What is the alternative name for Phylum Nematoda?
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Nemata
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What is the alternative name for Phylum Nematoda?
Nemata
How many species of Nematodes are estimated to exist?
25,000 species, probably many more.
What is the first step in the life cycle of Ascaris lumbricoides?
The host swallows the eggs.
What is a unique feature of the body wall in these organisms?
The body wall is muscular, similar to annelids.
What do the slime glands on oral papillae do?
They shoot out sticky fluid to hunt.
What is helminth therapy?
Infecting a person with roundworm to alleviate allergies, and then killing the worms to cure the person.
What is a characteristic feature of hookworms' anterior ends?
They curve dorsally and look like a mouth with a hook.
How do hookworms affect the intestinal wall?
They have large plates in their mouth that cut into the intestinal wall.
What is a potential consequence of extreme hookworm infections?
They can cause growth problems.
Describe the life cycle of hookworms starting from eggs.
Eggs pass in feces, juveniles hatch in soil, live on bacteria, then burrow into skin upon contact, go through lungs, and into the digestive tract.
Under what condition do hookworms affect humans?
They only affect you if you don't get enough calories.
What causes trichinosis?
It is caused by one of the many species of Trichina.
How do adult Trichina worms affect the intestine?
They burrow into the lining of the intestine and release living young.
How do juveniles of Trichina spread in the body?
They penetrate the blood and get everywhere, encysting intracellularly.
What is a common source of Trichina infection in the US?
It is usually contracted from eating undercooked bear meat.
What cooking temperature is recommended to kill Trichina in pork?
145°F.
What cooking temperature is recommended to kill Trichina in chicken?
165°F.
How many pairs of legs do water bears have?
They have four pairs of stubby, unjointed legs, each with four to eight claws.
What type of cuticle do water bears have?
They have a non-chitinous cuticle that is molted at least four times.
What is the function of the mouth in the described organism?
The mouth opens into a buccal tube that leads to a muscular pharynx for sucking.
How do the needlelike stylets function in this organism?
They pierce cells and suck out their contents.
What happens at the junction of the intestine and rectum in this organism?
Three excretory glands meet and empty into the digestive tube.
What type of body cavity does this organism have?
It has a true hemocoel and no circulatory or respiratory system.
How does the organism move?
It does not swim; it crawls.
What notable features does this organism have regarding its sensory and nervous system?
It has eyes and a huge brain.
How does this organism reproduce?
Males look for left eggs to fertilize, and some leave their eggs in the molting cuticles.
What is cryptobiosis in this organism?
It is a state of suspended animation where metabolism is barely perceptible, allowing it to withstand harsh environmental conditions.
What extreme conditions can this organism withstand?
It can withstand extreme temperatures, dehydration, radiation, and strong chemicals, and can survive for years.
Is this organism from Earth or did it evolve independently?
It is probably from Earth.
What are Filarial worms known for?
Females release live young called microfilariae into the circulatory system.
What diseases can Filarial worms cause?
Elephantiasis and river blindness.
What is the most commonly known Filarial worm in the US?
Dog Heartworm, spread by mosquitoes.
What is the common name for Phylum Nematomorpha?
Horsehair worms.
What is the typical length of Horsehair worms?
Up to 1 meter, most are smaller.
What is the body structure of Horsehair worms similar to?
Nematodes.
What systems are absent in Horsehair worms?
Circulatory, respiratory, and excretory systems.
How long is the fossil history of Phylum Onychophora?
500 million years with little change.
What is a characteristic of the body segmentation in the discussed organisms?
No segmentation except for paired appendages.
What type of cuticle do these organisms have?
The cuticle is soft and never hardens.
What is the structure of the head in these organisms?
The head has one large pair of antennae and a sensory bristle.
Describe the mouth structure of these organisms.
The mouth is ventral with claw-like mandibles and oral papillae with slime glands.
How many pairs of legs do these organisms typically have?
They have 14-34 pairs of unjointed legs.
What happens to the eggs after they hatch?
They burrow through the intestinal wall into veins or lymph vessels and migrate to the lungs through the circulatory system.
What do the larvae do after breaking out of the lungs?
They crawl up the trachea and are swallowed.
How long does it take for Ascaris lumbricoides to mature in the intestine after hatching?
About two months.
Where are Nematodes commonly found?
They live everywhere, abundant in topsoil and are parasitic on nearly everything.
What is a model organism in Nematodes?
Caenorhabditis elegans.
What is significant about the species Caenorhabditis elegans?
Every cell in its body can be traced from its origin to final state, known as a fate map.
Why are Nematodes economically important?
They are important to agriculture and medicine, causing food spoilage and livestock disease.
What is eutely in Nematodes?
A fixed number of somatic cells.
What is the shape of Nematodes?
Cylindrical shape.
What type of movement do Nematodes primarily use?
They have no cilia or flagella for movement except in one species, and they move well left and right due to their flexible cuticle.
How do Nematodes excrete waste?
They excrete waste through glands that empty into a pore, as they lack protonephridia.
What is the function of the muscular pharynx in Nematodes?
It aids in feeding.
What is the typical size of most Nematodes?
Most are less than 5 cm, with a few over 1 m.
What is the composition of the thick non-cellular cuticle in Nematodes?
It is made of collagen and protects from desiccation.
What type of muscles do Nematodes have?
They have only longitudinal muscles, with no circular muscles.
What is the role of the pseudocoelom in Nematodes?
It is fluid-filled and provides structural support.
How do Nematodes attach to the intestine?
They have spines and stickers to stick onto the intestine.
What are the main components of the digestive system in the organism described?
Mouth, muscular pharynx, long nonvascular intestine, rectum, and anus.
How do these organisms excrete waste in space?
They poop by airlock on a spaceship, allowing waste to fly out without pushing, using hydrostatic pressure.
What is the thickness of the cell layer in the organism's body?
The body is only one cell layer thick.
What type of metabolism do many of these organisms have?
Many have anaerobic metabolism.
What type of organisms have corresponding cellular machinery for aerobic metabolism?
Some obligate aerobes.
What is the structure surrounding the pharynx in these organisms?
A ring of nerve tissue.
What sensory structures are found around the head of these organisms?
Sensory papillae clustered around the head and a pair of sense organs called amphids.
What is the reproductive strategy of most of these organisms?
Most are dioecious, with males having a pair of copulatory spicules.
Where is fertilization occurring in these organisms?
Fertilization is internal, and eggs are stored in the uterus.
How many juvenile stages do these organisms have, and what separates them?
Four juvenile stages, each separated by a cuticle molt.
What is Ascaris lumbricoides commonly known as?
Roundworm.
What is the infection rate of Ascaris lumbricoides in Mississippi and Alabama?
25% infection rate.
What is the infection rate of Ascaris lumbricoides in other areas?
1-2% infection rate.
How many eggs can Ascaris lumbricoides produce?
200,000 eggs.
How are Ascaris lumbricoides eggs typically ingested?
By consuming uncooked vegetables or from putting unwashed hands in the mouth.
How do Horsehair worms reproduce?
They are dioecious, with gonads emptying into cloaca through gonoduct, and eggs discharged into water in long strings.
What is the common name for Phylum Kinorhyncha?
Move beak worms.
How many species are there in Phylum Kinorhyncha?
About 180 species, worldwide.
What is the habitat of most Kinorhyncha species?
They mostly live in sediment.
What are the regions of the Kinorhyncha body?
Head, neck, and trunk regions.
How many segments does the trunk of Kinorhyncha have?
11 segments.
What are the spines on the head of Kinorhyncha called?
Scalids, which function in locomotion, chemoreception, and mechanoreception.
What type of cuticle do Kinorhyncha have?
Chitinous cuticle.
What is the locomotion method of Kinorynch worms?
They cannot swim, burrow in mud, and anchor with spines.
Describe the digestive system of Kinorynch worms.
They have a complete digestive system with a mouth that has a proboscis, feeding on diatoms or by digesting detritus.
What is the structure of the body cavity in Kinorynch worms?
The pseudocoel is filled with amebocytes and organs, with little fluid space.
What type of excretory system do Kinorynch worms possess?
They have a pair of multinucleated solenocyte protonephridia that serve as an excretory system (flame cells).
How is the nervous system structured in Kinorynch worms?
The nervous system is in contact with the epidermis and has a multilobed brain.
What is the reproductive strategy of Kinorynch worms?
They are dioecious, with paired gonads and gonoducts, and have six juvenile stages and a non-molting adult stage.
What is the habitat of Phylum Priapulida (penis worms)?
They are marine and found in cold water, living in sediment from intertidal to very deep areas.
What is the body structure of Priapulida worms?
They have cylindrical bodies that can grow up to 40 cm in length.
How do Priapulida worms feed?
They are burrowing and predaceous, feeding on soft-bodied invertebrates.
What are the main body parts of Priapulida worms?
They have an introvert, a trunk, and one or two caudal appendages.
What is unique about the blood of Priapulida worms?
Their blood contains hemerythrin, which is not red.
What is the structure of the trunk in Priapulida worms?
The trunk is not metameric but has 30-100 rings covered in spines, which are probably sensory.
What type of fertilization do Priapulida worms undergo?
They are dioecious with external fertilization, and one genus has direct development while females brood embryos.
What is the total number of species in the Phylum Loricifera?
Less than 100 species.
What are the five body regions of Phylum Loricifera?
Mouth cone, head (introvert), neck, thorax, abdomen.
What is the function of the nine circlets of scalids on the introvert of Loricifera?
They are locomotor and sensory structures.
What is the larval phase of Loricifera called?
Higgins larvae.
What type of body cavity do Loricifera possess?
Pseudocoelomate or acoelomate.
What is the reproductive strategy of Loricifera?
Dioecious, with dimorphic sexes.
What are the two allied taxa included in the Clade Panarthropoda?
Onychophora and Tardigrada.
What is the primary habitat of Phylum Onychophora species?
Most are found in rainforests.
What is the diet of Onychophora species?
They are mostly predaceous on insects, gastropods, and annelids.
What is the function of the nephridia in these organisms?
Each segment with legs has a pair of nephridia for excretion.
What type of respiratory system do these organisms possess?
They have a tracheal system for respiration with openings called spiracles.
How is the nervous system organized in these organisms?
The nervous system is organized like a ladder with a pair of ventral nerve cords.
What type of reproductive organs do these organisms have?
They have dioecious paired reproductive organs.
What is the reproductive strategy of these organisms?
They give live birth, with some being matrotrophic and others lecithotrophic.
How many species are there in the Phylum Tardigrada?
About 900 species.
Where do water bears typically live?
They live in the water film surrounding mosses, lichens, or damp soil.
What is a characteristic of the body structure of water bears?
They have an elongated, cylindrical body that is unsegmented.
