2_Poriferans Flashcards
What do you call pore bearing animals?
Poriferans
Porifera
______ = pore
______= bearing
porus, fera
What are the 3 cell types of poriferans/sponges?
Choanocytes,
Amoebocytes
Pinacocytes,
What are the GENERAL MORPHOLOGICAL FEATURES of Poriferans?
- Simplest multicellular animal—an aggregation of cells embedded in mesohyl
- With spongin/spicules
- Body pores with canal system
What are thin, flat, epithelial cells covering
the exterior and interior surfaces of
a sponge, derived from the epithelial layer and some modified into myocytes or
“muscle cells”?
Pinacocytes
What specialized tube-like, contractile,
cells piercing the wall of the sponge
(asconoid) and regulate the flow of water into the sponge’s internal channels
Porocytes
These are ovoid cells – one end embedded in mesohyl and exposed end bears a
flagellum surrounded by a collar
collar is made up of microvilli connected
to each other (for filter feeding)
line the flagellated canals and channels
Choanocytes (collar cells)
It generate currents that help maintain
circulation of seawater within and thru
the sponge
capture small food particles
& capture incoming sperm for fert
Choanocytes (collar cells)
What are ameboid cells that functions to store and digest food captured by
choanocytes, as well as give rise to gametes?
Archaeocytes/Amoebocytes
Derived from archaeocytes
Spongin and Spicules
sclerocytes – ?
spongocytes – ?
lophocytes – ?
collencytes – ? ; may not be derived
directly from amoebocytes
spicules
spongin fibers
primarily silica
collagen
Spicules (rigid) can either be made up of what?
- calcium carbonate (calcareous)
- Silicon (siliceous)
These provide support, stiffen mesohyl, maintain shape
prevent collapse of the canals and chambers
taxonomic importance
Discourage predation
Spongin and Spicules
A type of spicules that is needle like, straight
Monaxon
Type of spicules:
3 rayed :
6 rayed :
4 prongs :
multiple short rods radiating from a common center; burr shaped, star shaped or like a child’s jack:
Triaxon
Hexaxon
Tetraxon
Polyaxon
What are the three main designs for the sponge body differing in the placement of the choanocytes?
Asconoid
Syconoid
Leuconoid
This type of sponge design is the most primitive and simplistic in
structure
* tube-shaped body with 1 osculum
* choanocytes line the spongocoel
(atrium)
* imposes definite size limits to
sponges due to the problem of
water flow (<10 cm)
Asconoid
This type of sponge design is the more complex – with invaginated walls to increase surface area and decrease volume in spongocoel
▪ tubular with 1 osculum
▪ choanocytes lie in radial canals
▪ can grow larger than the asconoid
Syconoid
This type of sponge structure desing is the most complex (and most common) – invagination of canals to form small flagellated chambers
o loss of spongocoel
o with excurrent canals
* irregular in shape
* colonial, each member has
an osculum
* may attain large sizes
Leuconoid
What is the locomotion and movement of sponges?
planktonic or motile at larval stage
sessile(immobile) at adult stage
______________remove mineral particles that
block the ostia by transporting and dumping into the outgoing water current
archeocytes/amoebocytes
supported by water flow system
and absorbs oxygen and excrete waste products (i.e.,
ammonia) through diffusion
Respiration and Excretion
generally feed on suspended particles in the water pumped through the canal system
Filter feeding
What is the reproduction of sponges?
Asexual
* Budding (with fragmentation )
* Gemmule formation
Sexual
* Fertilization
