276 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
through an aerating apparatus similar to that described above, to fit it for hatching 
purposes. 
These methods, if carried out rigorously will assure the success of hatching out the 
eggs of the sturgeon to the extent of many millions, so that the chances of survival of 
great numbers of protected young may be reasonably counted upon, and thus enable 
the Fish Commission to increase the source of a good supply, the value of which can 
only be appreciated by those who have investigated the magnitude of the sturgeon 
fisheries of the United States, and the large annual value of the caviare now very ex- 
tensively exported to Europe. 
15. SKINNING THE STURGEON AND PREPARING THE FLESH FOR MARKET. 
Except the eel and cat-fish the sturgeon is one of the few fishes which is skinned 
and dressed before it is sent to market.- Attempts have been made to convert the 
skin of the sturgeon into leather; the microscopic structure of the integument of this 
animal is in some respects very favorable to its conversion into leather, since the 
deeper layer of the skin contains a great abundance of fibrous tissue. The presence 
of the great dermal bony bucklers or scutes, however, interferes with the necessary 
processes of manipulation in tanning, so as to leave holes in the tanned skin. These 
bucklers are so firmly embedded and form such an integral part of the skin that it is 
not probable that it can be successfully or profitably converted into leather. 
The fish, when brought in to the floats to be opened to remove the caviare and 
dressed, are laid upon the side and the operator proceeds to cut about eight short 
longitudinal slits in pairs on either side of the middle line in the inferior part of the 
abdominal walls. These are very quickly made by thrusting the point of the butcher’s 
knife through the abdominal walls with a rapid stabbing motion. 
The abdomen is then slit open along a line midway between the four pairs of short 
slits, from a point just behind the inferior part of the pectoral arch backward to the 
anus. The short slits which are thus left near the edges of the great flaps formed by 
slitting open the abdomen, serve as “hand holds” and assist in a most important way 
in removing the skin, which is removed from the flesh of the trunk and anterior cau- 
dal region by freeing it first along the ventral and lateral region and at last along 
the back. 
The head is removed with a cleaver, cutting through the fore part of the trunk and 
so as to remove the lower part of the pectoral arch and pectoral fins. The tail is also 
cut off across the narrow peduncle. The tail is often cut ofl: first in order that the fish 
may bleed freely from the caudal aorta and die quickly, as the powerful tail, if the 
fish is still alive and struggling, may strike the operators disagreeable or even dan- 
gerous blows. The heads, tails, skins, and viscera are carried off from the floats, where 
the fish are dressed, by small vessels which gather this offal and take it to guano fac- 
tories where the oil is extracted and the remaining flesh, bones, and cartilage dried for 
the purpose of converting it into guano. 
After the removal of the skin the carcass of a large female sturgeon will weigh 
about 100 pounds, usually somewhat less. The value of the dressed carcass varies, 
according to the condition of the market, from 3 to 10 cents per pound. The dressed 
carcasses are packed in ice for shipment in the usual way. When the shippers are 
