tiny berried/saddled RCS

Baby_Girl · Post by **Baby_Girl** » Tue Oct 23, 2007 5:53 pm

I apologize in advance if this is a silly question. Lately I've noticed very small female shrimp in my RCS breeding tank that either have a saddle or are actually ovigerous. By 'tiny' I mean they are only ~13 mm in length. If it weren't for the large eyes, someone might mistake them for opae ula.

I have not seen cherry shrimp this small sexually mature before. This only started happening after the population in my tank reached pretty high densities. Like, there are probably 200 RCS in a 10 gallon tank. Most of those 200 shrimp are young, e.g. not full length yet.

At first I thought, uh oh, this must be bad. My first thought was they are not getting enough food and are shrinking like the opae ula in Torture Spheres. However, if they were starving they wouldn't be able to develop ovaries, much less lay and carry eggs, right?

I am used to RCS females beginning to saddle at around 2 cm in length. Again, I apologize if this question has been addressed previously. But I have not been able to find such an occurrence in any threads here yet. Or perhaps I am not wording my search correctly.

Neonshrimp · Post by **Neonshrimp** » Tue Oct 23, 2007 6:32 pm

However, if they were starving they wouldn't be able to develop ovaries, much less lay and carry eggs, right?

This is a true statement. Shrimp breed when they have enough food.

So how many of these little berried/saddled females do you see?

southerndesert · Post by **southerndesert** » Tue Oct 23, 2007 6:44 pm

I have seen this as well and have some that have had young before even getting much color... Makes the saddle really stand out doesn't it?

Being new to shrimp I didn't give it much thought, but they are quite small it seems. My population has reached the point now where there are always several, saddled, berried, and in between.

The small females have very small young as well I think as I have seen some that seem very tiny. Again I am new to this and have not enough time breeding to recognize oddities as yet

Bill

Baby_Girl · Post by **Baby_Girl** » Tue Oct 23, 2007 7:24 pm

thanks for the replies, guys. It makes me feel better, that I'm not doing something terribly wrong.

Neon, it's hard to say how many of these tiny mature females I have. Too many shrimp in there to keep track! But I'd estimate it's maybe 15-20?

southern, mine are actually quite red by that point. But I do know what you mean. In my community tank I see many pale pink females with a very distinct yellow/tan saddle. Those are all ~2 cm long by then, though. I purposely chose 'higher grade' shrimp to establish my RCS breeding tank, so I really don't have any pale females in there. Even the juveniles and males are red.

I hope this means the shrimp in my RCS tank are healthy and getting plenty to eat. Enough so that they are maturing at a smaller size, younger age? That was my secret hope, but I wasn't sure and didn't want to get my hopes up yet.

edit: when it is light tomorrow, I will catch one of these tiny 'precocious' females and photograph her next to a 'normal' sized female for comparison.

Newjohn · Post by **Newjohn** » Wed Oct 24, 2007 2:43 am

Just my thoughts

As the population grows, the compitition for food increases.
With less food, the shrimp will grow slower

The size / age difference may be different now than when there were fewer shrimp.

I have also noticed small females that were berried in a tank that was stating to get a little crowded.

Just My Thoughts
John

Neonshrimp · Post by **Neonshrimp** » Wed Oct 24, 2007 5:34 am

My tank must not be crowded yet or the shrimp are getting enough foood, as I have not seen this happen in my tanks. I have about 50 adult shrimp in a 10 gallon with two sponge filters. I try to do partial water changes twice a week.

How many shrimp do you have in you tank(s)? Are you keeping up with your water change?

Baby_Girl · Post by **Baby_Girl** » Sun Oct 28, 2007 5:52 pm

sorry for the delayed replies. I was offline for a few days.

That tank has at least 200 shrimp right now, it's a 10 gal. Almost all of them are quite small. I agree with John that they are probably exhibiting slower growth rates due to the crowding. I perform weekly 50% water changes, and NO3 remains < 10 ppm at all times. It already reads 7 ppm out of the tap so I'm not doing too bad

pH is 8.0, same as after it de-gases from the tap. So there is no overabundance of decaying matter that would result in lowering of hardness or pH.

Will take a pic tomorrow.

Baby_Girl · Post by **Baby_Girl** » Tue Oct 30, 2007 11:19 am

Sorry for the delay in posting a pic. Have been busy lately.

These are two females from my RCS breeding tank with a penny for size comparison. BTW, that penny is UNDER the specimen container, not IN it

These two aren't the best examples of my tiny precocious RCS, but I think you still get the idea that they're on the small side. The penny is ~18 mm in diameter, so the shrimp are 15-16 mm long. The redder shrimp has a more apparent saddle probably because she's a little older. The paler shrimp is just starting to develop ovaries.

Here's another shot of the same two shrimps next to an immature female RCS from my community tank. The community tank has less crowding because it's not one of my designated shrimp-breeding setups, and I'm sure the fish perform some population control.

I guess the small maturing shrimp aren't TOO much smaller than her. I had just never seen or heard of this before and wanted to make sure I wasn't doing something wrong to my shrimp.

Neonshrimp · Post by **Neonshrimp** » Tue Oct 30, 2007 11:29 am

Here's another shot of the same two shrimps next to an immature female from my community tank. The community tank has less crowding because it's not one of my designated shrimp-breeding setups.

The one shrimp is noticeably larger than the other two. Are they of the same age?

Baby_Girl · Post by **Baby_Girl** » Tue Oct 30, 2007 11:37 am

Newjohn wrote: I have also noticed small females that were berried in a tank that was stating to get a little crowded.

I'm glad you've noticed this same phenomenon, too. Guess it means I have to work harder to keep my shrimp-breeding colonies down to 'acceptable' levels (e.g. get selling!).

BTW, Neonshrimp, I also use two, sometimes three, sponge filters in my shrimp tanks. They are all over-sized, too, to give the shrimpies extra grazing room. So there's no trace of ammonia or nitrite. If there were, they'd be jumping ship and I'd find dry crunchy shrimp 'snacks' on the floor

Baby_Girl · Post by **Baby_Girl** » Tue Oct 30, 2007 11:41 am

Neonshrimp wrote: The one shrimp is noticeably larger than the other two. Are they of the same age?

I'm glad you could tell the difference. AFter staring at so many cherry shrimp for so long, they started looking the same to me.

I don't know how old these guys are (again, just too many to keep track). I'd suspect the larger one from the community tank is actually younger. This is based purely on coloration.

It would be interesting if I could 'tag' individual shrimp and have a record of their growth rates.

Neonshrimp · Post by **Neonshrimp** » Tue Oct 30, 2007 12:08 pm

I have lost my taste for shrimp for some reason, ever since I started keeping my dwarf shrimp

Baby_Girl · Post by **Baby_Girl** » Tue Oct 30, 2007 4:50 pm

Neonshrimp wrote: I have lost my taste for shrimp for some reason, ever since I started keeping my dwarf shrimp

haha

I know what you mean. My boyfriend used to tease me that he'd eat my little shrimpies. Make a multi-colored dwarf shrimp salad with red, yellow, green, and ghosts. I was horrified, but that was the response he wanted

Now I'm mostly vegetarian, but I really really enjoy seafood. So I guess I'm not really 'vegetarian' except in the Christian sense (only allowed to eat seafood on Fridays and Lent because they're not considered higher animals). Since I work in fisheries and breed lots of dwarf shrimp, I guess I feel my kharma is evening that out