A LOT of marine species have microbiomes too, and this topic is a hot new field of research. The coral holobioint is probably the most well-researched example. But for now, let me introduce you to the microbiome of my nematode friends.

The “badass microbiome award” goes to nematodes in the genus Robbea, because they *literally* carry around a coat of bacteria on the outside of their body. Robbea worms live in the sediments around seagrass beds, which are rich in sulfur compounds. And sulfur is exactly what their microbiome bacteria like to gobble up:

The worms migrate between oxygenated, upper sand layers and anoxic, sulfidic, deeper ones (Ott et al., 1991) allowing the bacteria to obtain the oxygen they need as eacceptor and the sulfur compounds (e.g. hydrogen sulfide, thiosulfate) as edonor (Polz et al., 1992; Hentschel et al., 1999). Stable carbon isotope incorporation experiments showed that the ectosymbionts are the major components of their host diet (Ott et al., 1991). [Bayer et al., 2009]

In other words, these nematodes are a party bus for their microbiome bacteria. But then shiz gets real when the party ends, because these nematodes then turn around and EAT the bacteria they carry around. No microbes gonna mess with Robbea.

What’s even crazier is that Robbea nematodes aren’t born with their microbes – much like the human microbiome, these bacteria are acquired from the environment. DNA sequencing seems to tell us that these symbiont bacteria can be found hanging out in seawater–hopefully not getting into any trouble–prior to latching onto their worm hosts.

Astomonema nematodes have a less tumultuous relationship with their microbiome; they’re more of a gentle shepherd compared to hotel-room-trashing Robbea rockstars. Astomonema species have pretty much evolved into a garden for microbes, herding and nurturing endosymbiont bacteria inside their body wall. In fact, this group has become SO reliant on their microbiome, that evolution has decided these worms don’t need a mouth, anus, or functional digestive system anymore (these features being reduced or absent).

…bacterial symbionts completely fill the gut lumen of Astomonema sp., suggesting that these [bacteria] are their main source of nutrition…symbionts use reduced sulfur compounds as an energy source to provide their hosts with nutrition. [Musat et al., 2007]

Nematode symbionts are related to symbiont bacteria found in other worms (particularly oligocheate worms, but also related to sulfur-utilizing symbionts of species found at hydrothermal vents). This raises some pretty cool evolutionary questions – for example, where (and in what organism) did these symbionts first evolve? Are similar microbiome species a result of convergent evolution? And are symbiont species widespread in the oceans, or only present in specific habitats where their hosts live?

We don’t have answers yet…but if I have my way, high-througphut DNA sequencing will soon shed some light on these questions. Stay tuned!

References:

Bayer C, Heindl NR, Rinke C, Lücker S, Ott JA, Bulgheresi S. (2009) Molecular characterization of the symbionts associated with marine nematodes of the genus Robbea. Environmental Microbiology Reports, 1(2):136–44.

Musat N, Giere O, Gieseke A, Thiermann F, Amann R, Dubilier N. (2007) Molecular and morphological characterization of the association between bacterial endosymbionts and the marine nematode Astomonema sp. from the Bahamas. Environmental Microbiology, 9(5):1345–53.

The post Marine nematodes have a microbiome too (and it’s way cooler than yours) first appeared on Deep Sea News.

This squid, like us, has its own body clock dictating it’s routine. But instead of waking up in the morning and heading to work, E. scolopes follows a vampire’s schedule. It emerges into the water column at night as a ruthless predator, and then burys itself in the sand once the sun rises, laying hidden during the day. All while looking super cute!!!

So obviously this squid is a Twilight vampire. Because in addition to drawing you in with its charming (but deadly!) looks, E. scolopes literally sparkles. This squid species can bioluminesce courtesy of extracellular V. fischeri bacterial cells, which live in “deep crypt spaces” in the squid’s light organ (I’m really not making up this vampire theme here).

And why would a squid sparkle?

Some behavioral evidence suggests that the night-active host animal uses the luminescence of the bacterial symbiont as an antipredatory camouflage in a process known as counter illumination. (Heath-Heckman et al. 2013)

What’s even cooler: these symbiotic bacteria function as a bacterial alarm clock, helping to regulate the squid’s daily circadian rhythms. A “circadian rhythm”, a.k.a. a body clock, is basically a giant cellular war between proteins — some molecules compete to accumulate, while others work furiously to break things down. This complex array of switches and feedback loops is ultimately regulated according light/dark cycles provided courtesy of the sun. Its the same process that makes us feel tired at night, and jet lagged when we switch time zones. In E. scolopes it regulates its urge to FEED!

A new study by Heath-Heckman et al. (2013) provides convincing evidence that bacterial light production (and metabolic products produced by V. fischeri during this process) are required for the squid to regulate its own body clock. This is crazy but totally cool biology – its akin to us humans being required to drink probiotic yogurt in order to sleep. In this hypothetical scenario, our own body wouldn’t know when it should sleep on its own, since sleep would only be cued after our body detected the correct signals from bacterial proteins.

Circadian rhythms in the Hawaiian bobtail squid are influenced by blue-light receptors called cryptochromes – way back in the day, these were DNA repair enzymes that have since mutated and evolved to respond to light. In E. scolopes, gene expression for one such receptor (escry1) *only* responds to light produced from bacterial bioluminescence, and not environmental light. Other bacterial products (lipid A, peptidoglycan monomer) are also important for regulating host gene expression. Experimental evidence is also supported by the fact that escry1 gene expression is crazy high in squid tissues surrounding bacterial symbionts.

We’re only just scratching the surface of this host-microbe interaction. The relationship between V. fischeri bacteria and E. scolopes is complex and interdependent – mutant squid that can’t support bacterial symbionts are defective in bioluminescence, and show stunted development of the light organ. V. fischeri appear to play a critical role from Day 1 of a squid’s existence.

The authors of this study consistently remind us that–in addition to being an awesome example of biology–bacteria in the gut may influence similar patterns on humans. But don’t start blaming bacteria for your late-night Twitter obsession just yet.

Reference:

Heath-Heckman EAC, Peyer SM, Whistler CA, Apicella MA, Goldman WE, McFall-Ngai MJ. (2013) Bacterial Bioluminescence Regulates Expression of a Host Cryptochrome Gene in the Squid-Vibrio Symbiosis, mBio, 4(2):e00167–13–e00167–13.

The post All hail! Bacteria that control their squid overlords first appeared on Deep Sea News.

Microbe species don’t fuck around. They’re everywhere. You just have to sequence lots of DNA to find them all.

Except…some deep sea species were *only* found in the Deep Sea…

For example, the marine cold seep biome contributed OTUs [Operational Taxonomic Units, a.k.a putative “species” defined solely from DNA] from the Halanaerobiaceae family. This family includes anaerobic, halophylic species, which have been found to be highly abundant in hypersaline brine pools such as those associated with cold seeps (19); this comparison suggests that a number of Halanaerobiaceae OTUs in the cold seep biome were not detected in the L4 [English Channel] site.

…the marine hydrothermal vent samples contributed members of the Campylobacterales not detected in the L4-DeepSeq [English Channel] sample. Campylobacterales is an order within the e-proteobacteria that includes both free-living and host-associated chemolithotrophs, such as those associated with tube-worms surrounding hydrothermal vents (22).

This study was only looking at bacteria and archaea – no DNA from multicelled microbes – and I’m not sure how intensively the deep sea ICoMM samples were sequenced. But I’m becoming more and more convinced that the Deep Sea is an untapped Candy Cane forest of genomes. So much endemic DNA for us to frolic and play with!

We won’t find these genomes roving around at the surface – marine biologists need to focus more on genomic technologies to sequence the deep.

Reference: Gibbons SM, Caporaso JG, Pirrung M, Field D, Knight R, Gilbert JA. (2013) Evidence for a persistent microbial seed bank throughout the global ocean. Proceedings of the National Academy of Sciences, USA, 110(12):4651–5.

The post Endemic Genomes? Reason #1 to sequence the Deep Sea first appeared on Deep Sea News.

When he made his historic solo dive into the Mariana Trench last month, James Cameron brought back images and descriptions of a “lunar like” marine landscape nearly devoid of life.-via National Geographic

Returning from humankind’s first solo dive to the deepest spot in the ocean, filmmaker James Cameron said he saw no obvious signs of life that might inspire creatures in his next “Avatar” movie but was awestruck by the “complete isolation.” –via Christian Science Monitor

The quotes above illustrate just two of the many mainstream media pieces that highlighted James Cameron’s comment of a lifeless landscape at the bottom of the Marianas Trench.  However, Cameron fell into a trap nearly 200 years old.

Edward Forbes is the whipping boy of deep-sea biology.  Forbes’s big mistake was concluding, in the mid-1800s, that marine life could not exist deeper than 550 meters, what he called the “azoic hypothesis.” Given the state of knowledge at the time, it seemed logical that no species could survive under the extremes of high pressure, lack of light, and cold temperatures characterizing the deepest ocean. Unsurprisingly, Forbes’s thinking spread quickly among the scientific community. The azoic hypothesis ultimately proved wrong or this blog would have a lot less fodder for writing and a different title.  How Forbes was wrong is the interesting part.

Forbes based is azoic hypothesis on sampling he did in the eastern Mediterranean Sea, an area that sees little phytoplankton production.  With less food at the ocean’s surface, less food will sink to the deep ocean floor resulting in little abyssal life.  Unsurprisingly, when Forbes pulled his trawled samples from the deep they were not brimming with a cornucopia of life.

Forbes also didn’t know that the low food arriving to the deep sea miniaturized animals.  In one of the earliest papers on the deep-sea fauna, Mosely (1880) noted, “Some animals appear to be dwarfed by deep-sea conditions.” Almost a century later, Hessler (1974) noted that “individuals of certain taxa are routinely so small that they are of meiofaunal size.” Thiel (1975) echoes these comments by noting the deep sea is a “small organism habitat.”

Consider that the entire collection of deep-sea gastropods from the western North Atlantic collected under the WHOI’s Benthic Sampling Program (44 samples, 20,561 individuals) would fit completely inside a single Busycon carica, a typical-sized New England knobbed whelk.  Forbes nets with their big mesh size allowed most animals to pass right through.  Today of course we use finer mesh sizes on nets or cores so we don’t miss the diversity of small life.

I cannot help but wonder if Cameron fell into the same trap that Forbes did so long ago, an underappreciation of the complexity and uniqueness of deep-sea life.

Was he waiting for charismatic megafauna that never arrived and potentially never existed at the deepest point in the ocean?

Bob McDondald in a recent Op-Ed  stated,

… there is no substitute for good science. Big budgets and lots of publicity gather public attention – a stunt such as a solo dive to the deepest part of the ocean will get an explorer into the history books, just as a free fall from the edge of space did.  But these are often one-off events. The whole point of the exercise was to get there. Science, on the other hand, is a systematic, step-by-step process that explores carefully, building on past successes and putting new discoveries into the broader context of the scientific community. A robot sub being hauled out of the water may not look as dramatic as the scene of a hatch opening and the triumphant explorer emerging to a cheering crowd, but what the science actually reveals is the most dramatic of all

Of course, I would be remiss not to mention another point glossed over and even blatantly misrepresented in the media.  Cameron’s dive, while worthy of praise on many fronts, is a not the first exploration of the deepest part of the ocean.  Scientists, especially Japanese researchers, have been sampling the bottom of the trench extensively for a few decades with robots and landers.

As McDonald points out, and the labor of many expeditions and scientists has demonstrated, the Marianas Trench is actually full of life.  Although contrary to what McDonald claims new research didn’t reveal this fact but only supports what we’ve known for a while.

Marianas Trench is teeming with microbial life.  In 1997, a species of the common bacteria Pseudomonas was discovered from 11,000 meters deep. In 1998, Japanese researchers using the remotely operated vehicle Kaiko found evidence of two barophilic, pressure loving as you would expect from trench critters, bacteria.  Both bacteria species were from completely different groups.  In 2006, Japanese researchers hit a biological gold mine of microbes.  Actinobacteria, non-extermophilic bacteria, three major groups of extremophilic bacteria, fungi…O my! And o’ how the reports of new microbial species just keep coming, and coming, and coming, and coming, and coming, and coming in.  Indeed, microbial activity is shockingly high…even for those of us expecting it.

Naysayers will surely point out how bacteria somehow don’t count as real life.  They live everywhere. These people have some size threshold for life to count. I give you naysayers protists!  Foraminifera, amoeboid protists vital for nutrient cycling in the oceans, also exist at the greatest depths of the Marianas Trench.  Perhaps some will need something even larger…a metazoan.

Multicellular life is also known from the Marianas Trench.  From even the earliest explorations the large crustacean, the amphipod Hirondellea gigas, was observed.  Scientists have even isolated bacteria from its body.  Indeed, larger organisms have been found at the bottom of several trenches (see photo below).  A specimen of sea anemone of the genus Galatheanthemum, a worm from the genus Macellicephaloides, an isopod crustacean of the genus Macrostylis, and a sea cucumber Myriotrochus bruuni are all known from the deepest trench on earth and reported back in the 1970’s by Torbin Wolff (of Haka fame).

Cameron stated after his dive the necessity of returning to the deepest point in the ocean, the Challenger Deep, once again to explore.  I could not agree more. Our understanding of this trench, like much of the deep, is rudimentary.  We only have a partial glimpse of the life that existing there. However, we do know that it is not a lifeless void.  A wealth of life exists at Marianas Trench. You just have to know how to loo for it.

The post Is Marianas Trench A Lifeless Void? first appeared on Deep Sea News.

Only…I don’t work with actual animals. I work with DNA sequences. I spent my PhD sitting under the microscope, where I vowed never again! Now I work with gigabyte-sized text files listing millions of gene sequences.

However! That will not stop be from pontificating on the Top 10 scariest species that I encounter in my daily life as a (computational) marine biologist. Be warned…you might not be able to sleep tonight.

5. “Environmental” species

Stop the presses. Big news. There are species. And they live in the environment. WHOA! This is news to me. I had no idea – someone needs to call the president! “Environmental species” are petrifying because you have no idea what they are. I mean I could have just sequenced Godzilla from my deep-sea mud (maybe I sampled next to his undersea lair?).

For anyone that works with DNA, it is common knowledge that database sequences are 100% trustworthy and researchers make every effort to put informative names on any data they submit. No scientist would be so cavalier as to dump thousands of unnamed sequences into GenBank. And GenBank certainly would never get clogged up with said type of sequences. So you see, I am still left scratching my head at my “environmental species” result.

4. “No Match” Species

These species have no good match to ANY DNA sequence listed in public databases. You should be terrified. What if we live in the Matrix, and DNA from these species has been conveniently erased from the reality construct? Or what if its Aliens?! The government might not want me to find a match for these bits of DNA.

You all know that we’ve done an amazing job counting and describing all the species that existed ever, so much so that scientists have now extensively characterized pretty much all the biodiversity on earth. The appearance of new species is practically unheard of. We’ve named all the worms and bacteria, and the thought of a new mammal species makes me roll over with laughter. Given our current state, I am left shaking in terror at my enigmatic “no match” DNA results.

3. Homo sapiens

Holy Crap, look at all that human DNA! There’s no ambiguity about what species I found, because this sequence has a 100% match to Homo sapiens. And it isn’t just one sequence. There are hundreds! This is frightening. What if my marine mud sample was collected on the EXACT SPOT where Jimmy Hoffa’s body is buried. All that human DNA I found could be evidence in a murder scene.

At least I can be sure that this is not routine contamination from the lab, because that never happens and all my data is 100% most certainly trustworthy. Should I call the police?

2. Command line error species

OMG I tried to process data and I discovered something I’ve NEVER SEEN BEFORE. And then I searched Google! The only person that has ever seen this before is Joe Programmer who asked about the SAME THING on a biology newsgroup back in 1996. But this thing I found is unknown in the scientific literature. Its like I stumbled upon a mythical creature that had been lurking amongst us all along. Soon the world will build statues!

I pressed a button and did everything the software tutorial said, so these results must be right. I’m the best computer user in the world! More so, all computer programs automatically know how to process our DNA data – because the biology is so simple!

My new species is scary because I don’t know if people will understand. What if they react badly to the news that I’ve just described use of uninitialized value $ncbi_name in concatenation (.) or string from the deep sea?

1. Tyrannosaurus rex

You heard me. Dinosaurs lurk amongst us. How do I know? Because the DNA TOLD ME SO. When processing my deep sea data, I found a sequence whose best match was to the T. rex sequence listed in GenBank. Either there are dinosaurs walking the earth (whereby I collected my sample in a fresh T. rex footprint), or T. rex DNA is so indestructible that it survived floating around in the dirt for millions of years. Either way I’m shaking in my boots.

There’s no way that that the information I got from GenBank is wrong. Because who would ever confuse DNA from common soil bacteria with DNA from a T-Rex fossil?! And there are three T. Rex protein sequences in the database. No one would mess that up multiple times. Which means I have to go find an underground bunker, because I have a sinking feeling that Jurassic Park was actually a documentary…

The post Top 5 scariest species…from, er, DNA? first appeared on Deep Sea News.

Descriptions of each melody from the Argonne Lab Website:

Blues for Elle: This composition highlights seasonal patterns in marine physical parameters at the L4 Station. The chords are generated from seasonal changes in photosynthetically active radiation. The melody of each measure is comprised of eight notes, each mapped to a physical environmental parameter, in the following order: temperature, soluble reactive phosphate, nitrate, nitrite, saline, silicate, and chlorophyll A concentrations.

Bloom: Some marine microbial taxa are most often present in the L4 Station community at very low abundance, but occasionally become highly dominant community members. To link these microbial blooms to relevant physical parameters, the chords in this composition are derived from changes in chlorophyll A concentrations and salinity. The melody for each measure is derived from the relative abundances of typically rare taxa that were observed to occasionally bloom to higher abundance in the following order: Cyanobacteria, Vibrionales, Opitulates, Pseudomondales, Rhizobiales, Bacillales, Oceanospirallales, and Sphingomonadales.

Far and Wide: Microbial species of the Order Rickettsiales, such as the highly abundant, free-living planktonic species Pelagibacter ubique, are typically, highly abundant taxa in L4 Station data. Its relative abundance in the microbial community at L4 Station follows a distinctive seasonal pattern. In this composition, there are two chords per measure, generated from photosynthetically active radiation measurements and temperature. The melody of each measure is six notes that describe the relative abundance of the Order Rickettsiales. The first note of each measure is from the relative abundance at a time point. The next five notes of a measure follow one of the following patterns: a continuous rise in pitch, a continuous drop in pitch, a rise then drop in pitch, or a drop then rise in pitch. These patterns are matched to the relative abundance of Rickettsiales at the given time point, relative to the previous and subsequent time points. The pattern of notes in a measure is mapped to the relative abundance of Rickettsiales with fewer rests per measure indicating higher abundance. For time points at which Rickettsiales was the most abundant microbial taxa, the corresponding measure is highlighted with a cymbal crash.

Fifty Degrees North, Four Degrees West: All of the data in this composition derives from twelve observed time points collected at monthly intervals at the L4 Station during 2007. The composition is composed of seven choruses. Each chorus has the same chord progression of 12 measures each in which chords are derived from monthly measures of temperature and chlorophyll A concentrations. The first and last chorus melodies are environmental parameter data as in ‘Blues for Elle’. The melody in each of the second through sixth chorus is generated from the relative abundances of one of the five most common microbial taxa: Rickettsiales, Rhodobacteriales, Flavobacteriales, Cyanobactera, and Pseudomondales. A different ‘instrument’ is used to represent each microbial taxon. Melodies for microbial taxa were generated as in ‘Far and Wide’.

The post TGIF: Some Friday jazz, courtesy of marine microbes first appeared on Deep Sea News.

But when I read Dr. M’s new (P ***ing NAS) paper last week, it hit me: I really should care. We all should. Its not about forcing to ourselves to waste time reading about topics or environments that aren’t relevant. All knowledge is essential–especially diverse knowledge, especially in today’s changing landscape of science.

How can energy limitation in the deep-sea be relevant to a parent trying to keep his/her kitchen germ-free? It’s all relevant, because in each case we’re trying to understand how complex communities function and change over time – regardless of whether a given ecosystem resides in the built environment or a natural setting.

Biology is heading towards integrated data – I study microbial genomics, but I should also be thinking about metabolism and temperature effects on the species I search for in environmental data. For us genomicists we’re so used to dealing with so little information. We just get (rather large) computer files listing lots and lots of DNA. The challenge for us is to relate those A’s, T’s, C’s and G’s back to something meaningful. But of course we don’t just want to look at DNA – we want a holistic understanding of ecosystem function. I want to know how one piece of DNA relates to a body size, how that body size relates to the type of food that pariticular species eats, and how all that interacts on a grand scale in an ecoysytem.

Often I feel like us genomicists have our hands tied – but we have a powerful tool in our pocket (that’s what she said) that can set us free in ways that no one else can experience. DNA is objective in ways that other types of data aren’t–taxonomy is subjective and decisions vary depending on the expert identifying a specimen. What if we could use parameters like temperature, depth and type of food input to predict what species will be there? Of course, that’s a lifelong obsession for researchers like Jack Gilbert (@gilbertjacka) and colleagues, and we’re steadily making progress towards these modeling goals. Some of the new microbial model papers are pretty badass.

To summarize the ongoing transformation in biology, I’ll bestow some eloquent foresight from Poole et al. 2012:

As researchers seek to go beyond function and understand the effects of global environmental changes on ecosystems [6], metagenomics will be essential. It has already helped to unlock the mechanisms for climate–carbon-cycle feedbacks [7] and, for simple microbial ecosystems, has illuminated the probable metabolic basis for key community interactions [8]. These examples underscore two crucial points. First, genomic knowledge is increasing the understanding of how simple organisms interact with their multicellular counterparts in an ecosystem context [9]. Second, the ability to zoom in on the functional roles of species within an ecological community [3] will make metagenomics indispensable for the future study of whole-ecosystem functioning.

And this data revolution isn’t simply relegated to basic research. In terms ecotoxicology and ecosystem monitoring, Van Aggelen et al 2010 note that:

Omic and bioinformatic tools offer sub­stantial promise for discovery of gene, pro­tein, and/or metabolite alterations indicative of the mode of action (MOA) of chemicals and improved understanding of mechanisms in prospective studies (Ankley et al. 2006). Knowing the MOA can reduce uncertain­ ties in chemical risk assessments, providing, for example, a basis for extrapolating effects across species (Benson and Di Giulio 2007).

Ideally, omics data would reflect both the MOA and deleterious outcome(s). To achieve this, the cascade of pathways asso­ciated with toxicity must be defined, from a molecular initiating event (e.g., receptor bind­ing) through subsequent biological alterations (reflected by omic and cellular changes) that culminate in a deleterious outcome (NRC 2007).

Thus, although gene expression is affected by many environmental factors, a subset of genes with altered expression can inform on stress responses.

The biology landscape (and earth’s climate) are changing and science must adapt. Scientific infrastructure and even researcher mindsets must change in order to accomodate a new order of thinking.

There is also a need to build capacity within academia, the private sector, and gov­ernment agencies to implement omic tools and to evaluate omics data, particularly with respect to biological and ecological significance. These institutions will require resources, support, and targeted training to bring scientists and deci­sion makers within their organizations to a point where these tools can be used effectively in regulatory decision making, especially in risk assessment. (Van Aggelen et al 2010)

The deep sea may face a perpetual energy recession, but in terms of scientific data we’re about to experience one hell of an economic boom.

References:

McClain CR, Allen AP, Tittensor DP, Rex MA. (2012) Energetics of life on the deep seafloor. Proc Natl Acad Sci USA. Advance Access

Poole AM, Stouffer DB, Tylianakis JM. (2012) “Ecosystomics”: ecology by sequencer. Trends in Ecology & Evolution, 27(6):309–10.

Van Aggelen G, Ankley GT, Baldwin WS, Bearden DW, Benson WH, Chipman JK, et al. (2010) Integrating omic technologies into aquatic ecological risk assessment and environmental monitoring: hurdles, achievements, and future outlook. Environ. Health Perspect. p. 1–5.

The post Capitalizing on recessions with economic booms of data first appeared on Deep Sea News.

The Tonga Trench Expedition is a Scripps Institution of Oceanography student cruise, led by Scripps graduate student/chief scientist Rosa Leon Zayas. (and if anyone out there is looking for a kick-ass female Latina marine biologist role model – look no further!) The purpose of the expedition is to “to understand the composition of the microbial community of the Tonga Trench and how it is affected by pressure and other environmental conditions.” They’ve just deployed their first instrument, “Deep Sound.”

Cold Dark Benthos is a research blog out of McMurdo Station, Antarctica, by Andrew Thurber (who did his PhD at Scripps with me) & Rory Welsh. They are looking at the role of microbes in the Antarctic food web:

Spiophanes tcherniai is a species of Polychaete that occurs in incredible densities. To be exact in every square meter of sediment there are 150,000 to 180,000 individuals of this species as well as a variety of other species that we call ‘macrofauna.’ The macrofauna are visible to the eye but amazing under a microscope and all are, by definition, greater than 0.3mm in size.  Its an diverse community with small shrimp looking animals, worms of every shape and colors, not to mention clams and anemones.  They co-occur with an incredible variety of bacteria and what we really want to know with this research is whether the bacteria are competing with the animals or facilitating the persistance of these animals, allowing this incredible density in a veritable dessert of food.

The post Two new expedition blogs: super deep South Pacific and super cold Antarctica first appeared on Deep Sea News.