TR clownfish deformities

[phender]

Has anyone done any research on what causes the common deformities seen in some tank raised clowns. I am talking about blunt faces, under bites, flared gill covers,etc.

Most of my 3 month old baby orange skunks seem to have blunt faces, some more than others. Will their noses grow a little as they get older (like mammals)

Any research on mismarkings? It seems some species are more prone to being mismarked than others.

Thanks

[robthorn]

maybe something to do with larvae water quality?

[JHardman]

To the best of my knowledge no one has done a formal study...

But...

1) The percentage of survival from egg to saleable size for WC (wild caught) versus CB (captive bred, there are not tank raised clownfish as no one catches them in the wild as yound and then raises them in a tank for sale) is vastly different. Estimates are that less than 1% of fish hatched in the wild make it to saleable size. But CB as many as 80% can and often do. So just based the vast numbers difference you are going to see many many more deformed and misbarred fish in a CB sample than a WC sample. Bottom line is that we do not know if WC has the same, less than or greater than percentages for deforms, misbars, etc because we can not compare apples to apples.

2) It is a well known "fact" that malnutrition and poor water conditions can greatly effect misbarring and survival rates in CB fry.

3) It is has been shown that two parents that are misbarred can produce higher percentages of misbarred offspring.

[EdMcNierney]

I don't think the WC/CB survivability rates alone translate into expecting more deformities in CB clowns. The only reason that would occur is if these are deformities that would result in reduced viability in the wild; otherwise they don't matter.

Assume, as you say, that 1% of the wild larvae make it to saleable size, and 80% of the CB ones do (the percentages don't matter). And let's also assume that 10% of all clown larvae have deformities. If I started with 4,000 wild larvae (400 of which are deformed), 40 will survive to saleable size and 4 will be deformed. To get 40 saleable CB fish I only need to start with 50 larvae, 5 of which are deformed; of those 5, 80% will live, so I'll still end up with 4 deformed fish.

Either way you end up with the same percentage of deformed fish; to produce a particular TOTAL number of saleable fish you need to start with a lot more WC larvae, but the final percentages are the same.

If, however, these deformities cause some competitive disadvantage to the fish in the wild, AND that disadvantage is not present or reduced in captivity, then one would expect a difference. Off the top of my head, the only thing I can think of is something that would make the WC clown more susceptible to predation, since things like difficulty breathing, trouble eating, etc. wouldn't matter and a vulnerability to disease might actually be MORE troublesome in captivity.

I'm not saying there isn't a difference, just that the different survivability ratios by themselves wouldn't cause it.

[Luis A M]

There are also specific differences.Ocellaris are frequently misbarred,frenatus seldom.Clarkii few times but some show blue eye margins.Wild WB maroons come often misbarred.

[robthorn]

luis what clowns are you breeding?

[JHardman]

You hit the nail on the head, the deformities are a disadvantage in the wild and even the tank but much less so in a tank. The vast majority of the deformities I see are head/mouth related followed by fin deformities. Both of these impact survival, i.e. feeding and fleeing.

In a tank, the food is "trapped" in a small area and the fish neither have chase or "hunt" their food, just get it into them. Aggression is also much less of a factor with a tank and no one is going to eat you whole in a tank.

[EdMcNierney]

Then I think we're back to your point about the lack of a good study, since we can't tell whether or not the RATE of deformity is higher in captivity than in the wild. If, for example, water quality is a cause, it's more likely to be better in the wild, etc.

I just continue to be impressed by how little we all really know, despite our best efforts!

[Luis A M]

Originally posted by robthorn
luis what clowns are you breeding?

Maroons,tomatoes,clarkii and ocellaris,but only frenatus and ocellaris right now.
I see I had a typo error:I mean wild YELLOW banded maroons come often misbarred.

[phender]

I don't think I buy the, wild clowns have just as many deformities, they are just culled by nature, arguement.

I have seen tanks full of 200 CB clowns where all of them had head and gill deformities, when similar tanks with the same species from a different breeder had no deformities. The same thing occurs with mismarkings.

I seems it would be worth it for a commercial hatchery to split a batch of fry and raise them under slightly different conditions to see if it made a difference.

[Shoestring Reefer]

Originally posted by phender
Has anyone done any research on what causes the common deformities seen in some tank raised clowns. I am talking about blunt faces, under bites, flared gill covers,etc.

Most of my 3 month old baby orange skunks seem to have blunt faces, some more than others.

When I got my two clowns I had never herd of blunt faces or gill deformities. One of my clowns has a blunt face and flared gills. I was worried for a while because he would barely eat when he first went into QT, but now he is a more aggressive eater than the other clown, and Gill may end up being Gillette. Does anyone have more info on clowns with flared gills? I did a search, here and on the net. I even started a couple of threads but didn't get much response. So far, it looks like Gill has a higher resperation rate than normal, but otherwise he's fine.

Anyway, if these clowns came from normal-looking parents and their fry are raised with good water conditions, will their offspring have a higher percent chance of having flared gills? That's what I'd like to know; if something is caused by mal-nutrition or poor water conditions, then it's not genetic so it shouldn't be heridatary. But, I don't know that it's not genetic.

[Luis A M]

Originally posted by Shoestring Reefer
Anyway, if these clowns came from normal-looking parents and their fry are raised with good water conditions, will their offspring have a higher percent chance of having flared gills? That's what I'd like to know; if something is caused by mal-nutrition or poor water conditions, then it's not genetic so it shouldn't be heridatary. But, I don't know that it's not genetic.

None of clown deformities,misbarring ,etc. are genetic.Mutations just don´t happen so easily or frequently.(Unless you keep your fish in outer space,subject to cosmic radiations )
I am keeping one of my flared gills fry.as broodstock.I chose it because it´s colour,vitality and size were over the average.
They do breath fast,because the operculum has limited movements,which impairs gill water circulation.But under normal conditions there is no handicap with that.

[Shoestring Reefer]

Ok, thanks.

[JHardman]

Somethings that have not been mentioned...

1) As good as we are at keeping and caring for clownfish, we can not duplicate the natural environment. As a result it is likely that a pair of breeding clownfish is missing something that could over time result in lower and lower quality of offspring.

I can say that this is the case with one pair of GSM I have. When they first spawned for me the rate of misbarring was very very low and the misbars were the norm that one would expect to see. Now the misbar rate has increase markedly and the resulting misbars are unusual in that many have extra barring such as spots and double bars.

2) Many CB fish are closely related either from line breeding or from close pairings. This can and does result in a higher deformity rates, e.g. Black A. ocellaris.

[phender]

Interesting that something missing in the parent's diet or environment might cause misbarring in the young.

I wonder if spawns from fish in reef tanks differ (as far as misbarring) from those kept in sterile breeding tanks?

[robthorn]

I recently had a hatch of 4 ocellaris all others were eaten by the parents. 2 of the larvae were born on the end of the 7th full day and the other 2 hatched at the end of the 8th day. these are from the same parents laid on the same day. one of the original 2 I accidentally killed transfering them to a permanent larvae tank. the other 2 went straight into the permanent tank. One of the fish has always seemed to be a step ahead of the other 2. appeared to start metamorphisis a day sooner and started eating other foods a day sooner. the 1 fish that seems to be a day ahead is a misbar and is yet too small to see any other deformities.
I have the 3 in a 10 gallon aquarium full by themselves. I do about 20% water change every 2-3 days. I don't believe water quality is an issue since the load is pretty low. I keep rotifers in there tank at all times.
I am starting to think that maybe this particular fishes deformity came from premature hatching. I have no clue if this is true to cause problems but since it only takes 7-8 days to progress far enough to live on there own . possibly somethings stop if they hatch too soon?
anyone else notice anything similar?

[cparka23]

is it possible that there is less misbarring in wild populations due to association of one's markings to fitness? i realize that misbarring doesn't affect a clown's ability to fight off or compete with other potential males/females, but perhaps it results in less frequent spawnings between a pair (thus fewer wc clowns with misbarring to begin with). it would be interesting to see if two pairs of healthy clowns in the same water conditions would reproduce as often where the variable is barring pattern. imo, it's too difficult to experimentally test.

luis, i would like to know how you can say that none of the defects are genetic. it is likely that there is significantly greater variation within a deme than you seem to allow regardless of mutation, which is not the result of just cosmic radiation (basic cellular processes also induce mutations into gametes). defects could be caused by poor water quality, but there is also the chance that there is an underlying genetic component of developing these defects in greater frequency among offspring where the water quality is not ideal.

imho, someone will just have to sequence the clownfish genome until one can definitely say if it is genetic, genetic but triggered by an environmental response, or purely environmental.

[cparka23]

i take it back, i just thought of a way in which one could test the barring question. it would require physically altering the markings of mated pairs, then observing whether or not matings occur less frequently before or after (w/ estimates of clutch sizes). of course, the purpose would be to determine whether there is any sexual preference for banding pattern (which in turn would affect the numbers & ratios of misbarred wc to cb clownfish). it's not a definitive answer, but it would be a nice graduate thesis.