Pomacentridae
Monarch damsel
Dischistodus pseudochrysopoecilus
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
SCROLL
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.
Monarch damsel
Monodactylidae
mono
Monodactylus argenteus
Pomacentridae
Monochrome chromis
Chromis monochroma
Apogonidae
Monster cardinal-fish
Jaydia melanopus
Pseudochromidae
Mooi's dottyback
Pseudochromis mooii
Citharinidae
Moon fish
Citharinus citharus
Citharinidae
Moon fish
Citharinus latus
Labridae
Moon wrasse
Thalassoma lunare
Gobiidae
Moon-spotted shrimp goby
Vanderhorstia nannai
Menidae
moonfish
Mene maculata
Pomacentridae
Moonstone Chromis
Chromis tingting
Zanclidae
Moorish idol
Zanclus cornutus
Mormyridae
Mormyrids
Mormyrus macrophthalmus
Mormyridae
Mormyrids
Mormyrus rume
Mormyridae
Mormyrids
Petrocephalus bovei
Polypteridae
Mottled bichir
Polypterus weeksii
Apogonidae
Mottled cardinalfish
Fowleria vaiulae
Caesionidae
mottled fusilier
Dipterygonotus balteatus
Grammistidae
mottled soapfish
Rypticus bicolor
Soleidae
Mottled sole
Aseraggodes melanostictus
Siganidae
Mottled spinefoot
Siganus fuscescens
Galaxiidae
Mountain galaxias
Galaxias olidus
Stevardiidae
Mountain stream sardine
Hemibrycon taeniurus
Stevardiidae
Mountain Tetra
Hemibrycon metae
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.