Anthiadidae
Hiva basslet
Pseudanthias hiva
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.
Hiva basslet
Gobiidae
Hoese's goby
Koumansetta hoesei
Pomacentridae
Honey-head damsel
Dischistodus prosopotaenia
Epinephelidae
honeycomb grouper
Epinephelus merra
Muraenidae
Honeycomb moray
Gymnothorax favagineus
Epinephelidae
Hong Kong grouper
Epinephelus akaara
Chaetodontidae
Hongkong butterflyfish
Chaetodon wiebeli
Syngnathidae
Honshu pipefish
Doryrhamphus japonicus
Labridae
Hooded fairy wrasse
Cirrhilabrus efatensis
Apogonidae
Hookfin cardinalfish
Ostorhinchus griffini
Chaetodontidae
Horned bannerfish
Heniochus varius
Gobiidae
Horned goby
Cerogobius petrophilus
Cyprinidae
Horse Barbel
Barbus fucini
Acanthuridae
horseface unicornfish
Naso fageni
Pomacentridae
Howson's Chromis
Pycnochromis howsoni
Cyprinidae
Huanghe naked carp
Chuanchia labiosa
Sisoridae
Huddah nangra
Gogangra viridescens
Labridae
Human's fairy-warsse
Cirrhilabrus humanni
Cyprinidae
Hump backed puntius
Puntius kyphus
Cyprinidae
Hump-backed mahseer
Tor remadeviae
Apogonidae
Humpback cardinal
Fibramia lateralis
Epinephelidae
Humpback grouper
Chromileptes altivelis
Epinephelidae
Humpback grouper
Cromileptes altivelis
Engraulidae
Humpback hairfin anchovy
Setipinna paxtoni
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.