Labial furrow

Labial furrows or labial pits are outer depressions in the area of ​​the corners of the mouth in cartilaginous fish , through which existing labial folds are separated from the surrounding tissue. Together with the labial folds, they represent an important taxonomic feature for the differentiation and classification of cartilaginous fish, especially sharks . In the original state there is a labial furrow above the corner of the mouth and another below.

literature

• Leonard Compagno , Marc Dando, Sarah Fowler: Sharks of the World . Princeton Field Guides, Princeton University Press , Princeton and Oxford 2005, ISBN 0-691-12072-2 , p. 331.