Monacanthidae
Fantail filefish
Pervagor spilosoma
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.
Fantail filefish
Mullidae
Farnis’ goatfish
Upeneus farnis
Cichlidae
Fat Oscar
Astronotus crassipinnis
Pomacentridae
Fatu Hiva Chromis
Pycnochromis fatuhivae
Cichlidae
Fenestratus Hap
Protomelas fenestratus
Badidae
Ferrari Badis
Badis ferrarisi
Labridae
festive parrotfish
Scarus festivus
Pomacentridae
Fiji Damselfish
Pomacentrus microspilus
Eschmeyeridae
Fiji Scorpionfish
Eschmeyer nexus
Labridae
Filament-finned parrotfish
Scarus altipinnis
Anthiadidae
Filamentous anthiine
Meganthias filiferus
Scorpaenidae
Filamentous scorpionfish
Hipposcorpaena filamentosa
Labridae
Filamentous wrasse
Paracheilinus filamentosus
Pseudochromidae
Fine-scaled dottyback
Lubbockichthys multisquamatus
Acanthuridae
Finelined surgeonfish
Acanthurus grammoptilus
Ophidiidae
finescale cusk-eel
Lepophidium microlepis
Alosidae
finescale menhaden
Brevoortia gunteri
Labridae
finescale razorfish
Cymolutes torquatus
Gobiidae
finespot eviota
Eviota punctulata
Labridae
Finspot wrasse
Xenojulis margaritacea
Apogonidae
Fire-eye cardinalfish
Nectamia ignitops
Pseudochromidae
Fire-tail devil
Labracinus cyclophthalmus
Acestrorhamphidae
Firehead tetra
Petitella bleheri
Pomacanthidae
Fisher's angelfish
Centropyge fisheri
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.