Senegal bichir fin morphology

[Ponera]

Hey I am curious about pectoral fin morphology. I have 3 of them and they each have different morphologies:

One is kind of plumate and very oval (top left) another has ones like rectangles pointing down (top right) and another that has ovaloid finds pointing horizonally.

I am curious if this is a result of regrowth of fins or if this is genetic. What do you guys think?

 

[Dr.B]

If you could get some pics it'd be great. I'd probably says genetic.

 

[Ponera]

Pics won't be happening, I'm total ass with a camera and it wouldn't help anyways. All you'd see is what is diagrammed. Do you know if their pectorals change shape when regrown?

 

[Dr.B]

I wouldn't think they'd be too different if re-grown.

 

[Ponera]

What do you base this on?

 

[Dr.B]

Well if fin shape is genetic then regrowing back different wouldn't make any sense.

 

[Ponera]

Sure it would. Insects and other arthropods that lose limbs grow them back smaller. Same with lizards that lose their tails and in many cases amphibians that lose limbs. It would also make sense, even if this isn't the case for bichirs, that if regrowing in poor water conditions (ie pet stores) that they would come out shaped differently (= deformed)

It has also been shown that their fin and pectoral girdle morphology is plastic based on useage of the fin (I am referencing this: http://www.cbc.ca/news/technology/w...eal-how-vertebrates-moved-onto-land-1.2748483 ). If their find is repeatedly sniped it would make sense for it to grow in a different shape to prevent further damages (for example in a crowded fish store tank.)

Just throwing that out there, I know there are now long find variants of senegals out there which are genetic so I'm trying to tease apart a bit of what is going on with my three morphologies in the tank.

 

[Dr.B]

Sure it would. Insects and other arthropods that lose limbs grow them back smaller. Same with lizards that lose their tails and in many cases amphibians that lose limbs. It would also make sense, even if this isn't the case for bichirs, that if regrowing in poor water conditions (ie pet stores) that they would come out shaped differently (= deformed)

It has also been shown that their fin and pectoral girdle morphology is plastic based on useage of the fin (I am referencing this: http://www.cbc.ca/news/technology/w...eal-how-vertebrates-moved-onto-land-1.2748483 ). If their find is repeatedly sniped it would make sense for it to grow in a different shape to prevent further damages (for example in a crowded fish store tank.)

Just throwing that out there, I know there are now long find variants of senegals out there which are genetic so I'm trying to tease apart a bit of what is going on with my three morphologies in the tank.

Ok well to be honest with you I was really just talking in general with my previous statements as you have pointed out in your first paragraph there are certain situations where the fin could grow back differently. However I was also unsure to the degree of bite you were trying to suggest. Looking upon your paragraphs I now see you were talking about being almost completely bitten off. I was talking about if it was only partially bitten or nipped. You also mentioned the study performed on them. I was under the assumption that it was more of a one time bite. If being bitten becomes routine then yes naturally the bichir's body will try to counteract that by sometimes growing back differently. However like I said I was under the assumption that it was more of a one time bite. In the study the bichir is continuously forced (not forced, but it makes things easier if it walks like it does) to move like that. As I said before if it is continuous the bichir's body will try to adapt.

 

[jclyde13]

To be honest, I really don't understand what you're getting at here... Fin shape is something I would almost expect to vary among every single individual, the same way shoe size varies in humans.

 

[Ponera]

The link to the study shows the plasticity in the limb structure of the bichirs. Nothing more. That's kind of the point of the thread- how plastic is the fin shape/structure.

I was saying if a fin had to be regrown completely, sorry if that was unclear. I suspect you are right that more minor bites produce similar fin structure to those they are derived from.

I was just giving examples that could easily produce different fin structures and referencing that it is widespread throughout other groups to bolster the notion.

Jclyde, I am just wondering what people's experience is with fin shape in senegal bichirs. Would be neat if someone had one get its fin ripped off and then it regrew normally or abnormally. It's also interesting to find out if it's just the bichirs at my fish stores or if this is more of a species wide deal, so just hearing back about what fin shapes people have encountered would be interested. If you look at the downward pointing square ones and the rather plumate other options (in my OP) you can see they are actually dramatically different. In the case of the downward rectangle ones, the fin rays are rather constricted and the structure supporting it is rather robust all the way to the terminus of the fin.

Maybe, given the demonstrated plasticity of their fin structures, it could have something to do with preferences in how they hunt growing up. I don't know.

Just trying to see if there is more to be learned than just saying "oh genetics move on." Thanks for help guys and sorry if I am being unclear somehow. I guess just post if you have had bichirs with extensive fin damage, if the fin shape changed as a result of regrowth and the variability of your bichir fin shapes (Note: pectorals only)