Flashcards in Fish growth and development, relevant stuff Deck (48)
What are the four stages of embryo development after fertilization?
What is blastulation?
Cell division to form hollow ball
What is gastrulation?
Differentiation and layer formation.
What is neurulation?
Forming basic nervous tissues. (make brain, spinal cord and peripheral nerves)
What is somite formation?
Forms muscle segments.
Generally, the series of steps in embryo development occur, internally or externally?
What is epiboly?
First cell movements of the blastoderm cells over the yolk.
What cell layers does involution form?
Endoderm, mesoderm, ectoderm
When do both epiboly and involution occur?
What does involution mean?
As cells crawl over the yolk sac in epiboly, these cells crawl over one another, generating cell layers.
What does the endoderm form?
What does the ectoderm form?
Mostly the skin
What does the mesoderm form?
What is the process that forms the neural tube?
What cell layer forms the nervous tissue?
Describe formation of the neural tube in fish.
Neural plate in the middle of the ectoderm will thicken and cavitate,
What is an embryo?
Fertilized egg prior to cell layer formation.
What is a yolk-sac larva?
When the embryo hatches out of egg and is feeding of the yolk.
Not feeding externally
What is a larva?
Free swimming, doesnt look like adult.
Yolk has been used up, feeding externally.
What is a juvenile?
Looks like mini adult, typically has scales (one of the last developmental steps)
Similar markings to adult.
What is an adult?
Has internal parts necessary for reproduction.
Can conceivably reproduce and is done developing.
What is an alevin?
Salmon term for yolk-sac larva.
What is a fry?
Salmon term for larva.
Between the alevin and fry stage, other than the yolk sac difference, what is the main difference?
Alevin - gravel
Fry - move up in water column
What is a parr?
When salmon start getting colourations, pigmented bars. - form of camo
Still in stream.
What is a smolt?
For salmon that migrate.
Older juvenile making transition to marine environment.
Change to saltwater chloride cells
What is a leptocephalus?
Larval form of elipomorphs.
Larva, no yolk sac anymore.
Head with lots of swimming muscles
Don't have a gut, feed and breathe through skin.
Swim to freshwater (spawn in marine).
Why do we care about larval forms?
Because this will determine how productive the fishery will be.
Growth is _______ in fishes.