Gracilaria repro.  1/16/06 Hi Crew!! <T.W.> One quick question... I'm looking to sell Gracilaria algae on a well known auction site here in the UK as I have loads of it and I would like to know one thing - does this go sexual like Caulerpa does? <Umm, no... No noxious, discoloring production...> Thanks for the great service - your site is my first port of call should I even need help...   Keep up the good work!! Tim Walters UK http://marine.kite-it.co.uk A history of a Marine Tank Setup <Neat! Bob Fenner> Growing Gracilaria [*Note to Bob: Chris has shared with us a nice summary of his experience growing the popular macroalgae Gracilaria here. Perhaps we can place it prominently I the archives or FAQs for easy access/referral by the crew and WWM readers? Thanks, Anthony] <Will do, Bob> Growing Gracilaria 11/11/03 Hi Anthony, Thanks for your advise in response my previous email regarding the growth of Gracilaria. <always welcome my friend> I am just reporting back to you some good results on growing Gracilaria - Red Macro Algae. <much appreciated... this will be very helpful to add to the consensus for all to see/read and learn from> In the first 4 weeks I have been very successful in acclimating the seaweed as I have seen some steady growth... new fronds and full color. I feel have established a very suitable environment for this macro algae to grow effectively. Here are the specifications... 1. A separate tank - One with high nutrient levels. A tank dedicated to feeding just the Algae... but high Nutrient Levels a must. I add a silverside or formula 1 once a week.. but being careful to not overfeed the tank; over feeding may allow growth of diatoms and other competing micro algaes. <good points here: monospecific culture, as algae and plants are competitive (chemically and otherwise) with each other just like reef invertebrates. And the finesse of nutrients... not too much or too little> 2. Trace Minerals - I dose about 7-8 drops of both Chelated Iron and Magnesium daily and perform a small monthly water change to replenish calcium levels and other trace elements. <the need varies by system... but you are finding your way here. Excellent> 3. Cold water - best growth for Gracilaria in between 60 F - 70' F. <this is not necessary, although fine if it worked for you. Much Gracilaria is grown commercially in the shallows (at surface level) in the tropical seas on lines and tumbling in baskets> 4. Strong Water Movement - I have a 800 GPH pump  in the sump and it's  return to the hex tank at  a 12 " vertical spray bar which pushes & tumbles  the Gracilaria around the tank in a circular motion (like a washing machine). At no time is any of the seaweed just sitting.... it's always tumbling. <yes... excellent and often overlooked by aquarists> 5. Strong Lighting - I have a 125 Watt Fluorescent Blue Actinic bulb hanging directly above the water column. Gracilaria grows in deeper waters and does better with Actinic Lighting. <again variable here... the commercial culture of Gracilaria ("Ogo" of food fame) is done so at the surface of the water. But the genus is adaptable and wide-ranging. I would suggest more/brighter daylight here to most aquarists> Please let me know of any individuals who are interested in purchasing 7-8 ounce portions of Gracilaria at a low price. They can contact me directly at XXXX@hotmail.com. <do be sure to establish it well in your local market through the LFS and aquarium societies so that you can retrieve some if/when your colony crashes> Thanks! Chris <thank you very much for sharing this Chris. Its always good to pay it forward. Anthony>

Growing Gracilaria 12/3/03 Anthony, Thanks again. Just another follow up... I have done a bid more research and testing and found that this particular species, (Gracilaria verrucosa) like most Red Gracilaria, reproduces seasonally, in the spring and fall by dropping off thousands of fine spores which attach themselves to the substrate and then germination and growth of spores are also influenced by environmental conditions such as seawater temperature, light intensity, salinity, etc.  Experiments have shown that the highest number of spores are released at 20--25 °C (approx. 70 F shows highest spore Desiccation). Any temperatures much higher or lower would not allow Gracilaria to develop the reproductive spores for Desiccation. Also, When mature plants are kept in seawater of different specific gravities, those in seawater of lower specific gravity would release spores earlier than those kept in water of higher specific gravity. I have seen spores develop immediately when I dropped the salinity between 1.015 to 1.017. This would explain why people have been unsuccessful with keeping Gracilaria alive for any length of time in systems with the higher Specific gravities. Just some more feedback. Here's a very interesting article on the culturing of Gracilaria... http://www.fao.org/docrep/field/003/AC263E/AC263E00.htm Thanks, Chris <much thanks for sharing this Chris. Please do consider though that what happened naturally is not always the optimal way of culturing an organism, but rather simply what they have adapted to in their given niche. Commercial culture of this genus in warmer waters with brighter light and in tumbling suspension are established methods of exploiting better growth. Much like aquarium grown clams and corals that grow 4-10 X or faster than expected wild growth as we learn to finesse/manipulate species for optimal culture. Best regards, Anthony>