Posts Tagged ‘hatchery’

The Post – Admiral Byrd is Peeking & New Aquarium Products

March 12, 2008

Some Fiddler Updates – New Product Technical Details and Romance

1) Preparations, Take 2, for the Fiddler Crab Nursery Tank:

I came home from PetsMart yesterday armed with calcium sand to replace the gravel in the nursery aquarium. That project will commence later today. The sand is actually something called Seachem Meridian Tidal Marine Substrate. It’s basically calcium carbonate precipitated from ocean waters by coral. It will stabilize the calcium and alkalinity levels in the water, and keep the pH from getting too low. Its porous structure and size supposedly are good for the growth of denitrifying bacteria. We shall see.

At the very least, it’s a dual purpose as I can also use this sand for the bottom of the land hermit crab cage I just bought. The land hermit crab project will be ramping up soon.

I also picked up some liquid food that should work fine for the larvae. I’d mentioned a product called JBL Nobilfluid that a gentleman from Finland used to raise his crab larvae. However the Nobilfluid is made in Germany and appears to be available in Finland, Germany, England, Italy and the UK, but I couldn’t tell if it was available here in the US. I could get it from a UK website but between the exchange rate and the shipping, I expect the cost is prohibitive. A JBL representative answered my email yesterday and said their product is not available in the US yet.

I found this new product at PetsMart called Kent Marine ZooPlex. The problem I had with the fiddler babies was trying to find liquid plankton to feed them. My mistake was getting live liquid phytoplankton, which made the tank toxic and killed them. I realized larval crabs need zooplankton, which is animal plankton = roughly translated: MEAT. Phytoplankton, being plant based, is the wrong plankton. Larval crabs are carnivores, not vegetarians. Anyway, Kent Marine ZooPlex is “concentrated aquacultured Marine Zooplankton” and is geared toward invertebrates including larvae. The bottle notes it can be used as a brine shrimp replacement. So this sounds like it might be just the thing for liquid feeding of newborn larval crabs who are too small to chase live brine shrimp around.

I will still need to get the dried brine shrimp eggs to hatch when I know I have a pregnant female ready to shed her eggs. The brine shrimp hatchery project will come a bit later.

2) How to raise the alkalinity of the water for the brackish tank without raising the pH?

The dilemma I have when using Instant Ocean to make up the brackish tank water for the adult crabs, is that I have to use it at about half strength. That way I get a salinity of about 1.010 instead of 1.020-1.024. The trouble is, that makes the alkalinity way too low meaning there’s not enough calcium in the water for the crabs when they molt.

I’ve tried adding Seachem’s Marine Buffer, to raise the alkalinity and it’s very successful, but it also raises the pH way up to 8.3. That’s fine for a marine tank, but for the brackish tank, the fiddler crabs seem to like the pH closer to 7.8-8.0 I have a constant battle trying to get the salinity low enough, the alkalinity high enough and the pH “just right” somewhere between a freshwater tank and a marine tank. When I use the Marine Buffer I have to then add something to lower to pH.

I was hoping to find something that would raise the alkalinity, but not the pH when I use Instant Ocean to make up the brackish water. Yesterday I came across Seachem’s Reef Calcium. The website description reads:

Reef Calciumâ„¢ is a concentrated (50,000 mg/L) bioavailable polygluconate complexed calcium intended to maintain calcium in the reef aquarium without altering pH.”

I am going to try the Reef Calcium product and see if that solves the problem. I will let you know.

3) Romance: a humorous update for a Wednesday:

Ever since his success with Scarlett O’Hara, Admiral Byrd has been out there claw-waving up a storm. Melanie Hamilton spends just about all her time inside the live rock. Yesterday afternoon is the first time I’ve seen her out of it in weeks. I think she took to hiding out in the rock when Scarlett O’Hara was living in the nursery tank. With Scarlett temporarily gone, Melanie was the total focus for Admiral Byrd. I don’t think she liked that.

Anyway, after giving birth, Scarlett O’Hara has been eating almost non-stop. I think she finally slowed up a bit yesterday, but she’s still pretty ravenous. In fact yesterday, I dropped a shrimp pellet in the tank and Scarlett scrambled up and caught the thing in mid-drop. It never even touched down on the gravel. And she’s pretty good. No fumbling and bobbling the shrimp pellet. She spotted it, she jumped, clutched it to her chest and landed on her feet, eating the pellet before she landed. She could probably earn a spot as an outfielder for the Red Sox.

Unlike Melanie Hamilton, Scarlett hasn’t been too concerned one way or another with Admiral Byrd’s where-abouts. She doesn’t run from him, or toward him. She just eats. Still, I don’t think she’s averse to his presence as she’s spent a fair bit of time in his lair, the fake rock cave, while he walks around waving his claw. I have to wonder if he realizes she’s sitting in his house?

Last night I turned off the tank lights, shut off all the house lights and went upstairs to bed. A little later I had to come downstairs for something and walked by the tank. Even in the dark, I could see Admiral Byrd standing there on his gravel hill, waving his claw. Total darkness, but the crab is still out there trying to get the attention of the ladies of the tank. What dedication.

He is also very funny in his pursuit of Scarlett O’Hara. He climbs to the top of the live rock, to wave his claw of course. Yesterday while claw-waving, he caught sight of Scarlett down on the gravel next to the live rock. He stopped waving, tip-toed to the edge of the rock, peeked over the edge at her to see which way she was going, then, like a teenage boy in love, scrambled down the rock and followed her around all the while waving his claw.

So watch out Scarlett, Admiral Byrd is peeking.

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.