Shrimp suddenly active - why?

[fatboy]

Maybe you can help me understand why all my shrimp have suddenly become so active.

The cherry reds are mostly 6-8 weeks old. Usually they spend their time nibbling at stuff but over the last few days they are all swimming around the tank. The girls seem quieter. It's the boys that seem most active, and I've noticed a few orgies going on, 3-7 shrimp all grabbing onto each other. Could the activity be horny shrimp looking for partners? They're all eating and will stop to nibble pellets.

My filter feeders (atya gabonensis) are also going nuts. Tonight I watched them run around for an hour and they aren't slowing down. Normally they spend all day filtering and walk around slowly at night. Over the last few days they've become more and more active and are now charging through the plants, lifting filters out the way and pushing rocks. They're so strong. I mean, amazingly so. The big one lay under the sponge filter on his back, lifted it up with his swimming legs and spent a minute filtering before dropping it and and trying to knock over some bogwood.

When I added the cherry reds last week I removed 2 dwarf puffers. Now the only fish are 1 otociclus and 1 britlenose pleco. I've also removed the power filter and added another sponge filter to the 2 mature ones I had in there.

Do you think the active atya gabonesis could be because they are no longer worried about the DPs? It's a big change in behaviour and the DPs never bothered the shrimp.

I've checked the water and it's fine, no change in PH (a constant 7.6) and no detectable ammonia or nitrate.

I feel like a worried parent, anxious about any activity, both too much or too little. lol

Any thoughts would be appreciated. :cool:

[gr81]

What you write about Cherries seems as mating rituals. But the age... how long are they?

[simcb]

it sound normal or rather good news cause the males are ready to mate.

[Robert]

Hi,
don't worry, everything seems to be ok. Your shrimps just grew fast and the they are able to mate now. Sometimes I'm also a bit skeptical if I see such tiny shrimps so active. But I also saw cherry females with a size of less than 1,5cm carrying eggs. So some of them seem to reach sexual majurity pretty fast, much faster than other species. Normally it takes 3 months before they reach sexual majurity but if you do lots of water changes and feed them well, they grow a bit better.

regards
Robert

[fatboy]

Cool, nice to know it's not a problem. Thanks, guys.

gr81, the shrimp are mostly 1.5 - 2cm long. The girls are all developing yellow saddles (eggs in the ovaries). I fed them Hikari crab pellets from birth and perhaps that enhanced their growth.

By the way, I think my Atya Gabonensis was trying to find a new spot to filter. He's used to live on the power filter and I've set up a sponge filter to create a water flow. He's now sitting in that flow instead of running around.

[YuccaPatrol]

I did my first water change today after receiving my cherry shrimp last week. I was amazed to find that they became VERY active afterwards.

I also did not feed them anything today. I just let them forage around and find what they could in the tank.

I wonder if they are more active if they have to spend their time searching for food rather than just gorging themselves on pieces of algae wafer?

Whether it is the water change or the fact that I backed off on the feeding, I do not know. I do know that I like the increased activity. :P

[retardo]

I'd take the bristlenose pleco out of the tank. They are opportunistic eaters and will make a snack out of any shrimp small enough to fit in its mouth. The oto should be ok.