Anatomy

Although the scyphozoan jellyfish are typically regarded as simple animals, they accomplish the same feats as many more complex animals enabling them to survive, grow, and reproduce. Jellyfish can, for example, prey on vertebrates, distribute food and oxygen to their tissues, remove metabolic wastes, sense changes in light and orientation, and use the sun to migrate. Different species may accomplish these feats in different ways that may be reflected in anatomical and morphological variation. The links below provide information on gross morphological variation among the jellyfish as well as examples of more specific anatomical differences.

Morphology of the jellyfishes

Members of each group of medusae—Class, Order, Family, etc.—are generally recognizable from their overall appearance. Their gross morphology, however, can also be divided into parts, and certain features of their morphology strongly indicate relationships with other medusae. For example, the coronal groove is characteristic of coronate medusae, the absence of tentacles from the bell margin is usually (but not always) an indication of rhizostomes. Here, schematic diagrams highlight the major features used to distinguish among groups of scyphozoans. Below, we look in more detail at a subset of features.

For more detailed information on jellyfish morphology, follow these links ...