Annelids Annelids

By Jonathan, Kate, By Jonathan, Kate, Effie, JaydEffie, Jayd

DefinitionDefinition

An annelid is something that does An annelid is something that does not have a back bone and has not have a back bone and has segments, bristles, paddles and segments, bristles, paddles and suckers.suckers.

Special features of a Special features of a annelid annelid

All annelids have a body made of many segments.All annelids have a body made of many segments.

Earth worms and sea worms grow longer by Earth worms and sea worms grow longer by growing extra segments as they get older.growing extra segments as they get older.

The new body segments are added at the end of the The new body segments are added at the end of the tail.tail.

This means that the younger segments are closest This means that the younger segments are closest to the tail and the older segments are closer to to the tail and the older segments are closer to the head.the head.

Paddles Paddles

Sea worms have paddles these are flaps of skin on Sea worms have paddles these are flaps of skin on the side of their body segments.the side of their body segments.

The paddles help the worm crawl swim or grip the The paddles help the worm crawl swim or grip the sides of their tubes or burrows .sides of their tubes or burrows .

They can be different sizes and shapes. They can be different sizes and shapes.

Many sea worms have two big paddles on each Many sea worms have two big paddles on each segment these form a row down each side of the segment these form a row down each side of the worms body worms body

Sea worms that live in tubes often have small Sea worms that live in tubes often have small paddles on their segments.paddles on their segments.

SegmentsSegments

All annelids have a body made up of All annelids have a body made up of segments. Earthworms and sea segments. Earthworms and sea worms grow longer by growing extra worms grow longer by growing extra segments as they grow older. The segments as they grow older. The new body segments are added at the new body segments are added at the tail end of the body. This means that tail end of the body. This means that the younger segments are closest to the younger segments are closest to the tail and the older segments are the tail and the older segments are closest to the head.closest to the head.

Suckers Suckers

Leeches are the only animals that have Leeches are the only animals that have suckers. suckers.

Suckers let a leech move about in different Suckers let a leech move about in different ways to annelids.ways to annelids.

When a leech moves it grips on to When a leech moves it grips on to something with suckers under the tail at something with suckers under the tail at the ends of its body then it stretches the ends of its body then it stretches forward to grip somethingforward to grip something

With its front sucker next to its wings With its front sucker next to its wings forward to make a loop with its body and forward to make a loop with its body and grips again with its big tail and suckergrips again with its big tail and sucker

Bristles Bristles

Leeches do not have bristles, but all annelids do. Leeches do not have bristles, but all annelids do. These bristles are found on the body of sea These bristles are found on the body of sea worms. Sea worms have many bristles their worms. Sea worms have many bristles their bristles help them crawl or swim. Some sea bristles help them crawl or swim. Some sea worms such as bristle worms have very long worms such as bristle worms have very long bristles but others such as tube worms have short bristles but others such as tube worms have short bristles these bristles help them grip the walls of bristles these bristles help them grip the walls of their tube. Most earth worms have tiny bristles in their tube. Most earth worms have tiny bristles in and out of their skin. When an earth worm sticks and out of their skin. When an earth worm sticks its bristles out, it can grip the ground better so its bristles out, it can grip the ground better so that it does not slip as it wriggles around.that it does not slip as it wriggles around.

Quick FactsQuick Facts

Most annelids can move backwards if Most annelids can move backwards if they need to but leeches can only they need to but leeches can only move forwards.move forwards.

Baby annelids are called annelids.Baby annelids are called annelids.

Sub groups of annelidsSub groups of annelids

LeechesLeeches

Sea wormsSea worms

Earth wormsEarth worms

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