October 25, 2008

Leptomedusae


Maximum diameter: About 20 cm, but on exceptional occasions up to 30 cm.

Appearance: The mouth is situated at the top of the tubular formation that hangs down from the underside of the "umbrella". Along the inside edge of the "umbrella" is a peripheral crease and the tentacles hang down from the "umbrellas" outer edge. The leptomedusae have many tentacles, the number of which increase with age. The "umbrella" form is rather shallow, and on the underside, the organs that produce eggs and sperms are situated. The leptomedusae are usually transparent, but on occasions can be milky white or have a light blue, brown, red or violet tone. Even with transparent medusae, the sexual organs, stomach and tentacles can be light red, greenish or light brown.
Compare the leptomedusae with the anthomedusae and the moon jellyfish.

Depth: From sea-level to unknown depth.

Environment: Pelagic.

Misc: The leptomedusae catches and eats small organisms and suspended remains from the surrounding water. These medusae do not sting enough to cause discomfort to people. Medusae representatives are found globally. The medusa stage is part of a life cycle where even an attached stage is present and the medusae build colonies.

Classification: The above photo shows a jellyfish (Tima bairdii). Leptomedusae are part of the hydroid, group under the cnidarians.