ZOO 137 - Invertebrate Zoology Phylum Info File -- Porifera

Classification You Need To Know

Kingdom Animalia
Subkingdom Parazoa (etymology: ______________________________________________)
Phylum Porifera (etymology: ______________________________________________)
Class Demospongiae (etymology: ____________________________________)
(examples: _______________________________________________)
There are other classes of sponges, but this is by far the largest.

Things You Should Do Before Coming to the Lab on Porifera

o Memorize the classification given above.
o Study Chapter 5 in Animals Without Backbones
o Complete exercises 8-9 in The Zoology Coloring Book (optional but highly recommended)

Things You Should Do During the Lab

o Examine each of the following prepared slides at your table:

Scypha (=Grantia) xs & ls (cross section and longitudinal section) - sections through the body of a simple sponge with a sycon or syconoid body architecture. See PAZ 3.1 and 3.4 to better understand what you are looking at.

Spongilla gemmules wm. - The gemmule or encysted stage of Spongilla shows bright red on the prepared slide if its outer dark colored, spicule-laden cover has been stripped off. Be sure to see both the "naked" and "clothed" states so you won't be confused later on. What is the protozoan analog of a sponge gemmule?

o Study the models of Scypha - a cross section and whole body. There are no keys to these models, but you should be able to figure them out by referring to ZCB 8 and 9. Be sure you can trace the route water takes from the outside through the spongocoel and out again. One of the principal features of sponges is their water canal system, and this sponge is a good one to see how water circulates. You will see at least one of these models on the lab practical - guaranteed.

o Examine the following demonstration specimens and slides:

-- Two slides showing the structural elements of sponge skeletons, spicules (PAZ 3.6-3.7) and spongin .

-- The dried remains of several different kinds of sponges, including demosponges and Venus' Flower Basket, a glass sponge. These remains are the intact sponge skeletons.

Things You Should Do After the Lab

o Using all sources available to you, make a list of ten important features, characteristics, etc. of the sponges. The first on your list could be that they have water vascular systems of various complexities. Another is that the degree of coordination among their cells lies somewhere between being a complex colony and being a metazoan (multicellular animal).

o Be sure to correlate what you've observed in lab with your readings and lecture notes.