Tag Archives: science

Fantastic Find Fridays: Feb 2016

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Hey plankton hunters!  We are bringing you another round of Fantastic Finds from the Plankton Portal.  Citizen scientists continue to reel in new captures of some truly awesome plankton.  Here are just a few neat finds, ID’s, and novel taxa:

Pteropod mollusk

pteropod

Did you ever learn about marine butterflies in grade-school?  Well good, because there is no such thing as a marine butterfly.  This elegant-looking critter is a pteropod, a type of gastropod mollusk—in other words, a slug!  These mollusks are highly adapted for life in the water-column, as you can see from the butterfly-like wings, (or “parapodia” to a malacologist).  The pteropod wings are actually a highly-modified molluskan foot, i.e. the muscular and slime-secreting mass that slugs glide on.  Evolution really did these slugs a favor, as I do not think anyone could say “ewww!” to such a beautiful animal.

Calycophoran Siphonophore

caly_sipho

Now this is a fantastic image.  A close-up, finely-detailed capture of the head (nectosome) portion of a calycophoran siphonophore—so aptly referred to as a “rocket-ship sipho” here on the Plankton Portal.  The two siphon-like features propelling this colonial critter are very apparent in this image.  Maybe, in truth, siphon-ophore is a pretty apt name for this plankter as well.

Ctenophore: Thalassocalyce inconstans

thalass

Thalassocalyce inconstans is a predatory species of ctenophore, captured feeding in this frame.  The body of the ctenophore is contracted and engorged about the anteroposterior (vertical) axis, giving it the appearance of an inflated, heart-shaped balloon.  Within the fragile and transparent body, you can see the 8 condensed comb rows captured as an array of ragged segments crowning the aboral end.  Fine mesenterial canals also appear as contoured markings that line the engorged body. Ctenophores are tactile predators, meaning all predatory behavior is triggered by physical, non-visual stimulus.  Something in the water column bumped into this Thalasso and got it all riled up, providing ISIIS a great opportunity for this detailed capture of foraging behavior.  If we had a hydrophone for this deployment, I am fairly certain a satisfied lip-smacking would be recorded in a few seconds.

Copepods: Families Eucalanidae and Metridinidae. 

copepods

Copepods are abundant in these ISIIS data, and it is easy to forget what a broad diversity of these important crustaceans are classified on the site.  Here we have two broadly identifiable PP copepods for sample.  The image on the left shows a copepod belonging to the family Eucalinidae: it has a narrow, torpedo-shaped body and the anterior end of the head forms a pointed-triangle.  We think this critter might be a Rhincalanus spp.—if you look close you might be able to make out a small rostrum-like appendage extending forward and tucked down from the head, as well as what may be lateral spination at the end of each mid-body segment (prosome).  This guy’s cruising, antennas spread out and scanning the surroundings.  On the right, we have a copepod belonging to the family Metridinidae, perfectly poised for the ISIIS cam.  How do we guess this ID?  At the end of this copepods lengthy tail (urosome), look closely at the paired fin-like feature (ferka).   Along the outer edge, right before the separation of the individual ferka, can you make out a small, skirt-like protrusion?  If so, just tell your buddies: “hmm, check out that lengthy urosome and ferka segmentation; it must be a Metrinidae species,” and blamo—you are a crustacean taxonomist!

Anthomedusae: Leukartia spp.

anthomed

At first glance, you might be thinking “is this medusae sticking its tongue out at me?” Or maybe it is sporting a ten-gallon hat?  While I couldn’t blame you for such outlandish assertions (I mean, who would write such silly things?), this odd anthomedusae is readily identified to genus by the conical appendage extending from the bell (“apical process”) and causing much confusion on the Plankton Portal.  In this image we get a great view of many internal and external features of this Leukartia sp., including a crenulated (ragged) bell margin, a tall mouth (“manubrium”) in the center of the bell, and many long tentacles projected both downwards and in front of the bell.

Larvacean and mucous house

larvacean

We find a good deal of larvaceans on the site, but this capture is a real beauty.  Larvaceans are gelatinous plankton that filter-feed on detritus in the water column.  You see the critter poking its head out, like the cap on a rolled-up toothpaste tube?  That’s the larvacean, curled up in preparation to pump surrounding detritus through its elaborate mesh-like mucous house.  For a critter that takes up residency in its own secretion, this guy is pretty adorable!

Physonect Siphonophore

sipho_forage

Now this is quite the fantastic find!  Here we are looking at a large siphonophore projecting numerous tentacles across the frame.  It is all-hands-on-deck for this colonial jelly, as it is putting on a mighty foraging display for us.  The big guy is hungry—watch out, ISIIS.

There have been way too many great images to fit in this small serving of photogenic plankton.  We look forward to serving up more fantastic finds in the future.  Keep exploring, plankton hunters!

1 million classifications!

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Last week, Jean-Olivier and Zuzana organized a push to one million (1,000,000) classifications here at Plankton Portal in honor of my defending my PhD on Friday, October 30, 2015.

Jessica_Luo_defense_titleslide

Title slide for Jessica’s defense seminar

The PhD defense at the University of Miami essentially consists of a 1-hour public seminar on my dissertation research, which I had conducted over the last five+ years, and then a multi-hour private question-and-answer session with my  committee. In my case, my committee consisted of my advisor, Dr. Robert K. Cowen, and four other professors, Drs. Su Sponaugle, Gary Hitchcock, Rob Condon, and Jean-Olivier Irission. At the end of the private session, if the work and the answers to the questions were deemed satisfactory, then the student passes and essentially is this granted a doctorate.

So I have two happy news: 1) My PhD defense was successful – all went well! and 2) We did it! Plankton Portal reached one million classifications by the time I defended!

PP_1million

The above photo shows Professor Cowen, me (Jessica), and Cedric Guigand with ISIIS (the instrument that collects all the cool images in Plankton Portal!) on board the R/V Walton Smith on a cruise in the Florida Keys this past summer. We had taken it in anticipation of a Plankton Portal classification milestone; little did I know that it would be in conjunction with my PhD milestone!

In my PhD, I looked at gelatinous zooplankton (jellies) in marine ecosystems from three contexts: in aggregations at fronts (that’s the California current dataset on Plankton Portal!), as predators of other plankton in driving vertical migrations, and as contributors to the global carbon cycle. For the first two parts (“chapters”), I focused on small jellies, and studied them using ISIIS, and for the last chapter, I conducted a modeling study on all jellies (medusas, comb jellies, and salps/pelagic tunicates) over the global oceans. It’s been a really educational process for me, learning about jellies, imaging systems, modeling, and overall, how to do science. I’ve been able to publish one of my dissertation chapters already, and look forward to publishing the rest over the next six months. Grad school has also been a really fun opportunity for me to get out in the field (on five research cruises), go to conferences all around the world (Japan, Spain, Hawaii), help run citizen science projects like Plankton Portal, and just overall meet some incredible people who do fascinating work. It’s been a total privilege, one that I haven’t taken lightly. And I look forward with anticipation to the journey to come. Onwards and upwards!

What’s the goal of this research project?

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The underlying objective of this research project is centered on a small-scale front and its associated biological activity. A front is a meeting of two water masses, and oceanic fronts are generally broken up into several broad categories, depending on the physical environment and phenomenon that cause these water masses to converge. Oceanographers have been interested in fronts for a long time, because they tend to be areas of high productivity. The elevated productivity at fronts is a result of the converging water masses physically aggregating many marine organisms.

Small-scale fronts are, as the name suggests, smaller in spatial scale: they tend to occur on the order of tens of kilometers instead of hundreds to thousands of kilometers like some of the other major fronts. Small-scale fronts occur frequently, but have also been harder to describe because they are more ephemeral than large fronts.

samplingsite

Sampling region in the Southern California Bight (SCB)

We set out to study one particular small-scale front in the Southern California Bight (SCB, see map for study region) because it was in an area that has received long-term oceanographic investigation – it is always good to do studies where there is lots of baseline data. We were primarily interested in exploring what biota was out there and seeing if there was biological aggregation at the front.  Indeed there was! We saw a large aggregation of our now favorite jellyfish, Solmaris rhodoloma, at the front and described it in a 2012 research paper. You don’t have to worry about reading it. It basically says what I just told you: we found a lot of Solmaris at this small-scale, salinity-driven front.

Solmaris rhodoloma aggregation

Solmaris rhodoloma aggregation

One of the interesting things about Solmaris is that they are part of a family of medusae that predate exclusively on other gelatinous zooplankton. They have been known to eat arrow worms and doliolids, but now, because of our images, we also think they are eating larvaceans and small siphonophores as well. So finding the large aggregation of Solmaris actually generated another research question for us: what’s going on with the rest of the gelatinous zooplankton at and around this front? What are the main processes driving their distribution? Is predation pressure from Solmaris affecting them in any way?

It turns out that the second question is much harder to answer than you would think. Not knowing exactly what Solmaris is eating, and how long they’ve been accumulating at the front makes it difficult for us to tell if they’re just happening upon a patch of prey or they have already eaten everything around them. One approach is to determine the movements and directions of the organisms, which is why we’re asking you to measure their orientation. We hope that knowing their orientation (and that of their potential prey) can help us model their movement patterns and “age” the Solmaris aggregation, so to speak. Of course, it’s possible that even with this data we will still not be able to determine how long Solmaris has been aggregating at the front. However, this kind of orientation information has never been acquired for jellyfish of this size and at this scale, so any data we gather will be new and interesting!

This is just one of many questions that Plankton Portal can help answer.  The biological data contained within these images can bring us closer to a greater understanding of zooplankton ecology in general.  Understanding the abundance, distribution and biomass (that’s where the size measurements come in) of this extremely understudied group of organisms – the small gelatinous zooplankton – can help us assess their broader impact in the marine food web, contribution to carbon cycling, and even help us learn how to identify hotspots of marine productivity in the future. This is how research grows and develops: it starts from a small, initial question (“hmm, I wonder if there is anything interesting at a small offshore front?”), which leads us to additional questions, and down the road, will hopefully help mankind appreciate and better protect its precious marine resources.

Thank you for your help and participation in Plankton Portal – you are contributing to a more knowledgeable future and hopefully one where we can better care for the sea around us.

Amazing Plankton Videos

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Hi all! we wanted to share this website, called Plankton Chronicles, with you. It is an amazing collection of plankton related mini videos. You’ll get to see some color videos of your favorite plankton. Who knows? it may also help you in your classification effort. Enjoy!

http://www.planktonchronicles.org/en

planktonchronicles

The Plankton Chronicles series was created by Christian Sardet (CNRS), Sharif Mirshak and Noé Sardet (Parafilms) in the context of the Tara Oceans Expedition and the Marine Station of Villefranche sur Mer (CNRS / UPMC). The series has received financial support from CNRS (INSB / INEE), IBISA, UPMC and the Ville de Nice.