shrimp size

pleco_breeder · Post by **pleco_breeder** » Wed Jun 06, 2007 6:01 pm

Hello,

As I posted in my RCS thread, I recently found a small group of 1/4 inch juvies in my RCS tank. I was hoping to find out the newborn size when they started spawning, but apparently missed out on that piece of crucial info. I've got other projects going that do need the info, so I'm hoping that someone here can clue me in on the length, and width if known, of newly hatched cherries.

Thanks,

Larry

Shrimp&Snails · Post by **Shrimp&Snails** » Thu Jun 07, 2007 2:23 am

This is taken from the Beginners' Frequently Asked Questions section in the Articles section.

2. How do shrimp reproduce?

Shrimp reproduce via eggs. Eggs are produced in the ovaries of the female, which may or may not show up (depending on coloration of species) as a light or dark patch right behind the head area of the female. After the female molts, the male mates with the female (facing each other) depositing his sperm at the opening of the female genital opening. Shortly after, the eggs migrate from the female's ovaries through her genital opening to the abdomen. As the eggs pass through the female genital opening, they are fertilized by the sperm that had been deposited there by the male earlier. The eggs rest in the pleopod ("swimmerettes", swimming legs) area of the female. She carries them around wherever she goes. Depending on species, it may take anywhere between 2 weeks to 2 months for the young to hatch. Most dwarf shrimp species take 3-4 weeks to hatch. The hatchlings are tiny, barely visible and only a few millimeters long. Some shrimp species produce fully developed young, whereas others produce free-floating larvae that usually need a special saltwater/brackish water setup to be reared to the postlarval (i.e. benthic mini-shrimp) stage, at which point they can be acclimated to freshwater. Time until hatching depends on temperature. The higher the temperature (within reason of course) the shorter the time until hatching. The young hatch directly from among the pleopods. The female does not deposit the eggs anywhere.

pleco_breeder · Post by **pleco_breeder** » Thu Jun 07, 2007 5:32 am

Already read that. Not accurate enough as a few can range from 2-9 before becoming a centimeter. I need accurate size.

Thanks,

Larry Vires

Shrimp&Snails · Post by **Shrimp&Snails** » Thu Jun 07, 2007 8:13 am

pleco_breeder · Post by **pleco_breeder** » Thu Jun 07, 2007 8:57 am

To make a long story short, I will be managing over 200 tanks within the next 6 weeks. Everything in my fishroom is automated, and the last thing I want to worry about is sucking newborns out of my shrimp tanks with the automatic water changer. The smaller the micron rating on the strainer, the more expensive to order it. Therefore, it is important that I get it right the first time.

Larry

mikedmatthews · Post by **mikedmatthews** » Fri Jun 08, 2007 12:21 pm

once you get your colony going, you should be having new fry all the time. why not get a good strainer from the start so you don't have to worry about it?

when you say "sucking out", do you mean you empty your tanks by suction? how's that work out? i use overflows and the fill is pretty slow. the water just gravity feeds out and of the fry in the tank are small, i can ocver the outlet with a filter sponge. would love to see some pictures/diagrams.

pleco_breeder · Post by **pleco_breeder** » Fri Jun 08, 2007 1:55 pm

Mike,

I use bulkheads and either fine or coarse pore pre-filters for the central filtration depending on the species. The water changer requires that I use a micron mesh in order to match up with the 1/2 inch plumbing. I tried foam early on, and there is too much risk involved if it becomes clogged. Because my water changers are controlled by a combination of timers and solenoids to both drain and fill there is a very real risk of overflowing a tank if the mesh is too small. Likewise, by the time that I have another batch of new shrimp to attempt to measure I will have either have found the correct answer to this question or gotten rid of the shrimp to keep the amount of time in the fishroom at a workable level. I'm actually on a time limit on this one.

Larry

mikedmatthews · Post by **mikedmatthews** » Fri Jun 08, 2007 2:24 pm

two ideas then:

1. assuming its a back drilled tank based on your reply, make a loop in your outlet and point the drain up like this (sorry, can't do i nice drawing right now, not at home). they won't want to be on top of it:

---v---______----X
--I-I_I--___-I___X___
--I-I_I-I----I____-___
--I____I-----------X
---------------------X

or

2. make the end in the tank much larger diameter than the bulkhead. if the foam is deep that you put in the PVC, it doesn't have to be super fine, they still won't go through.

i use nylon window screen on my bulkheads and its a problem for when i have egglayer fry in any of those tanks, so i try to cover the bulkhead sin those. my system is what i call "semi-manual". i run a hose from the sink and fill each rack level for 45 minutes each week. none of my shrimp are on that system, but will be eventually.

pleco_breeder · Post by **pleco_breeder** » Fri Jun 08, 2007 3:15 pm

Mike,

I think we're talking about 2 completely different systems here. My understanding of what you're saying is referring to draining from the bulkheads. My water changer is a stand alone so I can just program it and don't have to stand over it to overflow via bulkhead. The strainers I'm referring to are similar to what you're saying for the window screen idea, and I'd be tickled pink if something that cheap would work as a strainer. Nitex runs upward of $70 a yard and more for finer mesh sizes.

Larry Vires

mikedmatthews · Post by **mikedmatthews** » Fri Jun 08, 2007 4:17 pm

yeah, i'm having a hard time envisioning what you have set up then if your bulkheads aren't your drains.

pleco_breeder · Post by **pleco_breeder** » Fri Jun 08, 2007 4:59 pm

Bulkheads are the drains, but are useless as water changer drains because they are going to be at the waterline at all times. By using my method, you can drain 1 gallon per tank, or all but 1/2 inch of the water depending on how you set up the manifold. As you'll notice from the description, you can even set it up to drain different amounts from different tanks if you want to take the time to make it that way.

I don't have any made for the new systems yet, so there is nothing to take a pic of at the moment. I'll try to explain it. There are 2 versions I've used in the past that are options for this.

The first, and easiest, starts with a PVC drain manifold similar to what would be connected to a central filtration system with bulkheads. One piece of 1/2 inch PVC is drilled with as many holes as you can put in it. Hole size really doesn't matter as long as they are not excessively large. Screen/mesh is wrapped around this as a strainer and glued in place. The joints in the manifold, where the lines from your bulkheads would normally run to, have PVC in them that stick up just a slight bit above the water line. There is a "T" in this vertical which is equal to the height of the water level you want to drain the tank to. A second piece of PVC with a "T", and capped at one end just as long as the water depth is lined up along side of it with the "T's" glued. This protects the siphon so that it is never exposed to air and loses suction. A 3/8 inch silicone tube is primed and ran into both the short piece attached to the manifold and the strainer to work as a siphon. It will only siphon till the water line in the manifold and the tank are equal.

As for the automatic part, place a solenoid at the end of each row on the manifold just before it gets to the vertical main. This should be the type that is closed till it recieves a signal to open from a timer or computer software. The main vertical is ran to a floor drain, or as in my case, an irrigation line to the garden. As to timers, most any irrigation timer will work or it is possible to program Linux machines to signal a water change when any of your water quality monitors gets out of whack. It really depends how far you want to get into it.

When the solenoid opens, the water in the manifold drains and the siphon starts.

As mentioned, this is the simple version, and by far the easiest to work with. If you really want, I will try to explain the difficult one, but I serously doubt anyone wanting to use it for anything aside from fish that produce very large fry such as plecos and maybe a few mouthbrooding cichlids. Anything else would be removed from the tank before it ever has a chance to grow out.

Now back to my original question. Is there anyone here that can tell me what size mesh I need or just the dimensions of a newly hatched shrimp. An estimate is fine if accurate details aren't available, but it does need to be reasonably close +/- 1 mm is acceptable as I should be able to reasonably speculate width from that information.

Larry Vires

mikedmatthews · Post by **mikedmatthews** » Fri Jun 08, 2007 6:13 pm

oh that's ingenious! so you took the pipe overflow from the AKA site and set it up to stop flow to waste by shutting down the drain lines, and stopping that flow lets you pick your depth. i've only seen that used to gravity feed to a drain. that sounds seriously cool! you should write an article on your setup. what regulates the flow into the tanks? is there a separate bulkhead for overflow on filling?

ok, so i guess i understand your problem better now. based on using some seives for BBS filtering and seeing the size differences, i would say if you are spawning larval producing shrimp maybe 130 microns would be ok, but for RCS the babies are much bigger. i would think 300-500 micron would be ok, but in either case i think you need to cut your drain speed down. the babies might not pass through, but they could be crushed on the mesh.

what's ironic about your design is tonight i've been sitting here designing a priming piece so i can use that overflow on my undrilled tanks.

pleco_breeder · Post by **pleco_breeder** » Fri Jun 08, 2007 6:55 pm

Mike,

Adjusting flow is easy. Just place a valve inline, or use a smaller diameter silicone tube for siphoning.

I'm not following what you are talking about as a priming piece, but if you explain it I'll guarantee that I either have one or know how to make one. I've built hundreds of central system both hobby and professional both with and without drilling tanks. Let me know what it is you're working on, and I'll return the favor for the shrimp info with plumbing info

Larry

mikedmatthews · Post by **mikedmatthews** » Fri Jun 08, 2007 9:21 pm

well, the design they have on AKA needs to be primed somehow right? so it would seem the only way manually would be to lay under the rack, hold your thumb over the air break, and suck on the drain line. not too appealing. so i was going to put a cap on the drain line and do sort of an aspirator set-up connected to the air break. i figured if i run water past it and draw tank water into the pipe up over the loop to the air break, it should prime pretty quickly, then i just remove the aspirator and the cap. need to get off my butt and build these, i bought parts a couple months ago.

buddy of mine built a drain and fill setup (does one tank at a time) similar to what i want to do here.

pleco_breeder · Post by **pleco_breeder** » Fri Jun 08, 2007 9:34 pm

Using the double J design, you have to prime each tank separately. Use PVC caps to clog off each line. When using that design, I usually keep a bulb siphon around. Drill one of the caps and thread a hose barb in it. Just stand there and squeeze the bulb till water starts running out and go on to the next tank to prime. The solenoids on my racks block the siphon to the vertical main. It's slow to prime, but can really drain a lot of water fast.

Is that something like what you were trying to design?

Larry