single crayfish just laid eggs

[bcpon]

Our crayfish has laid eggs in the last few days and is spending a great deal more time in the cave she dug out of the gravel under a piece of slate. She's in a 50 gal. aquarium with a variety of tropical fish and everyone gets along fine. We've had her for about 6-8 mos and this is the 1st time she's laid eggs. Since we have no male, I assume they aren't fertilized? Is there anything I need to give her during this time? Will the eggs simply fall off eventually and get eaten by the fish? She's tripled her size since we brought her home.

Thanks!

[jbeining75]

springs coming crayfish usually lay eggs in the spring......... is this the first time you noticed eggs....... was she i a tank full of others when you got her. cold water crawfish can carry eggs for months.....

[bcpon]

Yup...this is the first time I noticed them....they are huge!! She was in a tank with lots of other crayfish, but like I said, we've had her for a long time. We really enjoy her...every morning we wake up and she's rearranged the tank and gravel.

[jbeining75]

hmmm... I'm not sure I know they can carry eggs for a while by the way welcome to ac...... someone else should answer the post also.. let me see what I can find

[jbeining75]

I don't know if they spawn eggs without mating or not....... usually the male and female lay belly to belly the male lays a sperm sac on the females belly then the female spawns the eggs and they are fertilized..... She may have had them and just now dropped them....

[bcpon]

She's carrying them under her tail, attached to the swimmerets? She hasn't been as active in the last few days. We usually see her wandering around, climbing on the rocks, up the plants (plastic) and begging for food...sometimes making a grab for a fish that gets too close. I was so surprised to see the eggs, though.

[jbeining75]

hmm I guess they may also spawn with no partner happens sometimes with fish too.....

[squirt_12]

they may be fertilized because i think i remember hearing somewhere that they can carry sperm for a while like mollies and such.
But if they arn't fertilized she will probably just end up eating them.

[shockshockshad]

I bet they aren't fertilized. If they are, make sure that you keep her in a tank thats dark, and the babies will hatch in 2 weeks or so. Then remove here because she will eat her babies.
BTW crayfish are coldwater and will die in tropical waters.

[marques-souza]

Hey guys,

I would like to tell you that some Crayfish species are parthenogenetic, i.e., they don't need fertilization to lay fertile eggs. The eggs are clones from the mother and ALL individual from this species are female.
I work with parthenogenetic crayfish in UC Berkeley.

So, if you have a lonely crayfish laying eggs out of a sudden, don't panic. They could indeed be unfetilized, but check the species you have, maybe they are parthenogenetic and you're gonna have a bunch of little clones of the mother pretty soon.

Best

[William]

what do you do with parthenogenetic crayfish in UC Berkeley?

[marques-souza]

Hey William,

I study molecular embryology in Arthropods, with enphasis in Decapods. You know, studying genes that are involved in embryonic development.
I started as a postdoc one month ago, so I'm still in the reading process and setting up the logistics. I have already some tanks with the Red Cherry Shrimp (RCS) and some with crayfish. Primarily I want to see how these animals develop from the fertilized eggs into the hatchlings and the RCS are really good for this since they have a high reproductive rate. The crayfish is specially interesting for me to see how embryogenesis take place in an animal reproducing clones of itself.

Best,

Henrique

[William]

Sounds like we have a new shrimp and crayfish expert on the forum.

You wouldn´t happen to have a list of which crwafish species that are parthenogenetic would you?

BTW Welcome to Aquaticcommunity, Henrique

[marques-souza]

Thank you very much William. At the moment I would be rather called a "potential" expert in shrimp and crayfish. I have a more molecular biology background and was working with insect development for my PhD. Actually, I've been learning a lot of interesting things here in AquaticCommunity.
I'm enjoying a lot to read and learn about this little shrimps and crayfish and I'm setting up a bunch of experiments to understand their development. Let's see.

About the crayfish, there is actually only one species, the Marbled Crayfish (or Marmorkrebs), that is parthenogenetic and it was firstly described in Germany, identified in domestic aquaria. It seems that one guy had the exact same question that "bcpon" had in this forum. "If I just have one guy, how could it reproduce??"
Then a German scientist studied this question experimentally and verified the parthenogenesis. Here is the original article:
http://www.nature.com/nature/journal/v421/n6925/full/421806a.html

This species is greatly widespread in Europeans aquaria and it seems that it has American origins, so it could well be that it is widespread in the States as well.
I will take a picture of the ones I have here and post it later today, ok?!

Sorry for the huge text, I just love discussing this beautiful creatures and the amazing ways nature has found to reproduce life.

Nice chating with you. I will post the pic as soon as I take it.

Best,

Henrique

[marques-souza]

Oh, the American relative of this Crayfish is the species Procambarus fallax, from Florida.

[William]

Sorry for the huge text, I just love discussing this beautiful creatures and the amazing ways nature has found to reproduce life.


Don´t apologise. Your post are very intresting and I enjoy reading them. So feel free to write long text in the future as well. Looking forward to seeing the picture.

Nice chatting with you too.

William

[zeon]

Thank you very much William. At the moment I would be rather called a "potential" expert in shrimp and crayfish. I have a more molecular biology background and was working with insect development for my PhD. Actually, I've been learning a lot of interesting things here in AquaticCommunity.
I'm enjoying a lot to read and learn about this little shrimps and crayfish and I'm setting up a bunch of experiments to understand their development. Let's see.

About the crayfish, there is actually only one species, the Marbled Crayfish (or Marmorkrebs), that is parthenogenetic and it was firstly described in Germany, identified in domestic aquaria. It seems that one guy had the exact same question that "bcpon" had in this forum. "If I just have one guy, how could it reproduce??"
Then a German scientist studied this question experimentally and verified the parthenogenesis. Here is the original article:
http://www.nature.com/nature/journal/v421/n6925/full/421806a.html

This species is greatly widespread in Europeans aquaria and it seems that it has American origins, so it could well be that it is widespread in the States as well.
I will take a picture of the ones I have here and post it later today, ok?!

Sorry for the huge text, I just love discussing this beautiful creatures and the amazing ways nature has found to reproduce life.

Nice chating with you. I will post the pic as soon as I take it.

Best,

Henrique

Great info! Thanks for sharing, and I agree long posts are great, especially like this one.