Re: NANFA-- Re: lamprey attack

Christopher Scharpf (ichthos_at_comcast.net)
Sat, 21 Feb 2004 07:59:53 -0400

> As weird sounding as this is, I"m afraid its not that unusual.... it happens
> all the time, especially when lampreys reach high population densities or
> when food is very scarce.

I've never seen this reported in the literature. What is your source for
this, Josh?

The only story of a lamprey "attacking" a human I've seen is from Scott and
Crossman (1973), in which they report that sea lamprey sometimes attach
themselves to long distance swimmers in the Great Lakes, but only after the
swimmer has been in the water a long time and his or her skin temp. is
lowered. Suffice it to say, I would be EXCEEDDINGLY interested in other
credible stories of lampreys attaching to humans.

> THey're opportunistic predators, and if they're hungry enough, they'll attack
> anything -- including a human being.

I would add a disclaimer to the "opportunistic predator" part. Most
parasitic lampreys have specialized feeding habits. Some species prefer
blood, others flesh, fins, bones, or internal organs. Lampreys also attach
to different parts of a fish depending on whether the lamprey prefers bodily
fluids or muscle tissue. According to NANFA member Phil Cochran, large
anadromous lampreys tend to attach to the undersides of their hosts, where
fewer scales, thinner muscles, and more numerous blood vessels allow
lampreys to receive more food for less work. Smaller freshwater lampreys in
shallower waters tend to feed on muscle tissue, and attach to the backs of
their hosts, possible to avoid abrasion against the bottom.

Matt, based on the location of the occurrence you describe, the lamprey must
have been either the short-headed lamprey (Mordacia mordax), or the pouched
lamprey (Geotria australis).

Chris Scharpf
Baltimore
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