Anthiadidae
Thread-tail basslet
Pseudanthias rubrolineatus
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.
Thread-tail basslet
Chaetodontidae
Threadfin butterflyfish
Chaetodon auriga
Apogonidae
Threadfin cardinalfish
Zoramia leptacanthus
Plesiopidae
Threadfin longfin
Plesiops gracilis
Gobiidae
Threadfin mangrovegoby
Mugilogobius filifer
Glaucosomatidae
Threadfin pearl-perch
Glaucosoma magnificum
Ephippidae
Threadfin scat
Rhinoprenes pentanemus
Dorosomatidae
threadfin shad
Dorosoma petenense
Anthiadidae
Threadtail anthias
Tosana niwae
Osphronemidae
Three spot gourami
Trichopodus trichopterus
Cichlidae
Three spotted tilapia
Oreochromis andersonii
Pomacentridae
Three-band anemonefish
Amphiprion tricinctus
Labridae
three-ribbon rainbowfish
Stethojulis strigiventer
Batrachoididae
Three-spined frogfish
Batrachomoeus trispinosus
Apogonidae
Three-spot cardinalfish
Pristicon trimaculatus
Histiophrynidae
Three-spot frogfish
Lophiocharon trisignatus
Caesionidae
Three-stripe fusilier
Pterocaesio trilineata
Chaetodontidae
Three-striped butterflyfish
Chaetodon tricinctus
Apogonidae
Threeband cardinalfish
Apogon tricinctus
Pomacentridae
Threeband damselfish
Chrysiptera tricincta
Chaetodontidae
Threeband pennantfish
Heniochus chrysostomus
Chaetodontidae
threebanded butterflyfish
Chaetodon humeralis
Siganidae
Threeblotched rabbitfish
Siganus trispilos
Polynemidae
threefinger threadfin
Eleutheronema tridactylum
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.