Lampreys abound in the Ribble. Some of them, of the large species
(_Petromyzon marinus_), weigh three and four pounds each, [12] but
owing to a prejudice against them (I suppose on account of their
ugliness) they are seldom eaten. I will illustrate this prejudice
by giving the remark of a keen fisherman to myself, on my saying
that I should eat a large one I had just caught. "Well," said he,
"if you can manage to eat such a thing as that, you would not
stick at devouring a child in the small-pox." This, if not an
elegant, was at least a forcible expression of his opinion on the
subject, and this dislike of them is almost universal in this
neighbourhood. (Jan. 17th 1832.)
"An Old Angler," in the "Magazine of Natural History," having
questioned the assertion of Sir Everard Home that the Lamprey was
hermaphrodite--in fact, that all were spawners and emitted eggs--
the following was addressed to the "Magazine of Natural History":--
When I had the pleasure of writing to you before, I had either
overlooked or forgotten the queries of "An Old Angler" respecting
the Lamprey. However, your remarks have induced me to pay a little
more attention to the subject. I can now confirm in the strongest
and most conclusive manner the supposition of "An Old Angler" that
the sexes are as distinct in the Lamprey as they are in the Cod or
Herring. How so distinguished an anatomist as Sir Everard Home
fell into such a mistake, it is not for me to say; but I am as
certain that the sexes are distinct in the Lamprey as that they
are so in any other animal, and I will now give my reasons for
making this positive assertion.
On the 8th of May, chancing to cross a small stream, I saw a
number of Lampreys in the act of spawning, and remembering the
queries of your correspondent, I stood to watch their motions.
After observing them for some time, I observed one twist its tail
round another in such a manner, and they both stirred up the sand
and small gravel from the bottom in such a way, as convinced me it
was a conjunction of the sexes. However, there were so many of
them together, and they kept so continually moving about, that I
could not single out the two individuals, and thus ascertain
whether they were male and female; but I felt so desirous of being
able to set this question at rest, that I went again next morning,
and was fortunate enough to find only two, a male and a female. I
then witnessed several sexual conjunctions, during which the sand
and small gravel was stirred up by them, and each of which was
followed by the ejection of a jet of eggs from the female. I then
caught them both, and dissected them. The sexual organ in the male
was projected above a quarter of an inch, and the body filled with
milt; the female, although she seemed to have shed a considerable
quantity of her spawn, had still a tolerable stock remaining.
I frequently afterwards witnessed the same thing, and always found
the same difference of sexes; in fact, there was generally no
difficulty in distinguishing the male from the female, without
taking them out of the water: the latter might be readily known by
the enlargement of her body, and the former by a still more
incontestable token. I have been induced to describe this more
minutely than I otherwise should have done, in consequence of the
mystery in which the propagation of fish has been wrapped
hitherto; and I am not aware that what I have described has been
witnessed by anyone before--at least I don't know that it has been
recorded.
I caught half-a-dozen Lampreys, four males and two females, and
preserved them in spirits, and these I now forward to you.
I am unable to give the same information concerning the large
Lamprey, having never seen it in the act of spawning; but I have
repeatedly caught both milters and spawners of species with the
milt and roe as distinctly visible in them as it is in the Salmon
or any other fish.
I am of opinion that the _P. marinus_ and the _P. fluviatilis_ are
distinct species, for the following reasons:--1st. Because the
latter stays with us the whole year, while the former only ascends
the rivers to spawn, and then returns to the sea immediately. 2nd.
Because fish that are in the habit of descending to the sea, never
(unless the small Lamprey be an exception to the general rule)
arrive at maturity [13] until they have visited it; and, 3rdly,
because there are no intermediate sizes (at least in the Ribble)
between the one which, although only six or seven inches long, and
an ounce in weight, is yet capable of propagation, and the one of
a pound. Not having one of the larger kind to refer to, I am
unable to point out any specific difference of form. (May 2nd,
1832.)
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