'Pairing' Wrasses: That's Not How Any of this Works!

[eatbreakfast]

I assume wrasses dont transform unless there are others nearby? There is a tank with a single female leopard wrasse where I worked and I assume it will stay female? How can you tell between sub male and female?

Nope. It's hit and miss with leopards. I've seen females transition, even when they were the only one in the tank, and I've seen others stay female in the same circumstances.

 

[MnFish1]

When the primary natural drive is to become male so you can breed with females unless another male can stop you, bad things happen...

Sorry - I still don't understand. The primary natural drive is to reproduce - its not to become male. So - if there are 2 fish in a tank - why would both ever become male? Thinking on it further - if the primary natural drive is to become male - there wouldn't be any females at all (ie what's the difference between having 2 fish in a tank both becoming male and having 10 fish in a tank and all of them becoming male (if thats the primary drive). Not trying to argue - just trying to figure out what you're saying)

 

[eatbreakfast]

Sorry - I still don't understand. The primary natural drive is to reproduce - its not to become male. So - if there are 2 fish in a tank - why would both ever become male? Thinking on it further - if the primary natural drive is to become male - there wouldn't be any females at all (ie what's the difference between having 2 fish in a tank both becoming male and having 10 fish in a tank and all of them becoming male (if thats the primary drive). Not trying to argue - just trying to figure out what you're saying)

Actually, the primary drive is "stay alive" followed by "reproduce." This can clarify things as wrasses are social animals and the BEST chances to achieve both is to be the dominant individual in the social hierarchy, so there is a stronger drive to be bigger, faster, stronger-i.e. male, than to stay status quo. So whenever there is a percieved opportunity to advance to male, fish will take that. However, there is greater competition the further up a fish goes in the social hierarchy, and greater consequences for success and failure.

 

[MnFish1]

Actually, the primary drive is "stay alive" followed by "reproduce." This can clarify things as wrasses are social animals and the BEST chances to achieve both is to be the dominant individual in the social hierarchy, so there is a stronger drive to be bigger, faster, stronger-i.e. male, than to stay status quo. So whenever there is a percieved opportunity to advance to male, fish will take that. However, there is greater competition the further up a fish goes in the social hierarchy, and greater consequences for success and failure.

Thanks - Maybe I didnt make myself clear. Why would 2 fish in a tank become male (I understand that perhaps the more dominant one would become male) - what I dont understand is why (in the absence of a female) - why one wouldnt remain female (so they can stay alive AND reproduce).

 

[eatbreakfast]

Thanks - Maybe I didnt make myself clear. Why would 2 fish in a tank become male (I understand that perhaps the more dominant one would become male) - what I dont understand is why (in the absence of a female) - why one wouldnt remain female (so they can stay alive AND reproduce).

It doesn't understand that they are the only 2 specimens. A male can spawn with several females in a relatively short time. Females don't have the same luxury. As far as any specimen is concerned, it is moments away from meeting up with a larger social group. So while it has excess food resources, no predator pressure, and not as much social hierarchy, it will try and take advantage of this opportunity to transition.

 

[A Toadstool Leather]

Nope. It's hit and miss with leopards. I've seen females transition, even when they were the only one in the tank, and I've seen others stay female in the same circumstances.

If a lone wrasse switches sex are there noticable differences in behavior?

 

[eatbreakfast]

If a lone wrasse switches sex are there noticable differences in behavior?

A little boldee. More inclined to display at it's reflection. More aggressive to similar species.

 

[MnFish1]

It doesn't understand that they are the only 2 specimens. A male can spawn with several females in a relatively short time. Females don't have the same luxury. As far as any specimen is concerned, it is moments away from meeting up with a larger social group. So while it has excess food resources, no predator pressure, and not as much social hierarchy, it will try and take advantage of this opportunity to transition.

I see this in the wild - I dont understand the dynamic in a tank. I think I'm missing something in the translation

 

[eatbreakfast]

I see this in the wild - I dont understand the dynamic in a tank. I think I'm missing something in the translation

They don't know that they are in a tank. As far as they are concerned the limitations of the tank could be gone at any moment.

 

[saltyhog]

Think of it this way. In the tank their competition is greatly reduced. Instead of multiple males suppressing their transition there is only one...or none.

When you have a species where one male mates with multiple females the competitive advantage for the species is for the most vigorous, superior male to father the offspring. That's why the competition exists and why all the females want to be males.

 

[MnFish1]

It doesn't understand that they are the only 2 specimens..

with apologies - these words make no sense in the English language....

 

[MnFish1]

They don't know that they are in a tank. As far as they are concerned the limitations of the tank could be gone at any moment.

Well - I was under the impression - that horomes/chemiclals released by the fish communicated which should be male an which female. Unless you have a reason to suggest otherwise - there is no sense to having all males in a tank - whether it is 2 fish or 15 fish.

 

[MnFish1]

They don't know that they are in a tank. As far as they are concerned the limitations of the tank could be gone at any moment.

How do you know this? because it makes no physiologic sense.

 

[eatbreakfast]

with apologies - these words make no sense in the English language....

Even though we as humans may understand that there are only 2 specimens in the tank, the fish don't understand that.

Well - I was under the impression - that horomes/chemiclals released by the fish communicated which should be male an which female. Unless you have a reason to suggest otherwise - there is no sense to having all males in a tank - whether it is 2 fish or 15 fish.

Not with wrasses. They communicate through social interactions, so if they aren't being dominated enough, they take that as a queue to advance to male. For most wrasses, such as fairy, flasher, Halichoeres, even if there is a male already in the tank, females tend to transition to male.

How do you know this? because it makes no physiologic sense.

Experience in watching their behavior and physiology.

 

[saltyhog]

Well - I was under the impression - that horomes/chemiclals released by the fish communicated which should be male an which female. Unless you have a reason to suggest otherwise - there is no sense to having all males in a tank - whether it is 2 fish or 15 fish.

And those hormones in these genera seemed to be controlled/affected by social interaction. There is less competition in a tank with one other male of the species (or none) than there is in a large community in the ocean where other females may exist that are larger, older or stronger.

Clown fish are another example of this principle. All are born male and the ones who are dominate transition to female.

The fish don't transition to male because of reasoning. Our tanks are not the environment their physiology was designed for.

 

[MnFish1]

And those hormones in these genera seemed to be controlled/affected by social interaction. There is less competition in a tank with one other male of the species (or none) than there is in a large community in the ocean where other females may exist that are larger, older or stronger.

Clown fish are another example of this principle. All are born male and the ones who are dominate transition to female.

The fish don't transition to male because of reasoning. Our tanks are not the environment their physiology was designed for.

I know - but for example with clown fish - one ends up being a male and one a female. Its not that I don't believe you and @eatbreakfast but it still makes no sense. I guess I just have to accept that some things dont make sense

 

[MnFish1]

And those hormones in these genera seemed to be controlled/affected by social interaction. There is less competition in a tank with one other male of the species (or none) than there is in a large community in the ocean where other females may exist that are larger, older or stronger.

Clown fish are another example of this principle. All are born male and the ones who are dominate transition to female.

The fish don't transition to male because of reasoning. Our tanks are not the environment their physiology was designed for.

Here is a nice article that explains the difference between wrasses and clownfish sex changes - and the theory why they happen (in case anyone is interested)
https://www.open.edu/openlearn/science-maths-technology/biology/why-do-some-fish-change-sex

 

[evolved]

I assume wrasses dont transform unless there are others nearby? There is a tank with a single female leopard wrasse where I worked and I assume it will stay female? How can you tell between sub male and female?

Nope. It's hit and miss with leopards. I've seen females transition, even when they were the only one in the tank, and I've seen others stay female in the same circumstances.

+1
All Macropharyngodon species are sexually dichromatic, so there are always visual clues to judge female or sub male.

 

[The Reefing Scotsman]

Just a bit behind on this one... sorry.

Anampses transitions are definitely the most inconsistent, and there's very little chance of offering any decent odds on predicting it. Keeping them in a group is a bit safer like Macropharyngodon, but there are still no guarantees.

Thanks for the reply .

In the meantime a friend of mine had a male / female "pair" of Anampses neoguinaicus become two males and try and kill each other .

A rather elegant, if violent proof of the theory.

 

[Brian1f1]

+1
All Macropharyngodon species are sexually dichromatic, so there are always visual clues to judge female or sub male.

Does anyone have any photos of the stages of bluestars transitioning? I’ve searched and can’t find any. I’ve had two small females in a 125 for about six months. Lots of growth, a few vicious spats that have completely resolved within days (odd to see). One female is noticeably larger than the other, but colors appear identical thus far.