This document provides information about segmented worms of the phylum Annelida. It discusses three main classes of annelids: Oligochaeta (earthworms), Hirudinea (leeches), and Polychaeta (marine worms). Earthworms live underground in moist soil, leeches live near freshwater, and marine worms live in the ocean. Annelids have segmented bodies and can regenerate lost segments. They have adapted to live in various environments through features like a water-conserving epidermis.

1. Akshay Chitturi

2. Giant earthworm (class Oligochaeta)
Leech (class Hirudinea)
Marine worm (class Polychaeta)
Bristleworm (class Polychaeta)

3. Introduction
 I am a segmented worm, also known as a member of
the Phylum Annelida.
 Why am I so unique?
 As an annelid, I am able to live in a variety of places. I
prefer underground, but sveral of my cousins are able to
live within sponges, or even “shells” of their own creation!
 My body is divided into several “segments” that can
regrow if I lose one.

4. My Habitat
 We annelids are divided into three classes:
Oligochaeta, Hirudinea, and Polychaeta.
 Oligochaeta (earthworms) live underground terrestrially
in moist soil, and come to the surface after heavy
rainfall.
 Hirudinea (leeches) live near freshwater
streams, because of an inability to store water very well.
 Polychaeta (marine worms) live in the ocean, filter-
feeding for survival.

5. Favorite Activities
 As an annelid, I enjoy burrowing underground
searching for food, avoiding enemies, and finding
potential mates.
 My cousins, the leeches, have a pastime of preying on
visitors. They enjoy sucking their blood for a meal.
 My very distant relatives, marine worms, enjoy sitting
on the ocean floor and filter-feeding. Sometimes I
envy their lifestyle…
 Sometimes, though, after a heavy rainfall, I venture
above-ground to mate (when the air is humid enough
for me). We have to be careful, though – many of us
get killed aboveground.

6. Genealogy
 Every Annelid has several functionally identical body
segments. This design helps regeneration – it is very
easy to replace lost/damaged segments.
 We have a very wide temperature and pH
tolerance, letting them inhabit a variety of
environments, from hypotonic (freshwater) to
hypertonic (terrestrial). I, for example, can thrive in
acidic or basic soils.
 Annelids have developed a special epidermis that
allows us to conserve water. We developed this when
our ancestors first made the jump to land.

7. Adaptations
 Annelids are made of easily replaceable segments. By
keeping the segment structure similar and spreading
organs, an annelid can replace damaged/severed segments
fairly quickly.
 Annelids have a membrane known as a cuticle, which
allows water molecules to diffuse inward (facilitated
diffusion) but doesn’t allow water OUT.
 Annelid blood is constantly circulating (no open sinuses
for draining) which means that the blood does not pool
and become useless for a time.
 Annelids move on land due to a system pioneered by their
ancestors; repeated contraction of oblique muscles. A few
annelids (marine worms) have appendages to aid them.

8. Terms/Conditions
 I am looking for:
 A highly resilient mate, capable of surviving in varied
pH / osmotic conditions
 A less motile mate, able to move slowly but not too
quickly
 An invertebrate who thrives in and enjoys very humid
conditions, but who isn’t picky

9. Bibliography
 Mitchell, Anne P. quot;All About Segmented Worms - Phylum Annelida.quot; All About
Worms. 2005. 17 Apr. 2009 <http://www.allaboutworms.com/segmented-
worms-phylum-annelida>. This website was instrumental in finding very basic
information about anelids, and was especially helpful with their history
(migration onto land).
 quot;Annelida.quot; McGraw-Hill Encyclopedia of Science and Technology. The
McGraw-Hill Companies, Inc., 2005. Answers.com 19 Apr. 2009.
http://www.answers.com/topic/annelida-2 This website was very helpful with
the specific adaptations that annelids developed to survive on land, and
described their pros and cons in detail.
 MSN Encarta - Online Encyclopedia, Dictionary, Thesaurus, and More. 1997.
Microsoft. 18 Apr. 2009
<http://encarta.msn.com/encyclopedia_761560164/Annelid.html>. This article
gave a lot of basic information on annelids, and was particularly informative
when it came to their habitat.
 quot;Earthworms.quot; Backyard Nature with Jim Conrad. 2004. 18 Apr. 2009
<http://www.backyardnature.net/earthwrm.htm>. This article was especially
helpful in the classification of Annelids, and helped me to categorize them by
freshwater, terrestrial, and marine classes.