Pentanchidae
Pinocchio Catshark
Apristurus australis
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.
Pinocchio Catshark
Myctophidae
pinpoint lampfish
Lampanyctus regalis
Syngnathidae
Pipe fish
Microphis boaja
Syngnathidae
Pipefish
Ichthyocampus carce
Syngnathidae
Pipefish
Leptonotus elevatus
Syngnathidae
Pipefish
Pseudophallus elcapitanensis
Syngnathidae
Pipefish
Pseudophallus mindii
Syngnathidae
Pipehorse
Amphelikturus dendriticus
Chaenopsidae
pirate blenny
Emblemaria piratula
Aphredoderidae
Pirate perch
Aphredoderus sayanus
Cyprinidae
Pisidian spring minnow
Pseudophoxinus fahrettini
Petromyzontidae
Pit-Klamath brook lamprey
Entosphenus lethophagus
Loricariidae
Pitanga Pleco
Pseudacanthicus pitanga
Ammodytidae
Pitcairn Sandlance
Ammodytoides leptus
Pimelodidae
Pito gordo
Pseudoplatystoma tigrinum
Cichlidae
Pixy Pike Cichlid
Crenicichla yaha
Pseudochromidae
Plain dottyback
Pseudochromis litus
Mochokidae
Plain squeaker
Synodontis zambezensis
Ophichthidae
plain worm eel
Pseudomyrophis micropinna
Macrouridae
Plaintail whiptail
Hymenocephalus aeger
Clinidae
Platanna klipfish
Xenopoclinus kochi
Callorhinchidae
plownose chimaera
Callorhinchus callorynchus
Petromyzontidae
Po brook lamprey
Lampetra zanandreai
Trichiuridae
Poey's scabbardfish
Evoxymetopon poeyi
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.