Invertebrates Part 1 Flashcards
What phylum is part of the clade Parazoa?
Porifera
What animal is part of phylum Porifera?
sponges
Where are sponges a found?
marine and freshwater
How are sponges in the larval stage compared to the adult?
larval are free swimming while adult are anchored onto a submerged object (sessile)
What characterizes the clade Parazoa?
no body symmetry and no tissues (have cells though)
What does sessile mean?
anchored
What symmetry do sponges have?
asymmetrical
What shapes do adult sponges have?
vase shaped
Are sponges simple or complex?
very simple
What are the layers of the sponge body wall?
inner, middle, and outer
What are the body walls of sponges made of?
layers of cells that lack discrete (?) organization
Describe the inner layer of a sponge’s body wall
specialized cells called choanocytes, or collar cells
Describe the middle layer of a sponge’s body wall
- gelatinous, protein-rich matrix mesohyl
- may contain spicules and/or spongin
What are spicules? Is it hard or soft?
skeletal spikes of silica or calcium carbonate, rigid or hard
What is spongin? Is it hard or soft?
protein fiber, soft
Describe the outer layer of a sponge’s body wall
protective “epithelial” cells
Do sponges have a epithelium?
no, the “epithelial” cells are simply a descriptive term
What layers of the sponge’s body wall are unique to sponges?
inner and middle
Do sponges contain both spicules and spongin?
some are exclusively spongin and some contain both
How do sponges eat?
filter feeders
How does filter feeding work?
move water from outside of the animal through pores where food can be filtered. Water moves from outer area through little channels into the inner space which opens to the outside on the top
What are the three body plans?
asconoid, synconoid, and leuconoid
What is asconoid?
simplest
What is synconoid?
increased surface area