Here's the follow up in this thread about my impending trip to the vet to do some ultrasound on some of my broodfish size smallmouth bass. The idea was to see if I could see some egg (ovary) development in some of my smallmouth broodfish. I wanted to test my hypothesis that the larger fish are females as I seem to be catching two groups of fish: larger robust fish and much smaller fish albeit healthy looking. However I'm just not seeing any obviously gravid fish like I do in my other species of fish, but I want to move them to their spawning pond ASAP.
Par for the course, I was running late due to some long distance taxidermy errands and was able to capture only 5 fish in a short amount of time to make my appointment. Only one smallmouth was distinctly larger than the rest.
Here are two after removal from the hauling tank in the process of being sedated in a five gallon bucket by some Finquel.
Here are Dr. Jennifer Lortie and I attempting to get something with the portable ultrasound.
Here is a pic of the ultrasound screen which doesn't show well in the photo due to the glare of sunlight.
The ultrasound wasn't very conclusive so Dr. Lortie suggested we try an xray.
Here she is getting one prepped for the x-ray machine.
Here are the two fish on their respective x-ray. Both are labeled # 1 because Dr. Lortie was shuttling back and forth to clients to accommodate me and was bit rushed. LOL It's obvious they are different fish as one is bigger than the other. Note how well the swim bladder sticks out!
Here is the larger of the two:
Dr. Lortie hasn't done much with fish yet, but believes we may be seeing some ovary development in the larger fish up to the urogenital opening, and whatever they are do appear to be somewhat granular. If they are ovaries I'm struck by the lack of impressive development past the middle of April. Perhaps they will develop faster closer to actual spawning? At least that is the case with my yellow perch.
Or course possibly finding ovaries in just one sample hardly backs up my theory that the large fish are females, but I will keep checking in the main pond as they get closer to spawning time.
BTW one of the bass spit up this partially digested frog or toad just before I put all five into the brood pond. It may have been the smaller of the two as Dr. Lortie was sure she could see something in the stomach of the fish. Sorry it's so blurred; I'm not sure what happened. The head and eyes are in the bottom of the picture pointed down.
Next I will catch several fish, sedate them and get close ups of the urogenital openings. I was planning on doing so with the fish from today but forgot to. I think I did see a difference in at least one of the fish having more of keyhole shape verses just round vs. another fish.
BTW my vet is a real trooper as I could see most other vets turning me down for this "fishing expedition." She also only charged me $35.00 for all the trouble although she was clearly very busy.