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Ecologists from the Smithsonian Environmental Research Center spotted this diatom, called Navicula, drifting in the waters of Belize. Diatoms are microscopic algae, or phytoplankton, roughly the width of a human hair or smaller. But though they're called algae and use photosynthesis to get their energy, diatoms aren't plants. They belong to a completely different group, known as Chromista.
(Photo: SERC Phytoplankton Lab. Artistically arranged)
Ever wonder what it's like to live in a glass house? Striatella unipunctata, a tropical diatom often found on coral reefs, spends its entire life like this. Because their cell walls are made of silica, the main component of glass, diatoms are often called "algae that live in glass houses." Though since the silica also contains water, "algae that live in opal houses" might be closer to the truth! (Photo: SERC Phytoplankton Lab)
Happy Microscope Monday! SERC marine biologists found this beautiful tunicate, known as Botrylloides violaceus, on the shores of Rehoboth, Delaware. Colonial tunicates are made of dozens of bottle-shaped individuals called zooids that together act as a single animal. Though attractive, Botrylloides violaceous is also an invasive species: It's already been spotted on both coasts of North America and Europe, and has a reputation for displacing mussels and other native species. (Photo: Brianna Tracy-Sawdey)
Meet the copepods, the marine creatures that may be the most abundant multicellular animals on Earth. Copepods are tiny, shrimp-like plankton that make up the foundation of the marine food web. Their name literally means "oar foot," for their pair of paddle-like swimming legs. Copepods are found all over the ocean, from the icy waters of the poles to active hydrothermal vents. Insects also put up a good showing for the title "most abundant multicellular animals," but while they have more species, copepods are estimated to beat them by sheer number of organisms. (Photo: Tim Mullady)
It's January, which means winter is in full swing! These white flower (or snowflake) patterns belong to the underwater tunicate Botryllus schlosseri, also known as the Golden Star Tunicate, for the star-shaped colonies it forms. No one knows where the Golden Star Tunicate came from, but it's been spotted on all seven continents. It often grows on piers, dock floats, boat hulls and other manmade structures—though it's also taken a toll on some seagrasses, by blocking off the light. It's garnered a reputation in the #Chesapeake as a "fast-growing pernicious pest" for fouling oyster trays. (Photo: Brianna Tracy-Sawdey)
It's official: We've reached the first full week of #winter, so we're celebrating with this snowman-shaped group of diatoms, called Detonula pumila. Diatoms are a kind of single-celled algae, though Detonula often forms long chains connected by a set of zigzag-shaped spines and a single spine down the center (look closely and see if you can spot it). Despite these diatoms' wintry appearance, Detonula are thought to do best in warmer, saltier waters, and they've been found on all seven continents!
Winter is in the air! These icy blue tendrils belong to a bryozoan called Virididentula dentata. Bryozoans, a.k.a. "moss animals," exist in colonies composed of dozens of individual organisms called "zooids." They're prolific invaders, because it's easy for them to latch onto ship hulls and travel around the world. This bryozoan is native to New Zealand and Australasia, but marine ecologists at the Smithsonian Environmental Research Center spotted during a fouling survey in Hawaii. (Photo: Brianna Tracy-Sawdey)
Would you guess that this close-up photo is a flatworm? Marine flatworms are some of the most beautiful creatures in the ocean. This one goes by the name Pseudoceros mexicanus, or the Mexican skirt dancer. Though some flatworms are parasites (like tapeworms and liver flukes), the Mexican skirt dancer isn’t. Flatworms evolved so that all their cells could be as close the the surface as possible, giving them maximum access to oxygen. SERC marine biologists found this Mexican skirt dancer on a fouling survey in San Diego. (Photo: Brianna Tracy-Sawdey)
This marine creature is a sea slug, a.k.a. nudibranch, a name that literally means "naked gills." Nudibranchs are hermaphrodites, with male and female sex organs, but they still need to find a partner to reproduce. This nudibranch (Onchidoris bilamellata) is known commonly as the "rough-mantled doris" or "barnacle nudibranch," for one of its favorite foods. When barnacle nudibranchs breed, they've been known to form crowds of more than 1,000 nudibranchs per square meter! Our marine biologists spotted it on one of their fouling surveys in Yaquina, Oregon. (Photo: Brianna Tracy-Sawdey)
A special #MicroscopeMonday for #WorldFisheriesDay! Would anchovies make your Thanksgiving menu? While popular on land, anchovies are also one of the most popular foods for creatures in Chesapeake Bay. Sea nettles and comb jellies prefer to dine on them caviar-style, by eating the eggs. Bay anchovies (Anchoa mitchilli) are the most abundant fish in the Chesapeake: A single female can produce 50,000 eggs in a season, and it's estimated all adult anchovies combined can produce 100 trillion eggs a year.
There are over 140 species of anchovy in the world. These anchovy eggs were photographed by former SERC marine biologist Rebecca Burrell.
The ocean is full of hermaphrodites—creatures that can be male and female at the same time. This one, spotted by SERC marine biologists in San Diego waters, is a colonial tunicate called Botrylloides diegensis. The golden tubes (called zooids) are individual organisms with some of their own organs, but they're all attached to a single cloacal chamber, forming their own colony. They can reproduce asexually by budding (creating new zooids) or by releasing eggs and sperm into the water, where they can fertilize each other. (Photo: Brianna Tracy-Sawdey/Smithsonian Environmental Research Center)
Learn more on our Marine Invasions Lab's NEMESIS database: http://invasions.si.edu/nemesis/browseDB/SpeciesSummary.jsp?TSN=-448
SERC marine biologists found this plumose anemone on one of their underwater survey panels in San Francisco. Plumose anemones (Metridium spp.) have two kinds of tentacles, one for feeding and one for defense. The defense tentacles are less common, but they're very dangerous: When searching the water, they can stretch three to four times their normal length. If they detect another anemone they don't like, the tip of a tentacle will break off and stick to the other animal, killing cells at that spot—and sometimes killing the entire animal! (Photo: Brianna Tracy-Sawdey)
The Halloween countdown continues with more #MonstersUnderTheMicroscope! Meet Perkinsus marinus, a deadly parasite that's been infecting oysters in Chesapeake Bay since the 1950s. This image shows a slide of oyster tissue (red) being overrun by the parasite (black dots). Because oysters are filter feeders, they can absorb the parasite in the water as they feed. Once inside, Perkinsus mutliplies, creating hundreds of thousands of cells that take over the oyster, obstructing its circulatory system and disintegrating its tissue
To up the chill factor, Perkinsus thrives in the nightly "dead zones" of the Bay's shallow waters. Read about how SERC marine ecologist Denise Breitburg's lab is tracking Perkinsus here: http://sercblog.si.edu/?p=5755 (with Rebecca Burrell and Andrew Keppel)
Happy #MicroscopeMonday! Our Halloween countdown continues with more #MonstersUnderTheMicroscope. This week: Eggs of the Chinese mitten crab (Eriocheir sinensis) just about to hatch. The Chinese mitten crab is an invasive species that's taken hold in San Francisco and parts of Europe. It's also been spotted 100 times haunting the U.S. mid-Atlantic, with the first East Coast sighting in Baltimore in 2005. The crabs can cause river banks to collapse with their burrowing, damage or destroy fishing equipment, and have killed vast numbers of fish attempting to migrate through a fish-salvage facilities in California. (Photo: Monaca Noble)
Want to help us track the mitten crab's latest haunts? Call SERC's Mitten Crab Hotline (443-482-2222) to report any sightings, or email them to [email protected]. And remember: If you catch one, don't throw it back! More details here: http://mittencrab.nisbase.org/
It’s Microscope Monday, and we're celebrating October with some of our favorite #MonstersUnderTheMicroscope. First up: The Terebellids, affectionately called the "spaghetti worms." Terebellids are a family of marine worms named for their extremely long tentacles. They capture the planktonic organisms and other tiny particles they feed on by secreting mucus from their tentacles, and then slowly funnel them toward their mouths. You make the call: Creepy or cool? (Photo: Brianna Tracy-Sawdey)
Happy #MicroscopeMonday! The ocean has some of the most beautiful worms on earth, but this marine worm has another weird quirk: It reproduces by growing a series of "clones" on its tail. The worm is called Myrianida pachycera, and was spotted by SERC marine biologists on a fouling survey in San Diego. To reproduce, it uses a process known as stolonization. Its tail grows a series of segments called stolons, with their own heads, three antennae, and either eggs or sperm. Once they're fully grown, they break off to fertilize with other stolons and create more little worms. As it grows, the tail of stolons can get vastly longer than the worm itself! (Photo: Brianna Tracy-Sawdey/SERC) See what a full tail looks like here: http://invasions.si.edu/nemesis/calnemo/SpeciesSummary.jsp?TSN=-479
Named in Latin for its star shape (Asterolampra), we've nicknamed this diatom the "lone star" diatom, because single cells exist on their own, and they seldom cluster in large populations. Diatoms are microscopic algae found in nearly every kind of water on Earth. The rays in Asterolampra diatoms are hollow, with openings at the end each covered by a thin membrane. The smaller circles between the rays are holes in the cell wall called areola.
Learn more about these starry diatoms here: Learn more about these starry diatoms here:http://www.sms.si.edu/irlspec/Astero_maryla.htm
