Since I got my PC lights my hair algae has continued to grow and a couple of my rocks are getting it all over them. I've tried scrubbing them when I do my weekly water changes but it does not seem to help. Within a couple of days they are hairy again. So, when I was at the lfs on Thursday I picked up a Sea Hare. So far it has been only cruising the glass. It is eating because I think I saw it pooping. Or at least there was dark stuff coming out of the hole on his back.
Genny Anderson's spectacular photo here of Aplysia californica producing clouds of reddish purple 'ink' illustrates one of the most common features of most Sea Hares. The commonly believed function of this ink is that, like the octopus, it provides a screen or decoy so that the Sea Hare can quickly escape when attacked. Howevere, anyone with even a fleeting knowledge of live Sea Hares will realise the a 'fast escape' is not in the repertoire of these slow crawling slugs. In fact we have no idea what the purpose of this purple ink is. I lean towards the idea that it is an excretory product associated with eating red algae, and there is evidence to support that (Chapman & Fox, 1969)(all be it an outdated ref.). Sea Hares have two main secretory glands in their mantle cavity, one we call the Purple Gland lies on the roof of the cavity, above the gill. It usually produces a purple secretion but can also produce a white ink in some species. This is not to be mistaken for the white milky secretions of the Opaline Gland which lies beneath the gill on the floor of the mantle cavity.
There is a lot of evidence, however, to show that Sea Hares store noxious chemicals from their algal food, particularly from red algae, in their skins, and when these chemicals are secreted, they provide a powerful defence against predation. One extreme example is found in a Western Australian species, Aplysia gigantea which has been implicated in the deaths of many dogs.
worst case carmie, if the rocks contain no animals, pull them completely from the display, and place them in a holding tank with a power head, no need for light. from there u can scrub the stuff out of existance over a day or two. just do a piece a week if its really starting to get out of control. just keep in mind a chunk of the surface bacteria will be disturbed somewhat everytime u use manual means!
Aplysia poop is usually kinda cylindrical, at least in californica. the poop is the same color as the food, so if it's eating green HA, then the poop should be green. Veriann, you gave a great description, better than I could have done! I do want to add, however, that I don't believe ink is directly related to eating red algea. I'm a biologist at the University of Miami's National Resource for Aplysia, and I have a few animals which we are feeding, as part of a feeding study, only romaine lettuce and Ulva, and I'm almost certain i've seen them ink the same purple ink. just my 2 cents.
carmie, i agree, Aplysia are cool. can you see the eyes? is it a green one? the ones usually in the aquarium trade are A. dactylomela, which are usually green. I think they look cooler than the A. californica. oh, and thats poop . I've heard the ink isnt great for aquaria, but i have no experience with it in a reef tank. I've always heard even if the ink is harmful, charcoal might help? i don't know. The only one's i've ever kept in a tank were post-metamorphic so they were barely visible, and i never saw them again. one thing to keep in mind is they can get very large, I have some that are a little under 1 yr (max life span of 1 yr-ish) and weigh over 2 kilos (maybe 2ft long stretched). and they can produce a lot of mucus when they are large. but if you can return them before they get too large... sounds good to me. they are super cool to watch
I am running ChemiPure so that should probably cover the carbon stuff. I haven't noticed if the eyes are green and he is turned so I can't see them right now. I'll let you know. There are green patches mixed in with the white, gray and tan on his body.
Aplysia poop is usually kinda cylindrical, at least in californica. the poop is the same color as the food, so if it's eating green HA, then the poop should be green. Veriann, you gave a great description, better than I could have done! I do want to add, however, that I don't believe ink is directly related to eating red algea. I'm a biologist at the University of Miami's National Resource for Aplysia, and I have a few animals which we are feeding, as part of a feeding study, only romaine lettuce and Ulva, and I'm almost certain i've seen them ink the same purple ink. just my 2 cents.
your the man in the science department, i'll definately take it on board! thanks
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. I've heard the ink isnt great for aquaria, but i have no experience with it in a reef tank. I've always heard even if the ink is harmful, charcoal might help? i don't know. The only one's i've ever kept in a tank were post-metamorphic so they were barely visible, and i never saw them again. one thing to keep in mind is they can get very large, I have some that are a little under 1 yr (max life span of 1 yr-ish) and weigh over 2 kilos (maybe 2ft long stretched). and they can produce a lot of mucus when they are large. but if you can return them before they get too large... sounds good to me. they are super cool to watch