Table 1.

Predictions of associations between most common sexual systems (pattern of distribution of the male and female function among the individuals of a given species), mating systems (pattern of sexual interactions that take place considering the number of males and females involved in reproduction), adult sex ratio, size of mates, and spawning behaviour (how the two sexes interact to release the gametes) in teleosts.

Sexual System	Mating system	Adult sex ratio	Size of mates	Spawning behaviour
GONOCHORISM (G)  Individuals reproduce as one sex throughout their lifetime (male or female)	Monogamy (pair bond) or random pairing Promiscuity Harem polygyny or temporary lek-like systems*	Variable	Males smaller, similar or larger than females	Pair spawning (pair of individuals) Group spawning**
PROTOGYNY (PG)  Female-first sequential hermaphroditism: individuals first reproduce as females, change sex once with increasing size/age and then reproduce as males	Harem polygyny or temporary lek-like systems* Promiscuity	Female-biased	Males larger than females	Pair spawning (pair of individuals) Group spawning**
PROTANDRY (PA)  Male-first sequential hermaphroditism: individuals first reproduce as males, change sex once with increasing size/age and then reproduce as females	Monogamy (pair bond) or random pairing	Male-biased	Females larger than males	Pair spawning (pair of individuals) Group spawning**
BIDIRECTIONAL (BD)  Individuals can change sex more than once, in either direction, throughout their lifespan, usually starting from PG	Monogamy (pair bond) or random pairing Harem polygyny or temporary lek-like systems*	Female-biased	Males larger than females	Pair spawning (pair of individuals)
SIMULTANEOUS (SH)  Individuals produce gametes of both sexes at the same time or in a short period of time	Monogamy (pair bond) or random pairing	1:1	Males similar to females	Pair spawning (pair of individuals)

*multiple females in a territory defended by a male.

**multiple males and multiple females or one female with multiple males.

This general set of predictions is applicable to most species, but exceptions are found in species with less common sex determination mechanisms and mating or spawning behaviour.