Nematocyst ratio and prey in two Australian cubomedusans, Chironex fleckeri and Chiropsalmus sp.

Functional characteristics of nematocysts found on the scyphomedusa Cyanea capillata

“…2) and nomenclatural classifications, had the most similar velocities and lengths and, therefore, are most likely to function similarly. The lack of correspondence between a nematocyst's nomenclatural classification and its function suggests that caution is appropriate when using medusan nematocyst assemblages as indicators of prey selection and trophic role (Purcell and Mills, 1988;Carrette et al, 2002;Peach and Pitt, 2005). Further, the lack of correspondence between capsule size, discharge velocity and kinetic energy may confound the use of nematocyst sizes to infer prey size (Purcell, 1984;Carrette et al, 2002).…”

“…The majority of described nematocyst types are assumed to be penetrants because the tip of their tubules are open and are inferred to be capable of delivering the toxins characterizing cnidarian stings. Beyond this, most of our current knowledge on prey capture by nematocysts is based upon studies which either relate the nematocyst assemblage found on a medusan species to its diet (Purcell and Mills, 1988;Carrette et al, 2002;Peach and Pitt, 2005), or studies using microscopy to examine preserved samples of nematocysts and their captured prey (Purcell, 1984;Heeger and Möller, 1987;Heeger et al, 1992;Östman and Hydman, 1997;Peach and Pitt, 2005). Due to the inherent difficulty in observing the fastest cellular process identified, few studies have directly observed and described the discharge properties of different types of nematocysts (Holstein and Tardent, 1984;Nuchter et al, 2006).…”

Getting information from ethanol preserved nematocysts of the venomous cubomedusa Chiropsalmus quadrumanus: a simple technique to facilitate the study of nematocysts

“…Some of these organelles, known as nematocysts, may inject toxins through a penetrative thread into the victim (Carrette & Seymour, 2004). In addition, nematocysts can be very useful to identify species (e.g., Williamson et al, 1996;Marques, 2001), even cryptic ones (e.g., Collins et al, 2011), and to infer feeding behavior and ecology (Endean & Rifkin, 1975), or even estimate the size of the individual (Carrette et al, 2002). Ideally, the study of nematocysts is based on fresh and live material, for which discharging of nematocysts is accomplished by adding ethanol, distilled water or even saliva (Gershwin, 2006a).…”

“…The species model used was the box jellyfish Chiropsalmus quadrumanus (Müller, 1859), a venomous species from the western tropical and subtropical Atlantic. The cnidome of C. quadrumanus consists of three types of nematocysts, isorhizas (ovoid and ellipsoid), microbasic euryteles and microbasic mastigophores (Calder & Peters, 1975;Carrette et al, 2002;Gershwin, 2006a). The study of the nematocysts of this species, as well as for many other cubozoans, is also made more difficult by the thick mesoglea, which gets hardened after fixation.…”

Phyllosomas of smooth fan lobsters (<i>Ibacus novemdentatus</i>) encase jellyfish cnidae in peritrophic membranes in their feces

“…Jellyfish consume planktonic crustaceans such as copepods (Ishii & Tanaka 2001) and shrimp (Carrette et al 2002) utilizing various types of tentacle cnidae including penetrant, venom-filled nematocysts (Tardent 1995, Nagai 2012, Ponce et al 2013. During nematocyst discharge, venom-filled tubules explosively penetrate the cuticle of the prey (Tardent & Holstein 1982, Purcell 1984 and inject their venom through the tubules (Lotan et al 1996, Yanagihara et al 2002.…”