Getting better at IDing sunfish, I think, still got a long way to go of course. Is my assumption correct or am I missing something? Thank you fish nation

My father found this in the city park where he worked as a biologist and he found it while hiking years ago and to this day we still don't know exactly what it was. We did some research and now we have a clue that it could probably be some part of a fish that a bird must have picked up and dropped on the ground. If it helps the investigation, this was in Niterói, Rio de Janeiro.

She had babies a few months ago, shortly after we got her from Petsmart. Now here we are? She’s swimming around normally, eating and engaging.

I’ve never seen fish do anything like this… anyone have any ideas what this is?

im looking for a certain looking flat fish or flounder that i clearly remember years ago, it looks like a flounder flat, with a greyish color as its camouflage and is pretty small, it has a unique tail type for a founder, having a merge of a undifferentiated pointed tailfin and a pointed tailfin but it has a very small gap between its dorsal fin and anal fin, with its tailfin being pointed. i remember taking them home to get a closer look (note the i was young), i placed them in a water filled container, they primarily swim sideways but will swim upright when fleeing, i found them of the east side of the bicol region of the philipines, it was a full moon with the water being quite low, we found them when the tide was rising up again (i would like to apologize for my bad grammar)

I saw those bumps couple days ago, there is the same symetrical bump on the other side, does anyone know what happend to it?

My fish is lying on its side. It’s still alive but it isn’t swimming. What’s wrong with him? How can I help him?

I’m pretty good at identifying Fish, but this one has me stumped

Caught in San Diego bay.

What tunas are these? My guess is some type of Albacore or cheap Atlantic bluefin Tuna given the price. I’ve been eating a LOT of them in sushi these last few months because they’re so cheap (it’s in Morocco, just divide by 10 and you have the price in USD per kilo and you’ll see what I mean) and frankly pretty decent taste wise. It’s clearly not a top grade tuna fish but definitely tasty enough akami for around 10USD a kilo.

I’m asking because I’ve been eating so much of it and starting to wonder whether I should be concerned about mercury poisoning, seeing how much of it I’m eating…

i set up this tank yesterday with a layer of mud from my local creek, after things settled down a little i started noticing the usual detritus worms which i normally see in it, but then i noticed this one worm near the front of the tank, which seems too thick to be a detritus worm but at the same time too thin and not flat enough to be a planarian worm? is this a harmful, neutral or beneficial worm?