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Coral Fat Storage Plays Big Role in Bleaching Recovery

Researchers from Ohio State University have expanded upon earlier research that concluded corals best suited for recovering after a bleaching event harbor large storages of fat in their zooxanthellae cells. “Three global bleaching events have already occurred since the 1980s, and will likely occur annually starting later this century, therefore, it has become more urgent than ever to know how coral can survive annual bleaching—one of the major threats to coral reefs today” says Lead study author Verena Schoepf. “Already, bleaching events have resulted in significant amounts of coral dying and causing impact to ocean ecosystems, but up until now it was largely unknown whether coral could recover between annual bleaching events,” Schoepf adds. Orbicella faveolata 2.3624d4b5The study adds new findings for the long term recovery rates of two corals best suited to withstand heat stress, as annual bleaching events are becoming more and more common along reefs all over the world. Both Porites divaricata, the species which kept the largest fat reserves, and Orbicella faveolata which kept the second to largest reserve out of the three corals studied, fared much better than Porites astreoides, which housed the smallest level of fat reserve. “They all look healthy on the outside, but they’re not all healthy on the inside,” said Andréa Grottoli, lead researcher and professor in the School of Earth Sciences at Ohio State. “We found that some coral are able to acclimatize to annual bleaching, while others actually become more susceptible to it over time. Our research will help with predicting the persistence of coral reefs, because knowledge of their capacity to recover from annual bleaching is critical information for these models,” concluded Grotolli. Read more here!… More:

Predicting the Vulnerability of Reefs to Climate Change

Data collected from the Reef Life Survey has allowed researchers from Ocean and Earth Science at the University of Southampton to measure the thermal-range tolerance of 2,695 shallow reef fish and 1225 reef invertebrates. From Greenland to Australia the team focused on the thermal “bias” within which inhabitants can adapt, while noting which groups are more susceptible to extinction and replacement. “They found that locations where the average summer sea surface temperature is presently 24 °C, such as the Gulf of Thailand, southwestern Caribbean and Three Kings-North Cape in New Zealand, are the most vulnerable to changing community biodiversity. This is because most of the species making up these communities are already living near the edge of their temperature distribution.” The effort has created new measurement tools for predicting the sensitivity of reefs to rising ocean temperatures around the world. Study co-author Dr. Amanda Bates adds: “A strong focus in climate change ecology has been on quantifying the exposure of different regions of the globe to warming. Our work offers new tools for measuring the sensitivity of communities to change including accurate indicators that can be used to predict vulnerability.” 151111143139_1_900x600 Photo Credit: Rick Stuart-Smith With the evolutionary notion that species come and go, this research provides an interesting look into the heat tolerance for thousand of reef inhabitants, while providing a predictive model for those most at risk: “In 100 years from now, 100 percent of species in many communities will be lost and replaced by new species able to tolerate warmer conditions, leading to a redistribution of species across the globe.” Read more here!    … More:

Symphyllia: So Stunning, Yet Success Eludes Me!

Symphyllia spp. coralSymphyllia are some of the most colorful large-polyp stony corals out there. Their bodies resemble Lobophyllia in many ways, but unlike lobos, they have a much more diverse color arrangement. I’ve seen them come in just about every color imaginable, and it is very common for them to have large bands of colors. Unfortunately, I don’t do very well with Symphyllia. As colorful and amazing as these corals are, they’re a no-go for me until I learn more about why they might be struggling in my system.

Signs that Allelopathy Might Be Agitating Your Inverts

Some soft coral species, such as Sinularia, are well-known for their chemical warfare tendenciesSince corals and other sessile invertebrates are more or less stuck in place and can’t chase away competitors or run from predators, many of them—particularly among the soft corals—have evolved the tactic of exuding toxins into the water to prevent other inverts from encroaching and to discourage predation. As you can imagine, this “chemical warfare,” known as allelopathy, can become problematic in closed aquaria because even the largest tank can’t remotely approximate the ocean’s capacity to dilute these noxious chemicals. Some inverts subjected to these toxins in an aquarium may be unaffected, others may remain in a contracted state, while still others may become stunted, suffer tissue necrosis, or even die as a result of the exposure.Of course, there’s no practical way to test for these toxins and all sorts of environmental issues can cause similar problems in corals, so the challenge from the hobbyist’s standpoint is determining when issues with invertebrate livestock might be attributable to allelopathy versus water quality or some other environmental problem (e.g. inappropriate lighting or current). Here are some signs that might indicate allelopathy is to blame: Your tank contains a lively mix of soft and stony corals In the typical “coral garden” tank stuffed with all different kinds of soft and stony corals, it’s not so much a question of whether allelopathy is going on but to what degree it’s going on. In this setting and assuming water parameters and other environmental factors check out okay, “chemical warfare” is often the best explanation for the odd coral refusing to open up for prolonged periods or the occasional inexplicable death or necrosis of specimens. Your tank contains species known to be toxic Some corals are just notorious for creating allelopathy issues. For instance, among the soft corals, various Sarcophyton, Lobophytum, Sinularia, and Lemnalia species are well known for their toxic tendencies

When is a Toadstool Coral not a Toadstool Coral?

"Sarcophyton" ehrenbergi, the False Toadstool Coral. Credit: Dr. Yehuda Benanyahu

“Sarcophyton” ehrenbergi, the False Toadstool Coral. Credit: Dr. Yehuda Benayahu

 Zoological taxonomy is not for the feint of heart. Take, for instance, the humble Toadstool Coral— a stalwart soft coral recommended to every rookie reef aquarist. Despite the ubiquity and importance of these corals in reef ecosystems, our understanding of their evolutionary relationships is in a nascent stage. There are no field guides enabling easy identification, and, in all likelihood, there never will be. Recent molecular study has shown that our current system for classifying the Toadstool Corals and their allies is inherently wrong in many different and important ways.… More:

Reef Threads Podcast #246

A little purple nephthea.

We return once again. This week we talk about salt, Gary’s new Live Aquaria t-shirt, the Reef Savvy Dream Tank giveaway, the Internet as a research tool, placing corals, and Level 1 and Level 2 fun. Download the podcast here, or subscribe to our podcasts at iTunes. Also, follow us on Twitter at reefthreads.—Gary and Christine

Sponsor: Rod’s Food
Rod’s Food website

Internet research
Is the Internet a Viable Resource for Marine Aquarium Research?, Jeff Kurtz, Saltwater Smarts

Coral placement
Need help with coral location, gam3ovr, Reef Central


The Hammer Coral: A Sizeable Stinger with Showpiece Potential

Hammer coral (Euphyllia ancora) can be quite variable in colorSeveral of the so-called large-polyp stony (LPS) corals offer the advantages of being very hardy, adaptable, and beautiful and, thus, make excellent reef aquarium candidates, even for relatively new reefkeepers. The hammer coral (Euphyllia ancora), however, I would characterize slightly differently. There’s no question this coral is gorgeous, but I would rate it as rather less forgiving than, say, Trachyphyllia geoffroyi. Still, if its care requirements and aggressive nature are given proper attention, this coral can be a showpiece reef aquarium resident. Physical traitsE. ancora has long, tubular tentacles with tips that resemble, as you might guess, the head of a hammer or an anchor. Most specimens I’ve come across have had brownish to grayish tentacles with the tips being some shade of green, gold, or cream, but the color can be quite variable. Colonies of this coral can get quite large—upwards of 3 feet across—which must be taken into consideration when determining tank size, placement, etc


Palythoa grandisMany of us are inspired to keep marine life for its exotic beauty or interesting behavior. But if we’re being perfectly honest, we have to admit there’s also something intriguing about keeping—and displaying to our friends and family—marine organisms that have dangerous or potentially deadly defense mechanisms, such as venomous spines, potent toxins, or razor-sharp teeth. For those hobbyists who like to flirt with danger, the marine aquarium trade certainly offers its share of prickly and poisonous characters—from venomous fishes to deadly cephalopods to noxious sessile invertebrates. There are even organisms we can buy that offer stunning beauty and potency in equal measure.Among these best-of-both-worlds critters are many of the zoanthids we’re so fond of keeping in our reef systems. These polyps (most of the ones we keep being from the Zoanthus and Palythoa genera) have much to recommend them, being very hardy and often stunningly beautiful. But some of them also contain a potent neurotoxin, called palytoxin, in their tissues and mucus that can make people very sick or even cause death if they’re not handled properly. Of course, blithely mentioning that certain popular zoanthids have the potential to sicken or kill people raises a whole host of questions that demand prompt, thorough answers. Among them: What is the nature of palytoxin is the world's leading destination for sustainable coral reef farming and the aquarium hobby. We offer a free open forum and reef related news and data to better educate aquarists and further our goals of sustainable reef management.