Girdle Wearers: Loricifera

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GIRDLE WEARERS: Loricifera

BUCKET-TAILED LORICIFERAN (Rugiloricus cauliculus): SPECIES ACCOUNT

PHYSICAL CHARACTERISTICS

Girdle wearers are 0.008 to 0.02 inch (200 to 400 micrometers) long. The body is divided into five sections: a mouth cone, a head that can be drawn into the body, a neck, a thorax, and an abdomen. The mouth cone consists of six to 16 ridges and a tube. Some girdle wearers have six sharp spears in the mouth. The head consists of nine rows of spines used for movement and sensing. The neck consists of three rows of plates with 15 plates in each row and 15 spines. The thorax has no spines.

The abdomen consists of an armored band, or girdle, with six to ten strong plates or 22 to 40 folds. There are sense organs toward the rear of the abdomen. Girdle wearers have a digestive system, a reproductive system, a simple waste-removal system, a complex muscular system, and a nervous system with a large brain and a nerve cord with groups of nerve cells outside the brain.

GEOGRAPHIC RANGE

Girdle wearers live all over the world.

HABITAT

Girdle wearers live in the sea at all depths. They are common around the North Pole and the South Pole, especially in the deep sea. Girdle wearers live in the spaces between sand grains or in mud.

DIET

Girdle wearers eat algae and bacteria. Algae (AL-jee) are plantlike growths that live in water and have no true roots, stems, or leaves.

BEHAVIOR AND REPRODUCTION

Girdle wearers attach themselves to sand or mud with a kind of glue made by glands located toward the rear of adults and on the toes of larvae. Larvae (LAR-vee) are animals in an early stage that change form before becoming adults. Adults crawl by using their spines and their mouth cones. The mouth cone telescopes out to its full length, fastens itself to a sand grain, and then draws in again so that the animal's body is pulled forward. The larvae use spines and bristles to crawl between grains of sand. They can also swim by using their toes. Girdle wearers eat by piercing bacteria and algae with their mouth spears and sucking out the contents.

Girdle wearers have separate sexes. Fertilization (FUR-teh-lih-ZAY-shun), or the joining of egg and sperm to start development, takes place either inside or outside the body. The primary larvae hatch from the fertilized (FUR-teh-lyzed) eggs and grow by shedding their outer layer. After two to five of these shedding stages, the larvae go into a resting stage and never feed. A male or female with fully developed reproductive organs emerges from the resting stage, and the life cycle repeats itself.

Some girdle wearers also have a cycle in which the larvae develop from eggs without fertilization. These larvae develop either into new larvae that develop without fertilization or into resting-stage larvae that shed their outer layer and transform into adult males or females.

GIRDLE WEARERS AND PEOPLE

Scientists may be able to use girdle wearers as indicators of pollution.

WHAT'S IN A NAME?

The lorica (luh-RYE-kuh) was the metal or leather plated body armor worn by Roman soldiers. The plated band or belt on loriciferans looks like this armor. In the old days a belt was called a girdle.

CONSERVATION STATUS

Girdle wearers are not considered threatened or endangered.

BUCKET-TAILED LORICIFERAN (Rugiloricus cauliculus): SPECIES ACCOUNT

Physical characteristics: Adult bucket-tailed loriciferans (LAW-ruh-SIH-fuh-ruhns) are 0.007 to 0.01 inch (180 to 264 micrometers) long. The head has nine rows of spines. The armored band has 60 folds. The anal (AY-nuhl) cone is pointed.

Geographic range: Bucket-tailed loriciferans live off the coast of North Carolina and South Carolina, United States; in the Mediterranean Sea; and around a small group of islands north of the United Kingdom.

Habitat: Bucket-tailed loriciferans live on sand at a depth of 660 to 1,640 feet (200 to 500 meters).

Diet: Bucket-tailed loriciferans eat bacteria.

Behavior and reproduction: Scientists do not know how bucket-tailed loriciferans behave. They have sexual and asexual life cycles. Asexual (ay-SEK-shuh-wuhl) means without and sexual means with the uniting of egg and sperm for the transfer of DNA from two parents.

Bucket-tailed loriciferans and people: Bucket-tailed loriciferans have no known importance to people.

Conservation status: Bucket-tailed loriciferans are not considered threatened or endangered. ∎