Exam 3 Review – Animal Biology 1604, Spring 2016. Remember that you are responsible for
all of the material that we covered in lecture even if it is not listed on this sheet.
Lecture 14. Nematodes
General Characteristics: non-segmented worms that can be free living or parasitic. Most
are microscopic and all are bilaterally symmetrical and pseudocoelomates. The do not
have a distinct circulatory or respiratory system.
o Cuticle: layer of tissue outside of the epidermis that forms an exoskeleton
o Pseudocoel: body cavity between the body wall and the intestine, which is not
lined with a mesodermal epithelium
o Ecdysis: the process of shedding the old skin (reptiles) or outer casing (insects
and arthropods)
Feeding
o Many free-living nematodes are carnivores and feed on even smaller animals
including other nematodes
o Some free living nematodes feed on phytoplankton such as diatoms, algae and
fungi. Many terrestrial species feed on plant roots.
o Species that live in sediments and other aquatic environments ingest particles of
the substrate and then digest associated bacteria and / or organic material.
Parasitic Nematodes
o Ascaris lumbricoides: Giant roundworm (host: humans), responsible of the
disease ascariasis in tropical and subtropical countries. The human ingests a
fertilized egg and the larval worm enters the bloodstream
o Necator americanus: New World Hookworm (host: humans, dogs and cats)
Contracted through contact with contaminated soil, they marture in the lungs of
the host and travel to the small intestine of their host when mature.
o Trichinella spiralis: Responsible for the disease trichinosis and is typically
acquired from undercooked pork (host: pigs, rodents, horses, bears and humans).
Larvae is in pig muscles, they are then consumed and travel to the new hosts
small intestine.
o Enterobius vermicularis: Human Pinworm (host: humans). Pinworm eggs are
ingested by a human and hatch in the small intestine. They continue to travel
through the digestive system and lay eggs.
o Wuchereria: Can develop into elephantitis and is spread by mosquitos. (host:
humans – definite, mosquitoes – intermediate)
Characteristics of Nematomorpha
o Bilateral symmetry, more than two cell layers, pseudocoelom, complete gut,
cuticle and longitudinal muscles, nerve ring, no circulatory system, aquatic or
moist soils (mostly freshwater). Adults are also non-feeding while larvae are
endoparasitic
, Lecture 15. Arthropods
Characteristics of Arthropods
o Jointed appendages, triploblastic, segmented body (head, thorax and abdomen),
exoskeleton, coelomate, gills or lungs, open circulatory system, brain and ventral
nerve cord
Characteristics of Subphylum Trilobita
o Extinct group of marine arthropods, many characteristics are still widely debated
among scientists.
Characteristics of Subphylum Chelicerata
o Absence of antennae, body divided into two portions (prosoma – head and thorax,
and opisthosoma - abdomen ), first pair of appendages are adapted for feeding
Characteristics of Merostomata
o Horseshoe crabs – gills, compound eyes, exoskeleton, caudal spine
Classes of Arachnida
o Order Araneae: True spiders
Primarily terrestrial, pedipalps present (sensory, reproductive, feeding), 4
pairs of legs
o Order Scorpionida: Scorpions
Florecent under UV light, tail with sting (venom gland), pedipalps and
chelate
o Order Solpugida: Sun or camel spiders
No venom, large in size, segmented body, massive chelicerae with “teeth”,
strong pedipalps, 4th leg pair has sensory organs, fast moving, occur in arid
ecosystems
o Order Opiliones: Daddy longlegs
Small round bodies, long slender legs, often colorful, omnivorous, forest
dwellers, do not spin silk (not spiders)
o Order Acarina: Mites and ticks
Small size, most diverse and abundant, prosoma and opisthosoma are
fused, no tail, mostly parasitic, mouthparts are usually fused into a buccal
cone
General Arthropod Questions
o What is a pedicel and who has it?
Joins the cephalothorax and abdomen in spiders, allows for movement in
all directions.
o What is a spinneret? What tagma is it located in?
Silk spinning organ of a spider, located on the underside of the spiders
abdomen.
o What are major differences between Araneae and Opilionea?
Opinioned do not spin silk so they are not technically spiders.
o What are the diseases that ticks cause in Oklahoma? Which ticks are responsible?
Rocky Mountain Spotted Fever, Tularemia, Lyme Disease, and Heartland
virus. They are caused by a rickettsial organism, Rickettsia rickettsia
o What are chiggers?
all of the material that we covered in lecture even if it is not listed on this sheet.
Lecture 14. Nematodes
General Characteristics: non-segmented worms that can be free living or parasitic. Most
are microscopic and all are bilaterally symmetrical and pseudocoelomates. The do not
have a distinct circulatory or respiratory system.
o Cuticle: layer of tissue outside of the epidermis that forms an exoskeleton
o Pseudocoel: body cavity between the body wall and the intestine, which is not
lined with a mesodermal epithelium
o Ecdysis: the process of shedding the old skin (reptiles) or outer casing (insects
and arthropods)
Feeding
o Many free-living nematodes are carnivores and feed on even smaller animals
including other nematodes
o Some free living nematodes feed on phytoplankton such as diatoms, algae and
fungi. Many terrestrial species feed on plant roots.
o Species that live in sediments and other aquatic environments ingest particles of
the substrate and then digest associated bacteria and / or organic material.
Parasitic Nematodes
o Ascaris lumbricoides: Giant roundworm (host: humans), responsible of the
disease ascariasis in tropical and subtropical countries. The human ingests a
fertilized egg and the larval worm enters the bloodstream
o Necator americanus: New World Hookworm (host: humans, dogs and cats)
Contracted through contact with contaminated soil, they marture in the lungs of
the host and travel to the small intestine of their host when mature.
o Trichinella spiralis: Responsible for the disease trichinosis and is typically
acquired from undercooked pork (host: pigs, rodents, horses, bears and humans).
Larvae is in pig muscles, they are then consumed and travel to the new hosts
small intestine.
o Enterobius vermicularis: Human Pinworm (host: humans). Pinworm eggs are
ingested by a human and hatch in the small intestine. They continue to travel
through the digestive system and lay eggs.
o Wuchereria: Can develop into elephantitis and is spread by mosquitos. (host:
humans – definite, mosquitoes – intermediate)
Characteristics of Nematomorpha
o Bilateral symmetry, more than two cell layers, pseudocoelom, complete gut,
cuticle and longitudinal muscles, nerve ring, no circulatory system, aquatic or
moist soils (mostly freshwater). Adults are also non-feeding while larvae are
endoparasitic
, Lecture 15. Arthropods
Characteristics of Arthropods
o Jointed appendages, triploblastic, segmented body (head, thorax and abdomen),
exoskeleton, coelomate, gills or lungs, open circulatory system, brain and ventral
nerve cord
Characteristics of Subphylum Trilobita
o Extinct group of marine arthropods, many characteristics are still widely debated
among scientists.
Characteristics of Subphylum Chelicerata
o Absence of antennae, body divided into two portions (prosoma – head and thorax,
and opisthosoma - abdomen ), first pair of appendages are adapted for feeding
Characteristics of Merostomata
o Horseshoe crabs – gills, compound eyes, exoskeleton, caudal spine
Classes of Arachnida
o Order Araneae: True spiders
Primarily terrestrial, pedipalps present (sensory, reproductive, feeding), 4
pairs of legs
o Order Scorpionida: Scorpions
Florecent under UV light, tail with sting (venom gland), pedipalps and
chelate
o Order Solpugida: Sun or camel spiders
No venom, large in size, segmented body, massive chelicerae with “teeth”,
strong pedipalps, 4th leg pair has sensory organs, fast moving, occur in arid
ecosystems
o Order Opiliones: Daddy longlegs
Small round bodies, long slender legs, often colorful, omnivorous, forest
dwellers, do not spin silk (not spiders)
o Order Acarina: Mites and ticks
Small size, most diverse and abundant, prosoma and opisthosoma are
fused, no tail, mostly parasitic, mouthparts are usually fused into a buccal
cone
General Arthropod Questions
o What is a pedicel and who has it?
Joins the cephalothorax and abdomen in spiders, allows for movement in
all directions.
o What is a spinneret? What tagma is it located in?
Silk spinning organ of a spider, located on the underside of the spiders
abdomen.
o What are major differences between Araneae and Opilionea?
Opinioned do not spin silk so they are not technically spiders.
o What are the diseases that ticks cause in Oklahoma? Which ticks are responsible?
Rocky Mountain Spotted Fever, Tularemia, Lyme Disease, and Heartland
virus. They are caused by a rickettsial organism, Rickettsia rickettsia
o What are chiggers?
