rosenbergi young

prawnman88 · Post by **prawnman88** » Thu Dec 22, 2005 4:33 pm

can u tell females when there just a inch long ? i have 5 running arroud and i i have noticed 2 have black stripes on there carpice like black linesi saw this on large females one time at petco or am i just seeing nothing ? thx guys

chlorophyll · Post by **chlorophyll** » Fri Dec 23, 2005 12:48 am

I believe at that size they're too young to sex just by looking at them. I don't know about the lines though. Young M. rosenbergii that I've seen have always looked more or less like clear ghost shrimp. I've never noticed distinctive lines on female adults, myself.

I don't know what the first sign to look for is, with regard to sexing. I didn't realize mine was female until it was carrying eggs. So I say if it's not carrying eggs by 4 inches, it's male. The ovaries of a female getting ready to lay eggs can also be seen as a faint orange patch under the side of the carapace. I think there's probably an earlier way to sex them just by appearance though. But I don't know.

prawnman88 · Post by **prawnman88** » Sat Dec 24, 2005 11:10 am

i might totally be wrong but my friend badlash has seen the lines or stripes on certin 1 inch roesenbergi also i have 5 in my tank and i have 3 that do and 2 that dont i think the 3 are female but this is only a guess i was looking at adult felmales they seem to have stripes of a sort so who knows i guess im just eager to watch them grow up lol

badflash · Post by **badflash** » Mon Jan 02, 2006 2:16 pm

Here is a pic showing the markings:

This shrimp is about 1.5" and growning very quickly. Too bad the arms don't show clearly. They are very long but very thin and transparent at this point. I'll need to find homes for some of these once they hit 2". I plan to just keep a male and 2 females in my 40 gallon tank.

chlorophyll · Post by **chlorophyll** » Mon Jan 02, 2006 10:04 pm

Oh, I forgot about this thread. You guys are right about the markings (although I don't know of any link to the sex). Depends on what kind of habitat they're in. I had my memory jogged by plopping a juvie into a new tank about a week ago. It got those stripes...really dark too... and also a orange or reddish rostrum. Normally we have these guys are in very bright looking, plain tanks dictated by this white coralline looking gravel. It causes a very boring plain appearance in the shrimp, although they're otherwise healthy. The one that changed color was put in a warm, lit, bare-bottom tank, which is now growing a layer of algae (it's just a water bath that I'm using to heat the water in smaller containers).

prawnman88 · Post by **prawnman88** » Tue Jan 03, 2006 4:33 am

thx dave for the help a good friend in new york sent me 5 of them i think i have 4 left and let me tell u they grow FAST!!!!!! but i love them to death i have mine in a 55 gal tank lots of driftwood and live plants to hide in and some guppies to chase

badflash · Post by **badflash** » Wed Jan 25, 2006 12:31 pm

Some of my prawns now have light blue arms. If that positive indication of being male? I have others that have arms the same length but are orange. I'm thinking these may be male too with the females having much less developed & colored arms.

Anyone confirm or deny?

prawnman88 · Post by **prawnman88** » Wed Jan 25, 2006 3:06 pm

dave 2 of mine have oragnge arms also i have 5 in there there getting very big so soon im going to get rid of atleast 2 of them and keep 3 man they grow fst i have some nice pics but i dont know how to post

prawnman88 · Post by **prawnman88** » Thu Jan 26, 2006 5:10 pm

my first posting a pic http://i40.photobucket.com/albums/e233/ ... miling.jpg

prawnman88 · Post by **prawnman88** » Thu Jan 26, 2006 5:11 pm

badflash · Post by **badflash** » Thu Jan 26, 2006 5:28 pm

I contacted the commercial breeder I got the shrimp from and ask him how to sex these guys. Here is what he said:

Without grabbing them, turning them over on their back and looking for their sex organs, the long blue claws are usually dominant males, the shorter orange claws are usually subdominant males and the lightly pigmented claws are usually females. Females will also develop yellow/orange areas along the back, behind the eyes. These are the ovaries. Depending on water conditions they may lay eggs and hold them under the tail If they are not fertile, they will disappear in a couple days.

I'm seeing a lot of sparing between the blues and orange arms.

prawnman88 · Post by **prawnman88** » Thu Jan 26, 2006 7:04 pm

best pic yet

chlorophyll · Post by **chlorophyll** » Fri Jan 27, 2006 6:00 am

At the stage of these pics, I would say that they can't be sexed by appearance yet.

Actually, all I can say is that the very first time I kept these, I kept 4 in one tank since around the time they were about 1 inch long. I knew little about them and they canibalized each other over the next few months. The first victim ironically was the largest one. From there, the second largest became the last survivor, and had bluish claws. Assumed to be a male, until one day she was carrying unfertilized eggs.

So while they're still juveniles, size, aggression, and perhaps even claw color, may not indicate their sex. But that's just my own very informal conclusion.

badflash · Post by **badflash** » Fri Jan 27, 2006 4:33 pm

OK, so it looks like I got to turn them upside down and feel. I have a manual that tells how.

prawnman88 · Post by **prawnman88** » Fri Jan 27, 2006 4:44 pm

im not touching those little guys i was cleaning the tank today stirring up the crap and one hit the reverse gear let me tell u warp speed i was like damm and another was pinching me thank god there small right now