An illustrated key and synopsis of the families and genera of carybdeid box jellyfishes (Cnidaria: Cubozoa: Carybdeida), with emphasis on the “Irukandji family” (Carukiidae)

Abstract

Box jellyfishes (Cnidaria: Cubozoa) have a profound impact on human activities because of their highly potent venoms that may lead to severe envenomations in humans. Cubozoa is one of the smallest classes within Cnidaria with only some 50 described species in seven families. The literature on Cubozoa is scattered and oftentimes difficult to access. In particular, comprehensive treatments of Cubozoa that present a comparative overview of the group are either non-existent or largely outdated. Here we provide a synopsis of the carybdeid Cubozoa (Carybdeida) including an illustrated key to the families and genera of this order. Of particular interest is the family Carukiidae, which contains the species that was originally attributed with causing a severe envenomation syndrome called Irukandji syndrome. One new species of Carukiidae, Malo filipina sp. nov., is described, Morbakka virulenta is redescribed and a neotype is designated, and an unidentified species of Morbakka is recorded from the Philippines.

Keywords:

• box jellyfish
• Cubomedusae
• Hikurage
• taxonomy
• nomenclature
• taxonomic key

Acknowledgements

Numerous people have contributed to our studies over the years by providing assistance in the field, during museum visits or through critical discussions. We are particularly grateful to Masato Kawahara for collecting the specimens used for the redescription of Morbakka virulenta and sharing his knowledge on the cubozoans of Japan with us. Tara H. Lynn prepared, photographed and measured nematocysts of the species described in this manuscript. We wish to thank Hermes Mianzan, Jennifer Purcell, Dale Calder and Antonio Marques who helped to improve this manuscript with their valuable comments. We would also like to acknowledge the excellent resources and staff of the Smithsonian Library at the NMNH. This work was funded through a PADI foundation grant, a Smithsonian Institution pre-doctoral fellowship to BB, US National Science Foundation (NSF) Doctoral Dissertation Improvement grant DEB 0910237, and NSF Assembling the Tree of Life grant EF-053179. The Department of Ecology and Evolutionary Biology at the University of Kansas provided generous financial assistance to support BB's attendance of the Third Jellyfish Blooms Symposium in Mar del Plata, Argentina, during which our research on the phylogeny and taxonomy of the Cubozoa was presented and the idea to prepare a key and synopsis of the Carybdeida was conceived.