Title: FISH REPRODUCTION AND DEVELOPMENT
1FISH REPRODUCTION AND DEVELOPMENT
Development
Stages
Reproduction
Egg - lt0.5 mm - 10 cm variable shape,
attachments variable buoyancy water
hardening Embryo - dependent on mother or yolk
sac for food (free embryo) Larvae - not
fully functional, may look totally unlike adult
ends when axial skeleton is formed Juvenile -
small functional individual, immature Adult
- reproductively mature
- Nearly all fish reproduce by sexual
reproduction-the fusion of sperm produced from
testes and eggs produced from ovaries.Fertilizatio
n is external in most species.
Types
Indirect development (perch) - larval stages go
through trophic phases different from
adults Intermediate (salmonids) - embryonic
stage with yolk virtually no larval stage Direct
development (gobies) - juvenile is fully
functional miniature of adults (no larval stage)
Asexual Reproduction (Parthenogenesis)
REPRODUCTION
- There are 3 modes of sexual reproduction
- Oviparity Egg Laying
- OvoviviparityLivebearing,no maternal nourishment
- ViviparityLivebearing with maternal nourishment