Sponges Flashcards
Where do sponges belong?
to the phylum Porifera meaning pore bearers: body is perforated by many pores and canals
features of the Phylum Porifera
- skeleton is composed of spicules or silica
- brightly colored because of dermal cells
-filter feeders
-some stand erect, some are branched, and encrusting
Ostia
small pores through which water enters
Osculum
the large opening where water exits
Spicules
tiny needle like structures that provide structural support made of calcium carbonate or silica
Spongin
a flexible protein that makes up the skeleton in some sponges. spongin fibers act as a “mortar” that holds together the hard, tiny spicules in a sponge’s skeleton
What are three classes that are traditionally assigned to living sponges?
calcarea, hexactinellida, demospongiae
Calcarea
- typically have calcium carbonate (calcareous) spicules
- have asymmetrical or radially symmetrical body structures
- simple organization, often with tubular shape
hexactinellida
- have six-rayed spicules called hexactines
- glass sponges
- live at extreme depths
have spicules made of silicon dioxide
demospongiae
- have siliceous spicules, spongin fiber or both
- the largest group of sponges
- play a crucial role in filter feeding, helping to clean water by removing plankton and organic particles
homoscleromorpha
previously a subgroup of demospongiae, have simple spicules or lack them entirely
What species of sea sponge is SpongeBob SquarePants based on?
aplysina fistularis
types of canal system
asconoid, syconoid, leuconoid
asconoids
have the simplest body form
syconoids
- resemble asconoids but they are larger with a thicker body wall
- wall contains choancyte- lined radial canals that fold back and forth so that canals empty into spongocoel
leuconoids
- most complex; larger with many oscula
- clusters of flagellated chambers are filled from incurrent canals and discharge to excurrent canals leading to oscula
types of sponge cells
choanocytes, amoebocytes, pinacocytes, porocytes
choanocytes
create water flow and trap food particles move them to amoebocytes
amoebocytes
transport nutrients and aid digestion
pinococytes
flat epithelial-like cells that cover the sponge’s surface
porocytes
tubular cells that form pores, pierce the body wall, and water flows through them
archaeocytes
are ameboid cells and can differentiate into other types of cells
what are the different types of cells can archaeocytes become
sclerocytes- secrete spicules
spongocytes- secrete spongin
collencytes- secrete fibrillar collagen
what cell is responsible for water flow and capturing food and assist in reproduction?
choanocytes
demospongiae and glass sponges secrete what?
siliiceous spicules
calcareous sponges secrete what?
spicules of calcium carbonate
internal buds of freshwater sponges that can withstand adverse conditions are__
gemmules
outline the order in which a drop of ink would pass by the structures in an asconoid sponge
water enters through microscopic pores ostia and moves into a large cavity, the spongocoel then, choanocyte flagella pull water through and expel through osculum
the water outlet in sponges is known as
osculum
reproduction and development of sponges
- most sponges are monoecious (male and female sex cells in one individual
- sperm released by one individual enter canal system of another individual
- some are oviparous, releasing both oocytes and sperm into water
- can reproduce asexually
