Tag: Science

The freeloading lifestyle of fresh water mussels

On By TheMeanderingScientistIn Ecology, Marine Science, ScienceLeave a comment
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Conglutinates of the Ouachita kidneyshell – Chris Barnhart

I study oystery things. In my little myopic scientific snowglobe, I know a few things about shellfish, and I know a few more things about oysters. Then I know the most things about oyster filtration. So there’s still plenty of room for surprise.

This very thing happened this year during a local American Fisheries Society (AFS) meeting where I heard a talk about freshwater mussels. Probably because I always seem to be mucking about in briny water rather than its fresher counterpart, I was rather taken aback learning that many of these species have parasitic larval stages.

After females collect sperm that males eject externally, they fertilize their eggs and stow them in their gills where they develop into a minuscule larval stage called glochidia. These juvenile mussels cannot fully develop however until they somehow reach a host fish. They will encyst themselves into the host’s tissue where they will stay until more fully formed, at which point they will drop off and settle on the river floor. The host fish has graciously and perhaps unknowingly provided the small creature with protection and dispersal.

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The strangest detail of this whole process seems to be the intricate tactics mussels have developed to get their little parasitic spawn into hosts. Some species concentrate their glochidia into structures called conglutinates that they then release into the water. Many resemble prey items attractive to fish like in the video  and picture below:

Others, like mamas in the Lampsilis family keep their little ones closer to them while dangling parts of their mantle tissue to the same affect at the conglutinates described above.

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Lampsilis’ display attracts host fish – Paul L. Freeman, Nature Conservancy

For most species of freshwater mussel, the choice of host fish seems to be relatively specific. In some cases, the species of host has yet to be discovered, which provides fertile ground for research into the topic such as the work that Florida Wildlife Commission’s Blackwater Research and Development Center in Holt, Florida has done.

As with other symbiotic relationships within nature, freshwater mussels are incredibly dependent on the health of their host and the system around them. This has further increased the need for continued research and conservation, and in some instances agencies and institutions have fostered cultivation and propagation efforts.

Speck of Science 8/15/16 – Nat Geo Writes About Pooping Comb Jellies

On By TheMeanderingScientistIn Marine Science, New Discoveries, Science, Science News, Speck of ScienceLeave a comment
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Still from Ryan M. Bolton 2016 video: https://www.youtube.com/watch?v=weeFO6kLu5o

Lest you think National Geographic is losing their edge, the reason why ctenophores (the phylum to which comb jellies belong) defecating is a big deal is because it was thought this group of creatures had a single opening for both feeding and excreting. University of Miami researcher William Brown debuted videos at the March 2016 Ctenopolooza gathering at the Whitney Lab in St. Augustine (where I’ve done much of my own dissertation field and lab work) that prove otherwise. One of the peculiar videos is featured partway through Nat Geo’s article here. Science writes about the find as well.

One of the most interesting aspects of this find is questions regarding the evolutionary history of gut development. It was thought to be a pretty straight forward pathway from one opening to two. However, because comb jellies evolved before other organisms that still have a single opening, such as sponges, things are looking slightly more interesting. Perhaps ctenophores branched off, and smartly evolved a more complex gut tract independent of these organisms. Or, perhaps some of these single-orificed organisms started with two but lost one over time – similar to the story of some marine mammals that long ago left the sea to become land-dwellers, only to ultimately return again.

 

 

Speck of Science – 4/19/16 – March of the Crabs

On By TheMeanderingScientistIn Ecology, Marine Science, New Discoveries, Science, Science News, Speck of ScienceLeave a comment
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Source: Animal Planet

Mass migrations fascinate me – massive swarms of creatures on robotic treks to satisfy deep-seated needs for resources – nature’s automatons reaching for food, for mates, for brighter skies. One of the earliest that captured my attention is expressed in this Animal Planet video documenting the movement of red crabs on Christmas Island:

http://www.animalplanet.com/tv-shows/wild-kingdom/videos/christmas-island-red-crabs/

(Note at 1:40, crustaceans seem to be playing “frogger” while obliviously scuttling across roads and railroad tracks. Not the unexpected result of the clash between crab and human.)

A gif of the oceanic equivalent has made a recent appearance online, showing an endless carpet of sandy colored scuttlers (they were in fact red,  or “tuna,” crabs who appeared that way as they stirred up a the sediment on the sea floor). However, this article sheds more light on the unusual event captured by a manned submersible exploring Hannibal Bank off of Panama (fitting name for the location of a slightly unnerving and intriguing event to occur? ). The following video comes from Woods Hole Oceanographic Institut and features scientist Jesús Pineda explaining the details around recording the migration:

 

 

Speck of Science – 4/6/2016 – Gimme Back My Buoy

On By TheMeanderingScientistIn Ecology, Marine Science, Science, Science News, Speck of ScienceLeave a comment

I have been through a blogging dry spell lately, but nothing like starting out again with the amusing news of 2 men essentially holding a USGS (United States Geological Survey) scientific buoy hostage.

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A Map of the Monterey Bay Aquarium Research Institute’s Coordinated Canyon Experiment. The buoy was associated with this particular project. Source: MBARI

The buoy, which was deployed to gather data related to El Niño events, drifted off its mooring during a recent storm. Two fishermen chanced upon it, recovered it, and are now demanding $13,000 in exchange for its return. Their lawyer, a seemingly rather colorful character and self-described “old trial dog”, initially set the price a bit higher based on the following mathematics: ” On good days fishing they gross $2,700. Taking the big and gouging thing onto the boat and having it there kept the boat out of action for nine days for a multiply of $24,300. Twenty percent of value would be $80,000. We offer to SELL (you can use any other word you like in an agreement) it to you for $45,000.” One has to wonder why they took it upon themselves to keep the “big and gouging thing” on their boat for nine days in the first place.

The article notes from several sources that salvage laws likely do not apply here, especially as the buoy was never properly abandoned. However, the loss of and tampering with of expensive research equipment has always been a known and pervasive issue in oceanic research.  I for one will be interested to follow the outcome of this eyebrow-raising case.

Intersect (Art & Science) #1 – The Introduction

On By TheMeanderingScientistIn Art, Intersect (Art & Science), Photography, ScienceLeave a comment

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I love art and every recondite and consuming idea it can encompass. But what really fascinates me is the porous little spaces where we examine or redefine the steady and concrete components of the world through an artistic lens. Also, the scientific world is surprisingly replete with individuals who are well tuned into their right-brain tendencies. The scientific process requires a surprising amount of creative thinking.

So with that introduction, I’d like to occasionally share ideas, art, and artists that strike me as passing back-and-forth through that veil.

One of my favorite places for finding inspiration is the Harn Art Museum at the University of Florida where I go to school. They even regularly host nights specifically to feature scientists who have an artistic bent.

To start off, the following photo was one I took from their 2014 exhibit: Repurposing the Wunderkammer, Building A New Space for Science and Art. As they explain here, the Wunderkammer were essentially collections of wonder, comparable to cabinets of curiosity. The specific piece represented below was titled the “Last Whole Earth Cabinet” and as constructed/curated by artist Sean Miller. 

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What a job to try and catalog the world, with only a few small shelves to fill with its treasures.

 

Depth of Field #2: The Sea Hare Emerges

On By TheMeanderingScientistIn Depth of Field, Ecology, Marine Science, New Discoveries, New Zealand, Photography, ScienceLeave a comment
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Photo Credit: Carrie Schuman

The sun is starting to set on expanses of mirror-reflective tide pools speckling the beach of the Tawharanui Marine Reserve in New Zealand. I’ve been walking along staring into them at random in my search for anything novel when I chance across what is at best guess an example of Aplysia dactylomela – the variable sea or spotted hare.

In a surprising contrast to the small chitins, tunicates, and other finds, the sea hare was relatively large, measuring somewhere in the range of 5 to 6 inches in length. As seen in this additional photo, a smattering of spots can be seen along its body:

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Photo Credit: Carrie Schuman

According to this source, sea hares are hermaphroditic though they do not practice self-fertilization. They may often form reproductive “chains”.

As suggested by one of their common names, they may be highly variable in appearance with their coloration primarily determined by the type of algae they feed on.

They release a purple dye as a mechanism to surprise and confuse predators. This particular characteristic was one I had once experienced first hand when handling my first sea hare in the mangroves of Key West. It certainly has a startling quality to it.

Variable sea hares tend to be more solitary, and nocturnal in nature. So perhaps no small amount of dumb luck governed this thrilling little chance encounter.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Aplysia dactylomela

Speck of Science – 1/11/2016: The Co-evolution of Poachers

On By TheMeanderingScientistIn Ecology, Science, Speck of Science1 Comment

I’m a little late in posting about this story that came out in the Guardian on New Year’s Day.

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Colour changing tree monitors or garden lizards annd Bronze skinks hung in a street market to be sold as pets in Hainan province, China. Photograph: Xiao Shibai/Alamy

The gist of the piece is that the journal Zootaxa has published recent papers omitting the data on where the described species may be found. This is to deter impact to these newly described organisms, after several incidences where animals were depleted or found for offer in the pet trade. This goes to show that seemingly the most innocuous and standard scientific practices (in this case, the standard documentation and provision of data surrounding the description of newly identified species) may still warrant ethical considerations.

This also represents an interesting and alarming co-evolution of illegal or unregulated poaching practices. But this is just a drop in the poaching bucket, as poachers have already clearly upped their game in recent years, arming themselves with high-tech equipment like night vision goggles. However, there is a whole range of combatant technologies emerging for use in the anti-poaching effort being billed as “smarter ways to fight wildlife crime.”

 

 

Whale Tales – Current Cetacean Communiqués

On By TheMeanderingScientistIn Ecology, Marine Science, Science1 Comment
Orcas as captured by drone surveillance. Photo credit: NOAA, Vancouver Aquarium.

There’s been a couple interesting whale-centric stories I’ve come across lately, so I thought I would share on the blog.

While the idea of drone surveillance is proving to make a large part of the public uncomfortable, the technology is proving to have less pernicious applications in observing natural phenomena.

Southern resident orca calf nursing. Photo credit: NOAA Fisheries, Vancouver Aquarium.

With regards to whales, drone footage of southern resident orca pods has recently been captured by a collaborative effort between the Vancouver Aquarium and NOAA (National Oceanic and Atmospheric Administration).  NOAA recently released beautiful close-up photos and a video conversation with ecologist John Durban giving some additional context to the what the drone captured.

Over more recent years with advances in genetics and stronger observational data, it was determined that orcas are not a uniform species and instead vary with regards to morphological characteristics, ecology, and behavior, generally referred to as “ecotypes”. The southern resident population of killer whales numbers about 81 individuals. Aerial footage provides a relatively non-invasive way to study and collect data on these animals.

Read more about the study and about “mobly”, the hexacopter used to study these creatures, here.

Another fascinating footage find was this picture posted of an albino southern right whale calf off the coast of South Africa:

Anton Schutte was alerted to its presence by a tourist he had recently befriended and was able to snap pictures and video of the blindingly white baby whale.

Omura’s whale lunge feeding. Photo Credit: Cerchio et al 2015.

Lastly, Discover Magazine released an interesting news bit based on a recently published paper about the Omura’s whale. This whale wasn’t classified as its own species until 2003, and was described based off of samples from carcasses that had washed onto beaches. Scientists spotted living populations off of Madagascar and were able to genetically validate the sighting as Omura’s whales. Surveys were completed over a course of 7 years in order to learn about their ecology and behavior.  They have rorqual pleats like those seen in humpbacks, that allow them to “lunge feed” – quickly engulfing large masses of water and using their baleen to assist with filtering out their prey items. They sport an asymmetrical white patch on their lower jaw, much like Fin whales. They also likely do not wander far from their home base.

Hope you enjoyed the updates. Until next time my friends!

A Vast Solar System: To Scale

On By TheMeanderingScientistIn Astronomy, Science1 Comment

I adore those simple science-based moments where someone gets me to stop and exclaim “huh”… Maybe it’s an upset of pervasively incorrect ideas about how the world works (See Radiolab’s Robert Krulwich’s fervently amused post regarding the true supposition that trees get most of their mass from air rather than the ground), or just a mild re-positioning of the nuances to how we see things.

Apparently all those beautiful little models of spangly little planets in orbit around one another are overwhelmingly flawed. Not surprisingly, if everything were to scale, the planets would both be greatly farther apart and almost microscopic in appearance relative to how they are often depicted. While I was aware of the need to bend some of these rules in order to allow us to develop a reasonable mental model of the solar system, I don’t think I would have appreciated the reality without a little help.

Luckily, filmmakers Wylie Overstreet and Alex Gorosh have filled that void by creating an elegant little video where they model the real relative sizes and distances of our planets  in the desert (albeit while Pluto was demoted to “not a planet”). Watch below and ruminate while we all rotate on this pale blue dot: