LESSON 2: PORIFERA Flashcards
Porifera is from the latin word?
porus (pore) and fera (bearing)
Porifera Bear myriads of tiny pores and canals that constitute a ________________________
filter-feeding system
2 simple layers of poriferan cell
- Outer pinacoderm
- Inner choanoderm
Porifera: Water flow through the unique _____ __________ brings in food and oxygen and carries
away their body wastes
canal systems
-lies between pinacoderm and choanoderm
- ECM home to up to ten different cell types
and stiffened by a skeleton of minute spicules
of calcium carbonate or silica and collagen
mesohyl
Most sponges have __________ or ___________, and even their cells show a certain degree of
independence
no organs or true tissues
Sponges have ____________ or ___________, but sponges do have simple contractile element
No nervous system or sense organs
Size of a sponge
few millimeters to great loggerhead sponges (2
or more meters)
Sponge are brightly colored. Pigments in their __________ cells
dermal cells
Once the sponges are removed from the water, what happens?
Its color fades
What is the symmetry of sponges?
Asymmetry (Irregular)
Different forms of Sponges
-stand erect
-branched
-lobed
-low, encrusting
-bore holes into shells or rocks
Sponges Are an ancient group with abundant fossil record extending back to
the _____________ to _________________.
Precambrian to early Cambrian period
4 classes of Poriferans
-Calcarea
-Desmospongiae
-Hexatinellida
-Homoscleromorpha
Homoscleromorpha was once a subset of?
Desmospongiae
How many sponge species is marine? and how many occupy freshwater?
Marine: 5000 or more
Freshwater: 150 species
The sponges embryos are _______________, adults are attached usually to rocks, shells, corals, or
other submerged objects
free- swimming
Some sponges with bottom-dwelling forms even grow on _____________-
sand or mud
The growth of sponges is affected by?
-Shape of substratum
-direction and speed of water current
-availability of space
Sponges in _______ may grow taller and straighter than those in __________ water
-calm water
-rapidly moving
Commensals or parasites in/or sponges
-crabs
-nudibranchs
-mites
-bryozoans
-fish
Larger sponges particularly tend to harbor a ________________________________________
large variety of invertebrate commensals
Sponges also grow on many other living animals such as:
-molluscs
-barnacles
-brachipods
-corals
-hydroids
One sponges has been described that preys ______
Shrimp
Some crabs attach pieces of sponge to their carapace for _____________________,
since most predators seem to find sponges distasteful
camouflage and protection
One reason for the success of sponges as a group is that they have _____________
few enemies
Reasons why sponges kay dli himoong prey sa other predators
-Eating them is like eating a mouthful of glass splinters
-They have noxious odor (evil-smell)
Sponges and the microorganisms that inhabit them, produce a variety of
__________________.
bioactive chemicals
One extract from a marine sponge appears effective against _________________
(caused by apicomplexan parasite)
leishmaniasis
Some sponge species is used for treating
_____________________
herpetic infections
Sponges tiny pores for entry of materials are called?
Singular: Ostium
Plural: Ostia
Sponges large opening for exits of material are called?
Singular: Osculum
Plural: Oscula
Sponges are usually stationary or ________
Sessile
Types of Sponges canal system
- Asconoid
- Syconoid
- Leuconoid
- Have the simplest organization
- Small and tube-shaped
- Water enters through microscopic
dermal pores into a large cavity
called spongocoel (lined with
choanocytes) - Choanocyte flagella pull water
through the pores and expel it
through a single large osculum
Asconoid
Asconoid have ___________________
Flagellated Spongocoels
A sponges large cavity is called?
Spongocoel
Examples of Sponges with Asconoid type of Canal system
-Leucosolenia (Gr. Leukos, white, +
solen, pipe)
- Clathrina (L. clathri, latticework)
Slender, tubular individuals grow in
groups attached by a common stolon,
or stem, to objects in shallow seawater
Leucosolenia
Bright yellow, intertwined tubes
Clathrina
All asconoids are in the class __________
Calcarea
- Look somewhat like larger editions
of asconoids (from which they
were derived). - They have a tubular body and a
single osculum, but instead of a
simple choanocyte layer lining the
spongocoel, as in asconoids, this
layer in syconoids is folded back
and forth to make canals. - The choanocytes line certain folds
are called radial canals - Water, entering the body through
dermal pores, moves first to
incurrent canals and then into
radial canals via small lateral
openings called prosopyles - From the radial canals, filtered
water moves through apopyles into
the spongocoel, finally exiting by
the osculum.
Syconoids
Syconoids is known to have
Flagellated Canals
Syconoids: What do you call the opening after radial canal to spongocoel?
Apopyles
Syconoids: What do you call the small lateral openings before radial canals?
Prosopyles
Syconoid dont have flagella in its __________ unlike asconoid.
Spongocoel
Where does syconoids filter the water?
Radial Canal (Flagellated)
Where does asconoid filter the water?
Flagellated spongocoel
Simplified system of Asconoid
Water enters the:
Ostia—>flagellated spongocoel—> osculum
Simplifie system of syconoid
Water enters the:
Ostia—>incurrent canal—>prosopyle—>radial canal—> apopyle—> spongocoel—> osculum
The spongocoel in syconoids are non- flagellated but is lined with ___________
epithelial-type cells
Syconoids are in the class ___________
Calcarea
Example of sponges under syconoid canal system?
Sycon (Gr. Sykon, a fig)
a commonly studied example of the
syconoid type of sponge
Sycon
- organization is the most
complex of the sponge types and
permits an increase in sponge size - form large masses
with numerous oscula - Clusters of flagellated chambers
are filled from incurrent canals and
discharge water into excurrent
canals that eventually lead to the
osculum - There is no spongocoel
Leuconoids
Leuconoid is known to have_____
Flagellated Chambers
Simplified system of leuconoid
Water enters the:
Ostia—> incurrent canal—> flagellated chambers—> excurrent canal—>osculum
Most sponges are of the ________ type
Leuconoid
Leuconoid system occurs most in _______ and all other classes
Calcarea
The sponge’s canal system demonstrate an increase in the
___________________________________, but they do
not imply an evolutionary or developmental sequence.
complexity and efficiency of the water-pumping system
The ______________ of construction has evolved independently many
times in the sponges
leuconoid grade
Possession of a leuconoid plan is of clear adaptive value. It increases the proportion of flagellated surfaces compared with the volume, thus providing more _________ to meet food demands
collar cells
Types of Cell in Sponges
-pinacocyte
-porocytes
-Choanocytes
-Archeaocytes
-Spongocytes
-Collencytes
Connective tissue of the sponge
Mesohyl
Tubular cells that pierce the
body wall of asconoid sponges,
through which water flows
Porocytes
- The nearest approach to a true tissue in sponges is arrangement by this cell of the external pinacoderm layer.
- These thin, flat, epithelial type cells cover the exterior surface and some
interior surfaces, but only in one group do they rest on a basal lamina ECM. - Some are T-shaped, with their cell bodies extending into the mesohyl.
- modified as contractile myocytes, which are usually
arranged in circular bands around the oscula or pores, where they help to
regulate the rate of water flow. - Myocytes contain microfilaments similar to those found in muscle cells of
other animals.
Pinacocytes
- Pinacocytes are modified as contractile myocytes, which are usually
arranged in circular bands around the oscula or pores, where they help to
________________________
regulate the rate of water flow
Which part of choanocyte do filter happens?
Sieve-like collars
-line flagellated canals and chambers, are ovoid cells with one end embedded in mesohyl
and the other exposed.
-The exposed end bears a flagellum
surrounded by a collar
-Electron microscopy shows that the
collar is composed of adjacent
microvilli, connected to each other
by delicate microfibrils so that the
collar forms a fine filtering device for
straining food particles from the
water
Choanocytes
Choanocytes: Particles too large to enter the collar become trapped in secreted mucus
and slide down the collar to the base,
where they are _____________ by the
cell body
phagocytized
secrete fibrillar collagen
Collencytes
- Are ameboid cells that move through the mesohyl and perform a
number of functions - They can phagocytize particles at the external epithelium and receive
particles for digestion from choanocytes - It can differentiate into any of the other types of more specialized
cells in the sponge
Archaeocytes
secrete the spongin fibers of the skeleton
Spongocytes
The major structural protein in the animal kingdom is _______.
-collagen
Gives support to a sponge, preventing collapse of canals and chambers
Skeleton
_______________ occur throughout the
extracellular matrix of all sponges
fibrils of collagen
Various Demospongiae secrete a form of collagen called __________
spongin
Demospongiae also secrete _____________-
silicious spicules
calcareous sponges secrete spicules composed mostly of ________________________
crystalline calcium carbonate
Glass sponges (Hexactinellida) have
siliceous spicules with _________ arranged in three planes at right angles to each other.
six rays
The smallest particles, accounting for about 80% of the particulate organic carbon, are phagocytized by ____________.
choanocytes
___________ may phagocytize particles at the surface
Pinacocytes
Sponges feed primarily on _________________pumped through their canal systems.
particles suspended in water
They consume detritus particles, planktonic organisms, and bacteria in sizes ranging from ______ (average diameter of ostia) to ______
(width of spaces between the microvilli of the choanocyte collar)
50 μm to 0.1 μm
Sponges consume a significant portion of their nutrients in the form of organic matter dissolved in water circulating through the system, such material is apparently ingested by a process similar to _____________.
phagocytosis
Digestion is entirely __________________, a chore performed by the archaeocytes
intracellular (occurs within cells)
Sponges have __________________________; these functions are performed by diffusion
no respiratory or excretory organs
Some sponges can crawl (move laterally over their supporting substratum) at speeds of up to ________ per day.
4 mm
___________ ___________ occur in the archaeocytes and choanocytes of freshwater sponges
Contractile vacuoles
Some large sponges can filter _______________ of water a day
1500 liters
In sexual reproduction, most sponges are ________
monoecious
All sponges can reproduce both ________ and _________
sexually and asexually
The term referring to an organism having both male and female sex cells in one individual
monoecious
In Calcarea and at least some Demospongiae, oocytes also develop from ___________
choanocytes
_______ arise from transformation of choanocytes
Sperm
Sperm arise from transformation of choanocytes by its ability to?
Differentiate
in other demosponges, oocytes apparently
develop from ______________
archaeocytes
Sperm are released into the water by one individual and taken into
the ______________ of another.
canal system
There, choanocytes phagocytize them, transform into ________________, and then carry the sperm through the mesohyl to the oocytes.
carrier cells
Other sponges are _________ and expel both oocytes and sperm into the water.
oviparous
Ova are fertilized by ___________ in the mesohyl.
motile sperm (without carrier cells)
the sponge zygotes develop into _______________, which break loose and are carried away by water currents.
flagellated larvae
The free-swimming larva of most sponges is a solid-bodied ___________
parenchymula
The loose organization of sponges is ideally suited for _________ of injured and lost parts, and for asexual reproduction.
regeneration
The outwardly directed, flagellated cells on the larval surface migrate to the interior after the larva settles and become ____________ in the
flagellated chambers
choanocytes
Sponges reproduce asexually by ____________
and by ___________________ that detach or
remain to form colonies
-fragmentation
-forming external buds
In addition to external buds, which all sponges
can form, freshwater sponges and some marine sponges reproduce asexually by regularly forming internal buds called __________
gemmules
Gemmules stays dormant with masses of encapsulated archeocytes form during unfavorable conditions and can survive _______________ without oxygen.
3 months
Size of Class Calcarea
10 cm or less
-calcareous sponges, so called
because their spicules are composed of
calcium carbonate.
-Their spicules are straight monaxons or
have three or four rays
Class Calcarea (Calcispongiae)
Form of Calcarea
tubular or vase shaped
Canal System of Calcarea
asconoid, syconoid, or leuconoid
Colors vary from:
drab, some are bright yellow, red, green, or
lavender.
Examples of Sponges under class calcarea
Leucosolenia, Clathrina, and Sycon
- is the skeleton of six-rayed
siliceous spicules bound together in an exquisite glasslike latticework - Collar bodies extend through openings in both sheets, but the
openings surround the collar bodies tightly. - There is a space between the two sheets.
- To collect food, the incurrent water is directed to the primary reticulum, where pores enter the space between the primary and
secondary reticular sheets
-Water entering this space must leave by moving through the mesh of
microvilli on collar bodies; water cannot go anywhere else because it
is blocked by the secondary reticulum.
Food particles captured on microvilli are shared throughout the
syncytium
Class Hexactinellida (Hyalospongiae)
Size of class Hexactinellida
7-10 cm to more than 1 m (radially symmetry)
Class Hexactinnelida body is ___________ (many nuclei inside a single very large plasma membrane)
Syncytial
Hexactinellida: This single, continuous syncytial tissue is called a _________ ________
trabecular reticulum
A ________________________ makes the largest syncytium known within
the animals.
1-m-diameter glass sponge
Hexacatinnelida: The trabecular
reticulum is ___________ and can be ______or
__________. Between the layers of the sheet, or
inside the tubes, is a thin collagenous
mesohyl in which cells,such as archeocytes or
choanoblasts,
bilayered and can be sheetlike or
tubular
Hexactinnelida: Choanoblasts and other cells are connected to each other, and to the
trabecular reticulum, by ________________
cytoplasmic bridges
Hexactinnelida: Choanoblasts are unusual cells that make two or more flagellated
outgrowths called ________________
collar bodies
An assemblage of collar bodies in hexactinnelida forms a ________________-
flagellated chamber
Hexactinnelida: the trabecular reticulum
branches to become two distinct
bilayered sheets that make a sandwich around the center of a collar body
- primary reticulum
- secondary reticulum (thin, lacks mesohyl)
Examples of sponge under class Hexactinellida
-Euplectella (NL. from Gr. euplektos, well-plaited)
-Hyalonema
comprise approximately 80% of all sponge
species, including most larger
sponges.
Class Demospongiae
Desmospongiae: Skeleton may be composed of:
-siliceous spicules,
-spongin fibers,
-both
Desmospongiae: Freshwater sponges occur ___________________________, where they encrust plant stems and old pieces of submerged wood.
widely in well-oxygenated ponds and
streams
All members of the class desmospongiae are __________, and all are marine except one
family, the freshwater ___________
-leuconoid
-Spongillidae
Desmospongiae: So-called bath sponges belong to the group called ________________,
which have only spongin skeletons.
horny sponges
-are marine sponges that occur in a range of
colors, but live in cryptic habitats, so they are often overlooked.
-They are more common in nearshore habitats, but they do occur in
deep water.
-Sponges in this class were formerly placed in Class Demospongiae,
but were separated because they possess unique features such a
basal lamina composed of ECM underlying the pinacoderm cell layer
Class Hosmocleromorpha
Habitat of Homoscleromorpha
cryptic habitats
Forms of Desmospongiae?
Some are:
-encrusting
-tall and fingerlike
-fan, vases, cushions or balls
Homoscleromorpha: Proteins called __________ function as adhesives in desmosome
junctions and are also used in making adherens junctions, but not all cells capable of making adherens junctions can make desmosomes.
cadherins
Homoscleromorpha: The pinacoderm layer fails to meet the definition of a true tissue
epithelium and is instead called an _____________
incipient epithelium
Two Clades of Class Homoscleropmorpha
- Lacks Spicules entirely
- spicules that do not form
Representative Genera of class homscleromorpha
Plakina, Oscarella, and Corticium
Representive genera of Class Desmospongiae
-Thenea,
-Cliona,
-Spongilla,
-Myenia,
- bath sponges.
Two groups of calcareous spongelike organisms occupied _________________.
early Paleozoic reefs
The _____________ saw rapid development of many glass sponges
Devonian period
Some proteins used in cell adhesion and cell signaling in sponges are
homologous to those in other metazoans; in fact many of these occur in
________________, evolving before the last common ancestor of all
animals
choanoflagellates
Whats the best canal system in terms of relatively large surface area for food capture and gas exchange
leuconoid body plan
One very novel way of feeding has evolved within a family of sponges,
called __________, inhabiting nutrient-poor deepwater caves
cladorhizids
Characteriestics of Cladorhizids
- fine coating of tiny,
-hook-like spicules over its highly branched body
Cladorhizins: * These animals are ___________, not suspension feeders; they lack
choanocytes and internal canals but have siliceous spicules like typical members of class Demospongiae.
Carnivores
CLadorhizids: In addition to capturing prey, some augment their diets with nutrients
obtained from symbiotic _________________.
methanotrophic bacteria
Example of Cladorhizids
Chondrocladia lyra (deep-sea harp sponge)
Chondrocladia lyra: Terminal balls on each branch contain _______________; eggs are held midway up the
branches.
spermatophores
