Leeches?

Killfrenzy · Post by **Killfrenzy** » Sat Dec 16, 2006 1:44 pm

How to get rid of them, specifically.

A couple of months ago, the manager of the store I worked at had ordered several red crayfish. The day after they arrived, the manager mentioned that some were acting sluggish and one had died already. I took a look, observed mass quantities of leeches on the crayfish, and showed the manager, who promptly went to soak her hands and all the nets in steaming hot water (and have a word with the wholesaler over the phone).

The big fish disease book mentioned manual removal and alcohol swabbing, but I was not about to attempt manual removal of over a hundred leeches on each crayfish (not exaggerating, I counted afterwards), so we went with very quick dips and shaking in alcohol, followed by soaking in clean water. It killed all the leeches on the crayfish, we treated that tank with copper, and put the crayfish elsewhere. The crayfish were already in rather bad condition, and only one survived the next two days (it was the healthiest and most active one to begin with, lasted another week and was sold, so I know absolutely nothing about its current condition).

So my first question, is there a better way of removing a leech infestation from crayfish?
(There HAS to be, right? Alcohol dips sounded kinda brutal at the time, but we were out of ideas, and that was a LOT of leeches)

Secondly, what about removing leeches from other invertebrates? A big, otherwise healthy crayfish might be able to tolerate an alcohol dip, but I don't think tiny shrimp will fare well.

badflash · Post by **badflash** » Sat Dec 16, 2006 3:58 pm

Are you positive it was leaches and not some other type of worm? Crays eat leaches and are used to get rid of them. I'm sure no expert, but I've not heard of a leach infestation in crayfish before.

Killfrenzy · Post by **Killfrenzy** » Sat Dec 16, 2006 4:31 pm

About half cm to just under one cm long, light brown, suckers on each tip, moved in typical leech style (both inchworming with only the suckers in contact consistently with the crayfish, and that thing where they anchor one sucker, and flail around trying to find something to cling to), and congregated on the joints of the crayfish.

Cableguy · Post by **Cableguy** » Sun Dec 17, 2006 12:45 pm

Killfrenzy wrote:About half cm to just under one cm long, light brown, suckers on each tip, moved in typical leech style (both inchworming with only the suckers in contact consistently with the crayfish, and that thing where they anchor one sucker, and flail around trying to find something to cling to), and congregated on the joints of the crayfish.

sounds like leeches to me

Veneer · Post by **Veneer** » Mon Dec 18, 2006 4:34 pm

Did they look like this? If so, they're probably crayfish worms (Branchiobdellidae). The great majority of these worms, generally unable to survive beyond crayfish, are not parasitic. Though most branchiobdellids are referred to as commensals (that is, they live without injuring or benefiting their host), the relationship between crayfish and at least certain crayfish worms may in fact be mutualistic (both organisms benefit).

As this paper asserted:

Branchiobdellids of the genus Cambarincola exploit their hosts through a variety of mechanisms; however, an effect of branchiobdellids on crayfish has not been conclusively demonstrated. We investigated whether branchiobdellids positively affect the host crayfish Cambarus chasmodactylus in the New River, North Carolina. In a laboratory experiment, we placed 0, 3, or 6 branchiobdellids on C. chasmodactylus and observed a significant effect of branchiobdellid presence on both growth and mortality of host crayfish; crayfish with branchiobdellids exhibited faster growth and lower mortality with increasing branchiobdellid density. A tracer experiment demonstrated that branchiobdellids feed on items found in the branchial chamber of C. chasmodactylus. We hypothesize that such feeding activity by branchiobdellids reduces fouling of crayfish gills by epibionts and particulate matter and could lead to the reduced mortality and increased growth rates observed in the laboratory experiment. Specifically, Cambarincola may improve the ventilatory and excretory fitness of C. chasmodactylus by cleaning gill filaments.

In other words, these branchiobdellids seem to keep the gills of the crayfish species at hand free of debris accumulation. Balance this fact against findings that other species may serve as facultative parasites or otherwise incidentally wound gill tissue when feeding. Branchiobdella hexodonta and B. astaci (both limited to the branchial chambers) are nonetheless the only bona fide parasitic forms I know of.

All of the external branchiobdellids I am aware of seem to feed exclusively on diatoms and the like.

Killfrenzy · Post by **Killfrenzy** » Mon Dec 18, 2006 5:21 pm

Interesting.

That looks to be about the right size and shape, with very similar movement. The ones I observed in the store did not have visible digestive tracts, however, I had no means of magnification at hand, and essentially resorted to mashing my face up against the glass, so that might explain that.

Also, the crayfish were still alive, but the worms occured in similar densities compared to that video. The rare ones on the larger pieces of shell were mostly just moving across them, whereas most stayed around the legs and underside. They did the same thing where they attached one sucker, and waved the other end around, but not all at once like in the video.

In any case, that's likely closer than my original exclamation of "LEECHES!"

Terran · Post by **Terran** » Mon Dec 18, 2006 6:07 pm

Awsome video Veneer thanks for posting it....

iturnrocks · Post by **iturnrocks** » Tue Dec 19, 2006 9:55 am

I would think any parasites attached to an invertebrate would be removed upon a successful molt.

For removing leeches from turtles, i soak them in tap water. I imagine that would have bad results for something breathing with gills however.