1. Aschelminths Roundworms: Phylum Rotifera & Phylum Nematoda

2. Some things to know about Aschelminths… 1. Aschelminths (roundworms) have a pseudocoelom. What is a pseudocoelom? 1. Aschelminths (roundworms) have a pseudocoelom. What is a pseudocoelom? –They have a body cavity, but it’s not in the mesoderm, meaning that it’s not connected to anything. –What were the flatworms? 2. They have a complete digestive tract, meaning a mouth and an anus. And the mouth is actually on their head! 2. They have a complete digestive tract, meaning a mouth and an anus. And the mouth is actually on their head! 3. Can be microscopic to over 3 feet in length. 3. Can be microscopic to over 3 feet in length. 4. Roundworms are dioecious, meaning that they are either male or female, not both. 4. Roundworms are dioecious, meaning that they are either male or female, not both. 5. Aschelminths have a cuticle, a thin, tough, external covering that may have spines, scales, or other form of protection. 5. Aschelminths have a cuticle, a thin, tough, external covering that may have spines, scales, or other form of protection.

3. How and Where Do They Live? Most live in freshwater. But like the flatworms, some are marine, some are terrestrial, and a few are even parasitic. Most live in freshwater. But like the flatworms, some are marine, some are terrestrial, and a few are even parasitic. Some (the rotifers) are even colonial. Some (the rotifers) are even colonial.

4. Phylum Rotifera Rotifers are microscopic roundworms found in freshwater. Can be found living independently or colonially. Rotifers are microscopic roundworms found in freshwater. Can be found living independently or colonially. The coolest thing about rotifers, is that males are very rare or nonexistent! This means that the females reproduce by parthenogenesis. (They don’t need a male rotifer to get pregnant!) The coolest thing about rotifers, is that males are very rare or nonexistent! This means that the females reproduce by parthenogenesis. (They don’t need a male rotifer to get pregnant!)

5. Phylum Nematoda Some of the most abundant animals on Earth! Some of the most abundant animals on Earth! They can live in freshwater, marine habitats, soil, or as parasites. They can live in freshwater, marine habitats, soil, or as parasites. Not only do Nematodes have a mouth, they also have lips! Not only do Nematodes have a mouth, they also have lips!

6. Parasitic Nematodes: Trichina Worms Trichinosis: Infection comes from eating undercooked infected pork. Worms live in the small intestine and muscles of pigs and humans. In the muscles, the worms can cause intense pain and permanent damage. Not very common in the US. Trichinosis: Infection comes from eating undercooked infected pork. Worms live in the small intestine and muscles of pigs and humans. In the muscles, the worms can cause intense pain and permanent damage. Not very common in the US.

7. Parasitic Nematodes: Filarial worms Filarial worms live in the lymphatic system, blocking vessels. This causes fluid to back up and body parts (usually legs) to swell. This is called elephantiasis. Transmitted by mosquitoes in tropical climates. In the US, the only type of filarial worm that survives affects dogs – heartworm. This condition is usually fatal, so prevention with heartworm medication is the best thing to do for your dog! Filarial worms live in the lymphatic system, blocking vessels. This causes fluid to back up and body parts (usually legs) to swell. This is called elephantiasis. Transmitted by mosquitoes in tropical climates. In the US, the only type of filarial worm that survives affects dogs – heartworm. This condition is usually fatal, so prevention with heartworm medication is the best thing to do for your dog!

8. Parasitic Nematodes: Pinworm Pinworm: most common worm infection in the US, usually in children. Infects the large intestine and anus, causing intense itching. After scratching, children don’t usually wash their hands and go on to infect other children, their parents, or pets. However, this is easily cured with an inexpensive medication from your family doctor. Pinworm: most common worm infection in the US, usually in children. Infects the large intestine and anus, causing intense itching. After scratching, children don’t usually wash their hands and go on to infect other children, their parents, or pets. However, this is easily cured with an inexpensive medication from your family doctor.

9. Parasitic Nematodes: Hookworm Found in the southern US. Resides in the small intestine, feeding off human blood and body fluids. Larval worms are found in grass and soil and usually enter through the feet. Symptoms of hookworm include anemia and lack of energy. Your dog or cat can get hookworm, too. Found in the southern US. Resides in the small intestine, feeding off human blood and body fluids. Larval worms are found in grass and soil and usually enter through the feet. Symptoms of hookworm include anemia and lack of energy. Your dog or cat can get hookworm, too.

10. Parasitic Nematodes: Ascaris The longest of all parasitic nematodes. They live in the small intestines of humans, and the eggs exit the body with feces. The larvae penetrate the intestinal lining and infect the lungs. This produces an itchy feeling in the trachea which makes you cough. When you cough, the larvae are swallowed back into the stomach to continue the cycle. The longest of all parasitic nematodes. They live in the small intestines of humans, and the eggs exit the body with feces. The larvae penetrate the intestinal lining and infect the lungs. This produces an itchy feeling in the trachea which makes you cough. When you cough, the larvae are swallowed back into the stomach to continue the cycle.