O subphylum Cephalochordata, whose animals are also called cephalochords, has as representatives the amphioxes, small animals that resemble fish, but without fins and with a differentiated head. With a flat body and tapering at the ends, the amphioxes they can only be found in marine environments, where they live buried in coarse sand beaches, with only their mouths exposed. They have filaments around the mouth called buccal cirrus, which prevent sand and other large particles from entering the mouth.
For being filter animals, you amphioxes filter all the water that passes through their gill slits. When crossing the cracks, the water falls into the atrium and then it is eliminated by the atriopore. When there are food particles present in the filtered water, these particles stick to the mucus produced by the endostyle, which is located in the animal's pharynx. Thus, food particles and mucus are sent to the intestine, where they will undergo the action of digestive enzymes and where most of the digestion will take place. It is important to remember that these animals do not have a stomach.
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Cephalochordates can be found in different parts of the world, including Brazil
O circulatory system of these animals is formed only by vessels responsible for conducting and pushing blood throughout the body. The gas exchange of amphioxes is done through the gill slits.
You amphioxes they are animals that have the notochord present throughout their lives, supporting their metamerized musculature, which is organized into myotomes, with a letter V shape lying down (<<<
They are animals that have a dorsal nerve tube with branches to all regions of the body; and have the ability to capture light through specialized cells, in addition to having smell and taste receptors.
You amphioxes they are dioecious animals (separate sexes) that carry out external fertilization and have indirect development (with a larval stage).
By Paula Louredo
Graduated in Biology
Would you like to reference this text in a school or academic work? Look:
MORAES, Paula Louredo. "Subphylum Cephalochordata"; Brazil School. Available in: https://brasilescola.uol.com.br/biologia/cephalochordata.htm. Accessed on June 27, 2021.
