Dorosomatidae
pilchard
Harengula humeralis
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.
pilchard
Anthiadidae
Pillai’s anthias
Pseudanthias pillai
Holocentridae
pinecone soldierfish
Myripristis murdjan
Ophidiidae
pink cusk-eel
Genypterus blacodes
Labridae
Pink flasher
Paracheilinus carpenteri
Brachionichthyidae
Pink Handfish
Brachiopsilus dianthus
Anthiadidae
Pink maomao
Caprodon longimanus
Salmonidae
pink salmon
Oncorhynchus gorbuscha
Holocentridae
Pink squirrelfish
Sargocentron tiereoides
Labridae
Pink-belly wrasse
Halichoeres margaritaceus
Apogonidae
Pinstripe cardinalfish
Lepidamia kalosoma
Labridae
Pintail fairy-wrasse
Cirrhilabrus isosceles
Pomacanthidae
Pitcairn angelfish
Genicanthus spinus
Cirrhitidae
pixy hawkfish
Cirrhitichthys oxycephalus
Pleuronectidae
plaice
Pleuronectes platessa
Pseudochromidae
Plain dottyback
Pseudochromis litus
Macrouridae
Plaintail whiptail
Hymenocephalus aeger
Anthiadidae
Plectranthias azumanus
Zalanthias azumanus
Trichiuridae
Poey's scabbardfish
Evoxymetopon poeyi
Serranidae
Pogi perchlet
Chelidoperca santosi
Malacanthidae
Pohle's tilefish
Hoplolatilus pohle
Gobiidae
Pointedfin shrimpgoby
Cryptocentrus epakros
Chimaeridae
Pointy-nosed blue chimaera
Hydrolagus trolli
Pomacentridae
Polynesian anemonefish
Amphiprion maohiensis
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.