Vad kännetecknar tagghudingar?

Innehållsförteckning:

1. Vad kännetecknar tagghudingar?
2. Var sitter Tagghudingarnas mun?
3. What is echinoderm?
4. Why are echinoderms so hard to get out of the sea?
5. What do echinoderms eat?
6. Do echinoderms have an anus?

Vad kännetecknar tagghudingar?

Tagghudingar är en artrik grupp med över 9 000 kända arter som lever i alla hav, flera vid svenska västkusten. Tagghudingarna rör sig långsamt över havsbottnen med munnen vänd nedåt. Ett undantag är sjöliljorna som åtminstone på ungdomsstadiet sitter fast på underlaget med ett skaft och har munnen vänd uppåt.

Var sitter Tagghudingarnas mun?

Hos de flesta tagghudingar sitter munnen på undersidan av djuret, nedvänt mot marken medan anuset återfinns på ovansidan. Detta gäller även sjöstjärnor. Tagghudingarna har ett speciellt och unikt system i sin kropp som kallas ambukralsystemet.

What is echinoderm?

... (Show more) echinoderm, any of a variety of invertebrate marine animals belonging to the phylum Echinodermata, characterized by a hard, spiny covering or skin.

Why are echinoderms so hard to get out of the sea?

Because of their catch connective tissue, which can change rapidly from a flaccid to a rigid state, echinoderms are very difficult to dislodge from crevices. Certain sea cucumbers have a cluster of cuvierian tubules which can be ejected as long sticky threads from their anus and entangle and permanently disable an attacker.

What do echinoderms eat?

Echinoderms form part of the diet of many organisms such as bony fish, sharks, eider ducks, gulls, crabs, gastropod molluscs, sea otters, Arctic foxes and humans. Larger starfish prey on smaller ones and the great quantity of eggs and larvae produced form part of the zooplankton , consumed by many marine creatures.

Do echinoderms have an anus?

Echinoderms possess a simple digestive system which varies according to the animal's diet. Starfish are mostly carnivorous and have a mouth, oesophagus, two-part stomach, intestine and rectum, with the anus located in the centre of the aboral body surface. With a few exceptions, the members of the order Paxillosida do not possess an anus.