Nemacheilidae
Kessler's loach
Paraschistura kessleri
FISH SPECIES
Explore fish with elongated, anguilliform or ribbon-like silhouettes, and learn how length changes locomotion and foraging.
01 / NATURAL HISTORY
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.
02 / 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
03 / SPECIES
Discover representative species illustrating the ecological diversity, morphologies and adaptations of this group.
Nemacheilidae
Paraschistura kessleri
Engraulidae
Anchoa cayorum
Ophichthidae
Ahlia egmontis
Cyprinidae
Squalidus chankaensis
Cyprinidae
Garra lissorhynchus
Nemacheilidae
Oxynoemacheilus kiabii
Bagridae
Chrysichthys brachynema
Muraenidae
Gymnothorax kidako
Liparidae
Careproctus kidoi
Rivulidae
Aphyolebias obliquus
Rivulidae
Austrolebias adloffi
Rivulidae
Austrolebias viarius
Rivulidae
Cynopoecilus melanotaenia
Nothobranchiidae
Scriptaphyosemion cauveti
Sillaginidae
Sillaginodes punctatus
Gobiidae
Gladiogobius rex
Ophichthidae
Ophichthus rex
Trachipteridae
Trachipterus altivelis
Ophidiidae
Genypterus capensis
Hepsetidae
Hepsetus kingsleyae
Stichaeidae
Zoarchias glaber
Dalatiidae
Dalatias licha
Nemacheilidae
Schistura jarutanini
Petromyzontidae
Entosphenus similis
04 / FIELD NOTES
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.
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.