Recent content by ATJ

  1. ATJ

    Lets talk about lighting an SPS tank

    In my opinion, yes. Photoinhibition has been demonstrated in shallow water corals, even at higher latitudes. The zooxanthellae don't photosynthesize during the middle of the day when light is at its highest. If you were to provide that much light for the whole day in a tank, they probably...
  2. ATJ

    Moorish Idols

    This is true for ALL wild caught fish, regardless of the species. The key to the success for any fish (or invertebrate) is finding suitable substitutes for their natural food as their natural food will rarely, if ever, be present in an aquarium. It just happens that suitable substitutes are...
  3. ATJ

    Moorish Idols

    Paul, You are correct in suggesting that it is unwise to make conclusions from only a few observations. Any observations are good and valuable, but you need a huge number to be statistically significant. Kuiter and Debelius (2001) claim "Commonly seen in pairs, occasionally forming large...
  4. ATJ

    Moorish Idols

    I'm just back from a week's diving on the Great Barrier Reef and the Coral Sea and made some careful observations of moorish idols while I was diving. I saw them at all depths from near the surface to right down to 30 metres (100 feet). I saw them as singles as well as in groups of 2 or three...
  5. ATJ

    Feeding corals

    tlmack, I use mysids all the time and find they do get consumed but I get reactions like those in the article. If your corals haven't eaten for a while they may be lacking some energy and their reaction to food may have changed. Keep at it and you will eventually get some reaction. You only...
  6. ATJ

    Feeding corals

    Ladipyg, I specifically tried the "food juice" method with Tubastraea and Lobophyllia and saw no reaction to the "juice" in the water. My other tanks with fish effectively get "food juice" on a regular basis when I feed the fish and the corals don't appear to react. At the moment I'm happy to...
  7. ATJ

    Can A Blacklight Stimulate Growth?

    Light is made up of photons. Each photon has a single wavelength. The wavelengths of photons in visible light range from 400 to 700 nm. A photon of one wavelength is identical to every other photon of the same wavelength regardless of how the photons were produced whether it be from a star...
  8. ATJ

    aplysia hare ID

    I'm very surprised that Bill wasn't able to help you. When did you ask? I know Bill was away for a while.
  9. ATJ

    To light, or not to light, that is the ?

    I don't believe you would have massive problems with algae by leaving the lights on. Assuming you were going to have massive algae problems, wouldn't you still have those same problems when you eventually turn the lights on? I see no reason for fluctuating pH if the lights are left off. In...
  10. ATJ

    Can A Blacklight Stimulate Growth?

    Well, yes, there are, but as already indicated there aren't many such pigments. In the long list provided by Riddle, only 6 pigments are identified as having excitation peaks of less than 400 nm. Of those 6, two of them aren't corals (one is the anemone, Condylactis gigantea and the other is...
  11. ATJ

    Can A Blacklight Stimulate Growth?

    I am not aware of any research into fluorescence being an attractant for prey. It seems an unlikely proposition. When there is twilight or moonlight and fluorescence is going to be far less significant that the source of the light - the moon and the sky. If the zooplankton where attracted...
  12. ATJ

    Can A Blacklight Stimulate Growth?

    Luke, First of all, the fact that you can "observe" anything under the blacklight suggests that it also includes visible light as human eyes are not sensitive to UVR. How do you know whether the reaction of the corals, zoanthids and clams are a result of the UVR or the visible light? Second...
  13. ATJ

    Can A Blacklight Stimulate Growth?

    I'm not aware of any benefits of UV radiation to marine organisms. There may be some sterilisation benefits but that's going to be about it. UVR can't be used (directly) for photosynthesis as it is beyond the reach of photosynthetic pigments which have a limit of around 400 nm, but can extend...
  14. ATJ

    Moorish Idols

    And we get them in Sydney each Summer. They come down as juveniles on the EAC live here for a few months and then die. Should we not take these ones, too?
  15. ATJ

    id please

    With some obvious exceptions, identification of invertebrates from photographs alone is generally difficult. The accuracy of the identification will vary between taxonomic groups but with sea stars most you will only be able to identify to family or genus at very best. The sea stars here are...
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