Cherry Shrimp Survival Techniques

[pedzola]

I have a paludarium with cherry shrimp and a single betta.

Unfortunately, despite having a lot of plants and hiding spots for the shrimp, the betta still finds them delicious and manages to get one sometimes.

I have seen him attack, kill, and eat a shrimp before (I didn't catch him on time to prevent it). But today I saw something unique...

He was chasing a shrimp around and nipped it. The shrimp immediately fell to the bottom of the tank motionless. Of course I thought that it was pointless to help at this point because the shrimp was dead so I observed for a few seconds.

The betta nipped at the motionless body again... I realized at this point that there was actually no physical damage to the shrimp... all legs intact, everything looked good... so I shooed the betta away and held the shrimp in a small net for a little bit, swaying him back and forth in the water.

First the legs started twitching, then after about a minute he came to life and swam away, seemingly unphased.

My conclusion is that the shrimp was playing dead.

Has anyone seen this before? My betta is vicious and I'm sure he would have eaten this shrimp, so playing dead actually made his situation much worse... and I can see how other shrimps could have met an untimely fate if they had a similar reaction.

But perhaps it helps them in the wild?

Comments? Anyone else ever witness this?

 

[pixl8r]

I have never notices this a a survival tactic (playing possum). I am more inclined to think that the shrimp had been stunned. The most common survival tactic that I've seen shrimp do is the tail flick. It quickly propels them several inches. I highly doubt that wild shrimp would play dead to avoid being eaten. Most fish, and invertebrates for that matter, don't mind eating carrion.

Also, the fact that the beta is harassing your shrimp will lead to drastically shortened life spans, for your shrimp. Stress kills. If you don't mind the predation, and your shrimp colony is able to maintain a stable population count, it's up to your preference, whether or not you take action.

 

[pedzola]

Yes, I'm trying to find a volunteer to take the betta. I will turn this into a shrimp-only tank as soon as I find him a new home.

I'm debating getting another tank for him, maybe a 5g mini-bow or something. But don't really have a place to put it. And don't feel like putting $50+ into a fish who has been nothing but a PITA! haha

But stunned... ok, I can buy that. They most certainly do the tail flick. Stunned might be a better explanation than playing dead.