Rotifer

Phylum Rotifera

• From the Latin Rota a wheel and Ferre to bear or carry

• Rotifera is divided into two classes, the Digononta and the Monogononta

• The members of the class Monogononta constitutes 90% of the known species

Characteristics of Rotifers• 1)Bilaterally symmetrical.

• 2)Body has more than two cell layers, tissues and organs.

• 3)Body cavity is a pseudocoelom[ second body cavity ].

• 4)Body possesses a through gut with an anus.

• 5)Body covered in an external layer of chitin called a lorica.•

6)Has a nervous system with a brain and paired nerves.

7)Has no circulatory or respiratory organs.

• 8)Reproduction mostly parthenogenetic [an asexual form of reproduction found in females where growth and development of embryos or seeds occurs without fertilization by a

male.] , otherwise sexual and gonochoristic[ reproduction with two distinct sexes].

• 9)Feed on bacteria, and protists, or are parasitic.•

10)All live in aquatic environments either free swimming or attached.

A Lil’ Video !

Physical Characteristics• The body is generally divided into a head,

a trunk, and a foot region

• The largest organ in the head is the wheel organ.

• The trunk shape varies from long to spherical or baglike .

• The foot has one or several sections, and it often has two toes with sticky glands at the tips.

Habitat

• Rotifers live in still water and flowing water environments such as lake bottoms, rivers, or streams.

• Rotifers are also commonly found on mosses and lichens growing on rocks and aquatic insect larvae.

FeedingFeeding The two wheels on The two wheels on

rotifers are made of rotifers are made of cilia that beat and cilia that beat and create a current create a current that draws water that draws water containing food into containing food into the gut of the the gut of the rotifer. rotifer.

Rotifers eat Rotifers eat bacteria (top left) , bacteria (top left) , protists (bottom protists (bottom left) , and otherleft) , and other small animals.small animals.

ReproductionReproduction The reproduction of The reproduction of

rotifers can be rotifers can be sexual and by sexual and by parthenogenesis. parthenogenesis.

The mictic female The mictic female produces eggs that produces eggs that undergo the usual undergo the usual double meiotic double meiotic division and are division and are haploid.haploid.

Sexual reproduction Sexual reproduction occurs in the occurs in the rotifers of Class rotifers of Class Monogononta Monogononta

QQuuiizz AAnnsswweerrss1.The body is generally divided into a head, a trunk, and a 1.The body is generally divided into a head, a trunk, and a

foot region. The largest organ in the head is the foot region. The largest organ in the head is the wheel organ. The trunk shape varies from long to wheel organ. The trunk shape varies from long to spherical or baglike .spherical or baglike .

2. Most Rotifers live in lake bottoms, rivers, or streams.2. Most Rotifers live in lake bottoms, rivers, or streams.

3. Mitic3. Mitic

4. Phylum Rotifera4. Phylum Rotifera

5.The corona is the part of a rotifer that is used as a 5.The corona is the part of a rotifer that is used as a feeding device and locomotive device. feeding device and locomotive device.

DiagramDiagram

The End

• Tishana

• Shanisa

• Janasia