Bell Work Typically in Arizona When does the Bass spawning season begin?

The Reproductive System of Fish Area: Animal Science Unit: Aquaculture Lesson #3

Objectives To determine the reproductive organs of a fish To determine the reproductive cycles of a fish To identify the young stages of a fish

What are the parts of the reproductive system of a fish? Reproductive parts are known a gonads Female – Ovaries – eggs develop internally Males – Testes – Produce Milt Fluid that contains the sperm

List conditions that are necessary for fish to reproduce. Temperature – Bass F – Tilapia F – Trout F Water Quality – A pH between 6.5 and 8.0 Well oxygenated water – Trout need running streams – Bass move water over eggs with pectoral fins

Day Length and Temperature

What are the different stages of the reproductive cycle? Stage 1- Oocyte development – Gonadotropin independent – Body size dependent Stage 2- Vitellogenesis – Egg yolk production – High nutritional demand – Longest phase Stage 3- Oocyte maturation – Resumption of meiosis – Water uptake

Reproductive cycles cont’ Stage 4- Spawning – Optimum environment – Mating behaviors Stage 5- Recovery – Restore body condition – New oocyte development

How do fish reproduce? Two ways – External fertilization Female lays eggs then male follows behind and fertilizes. – Live Bearing Not as common Male delivers milt through a gonopodium.

What are the young stages of fish development? Stage 1- Egg – Egg is fertilized – fish begins to develop on top of egg – 3-4 weeks Stage 2- Sac Fry – Fry hatches from egg – Yolk sac still attached for nutrition – About 1 week

Young stages cont’ Fry – Looses yolk sac and begins growth – Up to 2 inches long – Several months Fingerling – Final stage of youth development – 2-6 inches long – Lasts until 9-10 months of age