Percidae
Carolina fantail darter
Etheostoma brevispinum
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.
Carolina fantail darter
Gobiidae
Caroline Islands ghost goby
Pleurosicya carolinensis
Cyprinidae
Carpathian Barbel
Barbus carpathicus
Petromyzontidae
Carpathian brook lamprey
Eudontomyzon danfordi
Gobionidae
Carpathian gudgeon
Gobio carpathicus
Chimaeridae
Carpenter's chimaera
Chimaera lignaria
Pseudochromidae
Carpet eel-blenny
Congrogadus subducens
Orectolobidae
carpet shark
Orectolobus japonicus
Orectolobidae
carpet shark
Orectolobus ornatus
Callichthyidae
Cascarudo
Callichthys callichthys
Loricariidae
Cascudo Pit Bull
Parotocinclus jumbo
Gobionidae
Caspian gudgeon
Gobio holurus
Petromyzontidae
Caspian lamprey
Caspiomyzon wagneri
Gobiidae
Caspian tadpole goby
Benthophilus macrocephalus
Opistognathidae
Castelnau's jawfish
Opistognathus castelnaui
Muraenidae
Castle's moray
Gymnothorax castlei
Parascylliidae
cat shark
Parascyllium collare
Anarhichadidae
catfish
Anarhichas lupus
Claroteidae
Catfish
Auchenoglanis biscutatus
Ariidae
Catfish
Cephalocassis borneensis
Clariidae
Catfish
Clarias agboyiensis
Clariidae
Catfish
Clarias laeviceps
Sisoridae
Catfish
Gagata youssoufi
Heptapteridae
Catfish
Heptapterus mustelinus
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.