Lebiasinidae
Pencilfish
Derhamia hoffmannorum
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.
Pencilfish
Chaetodontidae
Pennantfish
Heniochus diphreutes
Chaetodontidae
peppered butterflyfish
Chaetodon guttatissimus
Callichthyidae
Peppered cory
Hoplisoma paleatum
Siganidae
Peppered spinefoot
Siganus punctatissimus
Ophidiidae
Pepperfin cusk-eel
Lepophidium gilmorei
Ehiravidae
Perak river sprat
Clupeichthys perakensis
Distichodontidae
Perch
Distichodus engycephalus
Percidae
perch
Perca fluviatilis
Apogonidae
perdix cardinalfish
Apogonichthys perdix
Pomacentridae
Perpetual Chromis
Chromis abadhah
Polynemidae
Persian blackspot threadfin
Polydactylus persicus
Cyprinidae
Persian chub
Acanthobrama persidis
Dorosomatidae
Perth herring
Nematalosa vlaminghi
Mormyridae
Peters' elephantnose fish
Gnathonemus petersii
Chaetodontidae
Phantom bannerfish
Heniochus pleurotaenia
Chaetodontidae
Philippine butterflyfish
Chaetodon adiergastos
Pomacentridae
Philippine damsel
Pomacentrus philippinus
Pomacentridae
Philippines chromis
Chromis scotochiloptera
Sparidae
picarel
Spicara smaris
Sparidae
picnic seabream
Acanthopagrus berda
Haemulidae
pigfish
Orthopristis chrysoptera
Anthiadidae
Pigmy basslet
Xenanthias nanus
Achiropsettidae
Pigmy flounder
Pseudomancopsetta andriashevi
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.