Labridae
Darktail parrotfish
Scarus fuscocaudalis
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.
Darktail parrotfish
Tripterygiidae
Darktail triplefin
Helcogramma aquila
Pseudotrichonotidae
Dart sand-diving lizardfish
Pseudotrichonotus belos
Gobiidae
darter goby
Ctenogobius boleosoma
Cottidae
darter sculpin
Radulinus boleoides
Erythrinidae
Darter Wolffish
Hoplias intermedius
Gobiidae
dash goby
Ctenogobius saepepallens
Gobiidae
Dashback Goby
Microgobius signatus
Blenniidae
Dashed-line blenny
Blenniella interrupta
Lumpenidae
daubed shanny
Leptoclinus maculatus
Syngnathidae
Davao pughead pipefish
Bulbonaricus davaoensis
Gobiidae
Day's goby
Acentrogobius dayi
Stomiidae
Ddusky boafish
Stomias nebulosus
Platycephalidae
De Beaufort's flathead
Cymbacephalus beauforti
Ophichthidae
deathbanded snake eel
Ophichthus frontalis
Aploactinidae
Deep velvetfish
Kanekonia queenslandica
Syngnathidae
Deep-bodied pipefish
Leptonotus blainvilleanus
Muraenidae
Deep-dwelling moray
Gymnothorax bathyphilus
Syngnathidae
deep-nosed pipefish
Syngnathus typhle
Clinidae
Deep-reef klipfish
Pavoclinus smalei
Serrivomeridae
Deep-sea eel
Serrivomer sector
Argentinidae
Deep-sea smelt
Glossanodon semifasciatus
Engraulidae
deepbody anchovy
Anchoa compressa
Stomiidae
Deepbody Dragonfish
Bathophilus brevis
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.