Lecture 7 porifera plus all sponges

Question 1

where do you find members of the phylum porifera?

Answer 1

Most of the species are marine.

• They are attached to surfaces as deep as 8 km.
• like clearer water because murky water may clog pores. ( cannot get nutrition & oxygen)

Question 2

Porifera main traits ?

Answer 2

• No true tissues
• filter feeders
• many brightly coloured due to dermal cell pigmentation.
• stand alone
• branched/ lobes

Question 3

How do you classify the sponges ?

Answer 3

Living sponges divided into 3 classes

- this is based on spicules ( skeleton components)

Question 4

What are the three type of canal that the sponges has ?

Answer 4

1. Asconoid
2. Syconoid
3. Leuconoid

therefore, sponges differ by how the water flows through the sponge.

Question 5

1. Asconoid

Answer 5

-most simple organization
- small & tube shaped members grow
in groups attached by a stolon
-water through porocytes
- water into flagellated spongocoel
(lined with choanocytes)

Question 6

2. Syconoid

Answer 6

• not just 1 choanocyte layer
• layer folded back & forth to make radial canals that are lined with choanocyte (i.e. flagellated canals )
• water 1st moves into incurrent canals & then into radial canals via prosopyles
• filtered water goes through apopyles into spongocoel line with epithelial-like cells (not choanocytes)

Question 7

3. Leuconoid

Answer 7

• most complex – permits increase in sponge size
• most form large masses with many oscula
• clusters of flagellated chamber filled through incurrent canals & emptied into excurrent canals leading to osculum
• no spongocoel

Question 8

mesohyl

Answer 8

gelatinous matrix

Question 9

Feeding of sponges

Answer 9

all filter feeder

• phagocytosis of suspended particles
• intracellular digestion ( archaeocytes)

Question 10

Archaeocytes

Answer 10

Intracellular digestion

Question 11

Respiration & osmoregulation of sponges ?

Answer 11

no respiratory or excretory organ
all done through diffusion
-contractile vacuoles in archaeocytes and choanocytes of freshwater sponges.

Question 12

Locomotion of sponges

Answer 12

Some capable of crawling behaviour

Question 13

Sponge reproduction

Answer 13

Both asexual and sexual reproduction

Question 14

Asexual

Answer 14

-usually by fragmentation or external budding
- some form internal buds ( gemmules )
-dormant masses of encapsulated archaeocytes
formed during unfavourable conditions

Question 15

Sexual

Answer 15

kj

Question 16

Monoecious

Answer 16

Both male & female sex found in an individuall

Question 17

parenchymula

Answer 17

ciliated larva

Question 18

Oviparous

Answer 18

release both oocytes & sperm

Question 19

cirri

Answer 19

fused cilia can form stiffened tufts

Question 20

infraciliature

Answer 20

kinetosome join fibrous structural system underneath the pellicle to form it .

Question 21

trichocyst & toxicyst

Answer 21

respond to mechanical stimulation & release thread like structure ( defence & predation)

Question 22

Holozoic

Answer 22

ingest solids or liquids

Question 23

cytostome

Answer 23

mouth

Question 24

macronuclei

Answer 24

responsible for day-to-day functions (metabolism , synthesis)

Question 25

micronuclei

Answer 25

exclusively for sexual reproduction (give rise to macronuclei after genetic exchange. )

Question 26

apical complex

Answer 26

contains organelles specialized for penetrating host cells & tissues

Question 27

endoparasite

Answer 27

live inside host

Question 28

Gregarinea

Answer 28

digestive tract & body cavity of invertebrates

Question 29

test

Answer 29

shell

Question 30

sclerocytes

Answer 30

secrete spicules

Question 31

spongocytes

Answer 31

secrete spongin fibres

Question 32

collencytes

Answer 32

secrete fibrillar collagen

Question 33

what are the skeletal component of sponges

Answer 33

• sclerocytes, spongocytes and collencytes.

Question 34

internal buds are called ?

Answer 34

gemmules