rodbigelow

While many people report them to be a fairly non aggressive species, my marmorkreb attacks and kills anything I put in her tank, including eating her own clutches of eggs.

OK, so last August I got 5 marmorkrebs, very young. I accidently killed one in an unfortunate cleaning accident, and three others died mysteriously, leaving me with one. She was very aggressive and would eat anything that went into her tank. ANYTHING. She ate her first clutch, although I didn't quite put it together at the time. She had a second clutch and they all mysteriously dissapeared, that's when I finally figured out she was eating them. So I dubbed her Highlander, since their could be only one. I moved her to a different tank hoping that one would stress her less and she would allow some babies to live. In the meantime, two weeks after I moved her, I noticed a tiny one that had survived her in the old tank, so I began feeding it. She is much older then Highlander when I first got her and she has kept a very distinctive blue color. They both have the same diet. Is this a color morph or is there some other factor in play? Anyone else ever see this in Marmorkrebs?

hey there, sorry I'm too new to tell you anything about this, but besides this being a smaller subgrouping of the shrimp people so less see postings here, there is another thread just a bit older with the same title that has a bit of information on the subject.

I feed mine whatever foods I have on hand, including rabbit food pellets and plant trimmings, but primarily Hikari crab cuisine. They seem to be determinately omnivorous and not at all picky. I suspect that mine are hunting snails, but can't prove it.

I don't usually get to see mine face-on, always a lateral view when I can get a glimpse. I guess I oriented their hiding tubes the wrong way in the tank. So I have no idea if mine display the same resting pose. It would be neat to compare, though.

I'll try to get a decent picture. I'm fairly new to Macro photography and don't have anything close to an optimal set-up, but occasionally I get a decent shot.

Grrr....had another fatality today so I'm down to two. It was such a stupid and avoidable fatality too. I hadn't realized it but my largest had just shed and I did a 20% water change. While siphoning I had to look away for a moment and the siphon went astray and grabbed up the freshly molted one and banged it around inside the tubing before I realized what had happened. Going to come up with a better solution for doing water changes immediatly. Was planing on it anyway so when I have a bunch of young they don't get swept up, but this makes a good arguement to change systems now.

Or they could be mimicking each other. My rabbits routinely copy each other's resting positions.

That is a possibility. Only way to find out would be to separate out a bunch of young ones at hatching and keep them apart and see what poses they adopt. Once I get better set up I'll try that.

It's near the end of week 3 since I got them and growth rate on the largest two seems to have slowed down, with only about 1/2 the former size being put on. Shells are getting more color,and or less transparent which is helping with color.

The smallest just today began recognizing feeding time, so it would appear to warrent looking into when I'm set up a bit better, have larger populations to look at and ways to get accurate measurements.

What are other people feeding theirs? I'm using veggie pellets, color flakes and guppy bites right now and they are in a planted tank by themselves. So far the only vegetation they seem to be eating is dead and dying leaves.

I tjink the spell check red lines have more to do with your browser and how it is set.

Maybe, I don't get any red lines at all here.

The second largest has now started recognizing feeding time, and it is roughly the same size as the largest when it did the same. The smallest one is quite a bit smaller, and probably won't hit that size until maybe mid to end of this coming week. It will be interesting to see what happens, and this isn't near large enough a group being studied to offically say so, but it does look like a developemental thing. Maybe the brain has to get "just big enough" to start handeling that information.

 Looking at my photos I also realized they all have exactly the same "at rest" pose. both front claws facing downward at maybe a 30deg angle, with one slightly raised and offset compared to the other. Must have come about as an ideal hunting pose.

I was getting confused because the pictures all looked so much the same even when I knew it was different ones in each photo.....

People often have the misconception that self cloning means the individuals look exactly alike to P1, when in reality coloration, pattern and growth may all be different.  Parthenogenesis is not the same as artificial cloning, and thus people get confused.

 

In theory you could select the largest from each clutch in the line to enhance the bell curve, but in actuality I don't know. Marms are still a bit of a mystery.  The nice thing is you should know pretty fast since they berry up usually by 2".

I knew the patterning and coloration could be different, but just didn't think growth rate would be effected that much.

Yeah, our little gals should soon offically be declared a new species, and one that's only been around for such a short period of time too!

That's one of the things that facinates me so much about them, there are tons of questions that haven't even been asked yet but will eventually need to be answered about our "virgin crayfish" and how this strategy plays out for species survival.

BTW-WTH? why doesn't this forum provide spell check as an option before posting? Mildly dyslexic and really hate when I post mis spellings and whatnot.

Something interesting about crays is that the clutch can grow at different rates.  Some may even look 2x as big as a sibling at any given point in time.

Now that is interesting, and good to know. I was assuming since they are clones growth rate would be about the same in any given clutch. Makes me wonder what the inluence is there and if there might not be a way to.......I don't even know what you'd call it since you can't breed two together.......to enhance the growth rate in a lineage for possibly bigger crays?

lot of info in this thread, thanks. It's helping me with ideas for set-ups with marbled crayfish

They are living things Sir & not test subjects so please respect the geometry of nature.  Are you trying some sort of Stanley Milgram crayfish experiment?  Please forgive me, I'm so confused by your long winded posts.

Forgive my wording if it offends, however it is possible for something to be a living thing and also a test subject, and I do respect the geometry(?) of nature. Right at this moment I am not doing anything other then observing anything I can about them, so I can better understand what and who I am dealing with. At this stage it is horribly inaccurate as I bought these at a very young age but they are all so varied in size I have to assume they are from different hatchings and do not have the data as to when each was born. Totally unfamiliar with Stanley Milgram or his experiments.

yeah, I am primarily looking for aquaponic/feeder/any other type of application I can figure out for them. They are pretty cool little test subjects. It's now 2 weeks since I got the 4. I've had one fatality, possibly a bad molt, but don't know for certain. The rest are doing very well and the largest is now 4x the width of my pinkie fingernail (terribly scientific measurement there, I know), so at this age they are still doubling in size every week. It is also interesting that the largest one has now started recognizing feeding time, the 2 remaining smaller ones have not. Will be interesting to learn if this is a developemental thing or not.

Posted in Biology, Plants & Animals

well, I can't say how old they were when I got them, but the largest of the 4 was not even the width across my pinkie nail. Now a week later it is more then twice as long as the width of my pinkie nail. Hopefully that is a good sign they are healthy and on track.

Interesting. Well, this was an older entry on a website from a laboratory. When I was reading it I was kinda wondering if some of their problem was that they might be keeping them in too sterile and too stressful or not natural enough conditions.

So I got 4 really small juvenile Marmorkrebs last week, they seem to be doing fine and have molted. Quite a bit of difference at this stage between sizes before and after molts. Anyway,I was reading one person's website that said there was a high mortality rate between the final stages  being juveniles into adulthood, and that as adult's the breeding seemed to happen in roughly 35% of the population.

I was wondering if the people here who have bred these are finding the same problems in both areas, or if someone has found anythng to improve either situation.

have an order of 4 juvenile and baby marbled crays coming in the morning. Feeling like a kid waiting for christmas. This is sorta a detour for me. I became interested in all the wonderful, colorful little freshwater  shrimp and decided I wanted to do some breeding programs with them. So I set out doing the research. One of the best methods I've found in this day and age of the interwebs is to go to vendor sites and see what they say and link to, so in the process of checking out shrimp I stumbled across the Marbled Crayfish. As soon as I read the words "self-cloning" I was on the hook and not letting go. In nature there are relativly few critters of any complexity that have the ability to reproduce asexually, and a crayfish?!? reading on about water tolerances,etc I knew no matter how deep I got into shrimp these guys were part of the plan.There is so much potential for a critter like this that reproduces on it's own. Just the numbers of critters that could be reached quickly from an animal that does not rely on two sexes is astounding:

1crayfish= 50eggs(just as an example)

51 crayfish= 2550 eggs

2550 crayfish= 127,500 eggs

127,500 crayfish= 6,375,000 eggs

you get the picture.......

So needless to say there will be experimenting going on trying to find useful real world applications for this little wonder.

and lets face it, even if I don't find some pot of gold in them, they are pretty darned neat looking, and just that would be enough.

Still working on making sure I can keep stable parameters for shrimp, so these guys are a bonus side project while I fine tune my shimp tanks.

glad someone started this thread. Been having similar thoughts myself, now I can learn and see if it is possible

Fish less cycle is quicker because you can have ammonia and nitrite levels that are toxic to any fish tank inhabitants.

Makes sense. So ideally you set-up a new tank, put in substrate and plants, crank up the heat to 86, and squeeze the good stuff out of a filter from an already established tank? I have read people on here saying they cycle a tank in less then a week, is this the golden path to that? Roughly how long do you maintain the 86 deg f temp? 

Do you have another tank already established that you ca rinse the filter media in this tank? I have cycled four tanks recently and non of them got cloudy. And you do not need to swap out bio rings they will last a long time. The majority of your bacteria live in the substrate and if you are using a double sponge filter just remove and rinse one sponge a month (in dirty tank water). A fish less cycle is quicker than fish in which can take a couple months and kill fish. I personally only do fish less cycles and it would help if your temp was higher, mine are set at 86 for cycling.

wow was I ever working on the wrong assumption! I put the fish and ghost shrimp in there under the idea that they would add to the bioload of waste products and whatnot and make it cycle faster.

No, unfortunately this is the first fish tank I've set up in many,many years and either the info has changed or my memory got muddy on certain aspects of cycling.

tanks. Thanks for the info about the bio rings and double sponge filter.

You did bring up an interesting point on the substrate, which this stuff is supposed to already have live cultures of the good stuff already in it.

I guess I just need to go ahead and buy my testing supplies next and stop guessing and get actual data going on.

Are you going to be keeping Neos?

 

Also how long has the cycle been going?

 

If you switch to RO water the 0 KH can cause wild swings in PH that can be deadly that's why most people used buffering substrate to stabilize the tank.

 

Last thing is if you switch to RO water for such a small tank you can get away with just using store bought RO water. Get a 5g jug and if you have a grocery store with a RO water dispenser then use that for now (cost me $1.50 to fill a 5g jug). You will also need to get GH+ to add to the RO water before adding to the tank.

I'll admit I haven't quite figured out which type of shrimp I'm going to start out with, still reading up on all the various types and care.

The tank has been cycling at this point for a week now.

Right after I posted this I read another post where someone brought up using RO water from Walmart, which is probably what I'll do at first until I see if I have the talent and patience to go bigger with this hobby. I must admit, while the shrimp look beautiful and I would love to get into the genetic aspect of breeding them, the true aquatic crabs and crayfish are also really grabbing my attention.I have an old 40 gallon square tank that I'm thinking would be great to set up for breeding marbled crayfish.

Ok, so last Saturday I started cycling a Fluval spec V. I used eco-complete planted aquarium substrate, put in several fernish looking plants, and two packs of water plant bulbs. the substrate is roughly 2 1/4" deep and I have the water pump running right now at about 3/4th's of it's peak flow, whatever that is,but will be cutting that back before adding any "fancy" shrimp to it and using unfiltered well water that I know is high in calcium.I used the bio rings but did not bother to put the charcoal in the filter, my plan is in a month from now add another bag of bio rings and then I can alternate changing them to cut down on any "bio shock" to the system. I'm also going to add one of those popular double ended foam air pump driven filters as an "assist" to filtration and pumping system already in place.

To give the cycling a jump start, I put in two Cobra guppies and 5 ghost shrimp, and have the temp set at 78.

It has been a good many years since I've cycled a tank, and it seems to me I should have hit the "cloudy" stage long before now, and I haven't. So is this faulty memory or did using that substrate with it's active colonies make for a very smooth cycle? or is it just making the cycle getting to the cloudy stage take longer?

From reading up on here I do understand that I will want to get a RO unit before I head seriously in shrimp, and I will, just like I still need to buy testing equipment and whatnot, but I wanted to get a tank cycling first just because of how long it can take to get it set-up to be stable for long term shrimp care.

Howdy, getting ready to start out Nano style myself. Just ordered a Fluval Spec V and the start of things to get it cycled properly.

good find!

welcome! completely in the research stage myself. Although not quite so much experience in selective breeding, but do have some experience with dart frogs and a few lizards. Although I do want to get into the shrimp breeding aspect a bit, my main concentration is going to be aquaponic systems utilizing marbled crayfish.

Anyway, glad to see you aboard.