Copepods in the Rotifers!

[mwp]

AHA AHA AHA! Got my jeweler's loop today and wow, what I THOUGHT I was culturing was L-Strain Rotifers. HARDLY! They're some sort of Copepod! Very few rotifers in the mix, but tons upon tons of tiny swimming copepods. I even compared what I was looking at with a fresh sample of rotifers from a local shop - DEFINITELY NOT rotifers I'd say the largest are on par with Brine nauplii, the smallest are much smaller but larger than rotifers, that's for sure...

Well, hmm...all this time the copepod I've been working with is Reed's "Tiggerpods"; somehow I inadvertently innoculated my rotifer cultures (from Florida Aqua Farms) with some sort of copepod that does QUITE WELL in culture that's much smaller than the "Tiggerpod". If anyone wants to take a closer look or trying starting up a sample, maybe tell me what they are, I'd be glad to get some to ya - PM me.

BTW, that explains why my GBG larvae all died in 24 hours...they couldn't eat these guys I guess!

MP

 

[mwp]

Got the little buggers slowed down (quick freeze will do that..). The rotifers sprung back to life, but the "copepods" were lifeless upon thawing. Here's what I can say 'bout them.

1. The females carry eggs hanging from the posterior, kinda like the "Tiggerpods".

2. They spend a lot of time swimming

3. The kinda fit the classic copepod look, having a tapered cylindrical body with 2 extensions at the head and 2 off the hind end.

Keep in mind, that's only 10X mag...wish I could see more.

Matt

 

[marinebetta]

Kind of look like this? but with eggs?

If they're smaller than BBS as an adult (which they would be with eggs), then they are pretty small pods.

And if they are swarming around in numbers enough for you to think they were rotifers, then they must be easy to grow and at high density too!....and free swimming to boot! :eek1:

Don't do anything different from what you're doing now, and get someone in the field to have a look - you may be on to something!! Remember....it's the copepod nauplii that are fed to larval fish - and they are much smaller than the adults...

 

[mwp]

Indeed, that's what I was thinking...while I personally don't have use for these, well, someone out there might, and they DOE seem to be growing fairly dense, at least at first glance.

The pic is fairly close to what they look like, although the anterior "antenna" are definitely shorter than the "tails"; at least from what I can see at 10X, proportionally, they'd be like 50% the length of the specimen pictured above, and the tails woudl be 100% longer.

Seriously, if anyone out there wants to take a closer look at these, I'd be glad to work something out to get 'em in your hands. I changed 75% of the culture today 'cause it was getting kinda rank. Did some quick collections; couldn't find any of these pods with eggs today but the ones I DID find were roughly 2X to 4X the total "mass" of the L-Strain Rotifers in the culture. So bigger than a rotifer, but still probably smaller than Brine nauplii (I'll get some out for comparison in a few days when I need nauplii again and see for sure).

In ANY case, very small pods. I'd hate to keep culturing them when I don't have any apparent NEED for them (afterall, it's rotifers & LARGER pods I'm after, not these little buggers - no doubt these guys are hindering rotifer production!).

FWIW,

MP

 

[marinebetta]

I'll be happy to try some of them out but....well....I'm kind of far to ship it . If you happen to still have it sometime in Feb/Mar, I might have an address in the US that you can ship it to for me - I'll cover the postage etc. I'll check with you then....

If the antennae are shorter, then it's good. Also it's mainly the width of the zooplankton that is important for larval fish ingestion - up to a certain length, I suppose....

 

[Luis A M]

You positive they swim in the water column and donÃ"šÃ‚´t glide on the walls?
Would be good to have pics,may be you found a good strain.
IME rotifers always take and destroy calanoid pods cultures,not the opposite.

 

[mwp]

DEFINITELY positive that they swim in the water column...they like to hang towards the surface and appear to be positively phototrophic. I've seen some on the sides of the culture container, but in one of the 2 remaining "infested cultures" they're clearly moving about the water's surface and such. To the naked eye, the look like little jerky moving white "rods".

MP

 

[GreshamH]

<a href=showthread.php?s=&postid=6616674#post6616674 target=_blank>Originally posted</a> by Luis A M
You positive they swim in the water column and donÃ"šÃ‚´t glide on the walls?
Would be good to have pics,may be you found a good strain.
IME rotifers always take and destroy calanoid pods cultures,not the opposite.

This has been my experience as well. I don't even grow the Tigriopus in the same green house as our rotifers because of this.

 

[GreshamH]

Here's a pic of a "Tigger-Pod" (Trigriopus californicus) adult:

And here's a pic of a L-Strain rotifer for you:

 

[spawner]

Man those Trigriopus are spiny.

Your copepods in your rotifers are most likley harpacs, not calanoids, form your lacking of a tail and short antenna comment.

 

[mwp]

Here's the best picture I can get you guys at this point (don't have any better equipment).

It's a microscope slide (have those on hand for spreading butterflies of all things!) resting on a small mag-light type flashlight, shot with the macro on my Nikon 5700. I'm not 100% that the "rotifers" are actually rotifers...it's one thing looking at them right there, it's another thing when I finally got back to review the photos.

Matt