Unit V Flashcards
➢ The relationship of two or more different organisms in close association that may be, but is not necessarily, of benefit to each. The main types of symbiosis are commensalism, mutualism, and parasitism.
Symbiosis
➢ A type of symbiosis in which either partner can usually live independently and in which neither partner is harmed.
Commensalism
➢ An obligatory symbiotic association of mutual benefit to both partners.
Mutualism
➢ A symbiotic relationship that is obligatory for the parasite and is more or less harmful to the other partner, the host
Parasitism
➢ Is an organism that feeds, grows and is sheltered on or in another organism (the host) without contributing to the survival of its host.
Parasite
➢ A group of animals whose bodies are typically differentiated into three segments: the head, the thorax and the abdomen.
Arthropods
➢ A worm; now restricted to parasitic worms such as flukes, tapeworms and nematodes
Helminth
➢ The organism that provides nourishment for a parasite.
Host
▪ where the adult (sexually mature stages) of the parasite is found
Final/Definitive Host
▪ where the asexual stages of the parasite is found; an additional and obligatory host in the life cycle of a parasite
Intermediate Host
▪ harbor the parasitic infection but show no outward signs of the infection but frequently act as source of infection to others
Reservoir Host
▪ The parasite do not undergo development in this host, it simply act as carrier of the parasite
Paratenic/Transport Host
➢ Refers to the development of a parasite through its various forms.
Life Cycle
➢ A marked change in appearance, structure, and habits of an animal as
part of its normal growth and development.
Metamorphosis
➢ An organism having male and female reproductive organs in the same
individual.
Hermaphrodite
➢ A tough, resistant, inert covering, as in nematodes and arthropods
Cuticle
➢ Within a fibrous tissue capsule laid down by the host.
Encapsulated
➢ Within a cyst secreted by the parasite
Encysted
2 classification of parasite
Internal parasite
External parasite
Live within the body of the host, occupying
the digestive tract, internal organs (liver,
lungs), blood, tissues and even cells
Internal parasite
Live at the surface or in the skin of their
hosts. They are noticeable because they
cause itching and skin lesions that become
more obvious as the number of invading
parasites increases.
External parasites
Live at the surface or in the skin of their
hosts. They are noticeable because they
cause itching and skin lesions that become
more obvious as the number of invading
parasites increases.
External parasites
General Clinical Signs of Parasitism
• Anorexia
• Retarded growth
• General Weakness
• Coughing
• Rough hair coat
• Rapid weight loss
• Persistent bloody diarrhea
• Death
Under Phylum Nemathelhelminthes Class Nematoda a eukaryotic (with nucleus), multicellular, cylindrical and tapered at each end, Have complete digestive system (mouth, SI, anus)
Roundworm
Under Phylum Platyhelminthes, a eukaryotic (with nucleus), multicellular, include to Class Cestoda (Tapeworms) and Class Trematoda (Flukeworms/Flukes), acoelomates, bilaterally symmetrical, hermaphroditic, digestive tract, if present typically has only one opening
Flatworms
• flat, leaf-shaped bodies
• with a ventral sucker and an oral sucker
• obtain food by absorbing it through their nonliving outer covering, called the cuticle.
Trematodes (Flukes)
➢ intestinal parasites
➢ Head: scolex (plural: scoleces), has suckers
➢ some species also have small hooks for attachment
➢ do not ingest the tissues of their hosts
➢ absorb food through their cuticle
➢ body: proglottids
Cestodes/Tapeworms
➢ jointed legs
➢ invertebrates
➢ external skeleton (exoskeleton)
➢ segmented body
➢ paired articulated appendages
Arthropods
• eukaryotic (with nucleus), multicellular
• head, thorax, and abdomen, and bears two eyes, two antennae, and a complex set of mouthparts.
• The thorax consists of three segments - the prothorax, the mesothorax, and the metathorax—and bears six jointed legs
and four, two, or no wings
Insects
eukaryotic (with nucleus), multicellular
➢ subclass Acari (mites and ticks)
Arachnids
eukaryotic (with nucleus)
• unicellular
• some with organs of locomotion
Protozoa
eukaryotic (with nucleus)
• unicellular
• some with organs of locomotion
Protozoa
