Loricariidae
Catfish
Hypostomus commersoni
FISH SPECIES
Long-bodied Fish
Explore fish with elongated, anguilliform or ribbon-like silhouettes, and learn how length changes locomotion and foraging.
FISH ATLAS / FIELD GUIDELong Bodied FishIN THIS CHAPTER01 / Characteristics02 / Lifestyle03 / Species04 / Field notes
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01 / NATURAL HISTORY
Characteristics
Elongated body plans reduce hydrodynamic drag, allow passage through tight apertures, and feature reduced or absent pelvic fins combined with extensive multi-vertebral muscular flexing systems.
- 01Anguilliform wave propulsion
- 02Crevice & conduit navigation
- 03Reduced appendages & low drag
02 / LIFESTYLE
Lifestyle
True eels swim via full-body anguilliform waves, sending lateral bends down their entire length to push against water, allowing them to reverse direction inside narrow subterranean burrows. Needlefish and pikes maintain a rigid elongated torso, keeping the body straight until their posterior fins and muscular caudal peduncle unleash sudden, explosive forward lunges.
OBSERVATION INDEX
- Full-body anguilliform undulation
- Reverse movement inside burrows
- Rigid body ambush alignment
03 / SPECIES
Representative species
Discover representative species illustrating the ecological diversity, morphologies and adaptations of this group.
Catfish
Loricariidae
Catfish
Otocinclus flexilis
Siluridae
Catfish
Pterocryptis cochinchinensis
Doradidae
Catfish
Rhinodoras dorbignyi
Amphiliidae
Catfish
Zaireichthys wamiensis
Nemacheilidae
Catfish-like loach
Triplophysa siluroides
Chlopsidae
Catherine's False Moray
Robinsia catherinae
Brachaeluridae
catshark
Brachaelurus waddi
Hemiscylliidae
catshark
Chiloscyllium griseum
Hemiscylliidae
catshark
Chiloscyllium indicum
Hemiscylliidae
catshark
Chiloscyllium plagiosum
Hemiscylliidae
catshark
Chiloscyllium punctatum
Gobiidae
Caucasian dwarf goby
Knipowitschia caucasica
Gobiidae
Caucasian goby
Ponticola constructor
Cyprinidae
Cauvery rasbora
Rasbora caverii
Clariidae
Cave catfish
Clarias cavernicola
Siluridae
Cave sheatfish
Pterocryptis buccata
Engraulidae
Cayenne anchovy
Anchoviella cayennensis
Gobiidae
Cayman cleaner goby
Elacatinus cayman
Callichthyidae
Ceara bulldog cory
Aspidoras raimundi
Gobiidae
Cebu shrimpgoby
Cryptocentrus cebuanus
Platycephalidae
Celebes flathead
Thysanophrys celebica
Anguillidae
Celebes longfin eel
Anguilla celebesensis
Adrianichthyidae
Celebes ricefish
Oryzias hadiatyae
04 / FIELD NOTES
A closer look
Why do eels and morays lack pelvic fins?
Pelvic fins create hydrodynamic drag and easily catch on obstructions when navigating tight crevices, burrows and rock cracks. Over evolutionary time, appendages were reduced or lost in favor of continuous median fins.
How do elongated fish like gar and needlefish hunt?
Rather than undulate their whole bodies, they hold their long torsos completely straight to resemble floating sticks or debris, then unleash rapid lateral head snaps or tail bursts to impale unsuspecting prey on their toothed jaws.