Blog post by Jean-Olivier Irisson
Blog post by Jean-Olivier Irisson
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:
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.
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
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 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.
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
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!
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!
Hey plankton hunters! Welcome to our 3rd round of Fantastic Find Friday here at Plankton Portal. There have been so many awesome finds on the site and we picked 5 this week for you to check out. If you see something really neat on the portal than tag it with #FFF so we can check it out for use on the blog. Here we go!
Physonect Siphonophore— #Sipho #Corncob
This is a stunning capture of a physonect siphonophore who seems to be waving hello to ISIIS as she passes by. Like all siphonophores, this guy here is a colonial organism comprised of many individual animals or ‘zooids.’ Each zooid is specialized and distinct, but work together so closely that they more resemble a single organism than a colony of animals. On display here are the branching tentacles used for foraging and the swimming bells that resemble a corncob. This one is a stunner!
Lobate Ctenophore — #Lobate
This is a really neat capture of a lobate ctenophore (Ocyropsis maculata), showing off the feature that gives this guy his name. In this image you can see clearly the internal structure and the striated texture of his muscular, gelatinous body. Lobate ctenophores swim lobes forwards by beating the ciliated comb rows situated on the opposite (aboral) end. The one depicted here would be swimming towards us and to the left. I wonder if larvacean is on the menu?
Chaetognath — #Arrowworm
Looks like an arrow shot by some undersea archer, right? Arrow worms, or chaetognaths, are carnivorous marine worms belonging to the Phylum Chaetognatha. They are notoriously ferocious predators that hunt other plankton with the help of hooked ‘grasping spines’ that flank the mouth. Chaetognaths have fins for propulsion and steering—you can see all of them really well in this capture! While these fins superficially resemble those of a fish, they are not related evolutionary and are structurally very different.
Calycophoran Siphonophore — #Rocketship #Triangle
I bet NASA would get a lot more funding if they built space shuttles that looked like this! This beautiful capture of a siphonophore really looks to me like some sci-fi monster a (horrified) astronomer might see in a telescope! Don’t worry though, this guy is just a couple of cm’s long and probably couldn’t hurt you if he tried. Just like the physonect siphonophore above, this guy is a colonial organism and would therefore be more appropriately referred to as guys. The tail, or stem, on display here contains two developmental stages of siphonophore simultaneously—both the medusa and polyp stages. Unlike most cnidarians that alternate between these stages generationally, this guy chooses to have them coexist within the same colony. If you look closely you can see them bickering over who is the prettiest!
Calanoid Copepod — #Copepod
This copepod is making a heart with his antennae! Do you think he might be in love? There is some 13,000 species of copepod in the world and they are a crucial component of plankton communities and global ecology in general. It has been suggested that copepods may comprise the largest animal biomass on the planet! Many species of marine life, large and small, rely on these guys as their main food source, including whales and seabirds. Looks like this guy here is a lover not a fighter!
Looking forward to next time !
Plankton Portal reached 100,000 classifications on Friday! In honor of our 100,000th classification, we’d like to publicly thank our top classifiers since our launch.
The top ten are (drumroll please):
The next ten classifiers are:
Lounalune, darylh69, mlmuniz, shocko61, SandersClan, jim24, Sheepdog, Steve3455, tadaemdg, and csams
A huge THANK YOU to everyone who has helped us reach 100,000 + classifications!
The Plankton Portal Science Team
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!
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
Liriope tetraphylla (#Medusae #4tentacles) with Arrow worm
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.
Sphaeronectes koellikeri – #rocketship #thimble
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!
Radiolarian colony – #radiolarian #colony
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!
Holy moly! Over 90,000 classifications and we’re not even done with a full 2 weeks!
Will you be the one who gives us our 100,000th classification?