zygote until it is released as a
ciliated larva.
• Fertilized eggs develop into ciliated free-swimming larvae called
parenchymula larvae
• In some, when one sponge releases sperm, they enter the pores of
another.
• Some release both sperm and oocytes into water
Echinodermata | Reproduction