We’re staying on the coral reef to explore more colorful camo. I know, it sounds weird, but last time we spoke about the Flame Angelfish, we discussed why coral reef fish are so colorful. It actually works in this clear, yet complicated environment where natural selection and sexual selection agree to create attractive colors that also help them hide. Today we’ll cover another denizen of the Indo-Pacific tropics to talk about one of the more popular methods of confusing predators - the eye spot. The fish that sports this today? The Threadfin Butterflyfish!
This one *just* appeared in AC Pocket Camp last month (March 2022) for the 48th fishing tourney. We may never see it again! Only time and Nintendo will tell!
Anyway. The threadfin is named to species - Chaetodon auriga, of the family Chaetodontidae, the butterflyfishes. Now, this group may look a lot like the marine angelfish - both groups sport some incredible colors and they are laterally compressed, which means they are really narrow when viewed from any angle by their left and right sides, which make them appear wider. This shapes is common in fish, but both these traits together make it really hard to separate which fish are butterflyfish and which are angelfish. The primary difference is that marine angels have a sharp spine on their operculum, the gill cover, while butterflies don’t. It’s such a tiny feature, but that’s the distinction. The threadfin itself distinguishes itself from other yellow-and-white fish with the long filament coming off its dorsal fin. AC did such a great, detailed work on that icon, dang!
One thing you’ll notice about some reef fish are a single black spot on the opposite end of their bodies, while their eyes are covered by a dark stripe. This is a common method to deceive predators into thinking the fish’s head is on the side with the false eye, or eye spot. True, no one wants a chunk taken out of them, but if you had to choose, I’m sure you’d choose dorsal fin over your face. This may also confuse even a smarter predator that thinks ahead - if it thinks the fish’s face is on that side of the body, it makes logical sense that it would move forward that way. In that instant, the butterflyfish can dart in the opposite direction and get out of dodge.
It’s an incredible play on mimicry and camouflage, but not every threadfin butterfly has the eyespot. Some taxonomists would say they aresubspecies of each other, and therefore they are named as such. The one without the eyespot - Chaetodon auriga auriga - is native to the Red Sea, while the one with the eyespot - Chaetodon auriga setifer - is native to the rest of the threadfin’s range, which is huge. It’s very widely distributed across the Indo-Pacific, from outside the Red Sea to Hawaii, north to Japan, and South to French Polynesia.
Oyster. Reading that word, you probably formed an image in your mind of a rough-shelled creature with a shiny mother-of-pearl (nacreous) inside that someone pulled out of some silt in an estuary. And yes, that’s what most oyster’s look like. Some oysters are of additional economic value through their creation of pearls. These pearl oysters have…
Tridacna crocea, bored into a coral head on a reef in Palau
There are many types of giant clam. Not all of them are giant; the boring giant clam, Tridacna crocea, only grows to 10 cm long or so. The boring giant clam is not so named because it’s dull; its main skill is its ability to bore into the coral of its coral reef home and live with its entire shell and body embedded in the living coral.…
The heart cockle (Corculum cardissa) is so named because of its heart shaped shell shape. It is native to warm equatorial waters of the Indo-Pacific. While many bivalves sit with the their ventral valve facing down, the heart cockle sits on its side, with one side of both valves facing downward. the valves have adapted to resemble wings and are flat on the bottom
Fragile and gorgeous like their real-life counter parts, these porcelain sculptures by artist and ocean activist Courtney Mattison draw attention to a precious ocean resource in danger.
Coral plays a vital role in ocean ecosystems and biodiversity — one-quarter of all ocean species depend on them for food and shelter. And we in turn rely on these species for commerce and nutrition.
Mattison’s ongoing handmade porcelain series “Our Changing Seas,” intends to inspire ocean conservation. We want to see more art like Mattison’s especially if it means that the real life version inspiring it will be better protected.
In a study published in the journal Global Biogeochemical Cycles on May 2, 2016, scientists from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science found that the limestone that forms the foundation of coral reefs along the Florida Reef Tract is dissolving at a very rapid rate during the fall and winter months on many reefs in the Florida Keys. The research also showed that the upper Florida Keys were the most impacted by the annual loss of reef.
For this study Dr. Chris Langdon and his team collected water samples in 2009 and 2010 along a 124-mile (200-kilometer) stretch of the Florida reef, from north of Biscayne Bay to the Looe Key National Marine Sanctuary in the Atlantic Ocean, about five miles off Big Pine Key in the Lower Keys. This data establishes a baseline of the health of the reefs, which could then be used for future studies that look at changes along the reef tract.
The team found that reef dissolution in the fall and winter months is a significant problem on reefs in the upper Keys, where the loss of limestone is exceeding the amount the corals are able to produce in the spring and summer on an annual basis. The northern-most reef is already net erosional (-1.1 ± 0.4 kg CaCO3 m-2 y-1) and mid-reefs to the south were net depositional on an annual basis (0.4 ± 0.1 kg CaCO3 m-2 y-1) but erosional during the fall and winter. Only the two southern-most reefs were net depositional year-round.
“The reef needs a certain amount of carbonite production every year to stay in place,” Landgon says.“if it’s in excess of that, the reefs grow. When it reaches zero, they are holding even. When it switches to negative, that’s when they start wasting away.”
On top of supporting most of the biodiversity in the oceans, coral reefs are also crucial for the economies and tourism industries of coastal countries. In Florida, it is estimated that the reefs have an asset value of $7.6 billion, and they support over 70,000 jobs.
(The thickets of staghorn corals (A. cervicornis) are gone today replaced by a structure-less bottom littered with the decaying skeletons of staghorn coral. Photo by Chris Langdon)
The results of this study indicate that parts of the Florida Reef Tract have already crossed the tipping point for carbonate production and other parts are getting close. Moreover, the area has suffered greatly over the last few years due to warmer sea surface temperatures, and heavy coral bleaching episodes that resulted in a significant loss of corals and in the spread of diseases.
Since the data for the study were collected in 2009 and 2010, it is now necessary to conduct a similar analysis to see how the reefs are faring today. Considering that the worst bleaching years on record in the Florida Keys were 2014-2015, it is very possible that the reefs are in a worse state nowadays.
Coral reefs are among the most dynamic and diverse ecosystems on the planet. They provide a safe habitat for hundreds of marine species, along with numerous resources necessary for the economic survival of smaller nations. Nevertheless, ocean acidification is one of the greatest threats that coral reefs face nowadays. It is now necessary to understand the problem, and to act quickly to limit the consequences potentially insuperable if coral reefs were to disappear.
How does a coral reef form?
Coral reefs are natural structures essentially built by hard coral colonies. Each coral is an invertebrate animal constituted of polyps. A polyp is an organism made of a mouth, stomach, wall and tentacles used for feeding and defense. Most of the corals are made of hundreds of those polyps, each genetically identical. Each polyp secrete its own exoskeleton made of calcium carbonate. Thus, hard coral species build reefs with the slow accumulation of these calcareous skeletons. Corals are furthermore considered as one of the biggest natural well of carbon on our planet.
The above video shows detailed and close-up shots of coral polyps feeding.
Why are coral reefs important?
Coral reefs have among the richest biodiversity on the planet, and provide ecological niches to numerous animals that find protection and food within the reef. According to the National Oceanic Atmospheric Administration(NOAA),more than 25% of the world’s marine biodiversity is found around coral reefs, as well as over 4,000 different species of fish.
Corals are also a necessity for many coastal countries. Coral reefs offer a natural barrier against erosion and flooding following strong weather events (hurricanes or typhoons, for example). Furthermore, coral reefs are of an invaluable economical importance, and supply essential goods and services such as food, raw material, water filtration, and tourism. Over 30 million people depend exclusively on those reefs for their subsistence and housing, particularly the populations living on coral islands or atolls (Wilkinson 2008).
It is difficult to calculate the exact monetary value of such an ecosystem, but according to estimations from experts at Diversitas in 2009, the goods and services supplied by coral refs have an average annual value of about $172 billion.
How are coral reefs threatened?
Corals are very sensitive animals, and do not tolerate big changes in their environmental conditions. They now have faced for multiple years various threats, such as overfishing, pollution, bottom trawling, warming sea surface temperatures, or ocean acidification.
It is possible that by the middle of the century, corals become incapable of surviving in numerous regions of the world due to ocean acidification, and that their dissolution will be faster than their rebuilding(Guinotte and Fabry 2008). As I explained in the first article on this topic, the more acidity increases, the more energy is required to form a skeleton, and corals thus become more vulnerable.
In 2008, Clive Wilkinson explained that the world had already lost over 20% of coral reefs. In 2011, a report from the World Resources Institute indicated that 75% of coral reefs were at risk of entirely disappearing. In July 2015, a team of international scientists lead by Dr. Jean-Pierre Gattuso of the Laboratoire d’Océanographie de Villefranche published a worrying studyon the future of our oceans. If we continue with the ‘business as usual’ approach and if the CO2 emissions increase at the same rate, we can expect irreversible consequences on the marine ecosystems.
Without corals, the marine biodiversity will sharply decrease, as it will equal a huge loss of habitat, food and protection for many species. Moreover, the sectors of tourism and fisheries in numerous local and national economies will highly suffer from the disappearance of coral reefs. Finally, coastal regions will inevitably face increased beach erosion,floods, and damages in towns located close to the oceans.
What can we do?
All hope is not lost yet. A team of scientist has already shown that some corals are capable of regulating their own pH levels internally(McCulloch et al. 2012). Moreover, scientists in many countries, like Ken Nedimyer in Florida, have successfully established coral nurseries to grow endangered coral species (see photo), and to insure the presence of numerous and different genotypes within the reef. These corals are then transplanted onto older reef sites, previously destroyed by storms, diseases or bleaching events, so the reef can rebuild. Additionally, scientific research on corals and their resistance to such events continues across the world.
(Photo of Acropora cervicornis trees at the CRF coral nursery down in the Florida Keys. Photo by Allan Bright)
In France, l’Initiative française pour les récifs coralliens (IFRECOR), dependent on the Ministère de l’Ecologie, has been committed since 1999 to ensure the protection and sustainable management of coral reefs in French waters.
Everything in our environment is connected, and it is therefore possible to help coral reefs indirectly in our daily life. Don’t hesitate to check out the Lemonsea article on 5 things you can do to fight ocean acidification. No action is too small.
Giant clams have been a hard-to-miss part of coral reef ecosystems for the greater part of the last 38 million years. However, experts will be quick to admit that the part they play in these incredible systems remains rather shrouded in mystery. Now a new study hopes to pull back the veil and further our understanding of these clam colossi. (Photo : Flickr: BBM Explorer – Rob)
Gliding through these gorgeous isles, meet green sea turtles, “boat boys” who feed and outfit you, and history in turquoise.
View from Petit Rameau, Tobago Cays, in the Grenadines. MICHAELA URBAN
By: Eric Vohr, For The Inquirer
Unspoiled white-sand beaches, turquoise-blue waters, frolicking green sea turtles, and bays, lagoons, and reefs so idyllic you have to pinch yourself just to make sure…
No, this isn’t a nonsense riddle form Lewis Carroll. But it is the subject of the most recent episode of This Week in Virology (TWiV), where host Vincent Racaniello talks with guests David Pride and Forest Rohwer about their work in the microbiomes of human mouths and the viromes of coral reefs. These two worlds have more in common than you might think when it comes to viruses and bacteria!
“Biology is really all mucus,” (10:09), says cohost Alan Dove, and this is certainly true of coral reefs. According to microbial ecologist Rohwer, coral has thick mucus layers that interact with the ocean and the microbes that come with it. Living inside coral are huge numbers of microorganisms, like dinoflagellates, and when different microorganisms from the water interact with them, a number of things happen. Usually, when phages meet bacteria, they constantly fight each other, but in some coral at certain densities the phages are likely to become prophages that instead protect the bacteria from other phages. The phages, with the mucus, create a kind of protective barrier.
And what about the mouth? “We’re just a coral reef turned inside out,” (12:17) says Dove, as Pride, doctor of Microbiology and Immunology, explains how the saliva microbiome washes over and interacts with the multiple microbiomes located within the mouth. These different microbiomes, called microniches, are all essentially distinct from one another, containing their own makeup of viruses. If some of the viruses are removed, as by using some antibiotics, the makeup is drastically altered, and a space is left open for many more things to come in.
Rohwer notes that the same is true for coral reefs; if phages are removed, bacteria increase and slow the system down. If you add the phages back in, the bacteria decrease again.
“If you mess with any one component of this,” says cohost Rich Condit, “you’re potentially reaching a crisis where the whole thing spins out of control and crashes” (52.48).
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