References: (1) Owen, G. 1955. Use of propylene 

 phenoxetol as a relaxing agent. Nature 175: 434. (2) Owen, 

 G., H. F. Steedman 1958. Preservation of Molluscs. Proc. 

 Malacol. Soc. London 33: 101-103. (3) Smith, J. L. B. 1947. 

 A neutral solution of forma ldahyde for biological purposes. 

 Trans. Roy. Soc. S. Africa 31: 279-82. 



(2) Sevin and rapid freezing : For full narcotization 

 and killing of muricid and naticid gastropods. This is the 

 only known method available to date which makes possible killing 

 and preservation of fully relaxed muricids. 



Prepare a stock solution of Sevin (1-naphthyl N-methyl 

 carbamate, available from Union Carbide Chemicals Co.) as 

 follows and store in refrigerator in tightly stoppered glass 

 bottle. Add 0.1 g Sevin crystals to 15 ml (11. 6g) acetone. 

 To prepare a solution of 10 ppm. of Sevin add 1.16 ml of stock 

 solution of Sevin to one liter of seawater and mix thoroughly. 

 This must be prepared daily before use as it does not keep. 



Narcotization : Place animals in the Sevin solution, 

 10 ppm. at room temperature for 1 hour, preferably keeping 



E-nimals out of touch with each other and in the case of gastro- 

 ods, upside down, and in a depth of fluid at least thrice the 

 eight of the specimens. After 1 hour transfer the animals to 

 a fresh solution of Sevin and leave them in it for 3 hours. 

 lEmploy a salinity of seawater in which the animals normally 

 live. Slightly better narcotization is sometimes obtained if 

 the second change of Sevin is held in 1 atmosphere of CO2, 

 and if a salinity some 30/00 below the environmental salinity 

 is employed. 



Killing : Remove relaxed animals from the Sevin solution 

 one at a time and place the extended soft parts (if possess 

 exoskeleton) , or the maximum flat surface of non-shelled forms, 

 against the surface of a block of dry ice held in a deep freezer 

 or insulated chamber. Insulate the preparation and leave for 

 24 hours or more. Adding chipped dry ice around specimens 

 accelerates freezing, although this is not always necessary. 

 Many animals have to be frozen for at least 24 hours to entirely 

 eliminate reaction to the preservative. Inject larger specimens 



If or fuller distension. Specimens may be held in the frozen 

 state for long periods provided they are not allowed to desiccate. 



I Freshly thawed, relaxed, unpreserved snails are ideal for 

 detailed anatomical study since the organs retain color, texture 

 and pliability characteristic of living relaxed tissues and take 



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