Posts Tagged ‘nitrogen cycle’

The Post – New Fiddler Babies

March 29, 2008

I was amazed to see babies born before Monday. Monday was 2 weeks to the best of my knowledge. So she delivered a couple of days earlier than I expected.

Anyway, yesterday started with me doing a 30% water change as nitrite levels in the tank since Scarlett has been in there, have been hovering between 0.5 – 1.0 ppm. I kept the water filter running to give the water the best chance of staying nitrite free and letting the nitrogen cycle mature.

This evening though, I noticed that Scarlett was very agitated. She kept running back and forth in the tank, climbing up onto the air bubbler and waving her claws in front of her as if trying to spread something in the water. There did not appear to be anything in front of her though. I noticed that the center of the egg mass seemed to be swelling. Given that, I went ahead and shut off the water filter.

For the next hour or two, Scarlett O’Hara kept moving around, seeming very uncomfortable. Around 8:30 p.m. I looked over at the tank and noticed she was sitting quietly in the front of the tank eating. She seemed “slimmer.” Looking closer, I realized, she no longer had the egg mass. So I missed the delivery again. However, a quick look around the tank and I could seen thousands of tiny little dots swimming around.

I fed them a small amount of Small Fry and ZooPlex. I wondered if this will go okay since I couldn’t get the nitrites to zero before they were born.

This morning I got up and looked at the tank. It was a white cloud. I thought, “Oh God, the water quality got worse with all the babies in there and the nitrites are probably through the roof.” I looked at the ammonia monitor and it is in the safe zone. I shined a light into the white murk and could see thousands of babies swimming around. So they’re still alive and ?healthy.

Wondering why the tank is so cloudy, I decided to recheck water parameters:

pH 8.0 – good; alkalinity 300, hardness >300, chlorine 0 – all great results, AND the REAL KICKER OF ALL: NITRITES AND NITRATES ZERO!!!! Puzzled, I repeated the nitrites test using a tube test instead of the dipstick. Again – nitrites are ZERO!!

So water quality is actually BETTER??? I looked in the tank and saw all the babies flitting around and MANY on the calcium sand at the bottom. That’s when the light bulb went off in my head. The water cloudiness is “white” like the bottom sand….could it be cloudy because thousands of little tiny guys are bouncing around against the sand at the bottom, eating whatever’s in it (since it’s ground up from live coral…possibly some microscopic food bits there?), and eating it for calcium for their molting?

If they were out in the ocean they’d have “bottom stuff” to dig around in so maybe this is a good thing? Though it certainly makes it harder to see them. For whatever reason, baby fiddlers seem to like to “head for the bottom” – at least some of them. That happened last time with many burrowing into the gravel and dying. So I will see how this calcium sand thing goes. I am PLEASED though that the water quality is so good.

For today – I need to go feed them again and I will need to start raising the salinity to ocean level. If that IS what should happen, they should survive. If not, well, we’ll find out. One step at a time.

The Post – Scarlett O’Hara “Labor and Delivery” Watch, and Ammonia Monitoring

March 27, 2008

For the last several days, Scarlett has been sitting on top of, or in, the water filter. Even though I shut down the filter Tuesday (so no babies would get sucked up in the filter material should they hatch), she continues to stay inside the empty filter. I guess it’s like a cave – nice and sheltered. She hasn’t come out to eat, but then I imagine that filter material has a ton of bacterial and algal critters all over it.

She DOES need to be in water at some point and on that count I’m not sure how long she can stay out of the water and in the filter. I tried chasing her out of the filter Tuesday afternoon, partially to see if she was okay, and partially to see if overcoming inertia and forcing her out would keep her out, but within minutes she was back inside of the filter. Who knows if she climbs out at night when the lights are off, to go for a swim.

Wed morning she was inside the filter, still sitting at the bottom. She wasn’t moving so I jiggled the filter cartridge enough to see her move. I left her alone until Wed afternooon when I pulled the filter cartridge up a bit. Scarlett O’Hara rushed up and out of the water filter and down into the water. She sat underneath the water filter, so I guess she’s just “staying put in sheltered places.” However, she does appear to be okay.

I tried giving her a couple of shrimp pellets, assuming she must be hungry, but she basically pushed them aside. She did pick at the calcium sand, so I expect she’s looking for algae. I dropped in a couple bits of algae pellets but she ignored those too. So either she isn’t hungry due to the pregnancy, something’s wrong, or she’s full from eating whatever is on that filter packing material. Right now she is still out in the tank and has even wandered over to the air bubbler at the other end of the tank. I am heartened to see her doing her usual activities: climbing up on the bubbler, trying to climb up the side of the tank, and resting on the suction cups behind the air filter that hold it in place. So, for now, I guess, all is well.

My only “curiosity” is “will she stay out into the water to deliver the babies?” I expect she will given that female fiddler crabs look for places in their estuary homes that have active water currents so the eggs can be washed out to sea. So “instinct” alone should propel her back into the tank water at about the time of delivery, no matter how much she likes it inside the water filter. Given she did it right the first time, I can’t imagine she’s forgotten what she needs to do. I missed the delivery the first time so I don’t know exactly what she does to release them. I hope I catch it this time. Also, I do wish I could just ask her why she likes living at the bottom of a dark empty water filter. In lieu of that conversation, all I can do is watch and wait…..

Water parameters Wed afternoon were good: Nitrates 10, Nitrite 0, Hardness >300, Chlorine 0, Alkalinity 300, pH 8.0 and the Ammonia monitor is in the “safe” range at < 0.02 ppm.

The ammonia monitor is a Seachem Ammonia monitor that you can hang inside the tank. No test strips or kits. This one is called the Seachem AmmoniaAlert for Fresh and Marine tanks. It continuously monitors the free ammonia level in the water for over a year.

The monitor is color coded for concentrations:

– Safe (<0.02 ppm), Yellow

– Alert ( 0.05 ppm), Green

– Alarm ( 0.20 mg/dl), Sky Blue

– Toxic ( 0.50 mg/dl), Lavender

The insert says that the “Alert Level” of free ammonia can be tolerated for several days; “Alarm” for a few days; and “Toxic” is rapidly harmful. It would have been interesting to see what it read when I had the phytoplankton overgrowth and high nitrites, the first time I did this.

While I knew that monitoring ammonia was important and somehow related to the level of nitrites and nitrates, I wasn’t sure exactly what was going on. I found a good website, The Tropical Tank, done in the UK, that discusses water chemistry, and in particular, ammonia, nitrites, and nitrates. It’s called: More on the Nitrogen Cycle: Ammonia, Nitrite, and Nitrate

In short, there should be no ammonia or nitrite in a mature tank. Any ammonia is present in two forms: ammonia (NH3) and ammonium ion (NH4+). Ammonia is more toxic than the ion, and the higher the aquarium pH, the higher the ammonia level. Since brackish and marine tanks are basic, ie higher pH, ammonia toxicity is a constant risk.

Ammonia in a mature tank is oxidized by nitrogen-fixing bacteria, to nitrites and again, in a mature tank, nitrites are oxidized to nitrates. While you don’t want to see nitrates run high, a lower level , say < 50 ppm, are considered okay, 25 ppm is even better. If your tank isn’t cycling well, is new and not enough nitrogen-fixing bacteria, you have too many tank inhabitants, or you’ve overfed them, ammonia (and hence nitrites and nitrates) will start to spike.

The bottom line, the appearance of rising ammonia levels is the first clue that things in the tank are not well and even toxic. Given that my last endeavor with crab larvae resulted in mass death due to high nitrites (and yes, the phytoplankton caused an algae bloom that caused ammonia and nitrites to spike and I won’t use it again) I thought it might be interesting to monitor the ammonia levels in the tank on a continuous basis through this project.

This article also gives information on how to start up the nitrogen cycle in a fishless tank. I wondered how you get the cycle going when there are no fish or fish wastes to start the process.

If you are interested, this same UK website has two other interesting articles:

The Basis of Cycling: a good overview of the maturing nitrogen cycle in aquariums

Fishless Cycling Data provided to them by a US forum member, William Wallace; some concrete data on how Mr. Wallace actually did this process.

To return to the tank and Scarlett:

Wed evening, the water looked cloudy and while other parameters were still fine, I noticed a trace amount of nitrites now. I also noticed a few green spots in the yellow safe zone of the ammonia monitor. The green spots are the beginning of a change to “alert.” Given that I think we’re a few days away from birth yet, I decided to turn the water filter back on for a day or so to try and improve the tank conditions. I suspect that adding Scarlett to the tank was enough to catalyze the nitrogen cycle into high gear. It’s to be expected to see “some” ammonia and nitrites, and there also is a “good” level of nitrates, but still, I don’t want to lose the battle of water quality before the babies are even born. I will continue to monitor water quality closely today today. If necessary, I’ll do some water changes, but I would rather not do that. Since the nitrogen cycle is in its early stages, every time I take water out and put in new water, it removes some of the very nitrogen-fixing bacteria I need. The gentleman at the aquarium store said it would be best to just let the tank evolve. So as long as we don’t go beyond “alert” on the ammonia monitor, I’ll let it “evolve.” Otherwise…I’ll have to start water changes. I wish I’d known earlier about the fishless cycling Mr. Wallace did. I could have done that with this tank to get the nitrogen cycle established before moving Scarlett into it.

Tank parameters this morning are the same as yesterday afternoon and Scarlett is out walking around the tank, so, no better, no worse.

Stay tuned.

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 Gift – A Fiddler Crab Extra From a Fellow Crab Enthusiast

March 18, 2008

One of our readers sent in some information the other day about her attempts to raise fiddler crab larvae. That comment was in response to my blog post entitled:

The Fiddler Babies are Dead But We’ll Start Over and Prove HorseyhannahWrong.

Yesterday Laurie has this update that she posted on one of my other blog posts: “Extra! News on Preparing the Fiddler Crab Nursery.”

She has such good info, and generously wants to share it with all, so I include it here for all to see.

I especially loved what she said toward the end of her comment, that maybe if all of us who have knowledge on the subject of fiddler crabs pool our info, we can prove that you CAN too raise fiddler babies without the hundreds and thousands of dollars of equipment that Horseyhannah (on the Animal Planet forum) says you need.

So here is Laurie’s information, her gift to all fiddler enthusiasts out there, updating us on her progress and also listing the many things she’s done to make this work. Thank’s Laurie! And to anyone else who might have more info for myself or Laurie, please do send your comments. They are welcome!

Fiddler crab lovers of the world, unite!!! 🙂

Comment:
Laurie’s Fiddler Crab fry–March 17th, 2008, Day 7 and still going…

Just an update. They were released on March 10th and true to the (artist!?) breeder of the mangrove crabs www.aquahoito.info/sesarma/index.html on March 15th, day 5, I had a little more than half die off. In the last 2 days no more have died, tho.
Today I was able to get supplies for them, including a salinity meter ($7.00) and some test strips for nitrate/nitrite etc. and Kent’s PhytoPlex (not live) for more food. As I didn’t have proper food for them I did the newborn fish fry trick of feeding them hard boiled egg yolk. About 1/2 a matchstick head’s worth smashed fine in some water and dispersed with the fry, twice a day. That was too much, no doubt, but I’m new at crabs and they did ok…

I tested my water (2 gallon hex w/no filtration, slight bubbling from airstone) and nitrates were 0, nitrites were alright-“caution” .5 ppm, salt is .015ppm, hardness 300 (ideal). I’m finding it’s cheaper to do water changes in a small fry tank than buy a whole salt water filtration system. 2 tbsp Ocean Reef salt/quart, 1 qt every couple days. The little squirts only have to get to 2 or 3 months old before they’re little crabs, by the looks of Mr. Mangrove Crab’s work, so that’s not much salt used over time versus the complexities of a nitrogen cycle filtration system. Now that I have test strips I’ll know how often that should be.

Again, shutting off the bubbler, wiping the bottom to free the slime that’s growing there (I don’t think I’m getting it all, so if it’s food it’s still present somewhat), then fluffing it to one side and siphoning it up w/airline tubing seems to clean the nitrite creating stuff pretty well. Shining a light in one corner for them to aggregate near keeps most of them out of the way, and I shine it again in the gunk glass I siphoned into to get the ones I accidently sucked up back into the tank.

One interesting note is that after the “D-Day” day 5 die off the herd that is left swims less and congregates on the bottom on the side facing the window. Their movement is now more like a thousand little frogs hopping around in the herd at the bottom of the tank. Some still swim, but majority is doing the new movement. I can see a bit of their tail now, but no major growth change.
Possible theories: 1.) they molted on day 5 and many didn’t make it through. 2.)Nitrites killed them at this stage and they haven’t molted yet. 3.) Maybe everyone’s dies at day 5 because they have 5 days of food stored in them or because when they molt the new contact with water conditions isn’t right for them…
Interesting to note that my water isn’t the right ppm for salt, but half have survived… I thought I saw somewhere it should be ocean water (1.020-1.024, and somewhere else 1.010. hmm. Wish I had more tanks to test all 3 salinities.

My hope is that with more postings from folks that are having success we can all help each other out to solve this mystery and not make silly statements like it taking hundreds of thousands of dollars to get the right water conditions for this. heh heh that one still makes me chuckle. I bet it’s possible.

Folks could try their filtration systems in their nursery tanks with a big ball of fiber-fill around the intake (intake on LOW!) with super fine cloth over that. That makes the drag into the intake almost nothing. You’ll see if the babies are being pulled onto it, it’s too strong still… but I still am having great water results with one gallon of water in a two gallon tank.
Best… Laurie

The Post – Odd Goings-On in the Fiddler Tank – Is Scarlett Acting Pregnant Again?

March 16, 2008

When I first I walked by the fiddler tank yesterday morning, I was sleepy and oblivious. Then I did a double-take. Sitting at the front of the tank was the discarded molted shell of somebody. On closer examination, and with my husband’s consultation too, we both agreed it was Melanie Hamilton’s discard. That means she is at the moment most likely to get pregnant if Admiral Byrd invites her in.

At the same time we noticed that Scarlett O’Hara was sitting on top of the water filter….again. The last time she did that, we noticed shortly afterward that she was pregnant.

Admiral Byrd of course, was marching up and down the tank, claw arm held high, and waving.

To continue – Scarlett O’Hara spent the entire day and evening yesterday, on top of the water filter. She is still there this morning. She has never done that before or since, except when she was pregnant. I know she is still alive because she is “blowing bubbles.” Crabs foam sometimes when they’re out of water, to moisten their gills.

Even when I freaked out Admiral Byrd yesterday, and scared Melanie Hamilton out of her live rock because I was cleaning the tank and accidentally bumped the live rock, Scarlett O’Hara didn’t leave the filter perch. She just moved down into the filter for a bit, then climbed back up. Admiral Byrd meanwhile kept trying to climb the heater power cord up to the top of the filter to be near her, but he couldn’t quite do it with that large claw.

Yesterday afternoon we noticed that Melanie Hamilton remained outside the live rock, sitting there on the gravel serenely watching Admiral Byrd flex his claw. Then she spent the rest of the afternoon and evening in his cave lair. This morning she was resting just outside his lair, picking algae off the rock. He was napping inside.

With any luck, we can try the larvae thing again somtime soon?

I am in the middle of re-establishing the nursery tank. I had emptied everything from the original set-up, cleaned out the tank, put down the one inch or so of the calcium-releasing sand, and added the water. Now I did forget to rinse the sand out, so the tank water was cloudy at first, but it has settle out by now. I’m not sure how one effectively rinses sand out anyway without half of it going down the drain. I will say the white sand really makes the inside of the tank bright when the light is on. If we get babies again, it should be much easier to see them in such a bright tank.

I couldn’t decide whether to make the 3 gallons of water I added marine or brackish. I guess I should start brackish because first we’ll have to move the mom, whichever one of them it is, from their tank, which is brackish into this one. I wouldn’t want to shock them. Right now the tank is on the “marine side” of brackish. I’ll adjust the salinity with a bit more water shortly.

The live rock is back in the tank hopefully doing its thing to establish the nitrogen cycle. Both the air filter AND the bubbler are running and so hopefullly the tank environment will establish itself as quickly as possible. Rather than replace the old water filter cartridge and lose whatever nitrogen-fixing bacteria that had started to thrive in it, I left everything in place and returned it to the tank.

An interesting about the old water in that tank. I tested it before I emptied it out just to see if the nitrite levels ever came down. They read zero, and the nitrates were in the “okay” zone. I guess once I stopped using the live phytoplankton and let the water filter run for a few days, that was what it needed. So the phytoplankton was most likely the culprit in the high nitrites. In any event, I dumped the old water and just started with fresh sea/brackish water all over again.

One thing – that Reef Calcium product that I’d hoped would raise the alkalinity but not raise the pH, when added to half strength Instant Ocean… maybe it didn’t raise the pH but it didn’t solve the problem of the pH being too high from the Instant Ocean even when I used that at half strength. So I still had to use a pH lowering solution and this morning it is about 8.0 vs 8.4 that it was yesterday. So that’s perfect . At least though, the Reef Calcium did raise the alkalinity.

I will keep you all posted on any news from the adult tank. Keeping good thoughts for a new crop of larvae babies. Stay tuned.

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 Post – A Fiddler Update – Water Issues and Decreased Numbers

March 7, 2008

I am not sure that things in the nursery tank are going well. A sudden reversal in fortunes over the last day or so. Very decreased numbers of babies. In fact, this morning, it’s hard to tell if there are any left. The water got cloudy, like an algae bloom, and the nitrites spiked high and even a touch of chlorine showed on the dipstick, odd since I use distilled water. So the chlorine is coming from tank conditions, not the water I used. Some thoughts:

I am not sure if the decrease in numbers is:

1) Normal? They cannibalize each other.
2) High nitrites?
3) Touch of chlorine?
4) Wrong food?
5) Too much or not enough food?
6) Salinity? Are the science articles wrong and should I have left it brackish?

Water quality:

It started out that the water would get cloudy for a little while after I put food in the tank. Then it would return to being clear. Now, however, it’s cloudy all the time. I replaced 1 gallon of water last night (still “marine” at 1.019), and I added buffer to raise alkalinity for them to have enough calcium to molt. I also added Prime to get rid of chlorine and decrease nitrites. I succeeded with raising the alkalinity, and eliminating the chlorine. Nitrates are still in the “okay” zone, but nitrites didn’t drop.

This morning the tank is still cloudy. I will recheck parameters in a little while, and probably replace another gallon of water. I hate to do that because if there are babies left, I am most likely pouring some of them down the drain with water I tank from the tank. I do pull the water from the side of the tank where the babies did not hang out much, but still. Nothing to be done there though. a.m.

It occurred to me this morning that maybe the phytoplankton was either a bad idea or I just gave too much. The phytoplankton is alive. I noticed the water I drew off last night had a greenish tint. That means the phytoplankton, which is PLANT plankton, and alive, may be blossoming, in fact, maybe it’s a phytoplankton bloom in the tank. Given it’s not the open ocean, but a closed environment, the bloom, while successful in generating more food for the babies, maybe too much of a good thing in an aquarium. If too much growth, is it raising the nitrites and killing off the babies? I am wondering if I should have left the food at “Small Fry” and maybe the ground up krill and not added the phytoplankton.

I will also put a sample of the water under my “precision” microscope later to see if in fact the water is jammed with plant cells.

I will update on the results of water change, microscope viewing, and repeated parameters later, as well as whether it looks like there’s any babies left.

Live and learn. As my husband says, “Next time”….I think there’s always things we can do better. AND, once this experiment is over, we’re going to leave that spare tank up and running empty so it can settle out with a matured nitrogen cycle. Stay tuned for updates.

The Post – My Husband, Alias Fiddler Crab Midwife

February 28, 2008

Again I will note, it is my husband who thought of something crucial. I’d finally gotten the new tank so the water is clear, the nitrites aren’t too high, Scarlett O’Hara is calm and exploring the tank. I got the main tank’s water changed, so it too is in great shape. Feeling satisfied with the world, I commented that now all we need to do is wait for the birth.

My husband turned and said: “I’ve been meaning to ask you something that bothered me. You have the water filter running in the nursery tank. When the microscopic babies are born, won’t they all get sucked into the filter material?”

“OH MY GOD.” The man is right. We’ll come down some morning and Scarlett will have delivered and there’ll be no babies in the tank – just this primal cry of the thousands emitting from the cloth and charcoal filter material – the crab baby equivalent of “Oh the humanity!!”

I first thought maybe I could just pull out the filter material and just leave the water pump running, but again, my engineer husband said, “Well that will be okay I guess while they’re microscopic. But what happens when they start to grow and get a little bigger? They’ll get sucked through the pump and won’t that grind them all up?”

“OH MY GOD again.” You know, for a person who started this whole thing out with “So, we’ve spent $4 on fiddler crabs and a $100 on support gear,” and laughed at the endeavor, he is the one the babies should thank if they make it because he is the one paying such close attention to their every need. When I hedged about spending yet another $30 on a tank heater, he was like, “But won’t they need heat?”

In any event, I ran to Petsmart to buy a tank bubbler. There’s all kinds – wands, rocks, bars, then there’s pumps – all kinds of those, not to mention you have to buy the right pump to handle the volume of your tank and the right sized wand to stretch across your tank, then there’s the check valve you have to install if the pump is going to be below the aquarium instead of above it – keeps the water from backflowing into the pump in case of power loss….you get the picture. I finally settled on a pump for aquariums up to 20 gallons instead of 10. Wanted something with more power to push air in there. And I selected a wand to extend across the back of the tank to create a curtain of bubbles. I thought that might circulate the oxgen better than a bubble rock. It won’t filter the water, but hopefully the huge live rock and the bacteria I’ve already seeded the tank with from the old filter backing, will be enough to jump-start the nitrogen cycle without the filter running. The bubbler will give them fresh air. So, keep your fingers crossed.

At least Scarlett O’Hara seems to like it. She climbs up on the wand and sits there with bubbles flowing up around her. I hope she thinks it’s “surf” and releases the babies soon. My husband wonders if she is scurrying around the tank so much because it’s getting close and she’s frantically trying to find that right spot to let them go and be carried out “into the open ocean.” Sigh.

Truly, those fiddler babies owe him a lot. He is the true fiddler dad. Admiral Byrd may be oblivious and not care, but my husband surely does. It’s that whole “Caring is Catchy,” thing.

The Post – Is Birth Imminent?

February 24, 2008

I will be returning soon to the evolution of my novel, Under the Pier, but given the goings-on here, I have to take some time to tell of events unfolding in the fiddler crab world.

I decided to see if it is possible to raise at least a few of Scarlett O’Hara’s and Admiral Byrd’s babies, should they survive birth. It’s a long shot, but I want to try. Scarlett looked really pregnant yesterday – that abdomen of hers is large and when she pushes at it, it’s like jelly. I have these observations again from my husband.

It is TRUE LOVE when your husband acts as midwife for your pregnant fiddler crab, keeping close eye on her while I ran out today to get a chunk of live rock for the aquarium. He even called me on my cell phone at the aquarium store to tell me that Scarlett was picking at the larval mass, pulling out a brown thread here and there and planting it in the gravel. He felt birth was getting close and I should hurry home with the live rock. I tell you, is that a friend or not? How many people would call you on your cell phone to let you know your fiddler crab is getting ready to deliver? 🙂

To back up, we went to Petsmart last night and picked up a new 10-gallon aquarium, tank top, light, light bulb, thermometer….. yes, another whole set-up. My husband is laughing but then, he is a geek, just one with different interests, so he respects this endeavor I’m involved in.

In fact, he is working on setting up his own blog that will have all kinds of tweaky things that reflect his interests. When it’s up and running, I’ll be sure to mention it. He finds the most unusual and interesting things out there. To give you a sample of the man, when we are out on a date it is not unusual to walk through the parking lot and have him explain to me the mechanisms for the inner workings of car backup lights and such. I just love it. Going somewhere with him is always interesting and an adventure. Sometime I’ll have to share how he and I hunted down the overgrown boarded up command bunker for a former Nike missile launch site in Newport News VA. 🙂 But a story for another time. Those are the kinds of dates I love. Anyway, I’ll let you know when his geek site is up and running.

To get back to fiddlers, I spent last night setting up the tank. This time I started with distilled water. We have a small water distiller and I proceeded to use up our drinking supply to make up salt water for the “nursery tank.” Mixed up Instant Ocean powder in the distilled water, set up the filter, and within a couple of hours, got the water parameters just about where I wanted them: pH 7.8, alkalinity 180, hardness >300, chlorine, Nitrite, and nitrates all zero. Salinity was about 1.008, a little lower than I wanted because I want this tank’s water to be an almost exact match for the main tank.

This morning I used some marine buffer to bump the pH up to 8.0 and alkalinity closer to 300. Added a bit more Instant Ocean to get the salinity up to 1.010. I seeded the new filter with a strip of “very well colonized” filter material from the old tank to jump start the nitrogen cycle, and brought home from Fish Pros the MOST amazing chunk of live rock – ALREADY had all kinds of marine invertebrates and microscopic algae on it because it had been in another tank that had just been dis-assembled. So, the live rock is well underway growing organisms and probably has another dose of nitrogen-fixing bacteria ready to go.

I debated about what to do with Scarlett O’Hara, leave her in the old tank and struggle with where to release her babies or put her in the new tank with plenty of room for all. Finally decided to take a chance and I’ve moved her into the new tank. She seems to be doing okay in spite of being rattled by being moved. I’m hoping it didn’t disturb her too much. It always shakes them up a bit to move them around. I have done my best to make her a good nursery and here she is free from Admiral Byrd’s claw-waving. I even took the heater from the old tank and gave it to her in the new one. I ordered a new heater for the main tank which should be here Wed. But I figured Melanie Hamilton and Admiral Byrd will be fine for a couple days with the tank lights to keep them warm. I figured “momma” needed it more.

By the way, the tank heater I use is a small one geared for 3 gal aquariums. It’s pre-set and can be mounted sideways with suction cups, and there’s no risk if it touches the gravel. It’s a Marineland Shatterproof Heater (10 watts) part number VTMD10 and found it online at That Pet Place.  Since my tanks are only a third full of water (to allow space for the crabs to get out in air), regular heaters won’t work. Not enough water for them to be fully submerged. And regular heaters are generally large and have to be vertical.  This guy is short and can be sideways. Keeps the tank in the range of about 78-80 degrees F. So for what it’s worth.

So…the nursery is up and running. So very much hoping that 1) Scarlett will do okay in the new tank; I would feel terrible if she doesn’t make it because of the move 2) the babies do okay.

Then all we have to worry about is how to sell off many many many many many grandchildren? 🙂 I’ll keep you posted.

By the way, if you want to have a few seconds of just staring at some nice marine creatures swimming amidst coral, click on the Instant Ocean link above. Neat intro.

The Post – Extra! News on Preparing the Fiddler Crab Nursery

February 23, 2008

So you’re like me and you’ve got a pregnant female fiddler crab. Now what?

Well, we just came home from Petsmart with a second 10-gallon tank, lid, light, and pump/filter assembly so I can set up a saltwater aquarium in which to put the babies. Maybe I’m crazy for trying to see if I can raise them …?then sell them? but the challenge of motherhood calls. My husband, a geek of a different nature, respects this need in me to see if I can do this. He quietly acknowledged that he would “understand and be willing to fund” a second tank for the “kids.”

The dilemma now is did I wait too long to get it set up and get the “nitrogen cycle” started before she releases the babies? I can take a patch of the filter gauze from my current tank, which is loaded with nitrogen-fixing bacteria, and put it in the new filter to “seed it” with bacteria.

Tomorrow I’m going to Fish Pros in Raleigh NC to get another good-sized chunk of live rock. Between the filter seeding and the live rock, that should get the water parameters in the safe zone and the bacteria up and running quickly. Also the live rock will provide calcium for the many molts the little ones will need to go through.

What I was not sure though was how I would be able to “catch” the babies since I won’t know when she releases them and I won’t know if they’ll be too small to see once she does. Also, should I make the second tank a regular “salt-water” tank to represent the “open ocean” like most fiddler babies go to, or make it brackish like what they’ll end up in? This last question got further complicated by the information I found on the blog below that indicates I should isolate mom before she releases the young. So I have much to ponder tonight while I get this up and running.

I did a search for info on pregnant fiddler crabs and come up with The “Dear Blue Lobster” blog entry” from July 25, 2007. The Dear Blue Lobster site claims to have been answering “your crustacean questions since 2002.” This entry is from someone who is concerned that her fiddlers make have “hooked up” and now what should she do? She is freaking out at the prospect of a 100,000 babies in her tank.

The gentleman who runs the blog gave good technical advice on taking care of the pregnant mom, saving the larval babies, raising them, and even indicated how much/lb. you can sell fiddler crabs for over the internet. The crustacean guru also gave the following emotional advice:

“So what do you do if your female is indeed pregnant? Comfort her. Her man has kicked her out and will no offer care for her children — in fact, he may try to eat them! ….Good luck to you and your Fiddlers. Motherhood is a special blessing indeed.”

Since it is well past July 2007….I wonder how the mom (human) and the mom (fiddler crab) made out with their situation? For myself, we shall see. I am off to set up the tank. I guess I’ll set it up brackish and isolate mom before she “delivers.” I have also emailed Dear Blue Lobster for help on what I should do. I’ll keep you posted on his reply.

I recommend the blog. The crustacean guru is Christopher Chimwish. His site description is as follows:

Christopher Chimwich received his MMN in 2000, specializing in decapod behavior. He is currently surveying benthic decapod populations in the Indian Ocean for his doctoral thesis. Chris answers questions about crustaceans, covering everything from DNA mutation in African crayfish to Fiddler crab sign language.

By the way, if you want to be a real geek, apparently the term for my fiddler crab when they have the brownish eggs attached to their abdomen is being “in berry.” So.

If you want to know what he has to say about fiddler crab sign language, click here.