RSS Yellow tang ‘Breeding Barrier’ is under attack

Discussion in 'RSS Feeds' started by MASA Admin, 25 Feb 2014.

  1. MASA Admin

    MASA Admin Moderator

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    It has been well over a decade since Yellow Tang breeding research began at the Oceanic Institute in Hawaii (OI), with many folks along the way making progress on tang breeding in general. When it comes to Yellow Tangs, the most notable progress to date had occurred at the hands of Syd Kraul in the early 2000′s, and while rumor upon rumor have piled up over the years, until this week no one had really proven they could go past Kraul’s 40 days post hatch with Zebrasoma flavescens at Pacific Planktonics back in 2004/2005. Even Kraul, who thought he’d have closed the gap by 2007, never seemed to get any farther.

    [​IMG]Yellow tang at 50 days post hatch- a new record and a step closer to a goal people have been dreaming about for decades – Photos by Dean Kline and David Hoy.


    That has changed today with word from Chad Callan at OI, who announced on Monday via the Rising Tide Conservation Blog that they have passed the 50 day post-hatch milestone with captive spawned Yellow Tangs. As he wrote, “On Jan 1, 2014 we stocked a 1000L tank with about 40,000 yellow tang eggs. In this rearing attempt we experimented with very high water turn-over rates, and very clean (ultra UV dose) water. As in previous studies, we used the calanoid copepod,Parvocalanus crassirostris, as our feed. While this was only one tank (we are currently testing these methods again), we immediately noticed far more fish making it through the early larval period than ever before.**We were really excited to see 1000’s of fish survive past the first 2-3 weeks and ended up with more than 600 at day 35.**We have since moved the fish to smaller tanks and are investigating potential settlement cues, like photoperiod and substrate.

    [​IMG]Yellow tang at 15 days post hatch – Photos by Dean Kline and David Hoy.


    The fish recently crossed day 50 and appear to be looking very close to settlement. We’re observing fairly high mortality during this period of transition, but still have more than 150 fish distributed among our tanks.**We are hoping at least a few make it through, but regardless are very encouraged by this recent progress!”

    [​IMG]Yellow tang at 20 days post hatch – Photos by Dean Kline and David Hoy.


    I asked Chad to provide some insights and explanations, most notably his mention of “ultra UV dosed” water. Callan elaborated that the used a “High-output, 300W UV that we only ran 5liters/min through. If you do the math, based on the manufacturer specs, that’s >4,000mJcm2.* The combo of high UV dose and high turnover rate are what (we think) helped provide a more hospitable environment( bacteria-wise) for the fish.” *Indeed, as breeding enthusiasts will continue to learn in the weeks and months ahead, there is growing evidence that bacterial populations (and similar) are seeming to have more and more of a negative impact on rearing when it comes to pelagic spawning marine fish. *It seems ever more likely that “sterile” tendencies might be a very necessary (and frustratingly difficult to provide) component of marine fish breeding.

    [​IMG]Yellow tang at 30 days post hatch – Photos by Dean Kline and David Hoy.


    Some other interesting tidbits; natural saltwater from a well is being used for these initial rearing efforts. *Is there something beneficial at play here that artificial saltwater can’t match? *Impossible to say at the moment, but it’s a question that has come up more than once now in relation to fish breeding. *Callan mentioned that rearing vessels themselves were nothing unusual either. *Their largest obstacle so far has been the production of sufficient populations of Parvocalanus copepod nauplii, which are THE only food they’ve used until the larval Zebrasoma start taking brine shrimp nauplii.

    [​IMG]Yellow tang at 40 days post hatch – Photos by Dean Kline and David Hoy.


    Settlement is believed to be around the corner; send the well wishes and good vibes to the team in Hawaii as their fish approach metamorphosis, a time typically frought with difficulty and more mortality (They’re down from 40,000 eggs to around 150 larvae at this point in time!).


    For the full story, visit the Rising Tide Conservation Blog.
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  3. regis

    regis

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    Awesome
     
  4. dallasg

    dallasg Moderator

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    Freaking awesome
     
  5. Stanley

    Stanley

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  6. viper357

    viper357 Admin MASA Contributor

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    At what point does it become slaughter when 1000's of baby fish are being killed on a regular basis? Nobody complains about that, yet put a single yellow tang in a nano and the world erupts and throws down accusations and abuse onto the person. lol. :p
     
  7. MistaOrange

    MistaOrange

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    Tang%20police%20copy.jpg

    Tang%20police%20copy.jpg
     
  8. regis

    regis

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    Well if they can work out the kinks, and breed yt, it is better for the population in the long run. I am sure it is just a small sample
     
  9. viper357

    viper357 Admin MASA Contributor

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    Agreed. I'm not arguing, just think a bit of perspective is needed now and again. ;)
     
  10. RiaanP

    RiaanP Moderator

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    is it not the same as when my clownfish laid eggs and they hatch in my display tank. Becoming food for the other fish and corals?

    hmmm.
    I'm a mass murderer... And I know a lot of other mass murderers... :blush:

    Anyway.
    If they manage to rear 150 YT from a 40000 eggs. That is a low success rate. But it is another 150 that enters the trade that was not harvested form around Hawaii. They will have failures, wipeouts. They will gain knowledge and one day the success rate will increase. Imagine a 20% success rate on 40000 eggs, YEAH!!!! That is 8000 young YT.

    I wonder what is the egg to adult rate in the wild? From a 40000 eggs, how many do reach adulthood?
     
  11. viper357

    viper357 Admin MASA Contributor

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    Exactly my point. A single person will get publicly crucified and run out of the hobby for putting a tang in a small tank, yet everyday thousands of aquarium fish are being killed. Like I said, a bit of perspective and restraint is sometimes needed when attacking others for "harming" a single fish. ;)
     
    Last edited: 26 Feb 2014
  12. regis

    regis

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    Agreed
     
  13. MistaOrange

    MistaOrange

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    I tend to agree here that's why I posted the tang police pic.
     
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