BULLETIN OF THE UNITED STATES FISH COMMISSION. 197 



19 DIRECTIONS FOR €Off>EECTIIYG AND PRESERVING FISH. 



By TABLETOK H. BEAN. 



1. Wash the fish thoroughly in water to remove the slime and dirt 

 that are almost invariably present upon them, not omitting the inside 

 of the mouth and the gills. In cleansing fish that have a tough, scale- 

 less skin, or such as have the scales firmly fixed, use a stiff paint brush 

 or a scrubbing brush; for thin-skinned fish and such as have deciduous 

 scales a softer brush must be taken. Some fish are covered plentifully 

 with tenacious mucus that is with great difficulty removed by water 

 alone ; in such cases a solution of two tablespoonfuls of alum in a pint 

 of lukewarm water will be found efficacious. 



2. It is often necessary to preserve fish that are stale, or partially 

 digested, and offensive to the smell. Such examples may be thoroughly 

 disinfected by the use of the disinfecting solution of chloride of soda. 

 Use a tablespoonful of the solution in one pint of water. With this 

 wash the gills and pour it into the mouth and stomach, allowing it to 

 return by the mouth. 



3. Inject alcohol in the mouth and the vent to preserve the viscera. 

 Make small incisions in the belly and in thick parts of the body to allow 

 the alcohol to penetrate the tissues. It is often necessary to remove 

 the liver, stomach, and intestines from large fish and to preserve these 

 separately, numbering them so as to correspond with the fish from which 

 they are taken. 



4. It is a good plan to keep freshly collected fishes in weak alcohol 

 for a day or two ; a mixture of two parts of 95 per cent, alcohol to one 

 of water will answer for this temporary immersion. Some species are 

 exceedingly soft and flabby, falling to the bottom of a glass jar or other 

 receptacle, becoming partly imbedded in their own mucus, and rapidly 

 disintegrating in consequence. Such specimens should either be sus- 

 pended in the alcohol by a thread or string from the neck of the jar or 

 the hook sometimes found on the inside of the stopple, or a bed of excel- 

 sior or muslin should raise them from the bottom ; these are necessary 

 precautions which will prevent many losses. Alter the fish have been 

 kept for not more than two days in the weak alcohol, transfer them to 

 a mixture of three parts of 95 per cent, alcohol to one of water. Ordi- 

 narily this latter will preserve specimens that are not crowded too much 

 at least three months; some, of course, will remain in good condition 

 still longer; but, generally, three months will reduce the preservative 

 power of the liquid so far as to make a renewal of alcohol necessary. 

 The tendency with many collectors is to overcrowd specimens, and, as 

 a result, museums frequently receive a lot of half-rotten material which 

 is too valuable to be thrown away and is yet always a source of trouble 

 and disappointment. Ajar, tank, or case of any kind should never be 



