Blenniidae
One-striped poison-fang blenny
Meiacanthus ditrema
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.
One-striped poison-fang blenny
Pentanchidae
onefin catshark
Pentanchus profundicolus
Gobiesocidae
Oneline clingfish
Discotrema monogrammum
Ophidiidae
Onespot cusk
Neobythites unimaculatus
Microdesmidae
Onespot wormfish
Gunnellichthys monostigma
Microdesmidae
Onestripe wormfish
Gunnellichthys pleurotaenia
Chimaeridae
Opal chimaera
Chimaera opalescens
Osphronemidae
Opallios Licorice Gourami
Parosphromenus opallios
Salmonidae
Opimus trout
Salmo opimus
Syngnathidae
opossum pipefish
Microphis brachyurus
Syngnathidae
Opossum pipefish
Microphis lineatus
Ophichthidae
Orange blotched eel
Apterichtus hatookai
Dinematichthyidae
Orange brotula
Dermatopsoides kasougae
Gobiesocidae
Orange clingfish
Diplocrepis puniceus
Pseudochromidae
Orange dottyback
Pseudochromis luteus
Myrocongridae
Orange eel
Myroconger nigrodentatus
Dinematichthyidae
Orange eelpout
Dipulus caecus
Poeciliidae
Orange finned toothcarp
Priapichthys annectens
Syngnathidae
Orange pipefish
Maroubra yasudai
Channidae
Orange seam snakehead
Channa ninhbinhensis
Ophichthidae
Orange snake eel
Apterichtus flavicaudus
Channidae
Orange snakehead
Channa marulioides
Pentanchidae
Orange spotted catshark
Asymbolus rubiginosus
Gobiidae
Orange-fin Stiphodon
Stiphodon maculidorsalis
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.