Review
Cell Cycle Phases, G2 Arrest & Gametogenesis
Meiosis, Diploid 2n4c Cell vs. Haploid 1n1c Gamete
Hormone Control - Spermatogenesis vs. Oogenesis
Fertilization – Blocks to Polyspermy
Animal Life Cycle Model
Cleavage Stage – Nuclear/Cytoplasmic Ratio
Blastula Stage – Hollow Ball of Cells
Mid Blastula Transition – Genome Turns On
Gastrula – Form 3 Tissue Layers
Review
Larval Classifications
By Food: Lecithotropic vs. Planktotropic
By Development: Direct vs. Indirect
Ecological: r and K Selected
Metamorphosis
Change to the Body Plan
Radical Rearrangement of Tissues
Degree of Transformation Highly Variable
Carp Breeding I
Existing Strains Removed from Wild
Carp Can Breed Throughout the Year
Carp Are Seasonal Breeders – Spring
Spawn After Dark or Early Morning
Segregate Sexes to Prevent Spawning
Eggs Laid on Foliage near Water Surface
Carp Breeding II
Induce Spawn: Transfer to Spawning Ponds
Fibrous Materials Substitutes for Foliage
Tropical Carp Breed 2 - 4x / yr
Temperate Zones –Pituitary Gland Extracts
Contains Gonadotrophic Hormones
Used to Provoke Natural Spawning or
Aid in Stripping Gametes.
Move Fertilized Spawn to Hatching Ponds
Carp Pituitary Removal
Zebrafish Pituitary
Hormones From Fish Anterior Pituitary
Gonadotropin I (GTH-I) –
Sequence Orthologous to FSH – αβ Chains
Gonadotropin II (GTH-II) –
Sequence Orthologous to LH – αβ Chains
Other Hormones
Thyroid Stimulating Hormone (TSH) – αβ Chains
Growth Hormone (GH)
Prolactin (PRL)
3 Pro-opiomelanocortin Hormones (POMC)
Adrenocorticotropic Hormone (ACTH
Lipotropic Hormone (LPH)
β-endorphin
Fish Hormonal Control Over Reproduction
Gonadotropins GTH-I and GTH-II
GTH-I - Follicle Stimulating Hormone (FSH)
Causes Ovary to Make LH Receptors
GTH-II - Luteinizing Hormone (LH)
Stimulates Ovary to Make Progesterone (P4)
Directs Ovulation & Corpus Luteum Formation
Testis to Make Testosterone (T)
Progesterone & Testosterone - Steroid Hormones
Testosterone –Maturation of Spermatogonia
Progesterone – Maturation of Oogonia
Pituitary Gland Hormones
Luteinizing Hormone (LH) in Both ♂ & ♀
♀ LH Stimulates Ovary to make Progesterone
Directs Ovulation & Corpus Luteum Formation
♂ LH Stimulates Testis to make Testosterone
LH is a GlycoProtein Hormone with α and β Chains
Gonad Target Tissue Produces Steroid Hormone
Comparative Endocrinology
Releasing Hormone
Location
Type
Target
Releases
Starfish
GSS
CNS
Protein
Gonads
MIS
Fish
LH or GTH-II
CNS
Protein
Gonads
MIS
Comparative Endocrinology
Starfish
Maturation Hormone 1-MA
Location
Ovary
Type
Purine
Target
Oocyte
Releases
Meiosis
Fish
Progesterone
Ovary
Steroid
Oocyte
Meiosis
Commercially Available Pituitary
Carp Pituitary
Carp Hatching and Rearing
Eggs prone to fungal infections, treat with
fungicide - or drying out hatching ponds
Hatched carp cement themselves to substratum
for up to a week while absorbing yolk sac.
Hatchlings plus 1 week need to feed –
primary foods zooplankton or phytoplankton
Most vulnerable from hatching to 3 gms
Need to be cautious with density
Swimming juveniles moved to nursery ponds
Controlled Spawning
While Hormones can Trigger Cellular Actions
Environmental Cues Regulate Gonad Growth
Hormones Induce Gamete Release
Needn’t Control Both Photoperiod & Temperature
In Tropical Species – Little Photoperiod Effect
Put Catfish Through an Artificial ‘Winter’ –
And Induce Gonad Development at Odd Time.
Fish Reproduction
Zygote (Fertilized Egg)
Eyed Embryo
Hatching
Yolk Sac Stage
Fry
(Metamorphosis if Present)
Juvenile
In Vitro Carp Fertilization
Fertilizing Eggs
Fish Egg Micropyle
Micropyle is Sperm Entry Point
Tour of Reproduction in Aquaculture
Similarities and Differences Between
Various Aquaculture Species Such As
Salmon
Eels
Halibut & Flatfish
Tilapia,
Milkfish
Crustaceans,
Molluscs
Frogs
Reproduction in Salmon & Trout
Eyed Embryos
Atlantic Salmon Alevin (Yolk Sac)
Chum Salmon Parr
Smoltification
Process that Changes Salmon Parr into Sea Run Smolt
Involves Profound Changes to the Fish Including:
Physiological (Change in Osmoregulation)
Morphological (Lose Parr Marks, Become Silver)
Biochemical (Imprinting Scent of Natal Stream)
Behavioral (Becomes Wary, Hides on Bottom)
Smoltification: Making the Salmon Anadromous
Is Smoltification a Little Metamorphosis?
Salmon Smolt
Trout Egg Take
Trout Spawning
Reproduction in Eels
Eel Farm
Eel Embryos
Eel Larva
Eel Juveniles
Reproduction in Halibut
Raising Young Has Been Incredibly Difficult
Cold Water Reduces Reaction Rates Q10
Time to Hatching 2-3 months
Time to Metamorphosis 4-5 Months
If Embryos Touch Anything They Die
Price of Healthy Seed Extremely High
Costs Foreclosed Option for Halibut Farms
Halibut Larva I
Halibut Larva II
Halibut Larva III
Flatfish Larva I
Flatfish Larva II
Halibut Metamorphosis
Halibut Metamorphosis II
Newly Metamorphosed
Halibut with Adult Body Plan
Reproduction in Tilapia
Tilapia Spawning Facility
Fertilizing Tilapia Fry Ponds
Main Objective – Stimulate Primary Productivity
Main Inputs: Nitrogen, Carbon & Phosphorus
Optimal Ratio:
45-50% C…
8-10% N
1% P
Organic Fertilizers:
Poultry Manure
Domestic Sewage
Cattle Manure
Green Manure
Composted Agricultural Waste
Fertilizer Stimulates Green Algae
Duckweed
Juvenile Fish Feed
Volvox
Diatoms
Adult Fish Feed
Melosira
Zooplankton eg. Daphnia
Rotifers
Zooplankton Ciliates
Larval Fish Feed - Zooplankton
Gravid Copepod
Tilapia
Fry Pond
Emptied Tilapia Fry Pond
Mouth Brooding Tilapia
Reproduction in Milkfish Chanos chanos
Seed – Traditionally Fry from Wild Stocks
Problems with Disease and Biosecurity
1970s –Hormonal Spawning Cultured Milkfish
Intensive Culture – $27.40 / 1,000 Fry
Unreliable – Marginal Quality of Seed
1980s – Cages Milkfish Spawnings
Semi-Intensive Culture $6.60 / 1,000 Fry
Reliable, High Quality Fry
Catching Wild Milkfish Fry
Milkfish Fry Intensive Hatchery
Milkfish Fry Semi-Intensive Hatchery
Milkfish Hatching
Milkfish Chanos chanos Fry
Milkfish – Feed & Early Growth Tanks
Milkfish Feeding - Pond Culture
Introduction to Aquaculture
Milkfish Penned Adults
Milkfish Harvest Philippines
Milkfish Processing
Milkfish Processing Plant
Reproduction in Crustaceans
Crawfish
King Crab
Lobster
Shrimp
Crawfish In Berry
Crawfish Post Hatch Larva
King Crab Mating Pod
King Crab Clutch
Red King Crab Embryos
Lobster With Embryos
Shrimp Carrying Embryos
Shrimp Mysis Larva
Molluscs
Oyster Spawning
Oyster Post Metamorphic Growth
Oyster Spat
Gastropod Veliger
Frogs
Pre Ovulation Glass Frog
Fertilized Frog Eggs
Tree Frog Embryos
Developing Frog Embryos
Advanced Unhatched Frog Embryos
Introduction to Aquaculture
Closing the Life Cycle
Obtaining the Knowledge and Developing
the Technology Required - to Maintain the
Entire Life Cycle of the Species in Captivity
Knowledge and Technologies Required to
Maintain Entire Life Cycle of the Species
Allows Initiation of Reproduction
Allows Control over Reproduction
Allows Selective Breeding Programs
Allows Genetic Manipulations
Allows Detailing Nutritional Physiology
Allows Defining Immune Function
Aim is Domestication of Species