Family PELAGIIDAE Gegenbaur, 1856

Museums

Regional Maps

Introduction

Three genera are included within the Pelagiidae, namely, Chrysaora, Pelagia and Sanderia; a fourth, Dactylometra, is sometimes separated out from Chrysaora based on having 40 tentacles compared to 24 in the strictrer sense of Chrysaora. All three, or all four for that matter, are represented in Australian coastal waters. At least three species of Chrysaora (including one in the Dactylometra stage) are found in the temperate regions; two species of Pelagia, one reported from all states and the other presently known only from New South Wales; and one species of Sanderia reported from tropical Western Australia.

The genera of pelagiids are easy to tell apart: Pelagia has 8 tentacles, i.e., one each in alternation with eight rhopalia; Chrysaora has 24, i.e., clusters of three in alternation with eight rhopalia; Dactylometra has 40, i.e., clusters of five each in alternation with eight rhopalia; and Sanderia has 16, i.e., one each in alternation with 16 rhopalia. Dactylometra is not recognised by all authors; when not recognised, its species are grouped into the genus Chrysaora.

The pelagiids are the so-called 'sea nettles', and as such, can deliver quite a painful sting; however, none of the Australian species are known to cause medical complications. If a sting from a pelagiid is suspected, rinse well with sea water (not fresh water!) and apply ice for the pain as necessary; seek medical care if symptoms persist or worsen.

Diagnosis

Semaeostome scyphomedusae with marginal tentacles arising from umbrella margin; with gastrovascular sinus divided by radial septa into separate unbranched pouches; without ring canal; with elongated oral arms with frilled lips.

Diagnosis References

Russell, F.S. 1970. Medusae of the British Isles. II. Pelagic Scyphozoa with a Supplement to the First Volume on Hydromedusae. Cambridge : Cambridge University Press 284 pp. [70]

General References

Gershwin, L. & A. Collins 2002. A preliminary phylogeny of Pelagiidae (Cnidaria, Scyphozoa), with new observations of Chrysaora colorata comb. nov. Journal of Natural History 36(2): 127-148 [127]

Russell, F.S. 1970. Medusae of the British Isles. II. Pelagic Scyphozoa with a Supplement to the First Volume on Hydromedusae. Cambridge : Cambridge University Press 284 pp. [70]

History of changes