13 September 2017

Collaborator of the Month: Dr. Charlie (J.E.N) Veron



If you have worked on corals and coral reefs, then you're probably well acquainted with the most comprehensive resource for corals there is, the 3-volume Corals of The World by John Edward Norwood Veron or as cited in the scientific community, J.E.N or Charlie Veron. Can you imagine your life without such a valuable resource? The thing is, Charlie Veron almost did not become a scientist. 

He is known today as the "Godfather of Coral" and likened by David Attenborough to Charles Darwin.

In his memoir A Life Underwater, Charlie chronicles his love for marine life as a child, his long holdup (how he almost didn't make it back to the sea), how one chance helped him pursue his true passion, and how he became a revolutionary self-taught coral specialist.



His work has been instrumental in our present understanding of coral reefs, from how they reproduce to how they evolve, and how they, in the light of climate change, have been dying. "Without his early work we wouldn't have had the basic benchmarks to see the nature of the changes that we are now seeing. He provided that baseline to put everything in context," says the scientist Tim Flannery [1].

Veron's contributions to coral reefs and marine biology are monumental. He was the first to compile a global taxonomy on corals. Also, contrary to common notion, he shed light that the the Indo-Philippines archipelago has the most diverse corals in the world, not the Great Barrier Reef. He is also known for his seminal theory, Reticulate evolution, on how corals have evolved [1]. 

To date, he he has worked on all the major coral reef regions of the world and has over 100 research publications, including 12 books and monographs on corals and coral reefs. 

Among his many books, his three-volume Corals of the World (2000), with his permission to use data and photos, has been invaluable to documenting the diversity of reef-building corals in SealifeBase. 

Over his 50-year career, Veron hasn't only been an insatiable learner of corals. He's been fearless in protecting the marine life he has reveled in his whole life. 

In his memoir, his adventures urge us not only to guard scholarly independence, but more importantly to learn to be persistent and take risks. He explains why today is the most pivotal time to protect our incredible marine life.

You may purchase Charlie's delightful memoir through this link.
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[1] Elliott, T. (2017, July 14). Live near the beach? Coral reef expert Charlie Veron has some advice for you. The Age. Retrieved from http://bit.ly/2vFfOMo


04 September 2017

Salute to the Gladiators of the Sea



Have you been vaccinated recently? Took medicine without any mishaps?
The merit goes to our clanky fellow—the horseshoe crab (Limulus polyphemus)for its precious blue blood.
Nope, they are not royalty, their blood is literally blue—it contains hemocyanin, a copper-based molecule carrying copper [1,2] which, when oxidized, turns bluish-green [1,3]. Meanwhile, our blood uses hemoglobin which carries oxygen (has iron in it), thus the reddish hue [1,3].
These ‘crabs’ are not true crabs, not even crustaceans [2,3]. In fact, they are under the subphylum Chelicerata [3,7], more akin to scorpions and spiders than they are to crabs [2,7]. They boast 10 eyes: large compound eyes, in particular, aid in locating a mate [3,4]. Their tails may look like a scathing weapon against predators; in fact, they use it to propel in different directions [3,4], or to flip them right up when capsized [2,3].
Thousands of these ‘living fossils’ form throngs in Delaware Bay every May and June, ready to mate. A female can release as much as 90,000 eggs per clutch but only around 10 are deemed to reach adulthood [3].
Horseshoe crabs are fine, robust, armor-clad creatures, as the paleontologist Richard Fortney remarked [1]. Time has been their ally, predating the dinosaurs for more than 200 million years [2,7]. A big hole on the head, a lump on the thorax, or a cracked tail spike did not obliterate these 450-million-year old ‘gundams.’ [1,4].
What helps them become almost invincible?
When a horseshoe crab gets wounded, its blood instantly releases an army of blood-clotting granules which seal the invading bacteria, preventing further infection [1]— the same, humbling reason, why we get to be safely injected with vaccines for four decades now [3].
Today, their blood is extensively used to test products, intravenous drugs and medical devices that come into contact with blood. Essentially, its active ingredient is a sentinel against “negative” bacteria, which is confirmed present if the cells clot in contact with a product [1,2,4,5]. Suffice it to say, horseshoe crabs have been saving millions of lives from unsanitary injections [3].
Photo credit: Popular Mechanics

One quart (almost 1 liter) of horseshoe blood is sold by Atlantic fishermen to pharmaceutical companies for an astounding $15,000, a lucrative business with more than 600,000 'donors' being bled [3,6].
To obtain the blue blood they are hosed up, sucking 30 percent of their blood [2,3,6]. They are released back into the sea after 48 hours, dizzy after a clueless donation [3]. It is estimated that 3 to 15 percent of these crabs die after being bled [1], while those that survive become sluggish [3]. Also, scientists saw a decline in the population of horseshoe crab in Delaware and so prompted the creation of a sanctuary [1]. They have been assessed as Vulnerable since last year [8]. Scientists, hence, are on their way to creating synthetic amebocytes [3].
We may not live for as long as they have, but next time we receive a safe vaccination or feel well after a medication, we ought to thank a horseshoe crab.
To know more about horseshoe crabs, visit SeaLifeBase.

If you have more information on horseshoe crabs and other non-fish organisms, we'll be happy to have you as one of our collaborators. Let us know by sending us an email or visiting our FaceBook page.

[1] Krulwich, R. (2012, June 1).What the vampire said to the horseshoe crab: ‘your blood is blue?’ Retrieved from https://goo.gl/66sdMC
[2] National Ocean Service (2015). Are horseshoe crabs really crabs? Retrieved from https://goo.gl/J9zEw6
[3] Mancini, M. (2015, September 21). 10 hard-shelled facts about horseshoe crabs. Mental Floss. Retrieved from https://goo.gl/JNBSHT
[4] Walker, K. (2014, July 15). 10 facts about horseshoe crabs. Retrieved from https://goo.gl/WTmg7M
[5] Jones, L. (2015, April 13). Are there some animals that have stopped evolving? BBC Earth. Retrieved from https://goo.gl/y8AQ22
[6] Moss, L. (2014, March 11). Why is horseshoe crab so vital to pharmaceuticals? Mother Nature Network. Retrieved from https://goo.gl/23czRv
[7] Edgecomb, M. (2002, June 21). Horseshoe crabs remain mysteries to biologists. National Geographic. Retrieved from https://goo.gl/Tz9Hys
[8] Smith, D.R., Beekey, M.A., Brockmann, H.J., King, T.L., Millard, M.J. & Zaldívar-Rae, J.A. 2016. Limulus polyphemus. The IUCN Red List of Threatened Species 2016: e.T11987A80159830. https://goo.gl/L8nZvT

15 August 2017

A Small Giant Makes Up For a House


 

Let's say we're the curious scientists here about to embark on a deep dive, an excursion to around 400 m down Monterey Bay. 

What what we're about to witness is a giant, floating... "tadpole"

They're called giant larvaceans, pelagic basal chordates [1]. Most adult species are barely half an inch [2] while giants are typically the size of a pinkie finger, even reaching 3.5 inches. They might look like tadpoles with a distinct head and tail. Aptly so, Larvacea derives its name from its semblance to a larval tunicate [1].

Now, back to our interest, let's maneuver with our remotely operated vehicle (ROV), a video, and a laser. Reaching the deep, dark waters, we spot a head, an undulating tail - a larvacean as we expected it to be. Until...

The Big, Transparent House

Lean closer and we see a fragile, mucus "house" which encases the larvacean. Depending on the species, the creature makes it a home either by being attached to it or by being cocooned within it. For instance, Fritillaria species attach to the outside while Oikopleura species usually live within it [1]. 

Photo of the giant larvacean Bathochordaeus mcnutti from Monterey Bay Aquarium Research Institute (MBARI).

It doesn't take much to build a bubble house. An Oikopleura sp. can inflate its house in a minute, and can construct 4 to 16 houses a day depending on the temperature and food availability. In a lifetime, it can construct 46 houses [1].

What's the house for?

It is a feeding apparatus: an efficient filter-feeding and trapping system [1,2,3].

Take the giant larvacean Bathochordaeus.

The Bathochordaeus' house can reach a diameter greater than a meter. It is basically an outer structure with a mucus screen that excludes larger particles, plus an inner filter which sieves and concentrates plankton and organic material. Attached to one another, the house's tail chamber receives the particle-laden water pumped by the creature's tail. The water is then directed into the inner feeding filter. When it's done, the concentrated particulate is delivered into the animal's mouth [2].

Food particles are shown in some species to be 100 to 1000 times more dense than the surrounding water: It's a rich broth like no other [2]. 

Fastest Zooplankton Filter Feeder

Larvaceans are second to copepods as ubiquitous marine creatures. In ideal conditions, their number could be massive. In British Columbia, each cubic meter of water holds 25,260 individuals. That's a lot of whipping tails and house expansion [1].

However, attempts to grow a larvacean's house in the laboratory proved impossible; the houses are way too fragile [2,3]. A recent study led by Katija used a tool called DeepPIV which permitted them to directly measure the filtration rates of giant larvaceans on site. To their surprise, each individual can filter 11 gallons (almost 42 liters) of water per hour [2]. 

That makes them the fastest zooplankton feeder, spearing them ahead of copepods, euphausiids, salps and small larvaceans [2]. 

At peak density and maximum filtration rate, giant larvaceans have the potential to filter their 200-m depth range in Monterey Bay within 13 days [2].

Fertilizing Discards

When its house gets clogged, the larvacean simply discards it and makes another one. These large, nutrient-laden houses immediately sink to the seafloor without time for mineralization by microbes.  Soaked with the ocean's upper productivity, these mucus houses contribute about one-third to vertical carbon flux from near-surface waters to the deep sea benthos [2,3]. 

Probing further into the mid-water filter feeders and their filtration capacities could someday shed more insights on the connection between deep water biota and their long-term removal of atmospheric carbon [2,3]. 

If you have more information on larvaceans and other non-fish organisms, we'll be happy to have you as one of SeaLifeBase collaborators. Let us know by sending us an email or visiting our FaceBook page.

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[1] Ruppert, E. E., Fox, R. S., & Barnes, R. D. (2004). Invertebrate zoology (7th ed.) A functional evolutionary approach.

[2] Katija, K., Sherlock, R. E., Sherman, A. D., & Robison, B. H. (2017). New technology reveals the role of giant larvaceans in oceanic carbon cycling. Science Advances, 3(5), e1602374.

[3] Yin, S. (3 May 2017). In Disposable Mucus Houses, These Zooplankton Filter the Oceans. The New York Times. Retrieved from http://nyti.ms/2qBhwgD