agnatha excrete(expulse non-needed matter) by using a propulsory system called the anal ejector. they usually excrete this matter during copulation in the form of sperm wikipedia has this answer too
Agnatha, which includes jawless fish like lampreys and hagfish, have all three germ layers: ectoderm, mesoderm, and endoderm. They exhibit the typical triploblastic organization found in most animals.
Examples of agnatha, or jawless fish, include lampreys and hagfish. These fish are characterized by their lack of jaws, paired fins, and scales. They are considered primitive vertebrates and play important roles in marine ecosystems.
Agnatha, which includes lampreys and hagfish, have a closed circulatory system with a two-chambered heart. This system allows for more efficient distribution of oxygen and nutrients throughout the body compared to an open circulatory system.
excretion
The advantage is that ammonia (NH3) is not converted in Ammonotelic excretion. Fish can excrete ammonia through gills because there is a lot of water to dilute it in without causing damage to their cells. In Uricotelic excretion, NH3 has to be converted to a solid form via a complex and ATP-costly route. So Uricotelic excretion takes a lot more energy than Ammonotelic excretion.
Externally
without jaws
skin
Agnatha, also known as jawless fish, lack jaws and scales. They have a cartilaginous skeleton, a round mouth, and a single nostril on their head. Agnatha are also known for their ability to produce slime as a defense mechanism.
by the gill slits
with gills; they're fish!
Class Agnatha
jawless fish. not very common today, but they were in the past.
I don't know but i will do some research...
no they have large bonelikes structures called the stonnes.
Agnatha, such as lampreys and hagfish, have a two-chambered heart. The heart consists of an atrium and a ventricle, which pump blood through the circulatory system.
Agnatha, which includes jawless fish like lampreys and hagfish, have all three germ layers: ectoderm, mesoderm, and endoderm. They exhibit the typical triploblastic organization found in most animals.