Cnidaria pt.3 & Ctenophores - 2.3.2025

What are Myxozoans?

Subphylum in Cnidaria that are parasites

(2) Key points about Myxozoans

Think body plan and cause

1. Highly reduced body plan & genome

2. Parasite of slamonoids that cause whirling disease

Draw the life cycle of a Myxozoan and label the following

1. Host fish

2. Actinospore

3. Myxospore

4. Host worm

Box jellies phylum and scientific name

Phylum Cnidaria

Cubozoa

How many species of Cubozoa?

~20

List (2) key points about Cubozoa shape

1. They have a square shape when viewed from above.

2. They have four evenly spaced-out tentacles (or more, even number)

Draw and label the following on a Cubozoa

1. Bell

2. Mouth

3. Rhopalia

4. Pedalium

5. Tentacles

Not only can Cubozoa swim fast, but they have a more accurate sense of their surroundings due to _______

Rhopalium with eyes

Cubozoa can see _______ skin in water clearer due to contrast, so they tend to accidentally sting _____

1. Melanated

2. Fair skin folks

Comb jelly phylum

Ctenophora

How many cell layers do Ctenophora have?

Two

Ctenophora do not have cnidocytes, they have ________

Colloblasts

What are colloblasts made of in Ctenophora ?

They are composed of a sticky crescent-shaped body fastened by 2 filaments(derived from a flagellum).

What are colloblasts for in Ctenophora?

Food is captured by the sticky colloblasts of the tentacles which are pulled over the mouth

Draw a Ctenophora colloblast

What type of symmetry do Ctenophora have?

Rotational symmetry

Draw and label the following on a Ctenophora

1. lobes

2. Mouth

3. Anus

5. Plane of rotational symmetry

What form of locomotion is used by Ctenophora?

- Comb of cilia beat in unison to generate a power stroke for swimming.

- Largest organism to utilize these for motion

Why do you see a rainbow of colors when Ctenophora swim by a submersible?

Light scattering off the cilia as they beat