#centrarchiformes

Too many girlfriends? Not a problem for the hawkfish! The species in this family are protogynous, meaning that all individuals start out as females at birth. As adults, they form harems around a dominant male; but if there are too many females, then one or more of them will change into males and branch off with up to half of the remaining females. Not enough girlfriends? Not a problem either! If the number of females in a harem gets too low, or if they lose a challenge from another male, the former harem leader will simply revert back to being female.

Smallmouth Bass (Micropterus dolomieu), family Centrarchidae, order Centrarchiformes, native to freshwater ecosystems in the Midwestern US and SE Canada

Introduced to many other parts of North America.

Girella tricuspidata

Luderick

Image source

Status: No IUCN evaluation

A red morwong (Morwong fuscus) in Swansea, NSW, Australia

Oh wow, what a cool looking guy!

(Sources - 1, 2, 3, 4)

Order: Centrarchiformes

Common Name: no common name for the collective order

Families: 19 - Girellidae (“nibblers”), Kyphosidae (“sea chubs”), Kuhliidae (“flagtails”), Terapontidae (“grunters”), Dichistiidae (“galjoen fishes”), Oplegnathidae (“knifejaws”), Caesioscorpididae (“Blowhole Perch”), Centrarchidae (“sunfishes”), Elassomatidae (“pygmy sunfishes”), Sinipercidae (“Chinese perches”), Enoplosidae (“Old Wife”), Percichthyidae (“temperate perches”), Perciliidae (“carmelitas”), Parascorpididae (“Jutjaw”), Cirrhitidae (“hawkfishes”), Chironemidae (“kelpfishes”), Aplodactylidae (“marblefishes”), Cheilodactylidae (“morwongs”), and Latridae (“trumpeters”)

1 genus without family: Percalates (“Australian Bass” and “Estuary Perch”)

Anatomy: perch-like; stocky build; spine-bearing dorsal fin

Diet: zooplankton; crustaceans; smaller fish; mollusks; seaweed; brittle stars; worms; algae

Habitat: worldwide, all temperate and tropical nearshore marine habitats, and some freshwater

Evolved in: Early Paleocene

(source)

Propaganda under the cut:

Two large aquatic animals, Long-finned eel and Sooty Grunter. Found around on the river shore feeding on food people had thrown to them.

Anguilla reinhardtii (top) Hephaestus fuliginosus (bottom)

Black Crappie (Pomoxis nigromaculatus), family Centrarchidae, order Centrarchiformes, native to freshwater systems in the eastern US and Canada, this fish has been widely introduced to other locations.