The Chaetognath Sagitta

Black and white image of a long rod-like object with fine, curved spines protruding from the sides.

Chaetognaths, or arrow worms, have a distinct jaw structure composed of dense protein matrix and a fibrous substance called chitin. These organisms display an ambiguous set of developmental and morphological features, making them difficult to categorize on the Tree of Life.

Chaetognaths, or arrow worms, have a distinct jaw structure composed of dense protein matrix and a fibrous substance called chitin. These organisms display an ambiguous set of developmental and morphological features, making them difficult to categorize on the Tree of Life.

Date:
21 December 2018
Credit:
Photo: Zatelmar (Wikimedia)

CC BY-SA 3.0

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