Cyprinidae
blacknose dace
Rhinichthys atratulus
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.
blacknose dace
Gobiidae
Blacknose dwarfgoby
Sueviota atrinasa
Pomacentridae
Blackray damselfish
Pomacentrus nigriradiatus
Epinephelidae
Blacksaddle grouper
Epinephelus howlandi
Dorosomatidae
Blacksaddle herring
Herklotsichthys dispilonotus
Cirrhitidae
blackside hawkfish
Paracirrhites forsteri
Pomacentridae
blacksmith
Chromis punctipinnis
Pomacanthidae
Blackspot angelfish
Centropyge nigriocellus
Apogonidae
Blackspot cardinalfish
Taeniamia melasma
Labridae
Blackspot cleaner wrasse
Labroides pectoralis
Pomacentridae
Blackspot damsel
Pomacentrus stigma
Gobiidae
Blackspot Mudgoby
Oxyurichthys zeta
Pomacentridae
blackspot sergeant
Abudefduf sordidus
Holocentridae
blackspot squirrelfish
Sargocentron melanospilos
Polynemidae
blackspot threadfin
Polydactylus sextarius
Neosebastidae
Blackspotted gurnard perch
Neosebastes nigropunctatus
Nothobranchiidae
Blackspotted nothobranch
Nothobranchius melanospilus
Labridae
Blackspotted wrasse
Macropharyngodon meleagris
Apogonidae
Blackstripe cardinalfish
Ostorhinchus nigrofasciatus
Labridae
Blackstripe coris
Coris pictoides
Pomacanthidae
Blackstriped angelfish
Genicanthus lamarck
Pomacanthidae
Blacktail angelfish
Centropyge eibli
Chaetodontidae
blacktail butterflyfish
Chaetodon austriacus
Pomacentridae
Blacktail chromis
Pycnochromis nigrurus
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.