Research On The Morphology, Discharge Regulation And Venoms Of The Nematocysts From Cyanea Nozakii Kishinouye (Cnidaria, Scyphozoa)

Cyanea nozakii Kishinouye(C. nozakii), widely distributed from the South ChinaSea to the Bohai Sea, is a kind of jellyfish which contain toxins. They are characteredwith plenty of nematocysts on tentacles, which could discharge and release venom forprey or defence under proper stimulations. Along the seaside, lots of tourists,fishersor staffs, who are involved in marine activities, were got injured by jellyfish stingevery year. But the study on this kind of jellyfish is deficient. In order to prevent orcure jellyfish sting by C. nozakii, a systematic research on nematocysts and venomsof this kind is quite necessary. In this paper,we studied C. nozakii on three parts,including: the morphology and identification of the nematocysts, the regulation ofnematocyst discharge and the collection and purification of jellfish venom. Theresults are showed below:1. In this paper, the morphological characters of nematocysts from C. nozakiiwere examined by light and scanning-electron microscopy and five nematocyst typeswere identified. Including three reported types in Scyphozoa: atrichous Isorhizas (a-atrich/o-atrich), microbasic Euryteles, microbasic Birhopaloids type II (Euryteles orTrirhopaloids) and two types which were seldom reported in Scyphozoa: microbasicb-Mastigophores and microbasic Birhopaloids. 2. In this paper, the effect of different pH values and temperatures on thedischarge of tentacle and isolated nematocysts were investigated. The results showedthat the tentacle nametocysts discharged obviously when the pH value was below3orabove11. Temperature below-20℃had the similar effect. But these factors didn’taffect the isolated nematocysts, which suggested that nematocysts were notindependent effectors and neural pathways may exist on the tentacles of C. nozakii. Inaddtion,common neuro-transmitters were also tested, but none of them was effective.3. In this paper, a novel way to collect venoms from Cyanea nozakii Kishinouyewithout destroying tentacles or nematocysts was designed basing on the discoveryabove. The intact tentacles were treated with ultra-low temperature to stimulatenematocysts to discharge and the released secretions were collected as the crudevenom. Through anion-exchange (DEAE Sepharose Fast Flow) and size-exclusionchromatography (SephadexG-200), a protein with a molecular mass of45kDa wasfinally purified. This protein was named CnP45temporarily and characters with anactivity of increasing vasopermeability by Evens blue assay.