Pangasiidae
Mekong giant catfish
Pangasianodon gigas
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.
Mekong giant catfish
Ehiravidae
Mekong noodlefish
Sundasalanx mekongensis
Adrianichthyidae
Mekong Ricefish
Oryzias mekongensis
Gobiidae
Mele's stiphodon
Stiphodon mele
Nemacheilidae
Melid loach
Oxynoemacheilus kaynaki
Syngnathidae
Menado pipefish
Microphis manadensis
Myxinidae
Mendoza's Hagfish
Eptatretus mendozai
Bagridae
Menoda catfish
Hemibagrus menoda
Nemacheilidae
Mentum barbel Yunnan loach
Yunnanilus mentibarbatus
Percidae
Meramec Saddled Darter
Etheostoma erythrozonum
Congridae
Mercy's garden eel
Heteroconger mercyae
Macrouridae
Merret's whiptail
Nezumia merretti
Poeciliidae
Merry widow livebearer
Phallichthys amates
Poeciliidae
Meshscaled topminnow
Lacustricola hutereaui
Malakichthyidae
Mesophotic Seabass
Malakichthys similis
Carapidae
messmate
Echiodon cryomargarites
Carapidae
Messmate fish
Echiodon rendahli
Syngnathidae
Messmate pipefish
Corythoichthys haematopterus
Malakichthyidae
Metalic Seabass
Malakichthys barbatus
Moridae
metallic codling
Physiculus fulvus
Siluridae
Metallic sheatfish
Phalacronotus apogon
Epinephelidae
meteor perch
Liopropoma susumi
Chaenopsidae
Mexican barnacle blenny
Acanthemblemaria macrospilus
Belonidae
Mexican needlefish
Tylosurus fodiator
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.