What are two similarities and two differences between cnidarians and echinoderms?
Cnidarians and echinoderms have radial symmetry; mollusks have bilateral symmetry. Cnidarians have no body cavity or cephalization; mollusks and echinoderms have a true coelom and cephalization. Echinoderms’ tube feet are filled with water which runs down the length of the arms and creates a hydraulic system.
What is unique about cnidarians?
All Cnidaria are aquatic, mostly marine, organisms. They all have tentacles with stinging cells called nematocysts that they use to capture food. Cnidarians only have two body layers, the ectoderm and endoderm, separated by a jelly-like layer called the mesoglea. Most Cnidarians have radial symmetry.
How are cnidarians different from mollusks?
Mollusks are invertebrates with soft unsegmented bodies that are often protected by a hard outer shell. Cnidarians (ny DEHR ee unz) are invertebrates that have stinging cells and take food into a central body cavity. Cnidarians use sting cells to capture food and defend themselves. Only bivalves can make pearls.
Do mollusks have stinging cells?
Molluscs have blue blood – instead of having haemoglobin in their blood they have another compound called haemocyanin which has a blue pigment. Many nudibranchs are poisonous and can either contain stinging cells or release toxins into the surrounding water.
Is a snail a cnidarians?
The cnidarians (or coelenterates), phylum Cnidaria (or Coelenterata), are soft bodied animals that exhibit radial symmetry and possess true tissues. (1) A large phylum of invertebrate animals such as snails, clams or squid.
What class is a jellyfish in?
True jellyfishes
Do jellyfish fall apart easily?
You must take the time to properly cycle your aquarium no matter what animals you choose to keep in it). Once jellyfish are added to the tank, they begin to produce ammonia. Jellyfish will fall apart if subjected to these levels of toxicity.
Do jellyfish feel or think?
So, the detailed answer to your question is that jellyfish do not feel pain the in the same way we humans do. However, they do have the ability to sense and respond to aversive stimuli.
Do jellyfish die when they get washed up?
Jellyfish are mostly made of water, so they die quickly after washing onshore. They’re cold-blooded animals and can lose mobility when water temperatures are below normal.
Can you touch a dead jellyfish?
The tentacles of the jellyfish have tiny stingers called nematocysts which can detach, stick to skin, and release venom. Even if the jellyfish is dead, it can still sting you because the cell structure of nematocysts is maintained long after death.