# 17 Annelid

#17 Annelid

Common Name: Polychaeta 

Description

- Pink/dark brown.

- About 15-20 cm in length.

- Since annelids are invertebrates they have no backbone meaning they have no skeleton. 

- They are bilaterally symmetrical.

- It has a segmented body and each segment is practically identical except that some have rectangular cross sections. They are also found to be pale and clearly segmented.

- The brain is found in the front most section called the prostomium

- The section that is directly behind the prostomium contains the mouth.

- They also have a pentagonal prostomium with two pairs of small antennae.

- They are active predators with a strong muscular proboscis which are armed with two well developed jaws.

- They are able to quickly through sandy environments and swim with sinuous movements. 

Taxonomy

Kingdom: Animalia 

Phylum: Annelida

Class: Polychaeta

Order: Phylludocida

Family: Nephtyidae 

Genus: Nephtys

Ecology

- Most annelids serve as food for birds and keep the soil aerated while leeches help with medical needs.

- Their bodies are covered by a cuticle that doesn't contain cells but is secreted by cells in the skin underneath and is made with a tough and flexible collagen.