Reproduction

Question 1

Frequency – semelparity vs iteroparity

Answer 1

Most are iteroparous
Salmon, Anguilliformes, Petromyzontiformes, Gastroosteiformes

Question 2

Gender System

Answer 2

Most are male and females
Hermaphroditic: fairly widespread
Parthenogenic: rare – guppies, sharks

Question 3

Place of fertilization

Answer 3

Mostly external
Internal fertilization: fairly widespread

Question 4

Spawning habitat

Answer 4

FW vs Marine
Anadromy vs Catadromous
Both are fairly widespread
Most anadromy in Northern hemisphere – high marine productivity
Catadromy higher in the south, but not much – high freshwater productivity

Question 5

Parental Care

Answer 5

No care – most species
Female care – 15 families (oviparity, ovoviviparity and viviparity)
Biparental care – 26 families
Male care – 36 families
Associated with external fertilization – paternitiy assurance
No families with internal fertilization have male care
All parental care has arisen multiple times across independent taxa