Chaetodontidae
Redtail butterflyfish
Chaetodon collare
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.
Redtail butterflyfish
Monacanthidae
redtail filefish
Pervagor melanocephalus
Nothobranchiidae
Redtail notho
Nothobranchius guentheri
Cyprinidae
Redtail Sanjika
Opsaridium ubangiense
Carangidae
redtail scad
Decapterus kurroides
Pempheridae
Redtail sweeper
Pempheris rubricauda
Plesiopidae
Redtip longfin
Plesiops verecundus
Chaetodontidae
reef butterflyfish
Chaetodon sedentarius
Apogonidae
Reef siphonfish
Siphamia spinicola
Apogonidae
Reef-flat cardinalfish
Ostorhinchus taeniophorus
Dorosomatidae
Reeves shad
Tenualosa reevesii
Pomacanthidae
regal angelfish
Pygoplites diacanthus
Pomacentridae
regal damselfish
Neopomacentrus cyanomos
Pomacentridae
Reid's damsel
Pomacentrus reidi
Labridae
Renny's Flasher Wrasse
Paracheilinus rennyae
Anthiadidae
Resplendent goldie
Pseudanthias pulcherrimus
Pomacanthidae
Resplendent pygmy angelfish
Centropyge resplendens
Pomacentridae
reticulate dascyllus
Dascyllus reticulatus
Epinephelidae
Reticulate grouper
Epinephelus tuamotuensis
Notopteridae
Reticulate knifefish
Papyrocranus afer
Acanthuridae
Reticulate unicornfish
Naso reticulatus
Gobiidae
Reticulated shrimpgoby
Tomiyamichthys reticulatus
Batrachoididae
Reticulated toadfish
Allenbatrachus reticulatus
Pomacanthidae
Reunion angelfish
Apolemichthys guezei
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.