01 June 2017

The Kraken's Timeline Unleashed Across Myth and Science

Photo of a Kraken depicted as a sea monster devouring a ship.

Have you ever wondered how much of myths and legends we know today are based on actual events or things? What inspired mythological monsters such as the Kraken? Isn't it curious how these various stories from different era, depict creatures with striking resemblance to each other and to some organisms we know today? Wouldn't it be short of amazing to trace back the identity of the organisms from which these monsters were based on? Journeying from legends to science fiction to scientific investigations before figuring-out that creatures like the sea monk, the sea monster and the sea serpent are all but the same organism?

That is exactly what biologists Dr. Rodrigo Salvador and Barbara Tomotani uncovered in their 2014 paper entitled: "The Kraken: when myth encounters science".

By bringing together myths, legends, and science, they have revealed the Kraken to be the giant squid (Architeuthis). They are historically depicted to be as humongous as an island or a mountain, lurking sea monsters that whip and sink entire fleets. Their mystery has been told with rich, cliff-hanging stories, around the world, which we can now access and flip like a storybook.

Gianpaolo Coro transforms the narrative of the elusive Kraken into a witty, compelling timeline - from Gessner's sea serpent in 1587 to the real dimensions of the giant squid in 1982 to the Clash of Titans in 2010 and so much more. 

A segment of the giant squid's timeline, where it is depicted as a sea serpent in "Historiae animalium."

The timeline also includes the first digital distribution map of Architeuthis dux computed using D4Science e-Infrastructure.

Photo from Coro et al (2015)

What made the timeline possible was a semi-automatic tool called the Narrative Building and Visualizing Tool (NBVT) which pulls information such as images and entities from 
Wikidata or Wikimedia Commons as a starting framework for a comprehensive visual narrative. NBVT allows selection among automatically generated semantic network of narrative ontologies, with the freedom to create new entities. Information is automatically saved and rendered graphically as tables, network graphs and timelines.

This can be a powerful tool to make your narrative come to life. You can also try it here.

To know more about the giantsquid, visit SeaLifeBase.

Salvador, R. B., & Tomotani, B. M. (2014). The Kraken: when myth encounters science. História, Ciências, Saúde-Manguinhos, 21(3), 971-994.

Coro, G., Magliozzi, C., Ellenbroek, A., & Pagano, P. (2015). Improving data quality to build a robust distribution model for Architeuthis dux. Ecological Modelling 305, 29-39.

22 May 2017

Ocean in focus: Species Fact sheets

In celebration of Month of the Ocean, we have created species fact sheets that would highlight different marine organisms and their biology, distribution and conservation status. 

First up are these three:


These one-page species profiles were created using information from SeaLifeBase.

Watch our for more species fact sheets in the remaining weeks of Month of the Ocean and towards the World Oceans Day Celebration in June 8.


As promised here is another species fact sheet, created using information from FishBase.

We've also produced species postcards, which we distributed during the Ocean Festival event, a culminating activity for the Month of the Ocean celebration. 

15 May 2017

A Gargantuan of Wonder: Meet the Giant Shipworm

The giant shipworm (Kuphus polythalamia), dubbed as the giant ‘tamilok’ in the Philippines, holds a lot of secrets. That is, until scientists saw a Philippine documentary on this giant ‘tamilok’ [1] on YouTube.

What we know today is actually a result of a detour. A team of scientists led by Daniel Distel of Boston’s Northeastern University were working with local scientists from the Philippines when a student of his prodded him to watch the said videoDistel knew they were on to something big.
The creature is only known from fossils; it took centuries to finally study in detail the first live specimens of the giant shipworm [1,2].
Echoing Margo Haygood, one of the authors, finding them is out of this world. It's like donning the role of an early, seminal naturalist where every seemingly trivial thing becomes an opportunity to bridge the unknown.

Fortunately, that time is now.
The giant shipworm, as scientists had recently discovered, is the only known member of the family Teridinidae (shipworms) that burrows in marine sediments rather than drill in wood [1,2]. Unlike the wood-munching, notorious ship-sinking shipworms [3], it is distinctly encased in a tube made of calcium carbonate, vertically speared through the black, organic sediments in a shallow lagoon, wherein more than 75 to 80% of its body is buried [1].

Pulling one off from its murky bed reveals an adrift bleached staff… or is it?

The giant shipworm in its calcareous tube( Photo from Distel et al.)

"Tok tok tok..."

Distel, the lead scientist of the study, is mystified. He didn’t know how to get the shipworm out. Still, instinctively and carefully, he chiseled the chalky head. 

"... the shell came off, just like an egg.", Distel said [2]. 

Swiftly, here goes the flabby giant.

Photo from PNAS

First impression: It's like a worm - a really big one. But it's actually a bivalve, a type of clam. The modified pair of clam shells is positioned unto its head. The bulging head houses the mouth as it tapers to a y-tail containing the two siphons. For them to grow, they need to open the mouth’s cap, dissolve or reabsorb the cap, grow and bury further, then seal it off again. These rare, enigmatic creatures are the biggest (yet) among the existing bivalves today, reaching more than 5 feet [1].

Its gunmetal black shade stunned the scientists. "Most bivalves are greyish, tan, pink, brown, light beige colour. It is much beefier, more muscular than any other bivalve I had ever seen.”, said Distel [2].

How Did It Get So Big?

Scientists surmised that for the giant shipworm to grow so humongous, the key must lie on nutrient abundance.

But their anatomy is odd: The anterior end of its tube is covered with a calcareous cap which only periodically allows it to grow; when the cap is present, excavation and ingestion of sediments is impossible. Also, instead of a large wood-storing sac found in shipworms, theirs is a small, poorly developed digestive system (See Fig. 1). These characteristics could suggest that they don’t filter particulates, ingest sediments, or store wood [1]. 

Figure 1. Anatomy of the giant shipworm (Source: Distel et al.)

So how exactly did they get bigger?

In essence, the giant shipworms are the descendants of their wood-feeding kin. That is, instead of munching their way through a wood with the aid of cellulolytic bacteria in their gills, the giant shipworms are left alone buried in the mud, while their sulfur-oxidizing chemoautotrophic bacteria do the job [1]. 

As wood degrades in the presence of bacteria, one of the wastes is hydrogen sulfide. It's a long chomping process. The giant shipworm's symbionts then re-oxidize the sulfide into sulfate, making available the organic carbon for its host [1]. In short, unlike the typical shipworm, it is readily provided with the fuel it needs. 

Now, imagine the shipworm and its bacterial comrade for years end, perching in a slew of rotting wood and organic deposits. Wouldn't a seafloor teeming with hydrogen sulfide be the most fitting, generous, stench of a paradise? 

That's their big story. 

To know more about shipworms and the giants of the sea, visit SeaLifeBase. Our current information about this species is limited (and the online version has not been updated). If you have more information about this species, help us and be one of our collaborators.

[1] Distel, D.L., Altamia, M.A., Lin, Z., Shipway, J.R., Han, R., Forteza, I., Antemano, R., Peñaflor Limbaco, M.G.J., Tebo, A.G., Dechavez, R., Albano, J., Rosenberg, G., Concepcion, Schmidt, E.W., & Haygood, M.G. (2017). Discovery of chemoautotrophic symbiosis in the giant shipworm Kuphus polythalamia (Bivalvia: Teredinidae) extends wooden-steps theory. Proceedings of the National Academy of Sciences, 201620470.

[2] BBC (2017, April 18). Live, long and black giant shipworm found in Philippines. BBC. Retrieved from http://bbc.in/2nXOeLm

[3] Gilman, S. (2017, April 25). The clam that sank a thousand ships. Hakai Magazine. Retrieved from http://bit.ly/2hd12Ki