05 June 2018

Symbiosis special: What makes the Hawaiian bobtail squid glow?

Photo by Todd Bretl, Monterey Bay Aquarium
As adorable as the endemic Hawaiian bobtail squid Euprymna scolopes can be, its famed relationship with a microbe is even more special: among thousands of marine bacteria, only one microbe, Vibrio fischeri, is known to successfully colonize the squid's light organ within its mantle, turning the squid into an enchanting and 'disappearing' luminescent creature [1-4,8]. 

Few hours after the hatchlings are out from their egg case, V. fischeri from the surrounding water begin to enter the pores on either side of the light organ, settling on the epithelium-lined inner crypt spaces (tiny spaces within the organ)  [1,2,5].

Specificity is achieved early on through a mutual dialogue between the young host and the symbiont (i.e., agreement on entry and attachment of the microbe). Once the microbes have established, this transformation triggers a series of biological changes in both organisms, strengthening their relationship [7].

Now, the squid matures, and as if charging a weapon for the night, V. fishceri reaches its highest concentration in the light organ. And the squid shines its brightest [2,6].

While the squid hunts for prey, the microbes perfectly match the intensity of the moonlight welling down from above, reducing the squid's silhouette, ultimately giving it an 'invisibility cloak' (counter-illumination) against predators seeing from below [5,8]. What's more interesting is that the host is equipped not only to detect but to also control the amount of light emitted by the bacteria through its specialized light organ features [5]. 

Here's a video from Ed Yong (The Atlantic), illustrating this fascinating partnership.

As the dawn breaks, it secretes from its light organ a thick mucous containing 95% of its symbionts back into the sea, while the rest of the microbes replenish themselves to start another cycle [2,6]. Over the rest of the day, the squid becomes dormant and retreats into the sand [6].

For over 20 years, this squid-vibrio relationship has been key in studying many biological phenomena, like cephalopod development and the structure of tissue interacting with light [6]; this one-on-one connection has also been crucial in understanding host-microbe interactions in a natural microenvironment [1,2]. 

Beyond this, the squid-vibrio partnership is important, because, it turns out, the microbe 'remakes' and protects its host: reaching the adult state is only possible when the squid harbors the right microbial ally [8]. 

And, charmingly, the squid need not look further.

To know more about bobtail squids, visit SeaLifeBase.

[1] Rader, B. A., & Nyholm, S. V. (2012). Host/microbe interactions revealed through “omics” in the symbiosis between the Hawaiian bobtail squid Euprymna scolopes and the bioluminescent bacterium Vibrio fischeriThe Biological Bulletin, 223(1), 103-111.

[2] Schleicher, T. R., & Nyholm, S. V. (2011). Characterizing the host and symbiont proteomes in the association between the Bobtail squid, Euprymna scolopes, and the bacterium, Vibrio fischeriPLoS One, 6(10), e25649.

[3] Boettcher, K. J., & Ruby, E. G. (1990). Depressed light emission by symbiotic Vibrio fischeri of the sepiolid squid Euprymna scolopes. Journal of Bacteriology, 172(7), 3701-3706.

[4] Yazzie, N., Salazar, K. A., & Castillo, M. G. (2015). Identification, molecular characterization, and gene expression analysis of a CD109 molecule in the Hawaiian bobtail squid Euprymna scolopesFish & Shellfish Immunology, 44(1), 342-355.

[5] Peyer, S. M., Pankey, M. S., Oakley, T. H., & McFall-Ngai, M. J. (2014). Eye-specification genes in the bacterial light organ of the bobtail squid Euprymna scolopes, and their expression in response to symbiont cues. Mechanisms of Development, 131, 111-126.

[6] McFall-Ngai, M. (2014). Divining the essence of symbiosis: insights from the squid-vibrio model. PLoS Biology, 12(2), e1001783.

[7] Visick, K. L., & McFall-Ngai, M. J. (2000). An exclusive contract: specificity in the Vibrio fischeri-Euprymna scolopes partnership. Journal of Bacteriology, 182(7), 1779-1787.

[8] Yong, E. (26, Jan 2018). The lovely tale of an adorable squid and its glowing partner. The Atlantic. Retrieved from https://www.theatlantic.com/science/archive/2018/01/the-lovely-tale-of-an-adorable-squid-and-its-glowing-partner/551549/

05 April 2018

FishBase and SeaLifeBase sign MoU with World Register of Marine Species (WoRMS)

Databases are rich sources of information, serving not only as learning tools, but a means toward fruitful collaborations and a catapult in advancing scientific research.

This has been the very aim when World Register of Marine Species (WoRMS), FishBase, and SeaLifeBase have officially formed a collaboration last March 2018 to best serve the scientific community.

Last September 2017, the WoRMS Data Management Team attended the 15th International FishBase Symposium in TervurenBelgium. The meeting focused on WoRMS’ underlying database Aphia and its potential use in global, regional and thematic registers, along with LifeWatch Taxonomic Backbone.

The team discussed the existing collaboration between FishBase and WoRMS, wherein FishBase has served as the taxonomic resource for fish names in WoRMS. Building on the ties that have strengthened both databases, the WoRMS team expressed their intention to also document in their database the fish distributions and traits from FishBase.

During the consortium meeting, the team has also seen the potential of FishBase's sister-database, SeaLifeBase—a joint project of the Sea Around Us (University of British Columbia, Vancouver, Canada) and the FishBase Consortium—in providing biological and ecological information of global non-fish species, which can then be maximized for biodiversity and ecosystem studies. WoRMS, in turn, would provide its taxonomic backbone to SeaLifeBase. 

Related links:
WoRMS-Q-quatics MOU

SeaLifeBase is on the lookout for a Research Assistant

Quantitative Aquatics, Inc. is hiring a Research Assistant I for SeaLifeBase, a database documenting all marine non-fish species of the world. 

Kindly see below the details for your reference. 

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.
[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