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V. Miscellaneous Observations on Animal Heat. 
By John Davy, M.D., F.R.S., L. and E. 
Received November 2, — Read December 14, 1843. 
I, On the Temperature of the Pelamides ( Pelamys Sarda, Cuv. and Val.). 
FlSHES generally are commonly considered as cold-blooded. In a work published 
in 1839, I have stated particulars tending to show, that this commonly received 
opinion is not universally correct, and that fishes of the genus Thynnus, with some 
others of the Scomber family, may be inferred to be an exception*. 
As this inference was founded chiefly on the reports of fishermen, it appeared very 
desirable to determine by actual thermometrical measurement what is the exact tem- 
perature of fishes of this family. 
Hitherto, although watching for opportunities, and promised the aid of friends 
favourably situated, I have not been able to make any observations of the kind 
required, excepting on one species of these fishes, the Pelamides, the Pelamys Sarda 
of Cuvier and Valenciennes. The Pelamides, like most of its congeners, is migra- 
tory in its habits. In the early part of summer it appears in the sea of Marmora and 
the Bosphorus, and in August in the Black Sea, from whence, after spawning, it 
returns in September and October, on its passage to the Mediterranean. It is caught 
in the same manner as the Tunny. 
In June 1841, whilst at Constantinople, I visited a fishing station for this fish, in 
an inlet of the sea of Marmora, and was present when a small capture was made, 
enabling me to ascertain the temperature of four specimens. This was done the in- 
stant they were taken out of the water, being in a boat alongside the net, by intro- 
ducing a thermometer with a projecting bulb, through a small incision, into the 
muscle of the back, about an inch and a half, and immediately after into the cavity of 
the abdomen. In three instances, the thermometer in the back rose to 75° Fahr. ; in 
one to 74° ; in all, in the abdomen it rose to 73°. The Pelamides were of moderate size, 
between two and three feet long. The air at the time was 71° ; the sea at the surface 
68° ; but probably at the depth from which the fishes were taken, it was a few degrees 
lower, the descending current of the Bosphorus then being, where coldest, at 62°. 
Supposing that the water from which they were taken was 62°, — and it might have 
been lower, as the Pelamides swim in deep water, — the temperature of this fish would 
appear to be about 12° above the medium in which it swims, and at least 7° above 
that of the surface. 
* Researches, Physiological and Anatomical, vol. i. p. 218. 
MDCCCXLIV. 
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