by Matthew Stansbery | Jun 1, 2014 | Conservation, Invertebrates
Newly appointed Professor Peter Ward, of the University Adelaide’s Sprigg Geobiology Centre is calling for a global ban on trade of the Nautilus sea shell. His efforts are stemming from a recent trip the Phillipeans where he found that the Nautilus is close to... by AquaNerd | Apr 22, 2014 | Aquaculture, Eye Candy, Invertebrates, Sustainability
Thanks to the extremely focused efforts of one individual, the world of Tridacnid clams has been completely changed. We’ve been following the work of one Australian “super aquarist” who goes by the name Acro Al. He has been breeding clams at his home for quite some time now, sharing much of his journey with fellow hobbyists on social media. And because we’re total clam junkies, we’re totally excited about the fact that his babies are getting old enough to hit the market. What makes the news even more exciting is that this is the first time that fully cultured maxima clams have ever been offered in the aquarium trade! To let the market fully dictate the price, this first individual, which is a total looker by the way, was posted in an online auction with a minimum reserve set at $250. The price quickly rose to well over $400 for this 40mm individual, which interestingly is about to turn one year old. The clam is not availalbe to purchase by US hobbyists, as the permitting and paperwork hoopla is far too difficult to overcome at this point, but it’s still groundbreaking news for the hobby. First fully aquacultured Maxima clam IN THE WORLD! Species: Tridacna Maxima (Röding, 1798) Batch No. by Admin | Apr 15, 2014 | Conservation, Fish, Science
3 day old P. venusta larvae. Photo credit: Karen Brittian. Larval rearing trials began with the spawning of a Paracentropyge venusta pair in the summer of 2013. The first successful larval rearing trial started with a small spawn on November 13, 2013. This was the fifth larval run with this species and the focus was on food density and consumption at different developmental phases. The diet consisted of both cultured copepods and wild collected plankton with all food items being less than 100 microns in size. To assess consumption rates, five random samples were taken for initial food counts at the start of each test period. All food items added to the larval tank during the test period were counted while maintaining a density of 1 to 2 food items per ml in the water column. At the end of the time period counts were again done to determine larval consumption. At this point a 75% water change was carried out. I was surprised at the amount of food these little larvae could put away and as an example, at day 28 post hatch the larvae consumed approximately 2,150 food items each over a 12 hour period, (5:00am to 5:00pm). 32 day old P. venusta larvae. Photo credit: Leighton Lum. At one month of age the larvae started targeting larger prey items and ignored the food items less than 100 microns in size. At this point newly hatched and enriched Artemia were added to the diet along with adult cultured copepods. The larvae also began to display benthic behavior by associating with the corners of the tank, the air stone and airline tubing. A piece of dried coral rubble was added where the larvae took shelter. The larvae continued to grow and develop; they were moved into a growout tank at 57 days old. At this point we had 17 larvae remaining which equates to 6% survival from hatch. The development of juvenile colors came slowly. On day 95 they had black pigment on parts of their fins and tail. A month later at 130 days old they were the beautiful blue and yellow of the adults. 115 day old P. venusta juvenile. Photo credit: Leighton Lum. Larval rearing of this species proved relatively “easy” in their first few weeks of the larval stage after which point larval development and growth seemed to slow. This could be attributed to the type and amount of wild plankton collected and fed out at that time. I feel that the larval phase could be shortened and improved upon in the area of diet. After metamorphosis the larvae were again slow to develop with a reluctance to accept non-living food items and this is also another area for improvement. The Reef Frenzy and Herbivore Frenzy frozen foods were the first choice of the juveniles when they began to accept non-living food. Currently these juveniles are fairly bold and are consuming frozen and dry foods with gusto. by Admin | Mar 26, 2014 | Conservation, Fish, Science
Female P. venusta (note the light precaudal band). Photo credit: Leighton Lum.Paracentropyge venusta were identified as a good candidate for captive breeding since they often do not adjust well to captive life after being collected in the wild. A juvenile pair from Japan was established for broodstock. The immature fish were introduced to each other during quarantine. Due to the timid nature of this species, quarantine was a dark blue barrel with black plastic pipe provided as hiding places. Male P. venusta. Photo credit: Leighton Lum. The pair is housed in a 440 liter tank with a foot print of 122cm by 46cm and a height of 76cm to provide room for a spawning rise. They are housed with a pair of Red Sea Regal Angelfish, Pygoplites diacanthus and a single Multibarred Angelfish Paracentropyge multifasciata. Feeding occurs at least 3 times daily with a varied diet of frozen clams, table shrimp, Mysis shrimp, krill, Artemia, commercial frozen and dry food and nori. The mature male now measures 8.5cm total length; the female is slightly smaller at 7.5cm. The female has a 1-2mm, pale colored band at the precaudal region of the body. This band is present in small juveniles and may be a simple trait of sexual dimorphism for this species. Spawning began when the pair was just over two years of age. Initial spawns were small and infrequent. During the summer of 2013, spawns became increasingly larger with a higher fertility rate although still on an irregular cycle. Spawns are now more regular and vary 300 to approximately 1000 eggs. Pre-spawning chasing activity generally begins around 7:00pm which is 2 hours before lights out. Spawning normally happens within 30 minutes of lights out. The eggs are approximately 700 microns in diameter with a single oil drop. They are positively buoyant and float at the water surface. The eggs are then collected using a 500 to 600 micron mesh net. They are placed in a container with water from the broodstock tank and allowed to incubate over night without aeration. Once the eggs begin to develop, the embryo becomes heavily pigmented appearing quite dark as compared to other angelfish eggs. This makes them easy to see and count. Fertile eggs hatch 16 hours after spawn at 27C. Special thanks to DJ Lineham of Tropical Fish Emporium for broodstock acquisition and species information. by Reef To Rainforest | Dec 13, 2013 | Fish, Science
Eastern Hulafish, new captive-bred reef fish native to New South Wales, Australia. Image: ORA. Meet the Eastern Hulafish, Trachinops taeniatus, the newest aquacultured fish for the reef aquarium and exclusively available from its breeder, ORA in Ft. Pierce, Florida. This sub-tropical species is from New South Wales off southeastern Australia and is related to the Assessors and Comets, all in the family Plesiopidae. The fish is not unknown to marine aquarists and divers who study the reef fishes of Australia, but it comes from cooler temperate waters where little commercial collecting takes place. “The Eastern Hulafish is native to the southeast coastline of Australia where the water temperatures average 65 degrees Fahrenheit (18 degrees C),” says Dustin Dorton of ORA. ”While these fish have fared very well in our Florida greenhouses, they can exhibit distress in water over 78 degrees (25 degrees C). Care should be taken to ensure their aquarium temperature always remains below 78 degrees.” They are very colorful fish with a black stripe running down the middle of their elongate body from the operculum towards the tail. They are red and yellow above the black stripe and their ventral portion is white. Some have iridescent blue scales on the face. As they age, their caudal fin grows into a spade shape, with the males having more exaggerated filaments. These are shoaling fish, and ORA recommends keeping them in groups of 4-5 or more. When kept in groups these fish exhibit a unique swimming behavior, hovering at an angle which is said to suggest a cluster of hula dancers. Trachinops taeniatus grow to a maximum size of about 4 inches (10 cm) and are micropredators, eating small food items such as copepods, Artemia, Mysis, small pellets and flakes for carnivores. ORA says, “They are peaceful fishes that do not harass other species. Eastern Hulafish are extremely fast swimmers and are prone to jumping out aquariums so is important that their tank be kept covered.” Available in limited quantities now from ORA. (Announced December 13, 2013.) Sources Oceans, Reefs & Aquariums - ORA Fishbase: Trachinops taeniatus
