Labridae
Polynesian pencil wrasse
Pseudojuloides polynesica
FISH SPECIES
Flat-bodied Fish
Compare fish with laterally compressed, dorsoventrally depressed or asymmetrical body plans across habitats.
FISH ATLAS / FIELD GUIDEFlat FishIN THIS CHAPTER01 / Characteristics02 / Lifestyle03 / Species04 / Field notes
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01 / NATURAL HISTORY
Characteristics
Flattened body forms represent two distinct evolutionary paths: laterally compressed forms engineered for agility in narrow vertical spaces, and dorsoventrally depressed or asymmetrical forms specialized for living flush against the ocean floor.
- 01Laterally compressed maneuvering
- 02Dorsoventrally flattened resting
- 03Benthic sediment concealment
02 / LIFESTYLE
Lifestyle
Laterally compressed fishes like butterflyfishes and batfishes orient vertically to dart through intricate reef branches, using broad median fins to execute instantaneous, low-radius pivot turns. In stark contrast, depressed rays and asymmetrical flatfishes bury beneath sediment with only elevated eyes exposed, remaining completely motionless until striking passing prey from underneath.
OBSERVATION INDEX
- Zero-radius turns in structural cover
- Sediment concealment with raised eyes
- Undulatory pectoral propulsion on bottoms
03 / SPECIES
Representative species
Discover representative species illustrating the ecological diversity, morphologies and adaptations of this group.
Polynesian pencil wrasse
Labridae
Polynesian wrasse
Pseudojuloides atavai
Ariommatidae
Pomfret
Ariomma brevimanus
Coryphaenidae
pompano dolphin
Coryphaena equiselis
Serranidae
Pond perch
Diplectrum radiale
Leiognathidae
Ponyfish
Deveximentum indicium
Leiognathidae
Pope's ponyfish
Equulites popei
Adrianichthyidae
Popta's buntingi
Adrianichthys poptae
Mullidae
Por's goatfish
Upeneus pori
Epinephelidae
potato grouper
Epinephelus tukula
Acanthuridae
Powder blue tang
Acanthurus leucosternon
Gobiidae
prawn goby
Ctenogobiops maculosus
Bramidae
Prickly fanfish
Pterycombus petersii
Anthiadidae
Princess anthias
Pseudanthias smithvanizi
Gobiidae
Princess pygmygoby
Trimma marinae
Zaproridae
prowfish
Zaprora silenus
Ophidiidae
prowspine cusk-eel
Lepophidium prorates
Histiophrynidae
psychedelic frogfish
Histiophryne psychedelica
Leiognathidae
Pugnose ponyfish
Deveximentum insidiator
Cyprinidae
Purple passion danio
Danio roseus
Pomacentridae
purple reeffish
Chromis scotti
Malacanthidae
Purple sand tilefish
Hoplolatilus purpureus
Anthiadidae
Purple-scaled perchlet
Plectranthias purpuralepis
Labridae
Purplelined wrasse
Cirrhilabrus lineatus
04 / FIELD NOTES
A closer look
What is the evolutionary difference between a ray and a flounder?
A ray is a cartilaginous fish flattened from top to bottom (dorsoventrally depressed) with eyes on top and gill slits on the underside; a flounder is a bony fish that lies on its side, whose eye migrates during larval development to make the body asymmetrical.
Why do disk-shaped fish like angelfish and discus have tall bodies?
A laterally compressed disc shape provides high vertical stability and exceptional turning agility, allowing fish to twist into narrow vertical crevices and maneuver between tangled roots or coral branches without losing control.