Fantastic Finds Friday: February 2014

Hey plankton hunters!  This week we are showing off four exceptional zooplankton found by you, our keen-eyed and inquisitive citizen scientists.  We are amazed at how many plankton species have been uncovered on the site and just how capable you all have been at discerning some truly tricky taxa from the varying forms and shapes captured by the ISIIS camera.  We thank all of the citizen scientists for your participation on the Plankton Portal!  These images found by our citizen scientists continue to excite and we are eager to discover what resides in the thousands of images yet to be seen by human eyes!

Annatiara affinis; Anthomedusa — #Medusa #morethanfourtentacles

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This capture of an anthomedusa is definitely a prime example of how the images captured by ISIIS can be equal measures fine-resolution biological data and one-of-a-kind organismal artwork.  This gelatinous organism is baring all for us in this frame and we get a clear view of not only the striations on the exterior of the bell (the exumbrella) unique to this species and the fully extended tentacles, but also the central gastric pouch (stomach) appearing as the dark mass within the bell and the internal network of radial canals where digested food is transported. I think I can also see this critter blushing as ISIIS takes the snapshot!  This medusa shown here is relatively uncommon in the images provided for you from the Southern California Bight, and we couldn’t be happier that our fantastic and dedicated group of citizen scientists spotted this gelatinous beauty.  Annatiara affinis is a hydromedusa like many of the #4tentacles and #morethanfourtentacle medusae found on the site.  The unique (and photogenic) lines appearing along the exterior of the bell were very helpful in pinning down an ID for this critter.  From what we have seen, this seems to be a rare image captured of Annatiara where the tentacles are fully extended from the margin of the bell, and we are extremely grateful that this lovely jelly was so at ease in front of the ISIIS cam.

Shrimp — #Shrimp

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This is one of the largest shrimps I have seen on the portal and provides a great side-view of the crustacean anatomy.  The orientation of this shrimp with the abdomen tucked under the carapace (upper shell) and the antenna trailing sharply away from the head indicates that it is moving rapidly towards its posterior (bottom left of image), using a swimming stroke known as the “cardioid escape reaction”—slapping the abdomen shut and quickly propelling the crustacean away from the perceived danger.  This specific behavior played an important role in the field of neuroscience, in fact.  When it was discovered, this behavioral response was the first example of a “command neuron mediated behavior”— meaning a specific behavioral pattern resulting from the stimulation of a single neuron.  I wonder what stimulated this crustacean’s command neuron? Perhaps it is camera shy.

Arrow Worm / Chaetognath — #ArrowWorm

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I’m curious if that dark blob may be some out-of-luck plankter soon to be nabbed by this voracious predator.   I am especially fond of these in focus captures of chaetognaths.  The dart-shaped body and the hydrodynamic taper of the paired lateral fins really show off the sleek and elegant body plan of these brutal invertebrate carnivores.  The chaetognath body has a protective outer covering known as a cuticle, a tough but flexible non-mineral layer exterior to the epidermis.  Chaetognaths are notoriously efficient predators and hunt other planktonic organisms using hooked grasping spines that flank the mouth.  A hood arising from the neck region can be drawn over or away from the hunting spines, much like the action of sheathing and unsheathing a blade.  Equipped with an armor of cuticle and sword-like spines these guys are definitely well suited for combat!

Physonect Siphonophore — #Sipho #Corncob

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The siphonophores love to put on a good show for us here on the portal and this frame is truly exceptional.  The shadowgraph imaging technique used by ISIIS lends itself to capturing in detail the elaborate gelatinous structures displayed by these colonial organisms.  Siphonophores are comprised of many single animals, or zooids, which are highly specialized and coordinated in function.  The zooids of a physonect siphonophore arise from a long stem at the end of which is a gas-filled float referred to as a pneumatophore.  The pneumatophore is on display in this image here appearing as the dark, oval-shaped appendage on the upper left end of the main “body.”  The portion that resembles a corn on the cob is referred to as the nectosome.  The nectosome is composed of many swimming bells, or nectophores, each one of which is a single medusoid zooid.  These nectophores display remarkable coordination among each other and the selective contraction of these zooids allows for the siphonophore to move and turn in any and all directions.  Physonect siphonophores are predators and rely on long, branching tentacles for prey capture.  The one whipping across the frame here is definitely on the prowl.  Each tentacle arises from a single feeding polyp situated below the nectosome in a region called the siphosome.  You can see the siphosomal region on this specimen as the narrowing, darkly filled feature curling upward from the base of the nectosome.  They sure have a lot of ‘somes’ and ‘phores’ but we forgive their repetitive nomenclature because we are always glad to find some siphonophores.

We hope this has been a fun and informative look at a few of the many tremendous critters captured by ISIIS and found by the citizen scientists.  If you come across an image you think is particularly cool on the portal then tag it with #FFF and we will check it out for use on the blog.  As always, looking forward to the next Fantastic Find Fridays!

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Fantastic Finds Fridays: Week 2! #FFF

We are at the end of week 2 and we pulled out some of the best finds from this past week. As a reminder, every Friday we will post a selection of Fantastic Finds. If you think you have found something really great on Plankton Portal then tag #FFF and we will check it out for use on the blog. Thanks for tagging your favorites this week!

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Larval fish
http://talk.planktonportal.org/#/subjects/APK00015nq

Larval fish are actually considered part of the plankton, as fish in their early life stages will drift along in the oceanic environment. Because larval fish are relatively poor swimmers, they are under high predation pressure and more than 99% of baby fish that hatch from eggs will not make it! It’s a tough life. You might not know it from this site, but studying larval fish is a major component of our lab. Dr. Cowen has spent his career studying larval fish, their distributions, dispersal and population connectivity. In this particular study, we did not sample very many larval fish so we did not include it as one of the categories. However, we are incredibly interested whenever we see one so definitely tag the fish in the forum when you see any! #Larval #fish

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Liriope tetraphylla (#Medusae #4tentacles) with Arrow worm
http://talk.planktonportal.org/#/subjects/APK0000q5x

This is one of my favorite pictures from this week because what you see Liriope tetraphylla actually eating the arrow worm! Here one of his tentacles has brought up the arrow worm into the gastric peduncle (that’s the long thin appendage in the middle of the umbrella that looks like a handle). He appears to be holding the arrow worm in place while he eats his dinner. As far as I know, the only scientific study of what Liriope eats is from a paper by Larry Madin in 1988, published in the Bulletin of Marine Science, where he found that Liriope eats larvaceans, crustacean larvae, heteropods and juvenile fish. No one has reported that Liriope also eats arrow worms … until now.

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Sphaeronectes koellikeri – #rocketship #thimble
http://talk.planktonportal.org/#/subjects/APK00002cl

This beautiful creature falls within the broad group of jellyfish-relatives called the Siphonophores. Here you see this animal in a stunning feeding display. Though these guys are small and relatively inconspicuous, other siphonophores can get up to hundreds of feet long, and as a group are considered the deadliest predators in the ocean.  One fun fact: these rocketship siphonophores grow from the base of the stem towards the tail end. So the tail end of the stem is one of the oldest parts of the body. Sometimes you’ll even see small rocketships budding from the tail!

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Radiolarian colony – #radiolarian #colony
http://talk.planktonportal.org/#/subjects/APK00003kq

We know that you’ve been frustrated by those small fuzzy round objects that invite classification but really aren’t supposed to be classified. Those are protists, a diverse group of eukaryotic microorganisms. One type of protist is the radiolarian, which are known for their glass-like exoskeleton, or “tests.” They are incredibly important in marine science because their tests are made of silica, which are preserved in marine sediments after they die and sink to the bottom of the ocean, and provide a record for paleo-oceanographic conditions, such as temperature, water circulation, and overall climate.

Radiolarians also form colonies. Colonial radiolarians are interesting because first, little is known about them, despite their abundance in the open ocean, and secondly, they are hosts to symbiotic algae that are modest but significant primary producers in the ocean. It has also been suggested that we are vastly underestimating the abundance of radiolarian colonies. Since primary production (photosynthesis, the conversion of sun energy into carbon) is the basis upon which all ocean life can exist, it’s incredibly important to understand who all the different primary producers are and how many of them are out there!

 

That’s all, folks. Thanks for reading, thanks for classifying, and remember: mark your favorites with #FFF for next week’s Fantastic Finds Friday!