Posts Tagged ‘grandchildren’

The Post – What to Feed the Babies and How Salty Should the Water Be?

March 1, 2008

Just a reminder that coming up over the next week, the next few installments on the journey of my Under the Pier novel. I had to take a break from those for taxes, actually finishing some more chapter revisions, and of course, taking care of the “grandchildren.” But stay tuned. More to come on Under the Pier.

Re the grandchildren:

What wonderful goings on! Soooo many little black dots in the nursery and they are definitely swimming around. Many are hiding out in the shadows of the live rock caves. So tiny and already they know to hide and avoid “predators.”

I am feeding them three times a day with a mixture of ground up mini-freeze dried krill, some ground up flake food, a few drops of the liquid Small Fry baby fish food, and a little distilled water mixed in. We shall see how it goes. And no, I am not grinding the mini-krill with my husband’s lovely stone mortar and pestle that he uses for grinding up herbs and spices in the kitchen!!

Regarding salinity – it’s a tricky call. While Uca minax, which are the type of fiddler crabs I have, are seen furthest up the estuary in areas of lowest salinity, there seems to be evidence that for at least the first two weeks of their larval development (zoeae) , they actually survive and do better at a higher salinity. However there is also evidence that for the next (megalopae) stage to metamorphose into crab Stage 1, this species does best with the lower salinity seen in the upper estuary environment that the adults live in. I will post more information tomorrow including the links to the two papers I found today on this subject. Long story short today though, is that zoeae of all the species of fiddler crabs, seem to need a couple weeks of “being at sea,” hence higher salinity.

I’ll also explain about the three species used in one of the studies and how their selectivity for salinity levels puts them in different spots in the estuaries and thus probably keeps them from competing with each other for resources and food.

Also to come – I dug out the small microscope I had as a kid and will pick up some microscope slides. So to follow, descriptions of babies, under the glass.

A couple of other notes – courtesy again of my engineer husband. He noted a bunch of white things all over the gravel and wondered if the babies had already molted. Maybe they have but these white dots were too big and irregular in size for baby shells. I believe it’s salt crystals that didn’t dissolve in the water before I added it. I added more water to bring the salinity up closer to a marine environment. I started at 1.010 (brackish) when they were born and over the course of yesterday raised the salinity first to 1.012, then by last night 1.015. Today I’ll finish raising it to 1.020. Then in two weeks I’ll bring it back down to 1.010-1.012, the optimal range for Uca minax adults.

Sand. Again, my husband was watching the babies swim – it is amazing to see these tiny things whiz around the tank – but he shined a light to see if they would follow the beam. The article I posted in yesterday’s gift mentioned that the babies will go to the light. My husband didn’t see evidence of that, but what he noted was that many little babies had worked their way down between the gravel bits, all the way down to the bottom of the tank. Unless they figure out how to get back up to the water, they’ve had it. Now let’s face it. Their parents had a brain the size of a pinpoint. How large a brain do you thing babies the size of a pinpoint have? So the odds of them getting back to the surface are not good. I said “evolution at work. Anybody who tunnels down in the gravel probably won’t live to reproduce. ” My husband noted that gravel is less than optimal for this (engineers talk like this by the way, things are optimal, less than optimal, sub-optimal 🙂 ).

The real important point though was his next comment: “The NEXT time we do this, we should use sand.” There you have it folks. My husband has fallen in love with the fiddler crabs. In all truth, he has. He watches them, thinks about how to make their lives better, anticipates the babies getting ground up in the water filter…..those babies are lucky to have him!!!

Anyway, stay tuned for the links on those two articles about optimal (yes, OPTIMAL) salinity levels for fiddler crab larvae.

 

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.