Any fish biologists out there???

Hondo · 04-12-2009, 11:36 AM

I caught a twelve-inch brookie at Harriet Lake yesterday. First brookie I've caught since I was a kid. She felt kinda soft in the middle, and she was pretty fat, so I was excited to see what strange thing I might find inside her. Turns out, she had what I believe to be the beginning of eggs forming inside her. They were real small, and cream-colored.

This wasn't the strange thing, though. Her large intestine was about six times wider than any I've ever seen in a fish, and it (along with her stomach) was full of tiny clam-shaped things, I'm thinking fresh-water clams?

I'm curious if anybody knows why this fish ate these clams?
Are they a parasite of some sort that I should be concerned about?
Can I eat the fish? (It is in my freezer now.)

Wild Chrome · 04-12-2009, 02:20 PM

Pictures would help.

Jedcraft · 04-12-2009, 02:48 PM

Clams or snails?

Hondo · 04-12-2009, 04:18 PM

Looked like clams...not the shape of snails...I didn't empty the contents of the intestines, a few of the clam-shaped things fell out when I cut the head off...I'll see if I can provide pictures...the insides of the fish are out in the trash.

will try to post picture tomorrow...

wilsonriverfisher · 04-12-2009, 05:50 PM

are you sure its not a brown

? I have not caught a brook

in harriet lake only caught browns, rainbows and cutthroats..

Mike

laxmike11 · 04-12-2009, 06:25 PM

there are brookies in harriet

newbergfishjunkie · 04-12-2009, 07:09 PM

Possibly a periwinkle?

Smalma · 04-13-2009, 06:12 AM

There are a number of freshwater clams and mussels found in PNW waters. So yes they mystery food item could well be a clam.

One of the clams that is sometimes found in the stomach of trout is a smallish clam (about the size of a cherry pit and pale in color). Rarely find a single clam in a the stomach of a trout (always in lakes); when they are feeding on them they seem to gobble up several of thems. Have found as many as two dozen in a single fish.

Tight lines
Curt

SandyRiverFisher · 04-13-2009, 07:30 AM

Ive seen the tiny clams in trouts belly contents before as well, but usually fish out of lower elevation lakes and ponds. Never gave it much thought until i read this post. Tried to google it thinking I could find some images of what ive seen. the only thing that amazes me more than what you can find on google, is what you cant. We've also seen the same or similar tiny clams in hydric soil(mud) while re-planting riparian areas, so I would imagine they live in the mud at the bottom of the lake. Im no biologist, but I would say they are not parasites, dont worry and go ahead and eat your fish. Ive eaten trout that have had these in their bellies and Im fine.

Hondo · 04-13-2009, 08:42 AM

Here's a picture...please disregard the tiny black specks on the outside of the stomach (which is in the bottom of the pic) and the intestine (up top in the pic)...the black specks are coffee grounds I couldn't get rid of. The tiny things at the very top are the clams...the intestines and stomach were stocked full of these little guys.

Hondo · 04-13-2009, 08:49 AM

One more pic for you...my son caught a monster 12-lb. rainbow in Trillium Lake late in the season last year...this one had a bunch of what looked like oats or some type of weeds in it's system...what was weird here is that the yellow plant matter wasn't in the fish's digestive system. Instead, it was around the outside of the organs, in the lower part of the belly cavity. Other than this, the fish looked quite healthy! We ate it, and we used the eggs to make bait.

Wild Chrome · 04-13-2009, 06:05 PM

The bottom photo/fish looks like parasites to me; maybe some type of fluke?

Hondo · 04-14-2009, 07:34 AM

Hello, everybody...I called ODFW and e-mailed a picture of the big trout to fish biologist. He showed it to a few of his colleagues, and they all agreed that the yellow "oats" were the egg skin or skein, not sure which, from the prior year. Apparently, the fish will re-absorb this stuff over time, but sometimes it doesn't all get re-absorbed...

Thanks for the input on the clams...the same guy at ODFW concurred and said this is a normal part of the trout diet. We will happily eat the fish.

Smalma · 04-14-2009, 08:23 AM

I agree that the "oats" in the large trout are re-absorded eggs from the previous year. It is not unusual to see that in mature trout in lakes that lack spawning tributaries. Without a good flowing creek rainbows and cutthroat can't spawn normally. If there are good spring upwellings along the shore line the females may attempt to spawn in the lake and "dump" their eggs but there is virtually no chance for the eggs to survive. If they can not spawn or dump their eggs they will slowly re-absorb the eggs - such eggs depending on where the fish is in the process turn yellowish in color and collapse ultimately looking like those shown in the picture.

For those that might be interested one some times see the same thing in summer steelhead. In this case it is more a survival strategy for a fish that has run out of the needed fat/oils reserves to stay alive. As a last resort the adult fish begin re-absorbing their gonads. It is more commonly seen in the females but males may do the same. Typically such fish are seen when conditions are such (warmer than normal temperatures, etc) that it takes more energy to stay alive than the fish brought with them from the ocean.

The female that have re-absorbed their eggs typically look much like re-conditioned kelts. They are often thin fish that ocean bright and are some times confused by anglers as a fresh run fish.

Tight lines
Curt

Hondo · 04-14-2009, 08:25 AM

Thanks, Curt! (and SandyRiverFisher, for the clam info...)

CWOregon · 04-14-2009, 08:43 AM

Quote:

Originally Posted by Hondo

I caught a twelve-inch brookie at Harriet Lake yesterday. First brookie I've caught since I was a kid. She felt kinda soft in the middle, and she was pretty fat, so I was excited to see what strange thing I might find inside her. Turns out, she had what I believe to be the beginning of eggs forming inside her. They were real small, and cream-colored.

This wasn't the strange thing, though. Her large intestine was about six times wider than any I've ever seen in a fish, and it (along with her stomach) was full of tiny clam-shaped things, I'm thinking fresh-water clams?

I'm curious if anybody knows why this fish ate these clams?
Are they a parasite of some sort that I should be concerned about?
Can I eat the fish? (It is in my freezer now.)

Kind of off subject but a couple years ago a buddy and I caught some brookies out of the Clearwater Forebay #1 up below Diamond and Lemola lakes that had eggs in them. I think it was in June...... I threw the eggs in a little borax and ended up catching a couple summer steelhead on them a couple months later. It was nice because I didnt have any eggs yet that year. The little brookies were great eating too.....