Posts Tagged ‘crab larvae’

The Post – Scarlett O’Hara’s Moved to the Nursery

March 25, 2008

Yesterday was one week that we noticed Scarlett O’Hara was pregnant again.

Looking back over my notes on the first pregnancy – we noticed her eggs (2/17/08), then moved her about a week later (2/24/08) into the spare tank I’d just set up. Five days later she delivered. (2/29/08) The one thing we weren’t sure the first time was how long she was carrying the eggs before we noticed. From my log notes, I saw her on the 14th and didn’t notice anything. So, I expect it wasn’t much before 2/17 that she brought the eggs out on her abdomen. Given that, it appears it was about a two week gestation period.

If history repeats itself, 2 weeks will be about 3/31/08, next Monday.

With that in mind, I decided to move Scarlett O’Hara to the nursery. She seems calm this time, doesn’t seem disturbed by the calcium sand, sat under the water filter for a while, then moved toward the side of the tank and greedily went after the shrimp pellets I dropped in.

Since I can’t be sure when the eggs will hatch, I will shut off the water filter today.

Yesterday’s water parameters show both the main aquarium and the nursery aquarium to be about equal. No nitrates in the nursery yet, but moving Scarlett into it should kickstart the nitrogen cycle; I did drop in some shrimp pellets into the nursery the other day, just so “something” organic would be “rotting” in there and feed the nitrogen-fixing bacteria. Hopefully that will be enough to do the trick.

Yesterday’s parameters:

Main aquarium (before moving Scarlett):

Salinity 1.0115, Chlorine 0, Alkalinity 300, Hardness >300, Nitrites 0, Nitrates 20, pH 7.8-8.0

Nursery aquarium:

Salinity 1.013, Chlorine 0, Alkalinity 300, Hardness >300, Nitrites 0-0.5, Nitrates 0, pH 8.2

I have brine shrimp eggs though I won’t start hatching those until the fiddler babies are born. According to the package they take about 24-36 hours to hatch. I have something called “San Francisco Bay Brand: Brine Shrimp Hatch Mix” It has eggs, sodium chloride and magnesium sulfate and you just add a liter of water. I have a container with an air bubbler to put the mix in. No heater though. Just not going to spend another $30 or $40 for a brine shrimp heater. The kid at the pet store who has a marine tank and raises brine shrimp for his fish told me there’s no reason you can’t hatch them at room temp. He does it all the time. I’ll let you know how that works. I don’t know how many shrimp I’ll get in one of these packets. There’s three packets to the package. If needed, I’ll go back to the aquarium store and just get the larger container of shrimp eggs.

If you want to see some good instructions on hatching brine shrimp, as well as some pictures of the shrimp as they go from eggs to the tiny shrimps, click here for the San Francisco Bay Brand website.

In any event, I have the Kent Marine “ZooPlex” product to feed the babies for the first few days until the crab larvae are large enough to chase down live brine shrimp. This food is made to work well for invertebrate larvae and is considered a good brine shrimp replacement. It’s available at PetsMart. Again, we’ll see how it goes.

The Post – Admiral Byrd, A Comforting Constant in Life

March 14, 2008

It’s been a day of taxes and bills and other aggravations…enough to drive any sane person to the comfort of their fiddler crabs. 🙂

Admiral Byrd has been robustly marching around the tank, and no matter if he’s on “gravel hill,” the top of his “fake cave” or perched on “live rock” he stands tall and waves his claw. We just walked back in the house from dinner and the first sight to greet us across the kitchen was Admiral Byrd waving. Now we know deep down inside that he really couldn’t care less about us unless we’re a female fiddler crab, but still, on a tired night we could live in denial and pretend our “pet” is welcoming us home.

On a bit more serious note, I received a great comment from someone about my post on the death of the fiddler babies and how the Discovery forum person, Horseyhannah, said not to even bother trying to raise babies.

This person currently has living crab larvae – day 3 – and she’s offered a lot of ideas from her own experiences. There is SUCH good information and several suggestions for fiddler crab owners in her comments. I wanted to first say THANK YOU! And secondly, for anyone who didn’t catch the comment, just click here to read it.

She noted that she doesn’t use substrate on the tank bottom, which is interesting to me. I have heard others who’ve done the same, so I think there might be some merit to that approach. For myself this time around I will use the calcium substrate, since by the time I got that post, I had already started setting up the nursery tank with the new sand. So I’ll see how the sand “experiment” goes. But still, her approach to not using substrate seems very interesting and if she wants to send any updates on how it’s going, that would be great. I imagine there are many others out there who’d like to know if that is a better way to go. So anyone with info on keeping the tank bottom bare, please do send along your experiences.

I also appreciated her kind comment about my blog postings – re my novel, the fiddlers, and my marriage. Many thanks. To respond to the requests in her comment:

1) – There are many more posts to come on the progress of my novel, Under the Pier, and about life in general.

2) – She asked if I could put all the fiddler crab posts together in one place for all those “crab junkies.” Well, have no fear – they already are. On the right-hand side of my main blog page, under the “Pages” listing, click on the page called:

“And What’s the Deal With All The Fiddler Crab Stuff”

Every fiddler posting is on that page with a live link to each and every post. So crab junkies – have a great time. 🙂

For anyone who is following the progress of my “Author Journey,” or for the process and progress of my novel, Under the Pier, I’ve done the same thing. Each topic has a page with all the posts listed there, and live links to them.

If you should find your way to my blog on a page that doesn’t have the “Page list” on the right, just click on the Soul Mosaic words in my header and it will bring up the main day’s page. Then you’ll see the Page list on the right.

Well, I will re-group tomorrow. It is simply nice to know that in spite of irritating taxes and bills and other life annoyances, there are those constants like Admiral Byrd waving his claw no matter what time, day or night, that you walk in the room.

Happy Weekend to you all.

The Post – The Fiddler Babies are Dead, But We’ll Start Over And Prove Horseyhannah Wrong!!

March 10, 2008

The fiddler babies are dead.

I am sad, because I really did like the fiddler babies. I looked around on the web last night for clues to their demise and that’s when I got ticked.

The Discovery Channel’s Animal Planet Online Forum had a discussion of how to raise fiddler crab larvae. “Horseyhannah,” a senior member on the forum basically told a member who asked how to raise fiddler larvae that it’s so hard and requires hundreds of thousands of dollars of equipment to simulate ocean environments, waves, tides, etc. so it’s really not possible. Horseyhannah told the person to just enjoy the adult fiddler crabs and don’t bother to raise the babies. Needless to say, the person asking the question was polite, said thank you, agreed it will probably be hard, but would still like to know horseyhannah’s info source…just in case she decided to raise them anyway. My answer to that person is: GO FOR IT!!!! PROVE HORSEYHANNAH WRONG!!!!!

In fact, I am determined to do just that. In my book, Horseyhannah has thrown down the gauntlet and I am determined to prove her wrong.

I will concede failure on this first attempt. I am sad as I was so looking forward to having some fiddler grandchildren survive. I was frustrated and disappointed because contrary to the advice above, I think it was not only possible, but it was happening. Because I lost them so quickly, that tells me something overwhelming happened in the tank to kill them all off at once.

To review, by Friday afternoon, there were no babies moving around. It was a rapid decline, and up until that point, we still had quite a large number alive. I have to conclude it was a water quality issue and I think the biggest culprit was the live phytoplankton. But to go through this methodically, let me look at several things. If it were salinity, ie they didn’t like the marine environment I don’t think they would have lived that long in it to start with. I suspect the following things were problems:

1) I used gravel and we did lose MANY babies because they burrowed into the gravel crevices and died there.

2) The nitrite levels in the water spiked suddenly and got very toxic. Thoughts on this point:

a) I didn’t get the tank set up early enough to have a mature and well-functioning nitrogen cycle.

b) I either fed them the wrong food, or too much, or both. The wrong food or too much food meant it didn’t get eaten, sat in the tank and rotted. OR it created a huge algae bloom that raised nitrite levels beyond a tolerable level.

c) I didn’t change the water fast enough once I realized the nitrites were a problem, though given the phytoplankton issue, I was probablly fighting a losing battle from the beginning.

d) I no doubt lost babies doing the water changes because my only option was to bail water out of the tank and pour it down the drain

So boys and girls, what have I learned from this first attempt that can be done better next time?

1) I will use calcium sand not gravel. Aside from the fact that the babies won’t get trapped in the substrate material, the calcium sand will provide enough calcium for the babies to stay healthy during many molts.

2) Figure out the right food and amount. The gentleman from Finland whose article I quoted a few days back (he raised the Red Clayed Mangrove crabs) fed his larval crab Artemia…brine shrimp. He had a hatchery right in the tank to have a fresh supply. He also used something called JBL Nobilfluid for when the larvae were too small for the brine shrimp. This product is probably similar to the Small Fry liquid food I was using. It it made by a company in Germany and I’m trying to find out if it is marketed here. It has 50 different vitamins and minerals as well as brine shrimp and is geared for newly hatched aquatic animals too small to tackle live brine shrimp yet.

3) DON’T USE LIVE PHYTOPLANKTON this time. In spite of an almost 50% water change, I could not get the nitrite levels down. In fact, they kept rising. Now I am finding information that phytoplankton excrete nitrites. The better the phytoplankton did, the higher the nitrites. And with each feeding I basically inoculated the tank with more. I created my very own algae bloom which released such high nitrite levels, the babies were doomed.

Frankly, the tank seemed to be doing okay until I started using the phytoplankton. I would feed the liquid Small Fry food and while the tank would be cloudy initially, it cleared quickly, telling me the babies ate the food. At that point, in spite of it being a new tank with an unestablished nitrogen cycle, the nitrite levels stayed pretty low. However, once I started using the phytoplankton, the tank got cloudy quickly, the nitrite levels spiked, the water had a greenish tint, and the larval crabs numbers dropped dramatically. So, NO phytoplankton.

4) For water changes, instead of bailing water out, I will use the water bubbler as my “filter” to keep the babies in the tank, and let gravity siphon water out of the tube. I have the bubbler’s pump set up beneath the tank and have a regulator valve in the line to keep water from back-flowing from the air bubbler, into the pump. If I remove the valve and let the tube sit in a bucket, it will slowly siphon off water through the bubbler. This should let me slowly get water out for changes, without bailing larval crabs out of the tank and sending them down my kitchen drain.

So. I will start over. Admiral Byrd is doing his part, trying to get Scarlett O’Hara to notice him. Scarlett O’Hara has been eating and hanging around Admiral Byrd’s cave den. I figure it’s only a matter of time before Scarlett has eggs again. Therefore, tomorrow, I will take down the nursery tank, clean it out, get some calcium sand, and get that tank up and running again with the live rock in it, and get that nitrogen cycle stable.

We are going to try this again! My husband and I would love some fiddler grandchildren, 🙂 and even he said that we must prove Horseyhannah wrong!!! Stay tuned.

The Gift – A Fiddler Crab Extra!! Meet the Babies!

March 2, 2008

fiddler-crab-under-100x-magnification.jpg

Okay. You’re wondering what in God’s name this thing is. Well, it’s one of the crab babies, at least my rough sketch rendition of one. (If  you want to see real photos of the zoeae and later larval stages of fiddler crabs, click here ).

It’s the best I can do. I’m spoiled because I am used to working in labs with good equipment.

In the lab I would have put an aliquot of liquid from the aquarium in a test tube, spun it down in the centrifuge, poured off the supernatant, and made a slide out of the sediment, which would be concentrated crab larvae, instead of chasing one unlucky soul all around the microscope slide trying to catch him long enough to see him.

I would have had nice stains to chose from to make the larvae show up better. Today I had McCormick’s yellow food coloring from Harris Teeter.

I would have had a nice Zeiss microscope with oil immersion lenses and fine optics. Instead, I have a Milben kids’ microscope, circa 1965, in a wooden case, with an EverReady 5 volt flashlight shining in the mirror to light the stage. (And if you want a kick, click here to see a similar setup to my microscope and wooden case. It even has the dissecting kit tool indentations in the styrafoam. I had those dissecting tools a long time ago. It says something when you search Google for Milben microscope and it’s listed under “antique sites.”)

I would have had a nice Zeiss microscope with a camera attached to photograph what I saw. Instead, I had to sketch it. I don’t have one of those neat electronic tablets to draw with. All I had is the “pencil” tool on my son’s Photoshop program that I barely know how to use.

So, I know, stop whining. I’m not in the lab anymore. Given all this, I still managed to catch one crab baby, watch him through my very “SUB-OPTIMAL” microscope, in food coloring stain, and draw you a WAY suboptimal sketch.

But still, what the sketch shows is the head part on the right, with two little “?claws” moving back and forth rapidly. It stretches out with the tail on the left. We could even see “material” moving through the crab from the head, out the tail. Yes, out the tail. My husband caught that one. So I guess we can assume the crab baby has been eating the food I served. 🙂

In any event, minus all the fancy equipment, it’s the best I can give you, but still it’s something. I should note that this was a 100x magnification.

We have noted that Days 1 and 2 there was a fair reduction in numbers of larvae and my husband noted the blackened area that looked like a mass murder in one corner of the tank deep down in the gravel where many babies perished. Still, there are LOTS of babies swimming in the tank AND they are bigger than yesterday. If you hold a magnifying glass up to the tank, you can see tiny tails. So some are thriving after all.

If many many thrive, at least the guys at Fish Pros said they’d be happy to buy some from me for cash or store credit. That would be great. I’m always in need of new supplies. 🙂

Salinity is almost “ocean” at 1.017. Should reach 1.020 later today.

Anyway, now you’ve “sort of” met the babies.

….about that centrifuge – it occurred to me I could take a small, capped plastic tube and tie a rope around it and spin it around my head. Then I thought, maybe even better – tape the tube to the inside of my washing machine and run it on the spin cycle. But leave it to my engineer husband: find a way to attached two capped tubes on a rod opposite each other, connect them to a power drill, and turn the drill on….THAT’S the best RPMs for the money. 🙂