Visual Ecology and Functional Morphology of Cubozoa (Cnidaria)

Abstract

Jellyfish belong to one of the oldest extant animal phyla, the Cnidaria. The first Cnidaria appear in the fossil record 600 million years ago, preceeding the Cambrian explosion. They are an extremely successful group present in all marine environments and some freshwater environments. In contrast to many animal phyla in which vision is a primary sense Cnidarians do not, generally, employ image forming eyes. One small class stands alone: the Cubozoa. Cubomedusae are commonly known as box jellyfish. They possess image forming eyes (Coates et al., 2001) which certainly evolved independently from other metazoans. Cubomedusae therefore offer a unique perspective on the evolution of image forming eyes. This literature review collects, into one place, what is known about: the multiple eye types of box jellyfish, cubomedusan life history and ecology, and the sensory and neural systems of box jellyfish. Here I discuss how these features set cubomedusae apart from scyphomedusae and hydromedusae. Knowledge in these areas is sparse; the work done to date inspires increased efforts.

Cubozoan jellyfish: an Evo/Devo model for eyes and other sensory systems

“…Each rhopalium has six separate eyes. There are two complex, lens-containing eyes, one larger than the other, situated at right angles to each other and two pairs (one pitshaped, one slit-shaped) of simple ocelli comprising photoreceptors on either side of the complex eyes (Coates, 2003). This eye diversity within Tripedalia may provide new insights into the mechanisms used in evolution for achieving greater anatomical complexity of eyes.…”

“…1) containing a well-developed visual system. In general among Cnidarians, it is the Cubozoa (known as 'box jellyfish' due to their square shape) that have lens-containing eyes (Coates, 2003, Piatigorsky, 2003b, although a few Hydozoa do as well (for example, Cladonema radiatum) (Weber, 1981) (Fig. 2).…”

“…Recent studies indicate that the camera-type eye has the ability to form a low resolution image on the photoreceptors despite the proximity of the lens to the retina (Laska and Hundgen, 1982, Pearse and Pearse, 1978. The behavioral role of the jellyfish eyes is under investigation (Coates, 2003). It seems likely that investigations of eye development in Cnidaria are directly relevant to eye development in other animal groups.…”

Rediscovery and description of the cubomedusa <i>Alatina grandis</i> (Agassiz & Mayer, 1902) (Cnidaria: Cubozoa: Alatinidae) from Pakistani waters

“…de). But besides this, the group also presents other interesting aspects, like courtship (Lewis & Long 2005, Lewis et al 2008, Garm et al 2012, Chiaverano et al 2013, Canepa et al 2014, Carrette et al 2014, vision (Coates 2003, Nordström et al 2003, Nilsson et al 2005, Garm et al 2006, 2007a+b, 2008, Garm & Bielecki 2008 and taxonomic classification (Bigelow 1938, Werner 1973, Gershwin 2005b, 2006, Straehler-Pohl 2014, Toshino et al 2013. Also the validity of some species, especially the ones of the alatinid family, has been discussed since the beginning of the last century (Mayer 1910, Bigelow 1938, Kramp 1961, Gershwin 2005a, b, Bentlage 2010, Lewis et al 2013.…”

First record of association between <i>Tamoya haplonema</i> (Cnidaria: Cubozoa) and stromateid fish, with a review on interactions between fish and cubozoan jellyfishes

“…Cubozoan jellyfishes, with unique features such as complex eyes (Coates 2003) and powerful venom (Brinkman & Burnell 2009), have drawn much attention from the scientific community and the public. Studies that observe interactions involving these jellyfish, such as predation, indicate that prey items vary usually from planktonic crustaceans to fish, with preference for fish commonly related to larger or more mature individuals, in which more potent venom is developed (Kingsford & Mooney 2014).…”