448 



REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



[16] 



PERCENTAGES OF FATS AND WATER IN FLESH OF SPECIMENS OF 

 FISH OF DIFFERENT SPECIES. 



It is interesting to observe the connection between the proportions 

 of water and those of fat in the flesh of the fish. In the tissues of fish, 

 as of other animals, as is well known, an increase of fat is generally 

 accompanied by a decrease of water. This is strikingly the case in the 

 flesh of the fish analyzed, as is shown in the following classification, in 

 which the specimens are grouped on the basis of their percentages of 

 fats (ether extract), in oider commencing with the fattest and ending 

 with the leanest specimens. Where more than one specimen was ana- 

 lyzed the average figures are given, as in the preceding classifications. 



SPECIMENS CQjNrTAIlSriNG OVEK 5 PEK CENT. OE FATS. 



o 2 



Kinds of fish. 



Lamprey eel 



Saluion 



Salmon trout 



Pnitter-flali 



Herring 



Shad ■ 



Spanish mackerel. 



Kinds of fish. 



Eel, ealt-Tvater . 



Pomp.ino 



Mackcrtl 



Wbiti'tisli ------ 



Alewilo 



Halibut 



Porgy 



Water. 



Per cent. 

 71.6 



72.8 

 73.4 

 69.8 

 73.0 

 15. A 

 75.0 



Fats. 



SPECIMENS CONTAINING- BETWEEN 5 AND 2 PEE CENT. OF FATS. 



Mullet 



White percli . 

 Sheepshead. . 



Cisco 



Striped bass . 



Masoalonse. 



WenlUisli ... 

 Butrilu-llnh . 

 Brook trout. 



76.3 

 79.0 

 78.6 

 77.7 



SPiSCIMENS CONTAINING LESS THAN 2, THE MAJOliITT LESS THAN 1, PEE CENT. OP 



FATS. 



Smelt 



Black bass .:. 



Skate 



Blackfisli 



Bluelish 



Bod snapper . - 



K.iDgtish 



Pollu.'k 



Ycliuy\' perch - 

 Pikfc perch (') 



Hake 



Flounder (2) -. 



Grouper 



Pickerel (-)..- 



Sea bass 



Pike i)erch (J) 

 Pickerel (■"') .-- 



lied bass 



Tomcod 



Cod -.-- 



Flounder (<■)-.. 



Haddock 



Cusk 



79.4 

 79.8 

 79. 3 

 79.7 

 79.7 

 81.6 

 81.5 

 82.6 

 84.3 

 81.7 

 82.0 



0.6 

 0.0 

 O.h 



0. .'■. 



0.5 

 0.5 

 0.4 

 0.4 

 0.4 

 0.3 

 0.2 



1 Stizostedium canadensis. 

 ^ ParaUchthys dentatus. 



^Esox lucius. 



'^ Stizostedium vitreum. 



^Esox reticulatus. 



8 Fseudopleuronectes americanus. 



From these figures the general decrease of the water with the increase 

 of fat is very apparent, though not perfectly regular, lids might 

 seem to be due sipiply to replacement of the water by fat in the tissues. 

 It will be worth wliile to inquire whether this assumption is borne out by 

 the amdyses. To answer tliis question we should compare different 



Per cent. 

 9.1 



7.5 

 7.0 

 6.5 

 6.0 

 5.2 

 5.1 



2.5 

 2.4 

 i3 

 2.1 



I 



