After almost 10 days without a sighting, FINALLY yesterday afternoon, I spotted Scarlet O’Hara. I wasn’t sure at first if she was just a corpse, dangling upside down inside the Live Rock with her eyestalk hanging down, but shining the flashlight into the rock’s cavity at 5 minute intervals, I was able to determine that a) she actually had moved her position, and b) on the second and third times, she reacted to the light beam and flinched. This latter point was important because it meant the movement was deliberate, not the result of her just being bobbed around in the cavity by the water’s movement.
Relieved to know she wasn’t dead, I went ahead and did the water change. (More on that below) Then last evening, Scarlett O’Hara emerged from the Live Rock Cavity, and slowly started moving around. She resembled a patient just released from the hospital – someone tentative in her steps and tired after her ordeal.
Okay. Right about now, I’m sure anyone reading this is wondering what the hell I am talking about. Let me back up to the beginning and give you the Readers’ Digest version of events. I am contemplating setting up a separate blog – Crab logs – to capture all the events since the beginning of this endeavor, for those purists who only want the “lab notebook stuff.”
As I’ve mentioned I am writing a mid-grade novel called Under the Pier. At least that’s the “working title.” The protagonist of the “under” the pier side is a hermit crab. While I had no trouble pinning down facts about the creatures in that world, those chapters lacked “heart.” They read more like a nature guide. My husband read the first few animal chapters and noted that frankly, he didn’t care about the creatures. That’s a death knell for any book, whether the characters are human or animal. The whole point of reading a story is to feel what the characters feel, live through the story struggle with them, and stay along for the ride because… you CARE about them. If my husband didn’t care about them at chapter 2, I had a problem. So, back to research.
It occurred to me that I just hadn’t captured what it felt like to be an undersea creature. Since I can’t live underwater, an aquarium is the next best thing. I couldn’t have a marine hermit crab like the one in my story as a pet because that meant setting up a salt water tank, something reputed to be very difficult. PetsMart had something called “freshwater crabs.” A freshwater aquarium meant cheap, at least cheaper than a saltwater one, and easier. I’d had aquariums as a kid. I figured I could set up a small tank very inexpensively, get a couple crabs, and voila….live research that would teach me how to emotionally bond with something I normally eat in garlic butter. As I’ll describe below, “cheap” didn’t take place, but emotional bonding did. My husband noted that I bought myself $4 worth of fiddler crabs, and $100 worth of support gear. 🙂 In reality, it’s been way more than that by now, but . . . more about that later.
Anyway, I bought two males, not through any particular strategy. Those 2 just happened to wander into the net the teenage employee swished through the store’s tank. I rushed home with my new “pets” and all my gear and rapidly set up the tank. Normally, when you set up an aquarium, they recommend getting everything established before bringing home your fish. However in this case, I figured why bother setting it up ahead of time when the saleslady made it sound like all these guys needed was some water and a bubbling air tube. Again, more later.
The larger male immediately ran around his new tank, explored every aspect, took command of the gravel hill (they need an area where they can be out in the air for up to 50% of the time), and showed no fear. Given his apparent “explorer” mentality, we named him after the South Pole explorer, Admiral Byrd. The smaller male immediately bolted under the water filter and stayed there for 2 or 3 days. Even when he came out, he skulked around in the background. My husband noted that he acted like the Peter Lorre character in the movie, the Maltese Falcon, so we named him Peter Lorre.
I’m going to skip over the travails of learning I should have set up the aquarium first before buying the crabs, the fact the people had us buy the wrong food (how are bottom-dwelling crabs supposed to eat krill shrimp that only float on the water’s surface and don’t sink?), and the many things that made me realize these crabs really do need more than a bubbling air tube if they were to live longer than the 2 weeks PetsMart’s written guarantee said they would.
As it turned out, Peter Lorre made it about 3 weeks before he died. I think his poor little body just wasn’t up to the stresses of toxic nitrite and nitrate levels, not to mention the fluctuating salinity levels (see below). By the time I learned about Live Rock and how it speeds up the nitrogen cycle in the tank and makes things healthy and non-toxic, Peter Lorre just stopped walking one day, tumbled off the live rock, and dropped headfirst to the bottom of the tank, dead. I was heartbroken…he was the quiet timid one, and I did like him. My husband couldn’t understand how I could care about him given that I ordinarily do not hesitate to go to a seafood restaurant and consume his cousins with great enthusiasm. Doing a twist on that line from the Godfather movie about things not being personal, but business, I said to my husband, “This is personal, not lunch.” When things get personal, you go to Google for answers.
Now, for any aquarium geeks – a couple things. Live Rock, as mentioned above, is rock taken from a tropical coral area, and contains microscopic sea life and bacteria. By adding a1 pound chunk of cured Live Rock (ie has been allowed to sit in a salt water tank and age and no longer smells like a salt marsh) to the tank, it essentially seeded the tank with nitrogen-fixing bacteria. They speed up the establishment of the Nitrogen cycle. That’s where toxic ammonia and nitrites generated by the biologic wastes in the water, are converted to nitrates. Eventually the levels of ammonia, nitrites and nitrates drop to zero. The Live Rock also has the benefit of leeching calcium into the water. This comes in handy for keeping things like pH and calcium at stable levels. Crabs need high calcium for molting. Anyway, once I added Live Rock to the tank, the toxic conditions subsided rapidly. But not in time for Peter Lorre.
I also learned that the crabs I bought were “red-jointed fiddler crabs,” otherwise known as Uca minax. Sometimes PetsMart sells the yellow-clawed ones, Uca pugnax, or mud fiddler crabs, but I definitely got the red ones. While these crabs can survive in freshwater, it apparently shortens their lifespan considerably. I read somewhere that they can live a year or more if kept at the right salinity. I figured salinity meant “marine.” After all, if they weren’t freshwater crabs, then they were salt water crabs. I went out and bought aquarium salt and made it up to the regular marine aquarium specifications, a minimum specific gravity of 1.020. I eagerly added the water to the tank figuring my guys would react with glee. Instead, Peter Lorre went into a daze and foamed bubbles out of his shell. Admiral Byrd bolted out of the water like I’d just added sulfuric acid and literally tried to climb the walls of the tank to get out. I didn’t understand it. I’d followed the directions and they “should” have liked the water, but obviously they didn’t. Even fiddler crabs deserve not to be in pain so I added some plain water to dilute things. They settled down.
In hunting around some more on Google, I discovered that these crabs are in reality, brackish water critters. That is that “estuary” type environment where the rivers meet the sea. The water is neither freshwater nor saltwater. Brackish water has a much lower level of salinity. Further, I found a study of fiddler crabs in the rivers of Delaware that really illuminated the problem. Uca minax – the red-jointed guys – prefers water with a specific gravity of around 1.008 – 1.018. Any higher than that and the LD50 (the time it takes for 50% of the population to die) is 2- 3 weeks. Same if you put them in freshwater.
Interestingly, according to the study, the yellow-clawed guys LIKE the higher salinity. If I’d had Uca pugnax crabs instead of Uca minax, they would have loved the higher salinity water. But my guys hated it. They needed….brackish. That’s how it goes with me. I start out to have a simple freshwater tank, then accept I must make it marine, only to find out I have to actually set up a brackish tank…something by the way, very few people do probably because there’s no books on the subject. In any event it’s been quite the adventure, and I sure have learned a lot, becoming a bit of an expert now on maintaining a good brackish water environment, a source of pride for me. However, this should explain now, my husband’s comment about $4 worth of fiddler crabs, and a $100 worth of support gear. It goes without saying I needed a gauge to monitor specific gravity not to mention water conditioner, solutions to decrease the ammonia until the Live Rock bacteria kicked in, and test strips to check the water…a lot. 🙂
Anyway, end of geek moment and back to the story:
Well, now that Peter Lorre was dead, Admiral Byrd was beside himself. He sat in his little cave tunnel near Peter Lorre’s dead body and just twitched. I thought he’d eat Peter Lorre given that they are scavengers, but apparently fiddler crabs don’t eat their friends. I removed Peter Lorre and gave him a proper pet burial in our front yard, next to the gerbils, hamsters, and pet rat buried out there. Then I set out to buy Admiral Byrd more friends.
I found this amazing aquarium store on the outside of Raleigh, NC – Fish Pros – Fishprosnc.com SALT WATER TANKS and ALL KINDS OF GEAR and PEOPLE WHO KNOW WHAT THEY’RE DOING!!!!. In fact some of their staff are marine science students or professors at NC State University nearby. In any event, I left there with not just ONE more friend for Admiral Byrd, but three. And this time, there would be WOMEN!
I figured keep the numbers even, so I bought 2 females and one more male. The man at the store noted that having the females would produce some neat “claw-waving” mating behavior in the males – the crab equivalent of “Hey baby, check me out!” Also, since females weren’t territorial, it was possible to have more crabs in the tank without having fights. Needless to say, Admiral Byrd perked right up when he saw he had friends, and when he realized there were ladies, well, he hasn’t stopped waving his claw since.
In any event, the male struck my husband as the “Rhett Butler” type, so, the new guy became Rhett Butler. That meant following the Gone With the Wind motif for the ladies names. The larger female demonstrated an overbearing, fearless, almost aggressive streak. She became Scarlett O’Hara. The more timid, fragile female, is Melanie Hamilton.
Again, for whatever reason, we lost one of the crabs – Rhett Butler lay dead in the back of the tank. No outward evidence of “foul play” ie – Admiral Byrd killing him off for territory or women. Again, another pet burial in the front yard. However, since then, the remaining three crabs have done fine. Yes, the women get fed up with Admiral Byrd chasing them around. And Yes, Melanie Hamilton got tired of Scarlett O’Hara stepping on her to get to the food pellets. Melanie Hamilton spends most of her time living INSIDE of the Live Rock chunk. She does peek out the front or side entrances long enough to grab a food pellet and pull it inside, and every now and then she will climb out and wander around, but she’s very skittish and races back in the rock at the slightest provocation.
My Scarlett O’Hara concern started about 10 days ago. She enlarged the front entrance to the Live Rock, ie, pulled out a bunch of gravel and tunneled under it to get inside it with Melanie Hamilton. For a few days I could see them both crammed inside the Live Rock if I shined a flashlight into one of the rock’s openings. But for the last 10 days I could not find a trace of her. At first I figured she went in there to molt. Molting takes a few hours. So, I figured give her another day or so to rest and she’d be back out. No dice. No matter how often I shined the light into the rock, all I could see was Melanie Hamilton. By yesterday I’d decided Scarlett must have died and I needed to pull the rock out of the tank, if only to remove her dead body for burial.
However, just before I did that, I shined the light into the Live Rock and lo, that’s when I saw Scarlett O’Hara. She was clinging to the roof of the cavity, and I could see her eyestalks hanging down. Since she emerged from the rock, all is back to normal. Scarlett O’Hara and Admiral Byrd run the tank and wander constantly, seeking food. Melanie Hamilton peeks out of her cave and pretty much stays out of sight. As odd as it sounds – I am so HAPPY!!! I really felt bad at the thought she died. Seeing everybody doing their usual thing, it’s like “aaahhh, back to normal.”
Oh – one last geek moment, a moment of pride for me. I did a 33% water replacement in the aquarium yesterday – almost double the 18 % change the time Admiral Byrd freaked out about the salinity, and more than the recommended 25%. I didn’t have much choice given that the water really needed changing. I added the water and held my breath, keeping a close eye on Admiral Byrd. Apparently, this time I did it right. The tank water was at a 1.010 specific gravity, and so was the new water I was adding. Not only that, but the other parameters were great : pH 8.0, total hardness (GH) >300 ppm, total alkalinity (KH) 300 ppm, chlorine and nitrite 0, and nitrates “okay” at 20 ppm. (I’ve been using the Jungle Laboratories brand Quick Dip 6 Tests in One strips). And Admiral Byrd? He just kept right on eating through the whole thing. Never once climbed the walls…he never even left the water. SUCCESS!!!
Now I’m saving my allowance to buy …. two land hermit crabs!!!! Stay tuned soon for their adventures.
And stay tuned…working on getting pictures of Admiral Byrd, Scarlett O’Hara, and Melanie Hamilton…if she ever comes out of her cave!
Soul Mosaic 