Parasite?

[Frank O]

Thanks for the reply. For the past few months when I've been seeing flatfish of this general size and shape, I've been thinking, "Sole? Flounder?"

Then I took this picture at Catalina Island in Southern California in June:

and a knowledgeable long-time dive operator said, "Oh, that's a sanddab!" (I was concentrating on the eyes in this shot, and would have to hunt around to see if I have anything of the body that would show the fins.)

One of the references I ran across while tracking down the parasite referred to it occurring on Pacific sanddabs in our area. But the coloring of the above two fish looks different to me. (Also -- am I correct in thinking that the two flatfish in my pictures are different in that one is left-sided and one is right-sided (not sure what the right term is for this)?)

I agree that the fin rays of the parasite-infected fish are more suggestive of the flounder in your reference picture.

 

[Diver0001]

(Also -- am I correct in thinking that the two flatfish in my pictures are different in that one is left-sided and one is right-sided (not sure what the right term is for this)?)

That's something I *do* know for sure. flat fish can be either left or right eyed. (That's really what they call it...) just like people are left handed or right handed.

R..

 

[archman]

I don't know how up to date my flounder taxonomy is...

Family Bothidae: Lefteye "flounder"
Family Cynoglossidae: Tonguefish
Family Soleidae: Soles

I believe there are some other flounder families too. Most people, even scientists, synonomize "flounder" with "flatfish". The bothids happen to generally look more like "flounder" than the other groups, but I won't penalize my own students for calling a sole a flounder, except on exams. Either the soles or tonguefish (maybe both) are "right-eyed", just like the critter in the closeup pic. The side in which all these various flounder families chooses to consider the "top" is distinct by fish family.

Fishbase would have the most current taxonomy. Someone go check... I'm lazy. :05:

 

[Diver0001]

I don't know how up to date my flounder taxonomy is...

Family Bothidae: Lefteye "flounder"
Family Cynoglossidae: Tonguefish
Family Soleidae: Soles

I believe there are some other flounder families too. Most people, even scientists, synonomize "flounder" with "flatfish". The bothids happen to generally look more like "flounder" than the other groups, but I won't penalize my own students for calling a sole a flounder, except on exams. Either the soles or tonguefish (maybe both) are "right-eyed", just like the critter in the closeup pic. The side in which all these various flounder families chooses to consider the "top" is distinct by fish family.

Fishbase would have the most current taxonomy. Someone go check... I'm lazy. :05:

Let me get this right. You mean that *all* individuals in a particular family are either left-eyed or right-eyed?

R..

 

[Diver0001]

Here's the fishbase taxonomy. How the heck to people remember this stuff?


R..

 

[Frank O]

Most people, even scientists, synonomize "flounder" with "flatfish". The bothids happen to generally look more like "flounder" than the other groups, but I won't penalize my own students for calling a sole a flounder, except on exams.

That's an interesting point. I was just looking at the taxonomy link that Diver0001 posted from fishbase.org, and after checking out the 11 families of ray-finned fishes said to myself, "But where are the halibuts?" Little did I realize (but soon discovered) that "California halibut" is a common name for Paralichthys californicus, which Fishbase calls a "California flounder" and which falls under the family Paralichthyidae, large-tooth flounders -- a family that also includes the Pacific sanddab, Citharichthys sordidus, interestingly enough.

Anyway, thanks for the link, I'll roll up my sleeves and start studying ...

 

[Diver0001]

Little did I realize (but soon discovered) that "California halibut" is a common name for Paralichthys californicus, which Fishbase calls a "California flounder" and which falls under the family Paralichthyidae, large-tooth flounders -- a family that also includes the Pacific sanddab, Citharichthys sordidus, interestingly enough.

They only did that to make the distinction perfectly clear for the casual observer.

When I first started diving I dove intensively (as in my gear was never dry) with my uncle who was a marine biologist at the university where I studied and a bonafide expert in flat fish with some kind of fancy degree about international halibut management.

And even after making two-hundred-and-ninety-seven-billion dives with my uncle (admittedly I didn't ask enough questions) I still see stuff I can't reliably identify.

In any case identifying flatfish is totally hopeless. My uncle used to say that this was the "last bastion of pure white thought".

R..

 

[archman]

Let me get this right. You mean that *all* individuals in a particular family are either left-eyed or right-eyed?

From that fancy link you found, you answered that question yourself! It seems that the Psettotids can have their eyeballs go "either way". I've never heard of this family before; heck I've never heard of HALF these families before.

FishBase is amazing.

 

[Frank O]

So if the sanddabs are in the family of large-tooth flounders (Paralichthyidae), which have their eyes on the left ...

And if my second flatfish above (the one in the closeup of the eyes) appears to have its on the right ...

Does that mean it's not a sanddab? Maybe a sole instead? (I can accept Diver0001's premise that identifying flatfish is hopeless, though I'm still wondering what "pure white thought" is. Is that like pink noise?)

 

[archman]

So if the sanddabs are in the family of large-tooth flounders (Paralichthyidae), which have their eyes on the left ...

And if my second flatfish above (the one in the closeup of the eyes) appears to have its on the right ...

Then it shouldn't be a sanddab. Is the photo reversed?