Microdesmidae
blacktail goby
Ptereleotris heteroptera
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.
blacktail goby
Pomacentridae
Blacktail humbug
Dascyllus melanurus
Ophidiidae
Blackthroat cusk-eel
Lepophidium entomelan
Epinephelidae
blacktip grouper
Epinephelus fasciatus
Dorosomatidae
blacktip sardinella
Sardinella melanura
Holocentridae
Blacktip soldierfish
Myripristis botche
Holocentridae
blacktip soldierfish
Myripristis hexagona
Carangidae
blacktip trevally
Caranx heberi
Chaetodontidae
blackwedged butterflyfish
Chaetodon falcula
Labridae
bleeding wrasse
Polylepion cruentum
Dorosomatidae
Bleeker smoothbelly sardinella
Amblygaster clupeoides
Pomacentridae
Bleeker's damsel
Chrysiptera bleekeri
Labridae
Bleeker's parrotfish
Chlorurus bleekeri
Dinematichthyidae
Bleeker's viviparous brotula
Beaglichthys bleekeri
Labridae
Blemished razorfish
Iniistius naevus
Nemacheilidae
Blind loach
Eidinemacheilus smithi
Dorosomatidae
Bloch's gizzard shad
Nematalosa nasus
Rajidae
Blonde ray
Raja brachyura
Tetrarogidae
Blotch-finned waspfish
Ocosia dorsomaculata
Siganidae
Blotched foxface
Siganus unimaculatus
Grammistidae
Blotched podge
Aporops bilinearis
Liparidae
blotched snailfish
Crystallichthys cyclospilus
Muraenidae
blotched-neck moray
Gymnothorax margaritophorus
Carangidae
Bludger
Turrum gymnostethus
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.