Clownfish sex change project

[scubanerd13]

Hey, i just joined this forum on the sugestion of the guy at my LFS. I starting a project to find out how the female clownfish prevents the other males in the from changing sex. I will be looking at visual cues as well as potential hormones in the water. As of right now, I have a 55 gallon tank set up with a filter and heaters, and a clam in the bottom to build up bacteria. My fish came in on Friday, and i will hopefully be adding them to the tank this week. This will be a 2 year long research project for my Jr and Sr years in high school. If anyonw wants to see my ED or backgroud reserch for more info, I'll be happy to post it. I can't wait to ask all of my question and get better answers tht looking it up online or using books from the library.

[Coral Hind]

Welcome to the club! I look forward to helping you out any way I can.

 

I think aggression and dominance hierarchy is the main cue. I am not aware of any hormones in the water but it will be interesting to see what you find out.

[Jon Lazar]

Sounds very interesting. How many and what species of clownfish are you using? Do you have a particular set of experiments in mind to measure and compare the effects of visual and hormonal cues you mention?

 

Jon

[Origami]

Hi Scubanerd! Welcome to WAMAS! Sean mentioned your project to me. It sounds exciting. Have fun with it.

 

What do you mean, by the way, when you say that you have a clam in the bottom to build up bacteria? Are you using any form of live filtration like live sand or live rock?

[scubanerd13]

I'm using 12 ocellaris clowns. I'm going to put all of the fish in the 55g tank, and when one becomes female, I will move her to the smaller isolation tank. This will test the visual cues becaseu while the female can't reach the males, they will be able to see her. I will alot be takign water samples thoughout the experiment, then running them through a set of tests called ELISA assays, one for 11-ketotestosterone and the other for estrogen. These tests can measure tiny amounts of these homones in tha water, and I will be able to see any differences between the tank with the female in it and the tank without the female.

About the bacteria- I was told that using a dead shrimp or clam would allow me to cycle the tank w/o accidentally killing a fish with an ammonia spike. There's no LS or rock, because I was told by Sean at Fins and Feathers that having sand and rock would lead to fights between the fish, each of which would end with a fish with a broken jaw that would then starve to death. Because of the rules assosiated with the science fair my school uses, a project using vertebrates cannot have more than 30% of the test subjects die, or the project will be shut down, i.e. no sand

[L8 2 RISE]

I'm using 12 ocellaris clowns. I'm going to put all of the fish in the 55g tank, and when one becomes female, I will move her to the smaller isolation tank. This will test the visual cues becaseu while the female can't reach the males, they will be able to see her. I will alot be takign water samples thoughout the experiment, then running them through a set of tests called ELISA assays, one for 11-ketotestosterone and the other for estrogen. These tests can measure tiny amounts of these homones in tha water, and I will be able to see any differences between the tank with the female in it and the tank without the female.

About the bacteria- I was told that using a dead shrimp or clam would allow me to cycle the tank w/o accidentally killing a fish with an ammonia spike. There's no LS or rock, because I was told by Sean at Fins and Feathers that having sand and rock would lead to fights between the fish, each of which would end with a fish with a broken jaw that would then starve to death. Because of the rules assosiated with the science fair my school uses, a project using vertebrates cannot have more than 30% of the test subjects die, or the project will be shut down, i.e. no sand

 

You're correct about the dead half a clam starting biological filtration, but it's not worth it if you aren't going to have any rock or sand in the tank. Now the tank is just building up ammonia, but since there is no bacteria in there to take it through the nitrogen cycle, it will just stay as ammonia. You are going to want to have some sort of biological filtration, even if it's just bioballs, otherwise you're going to have to go through tons of water changes.

 

I would worry that if the female is not in the same tank, then one of the 11 remaining males will turn female in the 55. Also, if your project is testing how hormones effect the sex changing of clowns, I assume a hypothesis could be: If there is a female in the tank, then it will release hormones to prevent the males from turning into females. Assuming this is correct, and the female is not in the tank, then what's to stop the one of the remaining males from changing sex as well? Granted you could use a guess and check type approach, so if the males can see the female, but she's not in the tank, but one of the males still turns female, then you know the sex change is most likely not triggered visually and so you can look for other culprits.

[bluefunelement]

Hmm cool experiment.

For basic husbandry and to make sure you don't have your experiment shutdown you should definatley run some more your questions for this crowd. Assuming you are using 1.5+" clowns that are closer to maturity and feed enough so even the runts get some you'll have a fair bioload for a 55. You're going to have a long cycle with no live rock or sand -the later doesn't cause fighting but barebottom is fine too.

What mechanical filter are you using?

 

Good luck.

[Jon Lazar]

With no corals or live rock in the tank, you should consider using a trickle filter or a hang-on-back filter. Either one will provide a lot of surface area to be colonized by ammonia-eating bacteria. But you'll have a very hard time without one of these methods for eliminating ammonia, which will kill your fish. Nitrite can hurt your fish too at high levels. Your fish are unlikely to die from nitrite outright, but are prone to secondary infections which they die from.

 

Have you already done a literature search to see what relevant research has already been done on clownfish?

 

Jon

[Origami]

With no corals or live rock in the tank, you should consider using a trickle filter or a hang-on-back filter. Either one will provide a lot of surface area to be colonized by ammonia-eating bacteria. But you'll have a very hard time without one of these methods for eliminating ammonia, which will kill your fish. Nitrite can hurt your fish too at high levels. Your fish are unlikely to die from nitrite outright, but are prone to secondary infections which they die from.

 

Agreed. The clam / shrimp is placed in the aquarium to seed the water column with ammonia that results from tissue decomposition. Without appropriate surface area for bacterial colonization, you will not develop an adequate capacity for breakdown of waste from fish and from excess food. A trickle filter or a HOB (hang on back) filter appropriately sized for the number of fish you are maintaining is needed before you begin to introduce large numbers of fish in the system. Otherwise, you risk a build up of ammonia which will very rapidly kill your fish. While levels as small as 0.4 ppm can be tolerated by many fish for a couple of days, 1 ppm demands immediate action. In other words, it doesn't take much to ruin your day.

 

What kind of filter are you running now? It may be that this filter will be where your bacteria will eventually set up shop.

 

You may want to consider keeping these on hand initally: 1) An ammonia, nitrite and nitrate test kit (to monitor the tank cycle); 2) Amquel plus (or some other chemical additive that can bind up ammonia in an emergency; 3) enough premixed (and preheated) change water to perform a 50% water change;

 

How long have you had your tank up cycling? Have you been monitoring byproducts of the cycle?

[traveller7]

A few things to think about:

 

- Clownfish pecking order includes not only the female, but also the male. (males have killed more of my aspiring juveniles then my females)

- Might want to assume the smallest remain juveniles vs. male/female for hormone testing

- Might want to plan for more then one actual pair in a 55gal, up to three pairs even with a bunch of well beaten juveniles.

 

IME, 55gal might not be the best size tank for this experiment with common A. ocellaris. They have been known to stay in fairly stable large groups for quite some time. Note an exception, B&W ocellaris have been much less likely to live in large groups.

 

Might want to check out this thread on RC that started with 27 clowns over 2+ years:

http://reefcentral.com/forums/showthread.php?t=1259398

 

Sounds like a fun and educational project, best of luck.

[Coral Hind]

Traveller7, What do you think would be a good tank size if the test only wanted to produce one female at a time? Would an anemone added to the tank change the dynamics at all?

 

Scubanerd13, Just to let you know that traveller7 is a wealth of information and he also moderates the RC "clownfish" section.

[traveller7]

Traveller7, What do you think would be a good tank size if the test only wanted to produce one female at a time?

I am not sure I understand the hypothesis and specific test set up enough to answer that question. I am a bit concerned about the species selection; common A. ocellaris are quite colonial and not as representative for the majority of clown species. To force a more typical hierarchy, I'd hedge toward a more constricted space. Maybe even as small as 24gal H with a wet/dry filter to handle the bio load. I'd need a bit more information and to think about it a bit. Variables are significant and are going to affect the outcome dramatically.

 

Would an anemone added to the tank change the dynamics at all?

Yes. But, given the proposed set up and clown species, it would likely skew results dramatically and injects difficulty in general husbandry. A similar effect, if desired can be achieved with a clay flower pot or three.

 

A few more random thoughts:

 

- Make sure the tank is tightly covered, there is going to be some chasing going on and expect jumpers.

- Keep protective cover to a single location to force tight grouping (powerheads, heaters, overflow boxes, etc. will all become "cover")

- Starting with a breeding pair of A. ocellaris and a 6" flower pot as a baseline, then adding 10 juveniles (<1" and even better if <.75") might force a single pair structure.

- Tossing B&W ocellaris into the mix would likely skew results vs. orange&white ocellaris.

[scubanerd13]

You're correct about the dead half a clam starting biological filtration, but it's not worth it if you aren't going to have any rock or sand in the tank. Now the tank is just building up ammonia, but since there is no bacteria in there to take it through the nitrogen cycle, it will just stay as ammonia. You are going to want to have some sort of biological filtration, even if it's just bioballs, otherwise you're going to have to go through tons of water changes.

 

I would worry that if the female is not in the same tank, then one of the 11 remaining males will turn female in the 55. Also, if your project is testing how hormones effect the sex changing of clowns, I assume a hypothesis could be: If there is a female in the tank, then it will release hormones to prevent the males from turning into females. Assuming this is correct, and the female is not in the tank, then what's to stop the one of the remaining males from changing sex as well? Granted you could use a guess and check type approach, so if the males can see the female, but she's not in the tank, but one of the males still turns female, then you know the sex change is most likely not triggered visually and so you can look for other culprits.

 

 

Part of the testing is to see if a male will change in the 55 after the female is removed. That will tell me whether they are using visual cues or not. If another male changes, just the sight of the female is not enought to prevent sex change. The experiment will answer a yes or no question.

Sorry, I cn;t figure out how to quote more than one person at a time

my filter is an Aquaclear hang on the bakc filter, sized for a 40-70 gallon tank. I have 2 sets of "cycle guard"(ceramic porus stone that come in the pakage with the filter) and the sponge in. I am not using carbon becaseu I was told it would remove homones from the water.

I have about 10 different sources of published reserch papers about protandric sex change in fish in general, as well as ocllaris clowns specifically. I you guys want the sources( and more details of the project overall, I can post the experimental design and backgroud research up here. I just didn't want to post it w/o interest)

Sorry, st this point I can't change what tank I'm using or what livestock I have, as the school has already paid for it. I went with what was shown to be the easiest to maintain and keep alive that I researched. Thanks for all the help so far. If i didn't answer your question, please just wait until I can look at the posts again or if you think I'm too slow, repost it. I'm already loving this site!!!!!

[F&Fmgr]

I recommended she put a clam in there like a week ago, and come back for some prodibio startup which a bacteria culture and ammonia blocker. The surface area in the aquaclear biomedia is plenty, plus she doubled up. Also I said BB would be better so that she could just siphon out any waste. Also irecommended going BB so that as part of the experiment she could introduce different stimuli that might incite possesive behavior( like a 1.5" PVC tee, and then maybe an Anenome)

 

Sean

[Jon Lazar]

If you decide the 55g tank is too large and allows the fish to spread out and avoid one another without much interaction, you could partition it with eggcrate to keep the fish closer together.

[traveller7]

Part of the testing is to see if a male will change in the 55 after the female is removed. That will tell me whether they are using visual cues or not. If another male changes, just the sight of the female is not enought to prevent sex change. The experiment will answer a yes or no question.

Sorry, I cn;t figure out how to quote more than one person at a time

my filter is an Aquaclear hang on the bakc filter, sized for a 40-70 gallon tank. I have 2 sets of "cycle guard"(ceramic porus stone that come in the pakage with the filter) and the sponge in. I am not using carbon becaseu I was told it would remove homones from the water.

I have about 10 different sources of published reserch papers about protandric sex change in fish in general, as well as ocllaris clowns specifically. I you guys want the sources( and more details of the project overall, I can post the experimental design and backgroud research up here. I just didn't want to post it w/o interest)

Sorry, st this point I can't change what tank I'm using or what livestock I have, as the school has already paid for it. I went with what was shown to be the easiest to maintain and keep alive that I researched. Thanks for all the help so far. If i didn't answer your question, please just wait until I can look at the posts again or if you think I'm too slow, repost it. I'm already loving this site!!!!!

As long as it is acceptable to allow the potential for multiple males or females, 55gal will be fine and the larger body of water should be helpful in keeping water stability.

 

Since I have been babbling so much in this thread already, a few more random thoughts before I shut up

 

- feeding regimen will impact the outcome, it takes quite a bit of food to support gender shift. Low amounts of food, will "artificially" restrict growth, gender changes, etc.

- because you have 2 years of time and the outcome of multiple pairs is acceptable, I would consider buying fairly small clowns to start (ocellaris can go from egg to breeding in <2yrs)

- I'd work with a local source of clowns, have them quarantined and treated at the shop, then introduce all 12 simultaneously to avoid future introduction of disease.

- I'd plan on introducing a single clay flower pot to contribute toward the pairing/breeding mechanism. (I'd skip the anemone factor, they require more husbandry, light, food, etc.)

 

For tracking the project, you might want 2 threads on the message board: 1 for general project discussion, 1 strictly for tracking progress/results. IMHO, a single thread will get quite cluttered over the years

 

Again, best of luck with the project

[F&Fmgr]

- feeding regimen will impact the outcome, it takes quite a bit of food to support gender shift. Low amounts of food, will "artificially" restrict growth, gender changes, etc.

- because you have 2 years of time and the outcome of multiple pairs is acceptable, I would consider buying fairly small clowns to start (ocellaris can go from egg to breeding in <2yrs)

- I'd work with a local source of clowns, have them quarantined and treated at the shop, then introduce all 12 simultaneously to avoid future introduction of disease.

- I'd plan on introducing a single clay flower pot to contribute toward the pairing/breeding mechanism. (I'd skip the anemone factor, they require more husbandry, light, food, etc.)

 

the clownfish are being QT'ed & treated here, and they are about 1"

Also I thought that with barebottom she could feed more and siphon the solid waste out without having the Nitrates spike. Emily might be a newbie to the hobby, but she is a very bright girl and I don't think she'd have problems keeping an anenome alive, but the anenome probably wouldn't be added for some time from what I understand with her schedule of the experiment.

[traveller7]

the clownfish are being QT'ed & treated here, and they are about 1"

Also I thought that with barebottom she could feed more and siphon the solid waste out without having the Nitrates spike. Emily might be a newbie to the hobby, but she is a very bright girl and I don't think she'd have problems keeping an anenome alive, but the anenome probably wouldn't be added for some time from what I understand with her schedule of the experiment.

Glad to hear you have the clowns QTing, your previously posted regimen would be perfect for this endeavor.

 

With high density clowns and the feeding required to produce maturity, nitrates would not be my major concern, I'd fear ammonia spikes and pH drops. I'd use weekly water changes for Nitrate management and expect them to be much higher than reef conditions.

 

I am quite sure she could keep an anemone alive, but the tank focus will quickly become what does this anemone need to keep from moving around, shrinking, dying, bleaching, staying out of the HOB filter intake, off the heater, etc. Having an anemone die, move, etc., with established/ing pairs is quite an event and has reintroduced pecking order squabbles among groups of clowns potentially altering the experiment. If the clowns are captive bred, they are likely generations away from being in water with an anemone. They'll still go into one instinctively, but an anemone is not a critical component within the clown pairing/bonding/breeding/gender changing process.

 

Added benefit of the flower pot, it stays where you put it, does not eat, does not require light, does not die, does not contribute bio load, and best of all: always provides a potential breeding substrate at the target shelter site. Take suitable breeding substrate and "cover" from the picture and the clown colony dynamic is dramatically altered.

 

Bigger questions, short of demonstrating fertile egg laying, how to baseline a female and male actually exist in the group? F-F, F-juv, and juv-juv "bondings" will skew the results yet are documented clown pairings.

 

Just when we expect clowns to follow the rules, they throw us a curve. I'd try to reduce the curve chances as much as possible while keeping the majority of the fish alive and healthy for the duration with low maintenance a priority.

 

Keep in mind, these are just my opinions which are biased and based on my limited experience. Most of my experience is in keeping clowns in groups of 7 or less with the specific intention of pairing for breeding. With my fish, I am attempting to drive the changes in a predictable manner vs. monitoring what nature allows ad hoc. My goal for 7 fish would be "3 breeding pairs and a spare."

 

All the best.

[scubanerd13]

So here's my update for the past few days:

I'm finally geting my temp stable (adding cold water to the tank does not does not help to keep the temp stable )

I added bacterial ampoules to start my tank, 4 of amino block and 6 of bio-digest. I also added about a tablespoon of sugar, and turned up the temp to 82. When I cam on this moring, the tanks was very cloudy, and my teacher said it looked that way yesterday. Any ideas for why this happened, and how to fix it?

I'm planning on adding my fish to the tank on Monday, weather permitting. I loved seeing my babies at F&F yesterday! I'm so excited to finally get them to their new home soon.

Edited January 21, 2010 by scubanerd13

[Coral Hind]

White cloudiness is probably a result of a bacteria bloom. It should clear up own it's own as the bacteria population stabilizes.

[Origami]

t few days:

I'm finally geting my temp stable (adding cold water to the tank does not does not help to keep the temp stable )

I added bacterial ampoules to start my tank, 4 of amino block and 6 of bio-digest. I also added about a tablespoon of sugar, and turned up the temp to 82. When I cam on this moring, the tanks was very cloudy, and my teacher said it looked that way yesterday. Any ideas for why this happened, and how to fix it?

 

My thinking is that you had a bacterial bloom in the water column from the addition of new bacteria and the carbon source (sugar) that you added. You probably don't have much bacteria built up yet and your provided what few you had with a good-sized food source. This has led to a sizable proliferation of bacteria in the water. You may even see strings of white stuff on some surfaces (glass, filter, etc.). This would confirm that you're experiencing a bacterial bloom, but it's not necessary that you see it for it to be a bloom.

 

Under these conditions, the oxygen level in the water may be low. I wouldn't add your fish in these conditions as they may fare badly.

 

The bloom would normally subside on it's own, in a system equipped with a skimmer as organic byproducts from the bacteria are removed. However, since you're not equipped with a skimmer, I'm not sure if it'll be a day, two, or even three. You can wait it out (and let the water clear on its own) or you can perform a large water change.

 

In the end, you probably didn't need as much sugar as you added given the limited filtration capacity that your new setup has.

[scubanerd13]

great, that's what I thought it was. I did a small water change today, and it won't be until Monday that I add the fish (Tuesday if we have a snow day tomorrow). Will the 2 air stones in i have in tha water keep it enough oxygen in the water? Or will I need to do a large water change instead?

[scubanerd13]

Ok, just an update. Yesterday I added my fish, after picking them up Sunday night. They looked great this afternoon when I left. They were swiming a lot more today. Yesteday, they just motored right down to the bottom and hung out there the rest of the day. I cleaned of the bottom of the tank where soem waste and leftover food had settled. It was so cool to watch them eat! I think I'm already seeing a couple of the fish show dominance to the others. BTW, can anyone tell me what specific actions the dominant fish will do? like chasing, nipping, ect? My teacher was thinking that a list might be a good idea, because I would be able to check off the actions as I see them.

[Jon Lazar]

BTW, can anyone tell me what specific actions the dominant fish will do? like chasing, nipping, ect?

 

When the clowns are juveniles, one clown will make an attack run at the other until the second fish moves away or shimmies in front of the victor, signaling defeat. Repeat about a zillion times until one clown realizes he's always on the losing end and gives up, to become the male.

 

Once they've bonded into a male/female pair, these displays become rare. Occasionally I'll see my female gently nip at the male, but it's nothing like when they were juveniles eastablishing their roles.

 

If you don't have it already, I recommend the book Clownfishes by Joyce D. Wilkerson. It's probably the most authoritative clownfish book at the hobby level, and discusses breeding and raising clownfish, as well as their courtship behavior.

 

Jon

[scubanerd13]

just a quick update:

I had a friend feed the fish on Friday before school got out. Becasue of the long weekend I came in today to check on them before school tomorrow. I was very sad to find one of the fish laying on the bottom of the tank, dead. I don't know what happened, because they all looked fine on Thursday, the last time I saw them. I fed them today, and all were eating and swimming well. I;m going to see them again tomorrow. I have now officially had a saltwater tank running for one week. Thanks for all your support!