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Temperature effects on Shrimp eggs hatching & gender of shrimplets


jayc
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While surfin in the quest to gain more knowledge about shrimp and shrimplets, I stumbled across this chart
(it's not my own and I don't claim any credits for it, I don't know who created it either apart from the text within it that mentions a name and site)

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Same info in a simpler chart.
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This is great info for an estimation of how long eggs will be held for before hatching.
However, this got me thinking.

Does the temperature of the water determine the sex of shrimp?
In most fish, as in mammals as well, their gender is determined by the presence of a pair of sex chromosomes present in each cell of their body. External environmental factors normally have no impact on their gender. In the case of some species however, it is now clear that the temperature is the crucial factor which controls the gender of their young. Known as temperature-dependent sex determination (TSD), this method of reproduction is most commonly associated with reptiles, such as certain Crocs and turtles which lack sex chromosomes, but also present in some fish. I have apistos that generally tend to develop more males in warmer temps, and more females in cooler temps.

Of course temperature is not the only thing that determines the gender of the species, chemicals in the environment also plays a role. But for the sake of simplicity, we are concentrating on temperature only.

So my thought was ... does TSD also affect shrimp?
I don't know for sure. There are some vague articles on the net, but not conclusive (not the ones I've read). But some articles shed some light of hope that temperature might determine the gender in shrimp (different kind of shrimp, not the ones we keep). There was one forum post (forgotten the site now) of a Singaporean (think hot weather) shrimp keeper who tends to get more male shrimplets than females.

This might be a good experiment for some breeders out there especially if they are trying for more males (higher temp) or for more females (lower temp).

We are only talking about a shift of 2-3deg C higher/lower. So assuming 24degC is ideal for CRS, then you'd adjust temps to 21-22 for more female shrimplets; or 26-27degC for more male shrimplets. This is only for the 3-4 week duration while the mama is berried until hatching. You don't want to keep them in temps that are not close to ideal for too long.

Happy to hear if anyone else has experienced similar or has more insight into the subject.

Edited by jayc
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Great post mate love the information and charts. I used to work at a freshwater crayfish farm and temp definetly affects the sex of the juveniles. One thing I would say is im not sure if the swing would have to be even that big of a difference. 22degrees for freshwater yabbies would produce a far greater amount of females. Increase it to 24 and it was reversed. Id also like to say our water was kept at that temp during breeding and gestation. The change in the male to female sex ratio is natures way of ensuring there is always sustainable populations and so if u only change It during the gestation you probably wont see the full effect. Tds is a tricky one cause it measures so many different minerals and so 2 bodies of water can have the same measurments of tds but totaly different chemical formulas

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Thanks for the response Michael. Your experiences in a crayfish farm is certainly handy.

That's good to hear, cause it's again one step closer to confirmation. Crayfish and Crystal Red Shrimp might not be the same, but I guess it's similar enough to count it as one step closer.

So what you are saying is .. the temps need to be set before the gestation period? Like when you start seeing the female shrimp saddled?

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During a wet season the fresh water will flow into the waterways lowering the water temp this affect signals the optimum conditions for all creatures living in the water to breed so this is why the change. If there is lots of food and freshwater the population will grow fast hence the female juvies. When the dry season comes the temp get higher and the population needs to be sustained not grown so more males are produced. Im not sure if the water is kept consistency lower during the saddling fase or during gestation only. But id suggest during both would be best . thats what we did. Id also say that if u raised it for a while then lowered it quickly it would probably help as well.

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  • HOF Member

The effect of a rush of cooler water is also noted with shrimp when doing a water change, if the water going into the tank is slightly cooler than the water in the tank often - not always- causes a bout of breeding . I'm not recommending that you suddenly put cold water into your tanks but if there is a slight difference it may trigger some breeding. When I was breeding the hardier Red Cherry I often just added room temp water and the next day I would find quite a few berried girls.:)

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Tds is a tricky one cause it measures so many different minerals and so 2 bodies of water can have the same measurments of tds but totaly different chemical formulas

Huh?

TDS (Total Dissolved Solids) or TSD (Temperature-dependent Sex Determination)?

I asked if TSD affected shrimp, like it does for some reptiles, and fish. And by the sounds of your reply it does, at least with crayfish.

Not "does TDS affect shrimp".

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The effect of a rush of cooler water is also noted with shrimp when doing a water change' date=' if the water going into the tank is slightly cooler than the water in the tank often - not always- causes a bout of breeding . I'm not recommending that you suddenly put cold water into your tanks but if there is a slight difference it may trigger some breeding. When I was breeding the hardier Red Cherry I often just added room temp water and the next day I would find quite a few berried girls.:)[/quote']

Yeah the change in cooler temperature is well know for triggering breeding.

Simulation of the wet season and fresh waters.

And we are starting to see more evidence that temperature also affecting the gender of shrimp.

I'd love to try this out. But not having enough tanks will throw any sort of experiment out the window.

We'd need a tank kept at 23-24C. A tank at 22C and a tank at 26C.

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This chart made the rounds a few months back. Great reminder though.

For those who bought the Breeders and Keepers Magazine, there was some minor mentions of temperature affecting the sex ratios of shrimp.

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This chart made the rounds a few months back. Great reminder though.

For those who bought the Breeders and Keepers Magazine' date=' there was some minor mentions of temperature affecting the sex ratios of shrimp.[/quote']

The chart is, as you said, just a reminder. The main discussion is how temperature affects the gender of shrimp.

What did the article say? - so is it confirmed 100% then?

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Interesting topic hadn't thought of it in Shrimp till now, funny though as I'm taking notes myself with cooking gecko eggs at 28.5c over 8 species to see if the slightly lower than normal temp favours tsd. Normal temps 29-30c for most Desert species I keep.

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Interesting topic hadn't thought of it in Shrimp till now' date=' funny though as I'm taking notes myself with cooking gecko eggs at 28.5c over 8 species to see if the slightly lower than normal temp favours tsd. Normal temps 29-30c for most Desert species I keep.[/quote']

Yeah, funny how everything revolves around shrimp at the moment, for me at least. I'm sure I'm not alone.

Just bought a mulberry tree from bunnings.

Building a new garage, and the priority is the rain water harvesting system. LOL :encouragement:

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The chart is' date=' as you said, just a reminder. The main discussion is how temperature affects the gender of shrimp.

What did the article say? - so is it confirmed 100% then?[/quote']

I wouldn't say confirmed, at least nothing I've seen in the scientific literature has proven anything. But if top breeders are noticing these things it is worth betting that there is something to it.

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I wouldn't say confirmed' date=' at least nothing I've seen in the scientific literature has proven anything. But if top breeders are noticing these things it is worth betting that there is something to it.[/quote']

Well, there are enough top breeders here. We should be able to confirm this.

I admit it's not an overnight experiment. But I'll certainly give it a go. Summer is around the corner, so temps in my tank will naturally be higher. I'll see what ratios I get at the end of summer.

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Just had another brain snap,....has anyone got water temps that swing a few degrees?

In reptiles (pythons so far) some keepers have weird colour/pattern variants pop up when the temps were altered at an integral part of colour development in the animal whilst incubating.

Wondering if a swing of water temps at various times while in berry would possibly have the same effect. ??

I know were talking about aquatic v land based and the eggs are completely different just while were on the subject thought I'd inform others.

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That's another cool thought on the subject.

However, seeing as colour variations are already so diverse, it would be pretty difficult to determine if it was impacted by temperature.

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Do I hear you volunteering BB?

You sure have enough tanks of shrimp to be able to conduct such a test.

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  • 6 months later...

Bump.

Good info to have around.

I vote for this to be a sticky.

The info on hatching times is useful, and the discussion on temps influencing gender is ... Awesome!

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Thanks Admin.

You guys are ninjas - turned this into a sticky very stealthily.

If no one has said it yet today ... GREAT WORK ADMINS! :beer:

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  • 2 years later...
On 6 August 2013 at 11:49 AM, jayc said:

Does the temperature of the water determine the sex of shrimp?
In most fish, as in mammals, their gender is determined by the presence of a pair of sex chromosomes present in each cell of their bodies. External environmental factors normally have no impact on their gender. In the case of some species however, it is now clear that the temperature is the crucial factor which controls the gender of their young. Known as temperature-dependent sex determination (TSD), 

Of course temperature is not the only thing that determines the gender of the species, chemicals in the environment also plays a role.........

Happy to hear if anyone else has experienced similar or has more insight into the subject.

Interesting article @jayc only being new to shrimp I haven't even thought of this however in the past breeding cichlids kribensis can manipulate sexes if the ph is under 7 you should get more females and above 7 it should produce more males. My experience is I normally get an even spread of males and females maybe because the breeding tank is neutral 7.

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  • 1 year later...

Have you guys tried using Bonsai Driftwoods? Based on my research, Bonsai Driftwoods lower PH levels and stabilize water that makes fishes and shrimps have the best environment. I'm clearing some now, so let me know if you guys want to purchase one!

0A06F024-D56B-47FF-876C-70C1D2E722FE.jpg

20F30B08-492B-4E23-8EA7-3F8B78AA66D7.jpg

383AC351-FDE6-41DA-B2CA-BEB85C74B1F5.jpg

C2DA6F45-3E52-4648-9EA6-E7DC9D382404.jpg

C6022545-3F45-4C55-A9EC-742840ADF8FD.jpg

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7 hours ago, NatefromSa said:

Does the bonsai as much or as long as the driftwood?

 

Not sure I understand your question.

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Not sure I understand your question.
Oops sorry,

Does the bonsai wood take as long as the driftwood to get waterlogged.

Sent from my VKY-L29 using Tapatalk

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28 minutes ago, NatefromSa said:

Does the bonsai wood take as long as the driftwood to get waterlogged.

 

It really depends on the type of wood and how thick it is.

But in general, Bonsai driftwood is not as thick, as it's mainly roots and branches, with the middle being the only thick part. So it won't take as long to get waterlogged. The bottom root part also helps in making it easy to place rocks on the them to weigh the wood down.

 

Driftwoods that are from hard woods can take a long time to get waterlogged. And the thicker they are the longer it also takes to get waterlogged.

 

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    • sdlTBfanUK
      You may end up losing this batch entirely but then you can start completely fresh and get the aquarium set up right for the next batch of shrimp! If you do any large water changes then try and add the new water slowly, either dripper or some other way. You should get yourself a TDS meter (as JayC above), they are cheap and readily available. You should always use a GH tester kit as well with shrimps, if you do the 50% water change that should halve the GH so you should get a reading after that, or if you can get a local fish store to test it for you that will give you an idea of the GH. If your water supply is as hard as it appears it may be you will need to mull over how (or even IF) you want to keep shrimps as that may mean using RO or distilled/bottled water and buying a proper shrimp specific remineraliser? That will be quite expensive but you won't then have to mess about adding crushed coral/eggshells etc, but only you can decide whether you want to do/spend that much etc? If you live somewhere that gets a lot of rain, then you can use rain water? Also, as JayC states, you need to know what you are using/adding to the water and aquarium, ie fertilizers, rocks. Unless you have very exotic plants you shouldn't need any fertilizers. Just as a note, we have come across quite a few experienced fish keeprs that have this sort of start off issues with shrimp. Shrimp are more difficult than fish, and the aquarium and water etc need to be ready and within the required parameters before getting the shrimps. Usually people jump in, get the shrimps before everything is ready/sorted. Hopefully though you will keep at it, or if this lot die you will have another go and we can help you get it sorted?
    • jayc
      These are all classic symptoms of shrimp moulting problems.   Again, another high GH symptom. High GH not only causes harder carapace (shell), but it also makes eggs harder. When the egg is harder the male finds it more difficult to fertilise the eggs.   That's a worry if you can't get a good GH reading because that is going to be most likely issue right now for you.   Because snails don't moult.    If you dont already have a TDS meter, I suggest getting one asap. It's another test to narrow down your water parameters, and not have to trust one test by it's own - in this case the GH test kit. I would wager your water parameter is too high in dissolved minerals - likely from the tap water source, fertiliser dosing and/or any rocks/crushed corals you might have in the tank. To remedy this, you need to start doing water changes with RO, distilled or rain water immediately. I would do a 50% water change with RO water asap. Then look for sources that increase GH in the tank and eliminate it - fertilisers, rocks, crush corals, shells.    It's difficult to save a shrimp who's carapace is already too hard, but hopefully any younger shrimps will benefit from the water change and the reduced GH.   Good luck and keep us updated.
    • professionalshrimphugger
      United States. I have tested my tap water; it yields the same results. GH: ??, KH: 3, pH: 7.8. I cannot say for sure if my GH test is faulty or not, the expiration is until 2023. It's more of a twitching, then stasis. I have one shrimp that's having a hard time balancing itself, but it's swimmerets and mouth keep moving in attempt in getting back up. I allowed it to stick to my sponge filter. The tank is cycled. I used established media. Readings would not show 0 otherwise. I do use EI Dosing, half dosage recommended for a 20 gallon. It has been said on other forums that it does not affect shrimp, but I stopped dosing to isolate variables a week ago. No CO2, that's too costly for me, hah. I drip acclimated the shrimp for 2 hours, 1 drop per second. I tested for copper in my tank, nothing. Funnily enough, my mystery snails in my community tank don't seem too affected by it.
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    • professionalshrimphugger
      Hello all, I am new to the forum, although experienced at fishkeeping, I am relatively new to shrimpkeeping. Let's start with my issue. I had started a colony of 18 juvenile cherry shrimp (Neocaridina davidi) in a 20 gallon long as of last month. I solely use tap water and change 5% per week. They are the only inhabitants alongside a single juvenile Malaysian trumpet snail. Today the numbers have been reduced to 9. The deaths did not start until the shrimp turned into adults, where they have struggled, twitching as if provoked, becoming lethargic, and eventually flipping over to their side and dying. Only the ones on the verge of death exhibit this behavior, whereas the rest simply graze on as usual. I measured my parameters today - my tank has been established for two months as of now and is densely planted. They have never bred despite being of adult size and having visible saddles. Never an issue with molting. Ammonia: 0 ppm, Nitrite: 0 ppm, Nitrate: 0-5 ppm || pH: 7.8, GH: ??, KH: 3 I cannot get a single good read off API's liquid GH test. I have dropped beyond 30+ and gave up as I knew the numbers were already extreme. The thing is, I need a temporary, inexpensive solution to keep my shrimp safe. I believe by the time I order supplies, the colony would already give. I was planning on moving the colony to a 5.5g, barren with my floating plants and mosses, using just distilled water, Seachem Equilibrium (only GH additive I own) and crushed eggshells (potential source of KH). Possibly crushed coral to substitute for the lack of any real mineral additive. I did not believe that high GH would possibly become a problem, and I am fortunate that the strugglers are still alive. If anyone has a solution to this problem, or approve of my plan of action, please let me know. TIA
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