Lecture 3 + 4: Sponges

Question 1

3 Sponge Body types

Answer 1

Ascon, Sycon and Leucon (has several oscula)

Question 2

Choanocytes

Answer 2

The main and most typical cell in sponges. distinguished by their flagellum and collar, Flagellum moves the water, collar retains the food particles

Question 3

Spicules

Answer 3

Not cells, just structures forming the skeleton of sponges, made of calcium

Question 4

Sclerocyte

Answer 4

Cell that secretes spicules

Question 5

Pinacocyte

Answer 5

T-shaped epithelial external cell

Question 6

Porocyte

Answer 6

Water flow regulation cell cells

Question 7

Archaeocyte

Answer 7

Multi-purpose cell (digestion / Reproduction)

Question 8

Class calcarea

Answer 8

3-ray calcarean spicules, mainly shallow water species

Question 9

Class hexatinellida

Answer 9

Glassy sponges with 6-ray siliceous spicules, all deep sea species

Question 10

Class Demospongiae

Answer 10

Various shape, silliceous spicules and collagen, very diverse

Question 11

Asexual Reproduction of Porifera

Answer 11

1) Fragmentation: a portion of the sponge detaches and builds a new one
2) Gemmules: similar to seeds filled with archaeocytes that are sealed during harsh conditions and released when conditions improve.

Question 12

Sexual Reproduction

Answer 12

Hermaphrodites: produce sperms from choanocytes and oocytes from archaeocytes

Question 13

External fertilizations

Answer 13

Sperm and oocytes are released into the water colomn

Question 14

Internal fertilization

Answer 14

Sperms released into the water are caught by another sponge and moved into mesoglea where oocytes wait

Question 15

Dispersal stage

Answer 15

Important for genetic exchange and sessile species, after drifting, larva will settle and form a new sponge