Species by Order: Hydrozoa: Leptothecatae

Natural History
Aequorea spp.

Commonly called crystal jellies, they are raised in many aquaria.  Generally present during the spring or early autumn.  Large blooms occur in British Columbia, but blooms are not common in southern California.  The polyp stage is rarely found in the field.

Clytia lomae

Medusae seen most often in late summer and early fall.

Eirene mollis

Rarely reported.

Eucheilota bakeri

The hydroid phase is often found on mollusc shells in intertidal and slightly subtidal zones.

Eutimalphes brownei

Known from San Diego Bay in 1909. Few reports since then.

Mitrocoma discoidea

Not extremely common in San Diego; most often seen in the late fall.

Obelia spp.

The hydroid phase of the life history is better known than the medusa stage.  The hydroids grow in branching stalks and are commonly found as part of coastal benthic fouling communities.  The medusae are small and are often found during the summer.

Phialopsis diegensis
Ptychogena spp.

Rare along southern and central Californian coasts. Two different species have been collected in this area.

Tiaropsidium kelseyi