OBSERVATIONS ON THREE SPECIES OF JELLYFISHES FROM CHESAPEAKE BAY WITH SPECIAL REFERENCE TO THEIR TOXINS. I. CHRYSAORA (DACTYLOMETRA) QUINQUECIRRHA

¹ Department of Biology and Department of Chemistry, University of Richmond, Virginia 23173

1. The response of the human body to the toxin of the summer nettle, Chrysaora quinquecirrha, is allergic in nature.

2. Four types of nematocysts were identified: atrichous isorhizas; holotrichous isorhizas; euryteles; and a round type.

3. Application of faradic electrical shocks and the fixative FAA were effective in producing discharge of nematocysts in living nettles but not of isolated nematocysts.

4. The tubes of freely discharged nematocysts measured from 500-2000 µ in length. When discharged into 2% agar, the majority of tubes penetrated a distance of only 200-400 µ.

5. An efficient method of isolation and rupture of the nematocysts with subsequent isolation of the toxin is described.

6. The toxin is non-dialyzable. It gives positive ninhydrin and Biuret tests but negative Molisch and Benedict's tests.

7. The toxin is a protein or several proteins and is contained in the free fluid discharged from the nematocyst capsules. It is not membrane bound.

8. When inoculated intraperitoneally into white mice, the toxin gave an LD 50 of 19 µg/g, 15 µg/g, and 16 µg/g in three experiments.

9. There is little if any loss in toxic activity of nematocyst contents after storage in the frozen state over a six-month period.

10. The toxicity of the supernatant is retained after freeze-drying.

11. Thoroughly washed empty capsules, capsular fragments, and tubes do not appear to have any toxic effect when injected intraperitoneally into white mice.

12. Thoroughly washed empty nematocyst capsules, capsular fragments and tubes, and residues from high speed centrifugation gave negative results when tested with ninhydrin, Biuret, Molisch, and Benedict's reagents.

13. Empty washed capsules, capsular debris, and tubes do not stain with aniline blue nor picrofuchsin which are accepted stains for vertebrate collagen.