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A Dorsal Longitudinal Ligament in Sea Lampreys ( Petromyzon marinus ): A Novel Structure Involved in Trunk Movements
Author(s) -
Wood Bradley,
Kynard Boyd,
Homberger Dominique
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.867.11
Subject(s) - anatomy , trunk , biology , ligament , dorsum , dorsal fin , ecology
Lampreys are capable of a wide range of motions, including flexion, extension, and twisting. Sea Lampreys, in particular, are capable of extreme ventral flexions up to a 90 degree angle, which was observed during their upriver migration, when they navigate high velocity rivers, transport stones to build nests, spawn, and defend their territory. This range of motion has not been observed in basal gnathostomes, such as sharks, which, in contrast to lampreys, possess a pectoral girdle, horizontal and vertical septa, and a stiff vertebral column. Employing a mesoanatomical approach, we investigated the morphology of the trunk musculature and connective tissue that are responsible for these extreme movements. We discovered a thick longitudinal ligament running along the mid‐dorsal line between the head and the first dorsal fin and anchored within the connective tissue between the skin and the epaxial musculature. We hypothesize that this ligament serves as a possible passive antagonist supporting the epaxial musculature to straighten the flexed trunk through its resilience.