Parasite: is a living organism that lives on or in another species (host) where it obtains nutrients, shelter transportation and other benefits. The host organism is negatively affected by the parasite.


Ecto-parasite: a parasite that lives on the outer parts of the host such as the skin and gills.


Host specificity: A term used to say something about how many different host species a given parasite is occurring on.


Arthopoda: includes all invertebrate animals that have an exoskeleton made of chitin, a segmented body and jointed appendages. The animal group includes insects (ex: butterflies, bees, head lice and cockroaches), chelicerates (spiders and scorpions), crustaceans (ex: lobster, crab and sea lice) and myriapods (ex: millipeds and centipeds). About 80 % of all animals in the world belong to the arthropods and they are found everywhere from the driest deserts to the deepest ocean floors. Fossils of arthropod species date as far back as the pre-cambria more than 550 mill years ago.


Copepods: form a subclass of the crustacean subphylum (Arthropoda phylum) found both in marine and freshwater ecosystems. Over 13.000 species of copepods are known and their size is typically between 1-2 mm long however, smaller animals exist. They can be recognised by their tear shaped body form with antennas attached in the front. Copepods, like other arthropods, are protected by a rigid outer chitin layer called an exoskeleton. In order to grow, the exoskeleton is lost in a process called molting.


Molting: In arthropods it is the referred to the process where the exoskeleton is exchanged so the animal can grow. Molting is commonly known as ecdysis as hormones called ecdysteroids control the process.


Genome: an organisms complete set of DNA.



DNA- deoxyribonucleic acid: is the hereditary material of an organism. DNA is built up of nucleotides. A nucleotide consists of the sugar group deoxyribose, a phosphate group and a nitrogen base. The four different types of nucleotides: adenine (A), guanine (G), cytosine (C) and thymine (T). Two nucleotides pair up: C-G and A-T. The DNA is shaped like a double helix with complementary strands.



RNA-ribonucleic acid: is a nucleic acid that differs from DNA by consisting of the sugar group ribose, a phosphate group and the nucleotides adenine (A), guanine (G), cytosine (C) and uracil (U). Two nucleotides pair up: C-G and A-U. RNA comes in many different shapes. The three most familiar types of RNA are messenger RNA (mRNA), ribosomal RNA (rRNA) and transfer RNA (tRNA).


mRNA: messenger RNA is the hereditary molecules that are transcribed from DNA and conveyed to the ribosome for translation into long amino acid sequences that make up a protein.


Phenotype: an organism’s observable characteristic such as morphology or other properties.

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