Re: NANFA-- catfish trematodes

tony (anutej_at_loxinfo.co.th)
Mon, 19 Jun 2000 02:06:47 +0700

I think in the original post they are talking about black carp is 1 of 20 top
cultured fishes and the US [?] market is emerging. If they do not plan to sell
black carp as well why would they mention this? Please correct me if I am wrong
about this.

Tony

nation. Third, there is currently a market for black carp. According to FAQ
statistics black carp are among the top 20 cultured fish in the world. While
it remains true that the current carp market is small in the US, it is on
the rise. Fourth, the trematode problem is not new to the industry. Black
carp have been used in the US since 1980's as a biological control. There is
only one reported escape of triploid black carp, however, this has not been

Jay DeLong wrote:

> > A few questions about this:
> > 1] How does the trematode get to the catfish? Via eating the
> > snail, eating snail
> > droppings, or the parasite leave the snail and actively get into
> > the catfish?
>
> Some trematodes have an immature phase which emerges from the snail, which
> then attaches to, or is passively taken up by, the fish host. They form
> cysts in the tissues of the fish, the fish is eaten by birds, and the
> trematodes mature there, producing eggs which are released in the bird's
> feces and the eggs are ingested by snails.
>
> > If
> > the black carp eat snail with parasite won't it be infected or
> > become the host and become inedible?
>
> Edibility of the carp isn't a concern. If the carp isn't eaten by a bird
> the cycle ends.
>
> > 2] Aren't there other NA fishes [bullheads, buffalos, suckers,
> > perches, etc.] or
> > turtles or birds that can eat snail? Isn't reducing the number
> > of small snail enough to reduce the parasite problem?
>
> I imagine using a known (or potential) piscivore to control the snails is
> not an option to the catfish growers. Also, I kinda think there aren't any
> other effective snail-eating fish species.
>
> I think we're just going to have to spend more money at the grocery for our
> catfish and insist that growers find better ways to run their operations,
> such as covering their ponds with netting to keep the pelicans out.
>
> --
> Jay DeLong
> Olympia, WA
>
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