A new species of Australomedusa (Cnidaria: Hydrozoa: Anthomedusae) from a saline lake in south-western Western Australia

Abstract

Australomedusa thrombolites sp. nov. is described from Lake Clifton, Yalgorup National Park. It is a small medusa with a bell height (BH) of about 1.5 mm. It differs from its only other congener, A. baylii, primarily in the shape and location of the gonads, and in having only 3–5 tentacles per cluster (verses 5–9). Furthermore, in preserved specimens, the tentacle length is relatively longer, about 75% BH, though this character tends to be highly variable in most medusa species.