Meet the Oregon Coast Aquarium's 'jelly mom' - OPB News

Posted: 05 Feb 2021 06:02 AM PST

Of all the creatures of the sea, few are as strange and surreal as the sea jelly.

Their most famous feature, of course, is their stinging tentacles. But from there, they get even more unusual.

Contrary to their common nickname "jellyfish," they are not actually fish. As invertebrates, they have no bones at all. Or teeth, or eyes, or ears. They don't even have a brain.

And they never sleep.

Sea jellies have been on this planet for more than 500 million years, making them the oldest multi-organ animal on earth.

Curator of the Fish & Invertebrate Department at the Oregon Coast Aquarium, Evonne Mochon-Collura has earned the nickname "jelly mom."

*Ian McCluskey*

"It's an incredibly different animal that is so simple and yet so complex when you start to look more closely," said Evonne Mochon-Collura. Her official job title at the Oregon Coast Aquarium is the curator of the Fish & Invertebrate Department. Her informal title: "jelly mom."

Mochon-Collura is the keeper of the sea jellies.

Taking care of sea jellies

Thousands of visitors to the Oregon Coast Aquarium in Newport marvel at the sea jelly exhibit, but few notice Mochon-Collura. She works behind the scenes in a specialized lab set up to raise sea jellies.

She spends her time working in a large room, with a rollup door like what you'd find at a loading dock. It holds bubbling vats of algae, pipes running up walls and across the ceiling and several aquarium tanks, each of different shapes and sizes, filled with jellies.

"They are beautiful and at the same time they can be frustrating from an animal care standpoint," Mochon-Collura said. "We are not trained specifically for jellies when we go through marine biology degrees in college. So it was a whole new world to me."

Moon jellies (Aurelia aurita) get their name from their pale luminance and similar shape to a full moon.

*Ian McCluskey / OPB*

Keeping sea jellies is a relatively new branch of aquarium science. Until the 1990s, it was thought impossible to keep open-ocean sea jellies for any length of time in captivity because they were too delicate for standard aquariums, getting sucked into filters, or ending up stuck in corners, or helplessly bobbing on the surface, while the fine particles of their food sifted to the bottom.

In the wild, sea jellies live in the swirling currents of the open ocean. So aquariums turned to a specialized tank that had been invented to keep planktonic animals alive on research ships. Called a "kreisel," these tanks take their name from the German word for gyro, or circular turn. Kreisel tanks are often square on the outside, but rounded on the inside, with no corners, to allow the water to flow in a continuous current like a hand sweeping round and round a clock.

Jelly keepers discovered that the non-turbulent flow of kreisel tanks could keep jellies slowly swirling, allowing their bell-shaped bodies to move in their mesmerizing pulse, with their tentacles unfurling, pulling in suspended particles of food.

“They are beautiful and at the same time they can be frustrating from an animal care standpoint,” says Evonne Mochon-Collura, curator of Fish and Invertebrates at the Oregon Coast Aquarium. — "They are beautiful and at the same time they can be frustrating from an animal care standpoint," says Evonne Mochon-Collura, curator of Fish and Invertebrates at the Oregon Coast Aquarium.

*Ian McCluskey / OPB*

Climbing a ladder to the top of the large kreisel in her lab, Mochon-Collura gently scooped up a sea jelly. Mochon-Collura noticed lavender clusters under the bell, signaling that this individual is a pregnant female.

She looked through her microscope to confirm. "There are thousands of plangela, or jellyfish larvae," she said. And with a bright smile, added, "That is fantastic!"

In order to raise jellies, Mochon-Collura had to become an expert in each stage of their life cycle. As if sea jellies were not already unusual enough, their life cycle makes them even more so.

Jellies assume six distinct forms through their life cycle — only one of which actually looks like what people know as jellyfish.

After the larvae have settled, they attach to a hard surface and form polyps — which look like tiny bumps, like those of corals (which turns out, are related to sea jellies). They can stay in this stage for weeks, months or even years.

"Jelly care is a lot of chemistry and physics," Mochon-Collura said. She monitors the temperature and salinity of her tanks. When conditions are just right, a polyp does something rather amazing: It creates a stack of clones, about a dozen or so, flat and round, almost like a stack of coins.

Then it buds and releases the baby jellies into the water. Each tiny baby has eight arms, looking perhaps more like an octopus than a sea jelly. Eventually, the babies will grow into the shapes we recognize as jellyfish.

Better known as jellyfish, sea jellies are elegant in their simplicity. They have no eyes, ears, or brain. They never sleep. The glowing shapes are their gonads.

*Ian McCluskey*

Gathering wild jellies

Mochon-Collura has been successfully cultivating her collection of jellies in her lab at the aquarium, but for genetic diversity, and to gather more types of jellies, a team from the Oregon Coast Aquarium sets out from Newport Bay into the Pacific every couple of years to gather jellies from the wild. We tagged along on a recent trip.

Once out in the open ocean, the boat slowed.

"There!" one of the crew members shouted, pointing, as she spotted the shadowy shapes of jellies just under the surface of the dark blue water. Carried by the ocean's currents, sea jellies are drifters. Where the currents converge, so do jellies. A group of sea jellies is called "a smack."

The boat operator cut the engine. Two divers slipped on fins and tugged on snorkeling masks and dove from the boat with a splash.

All around the divers are jellies of bright orange and crimson, with long trailing tentacles that look almost like billowing lace. Jellies come in various species, as large as the 120-foot long lion's mane, or as small as the size of a pinhead. We found a smack of Pacific sea nettles.

The divers scooped up the jellies with their specialized nets that have a fine mesh, which won't hurt the fragile jellies and can also collect some of the seawater they swim in.

The seawater is not just to transport the jellies — floating in it are unseen gametes. They're sperm and eggs of the jellies, which Mochon-Collura uses back in her lab.

A diver from the Oregon Coast Aquarium scoops up Pacific sea nettles, a type of sea jelly, in a specialized net.

*Ian McCluskey / OPB*

A diver poped her head above the rolling waves and shouted back to colleagues on the boat, "we're coming in with three."

After a more dive, they've collected 18 nettles in all to take back to Mochon-Collura.

Back in the lab

At a table in her lab, Mochon-Collura carefully scooped the jellies out one at a time, combing her fingers through their tentacles, inspecting for small creatures that came with them. Marine animals can often hitch a ride on jellies, like juvenile crabs and small fish. They take advantage of the food particles captured on the jelly's tentacles.

Mochon-Collura spotted several tiny creatures, so small she needed tweezers to pick them up. One of them had a pale, opaque body and large dark eyes. It squirmed in her tweezers. It's a parasite that feeds on the flesh of the jellies.

Pacific sea nettles swirl in a kreisel tank in the lab at the Oregon Coast Aquarium.

*Ian McCluskey / OPB*

After grooming out all the marine hitchhikers from the jellies, Mochon-Collura slipped them, one at a time, into her largest kreisel.

As they slid from her bucket and into the tank, they joined the current, unfurling, billowing out their bell-shaped bodies, and began to slowly pulse. And pulse. And pulse.

Mochon-Collura paused, empty bucket in hand, and watched.

“Whether I’m cleaning a tank, or feeding the jellies, or simply watching them to see what the flows are doing in the tank, I simply can’t take my eyes off of them,” says Evonne Mochon-Collura, curator of the fish and invertebrate department at the Oregon Coast Aquarium. — "Whether I'm cleaning a tank, or feeding the jellies, or simply watching them to see what the flows are doing in the tank, I simply can't take my eyes off of them," says Evonne Mochon-Collura, curator of the fish and invertebrate department at the Oregon Coast Aquarium.

*Ian McCluskey / OPB*

"I never grow tired of that," she said. "Whether I'm cleaning a tank, or feeding the jellies, or simply watching them to see what the flows are doing in the tank, I simply can't take my eyes off of them."

"I've been doing this for over 13 years and I'd love to keep doing this through the rest of my career," she said, then chuckled, "chances are after I retire, I'll probably set up a small jellyfish tank at home and take care of them then."

The Best Fish Tank, Heater, Light, and Accessories - The New York Times

Posted: 30 Apr 2019 12:00 AM PDT

Tank kit

The Marineland Bio-Wheel LED Aquarium Kit 20 came with the second-best filter of the bunch, but its light was dim and the kit cost one and a half times as much as all the other kits at the time of our testing.

We were intrigued by the affordable Elive Aqua Duo 20 kit's optional aquaponics filter, which allows you to grow a terrestrial plant on top of the filter to help reduce fish waste. But the setup looked a little strange, and as the tank was explicitly designed for this aquaponics setup, it makes little sense without it.

The Tetra 20 Gallon LED Aquarium Kit looked almost identical to the Aqueon kit, except with an inferior filter and five free plastic plants. We value the filter more.

Standalone tank

During our testing, we had difficulty finding any glass tanks available online from reliable retailers due to how hard it is to ship just one empty glass box. When we first published our results, we recommended the Aqueon 20-gallon tank and the Innovative Marine Nuvo Black 20 tank, but neither model is available online anymore.

We also looked at the 18.1-gallon AquaMaxx low-iron rimless aquarium, but it cost slightly more than other tanks we considered, held fewer gallons, and had a less traditional shape. Still, it's a pristine tank, and it could be a great choice if you want your tank to be viewable from all sides.

If you're interested in a standalone tank, however, we recommend visiting your local fish store or a pet superstore and finding one there.

Light

The Marineland LED Strip Light was affordable, but the body of the light was far too wide and dim to compete with the superior and cheaper Nicrew.

We also considered a slew of similar-looking, well-reviewed cheap aquarium LED lights from Coodia, Deckey, Koval, and Mingdak. But like the Nicrew model, none of those lights are made by companies known for aquarium goods, and they're available for purchase only on Amazon. If you're going to take a chance on an unknown brand, the Nicrew light is significantly cheaper.

Heater

The Marina Submersible Aquarium Heater is a good, affordable heater, but it's only marginally cheaper than the Eheim Jäger, and we think it's worth paying the extra $12 or so for a more accurate and more precise model that's widely known and trusted. Each number on the Marina model's internal thermometer is marked in intervals of three or four Fahrenheit degrees (for example, 72, 75, and 79 are in sequence), and a sliding red band allows you to set the temperature somewhere in the middle of those intervals. Although this design allows you to set somewhat accurate temperatures, it's not as precise as on the Eheim Jäger.

The Penn-Plax Aquarium Heater, though three-quarters the size of the Eheim Jäger, stood out much more due to the bright blue color of its internal thermometer.

Although the Tetra HT Submersible Heater remains the unshakeable best-selling heater on Amazon, it's preset to 78 °F, making it an inflexible option that's more vulnerable to manufacturing errors.

While we appreciated the Finnex Compact Electronic Titanium Heater's external temperature selector, we struggled to find a place to put the controller where it would be easily accessible but not an eyesore.

The Aqueon Submersible Aquarium Heater had temperature markings only every four degrees, the same issue we found with its more indestructible twin.

Filter

The Marina Power Filter Slim S20 (for up to 20 gallons) remains the best filter included in a tank kit, but the small ceramic pebbles in its cartridges aren't as large or powerful as the AquaClear filter's larger stones, so get the AquaClear model if you're buying separately.

Pacific Aquarium's Chi Cho recommended the versatile DeepBlue Professional BioMaxx Power Filter ADB88702 (for up to 30 gallons) as a runner-up to the AquaClear. This filter contains two deep buckets that can each hold one piece of foam and one cartridge, or any kind of custom filtration media. But unlike with the AquaClear model, the preset cartridges don't include ceramic stones.

The Marineland Penguin Power Filter 150 stood out for its innovative Bio-Wheel, a rotating cylinder meant to maximize habitable surface area for bacteria. But the filter contains just one cartridge, which means your tank will cycle again when you replace it.

The popular Aqueon QuietFlow LED Pro Aquarium Power Filter and Tetra Whisper Power Filter are the same filters in those companies' respective kits; both lack sophisticated, stable filtration because they rely on one cartridge.

The Fluval C-Series Power Filter's five-stage filtration system looks just as effective as that of the AquaClear, if not more so. But those five parts (instead of the AquaClear's three) all need to be cleaned and replaced on different timelines and are available mostly in aquarium specialty stores, so it's more difficult to maintain this model well and procure replacement parts.

Water conditioner

API's Tap Water Conditioner, Aqueon's Water Conditioner, and Tetra's AquaSafe Plus all have positive reviews and seem to work well, but they each treat only 10 gallons per teaspoon as opposed to Seachem Prime's 50 gallons.

Fluval's Water Conditioner has positive reviews but treats a meager 5 gallons per teaspoon; per ounce, it's the second most expensive conditioner we tested.

Water test kit

Testing strips, such as API's 5-in-1 Test Strips and Tetra's EasyStrips 6-in-1 Test Strips, are a recently popular alternative to solution kits. After you dip these small tabs of paper into your water, they change color to reflect the test results. But currently a box of 25 strips will run you around half the cost of the API Master Test Kit—testing just once for pH, nitrite, nitrate, and water hardness costs around 50¢. On the other hand, testing once for pH, high-range pH, nitrite, nitrate, and ammonia with the API Master Test Kit costs just 16¢. Strips are also an all-or-nothing kind of test, as each strip contains colors for those five parameters. We like how the Master Test Kit allows you to test for just one compound at a time. In addition, since high ammonia levels are one of the most common downfalls of a tank, we think a good kit must contain an ammonia test.

We also looked at the Nutrafin Master Test Kit, a very professional-looking kit that comes in a durable carrying case and can test 10 water parameters. But at close to $100 at this writing, it's an exorbitant buy for even for the most passionate water-parameter-heads.

Gravel substrate

When it comes to aquarium gravel, CaribSea's Instant Aquarium freshwater substrate is in a league of its own. You can find most gravel for fish tanks sold in 1- to 5-pound bags that cost around $10. Buying enough of those other bags of gravel to fill a 20-gallon tank adequately is easily twice as expensive as buying one bag of CaribSea. Plus, during our research, most of those bags looked artificial or less elegant than our pick.

Soil substrate

You need two bags of Seachem's Flourite Black to fill a 20-gallon tank, whereas just one of CaribSea's Eco-Complete will do the trick. And one bag of the Seachem substrate costs as much as a CaribSea bag. Some owner reviews also say this Seachem substrate is better for aquariums that focus more on plants than on fish.

The popular Mr. Aqua Aquarium Soil has good reviews, but is sold in 1-liter bags that each cost around $17 currently, meaning you'll need to spend more than $85 to properly fill a 20-gallon tank.

ADA's Aqua Soil Amazonia also has great reviews, but you need four bags to fill a 20-gallon tank, and one bag currently costs nearly as much as a bag of CaribSea Eco-Complete.

Siphon

We looked into some other popular siphon models with different features, but none stood out as being quite as useful as the Terapump.

The snaking, 25-foot-long Python No Spill Clean and Fill Aquarium Maintenance System comes equipped with a nozzle that can attach directly to your faucet, allowing you to pump water directly from your sink into your tank. But we don't recommend pouring untreated water directly into your tank; the toxic chlorine could shock your fish, even if you add conditioner right after.

The battery-operated Eheim Quick Vac Pro's ability to suck out sludge without removing water sounds great for spot maintenance, but you'll still need to remove dirty water one way or another.

Food

Many aquarists swear by Hikari's Micro Pellets fish food, and we liked that it didn't come as a flake. But this food contains just 43 percent protein, which pales in comparison to the 49 percent protein of our pellet pick from New Life Spectrum.

Pacific Aquarium's Chi Cho also recommended Ocean Nutrition Community Formula Flakes, a food that has 48.8 percent protein but is hard to find online.

Algae sponge

If you're at all tuned in to the algae-scraping community, you may have seen the innovative magnetic scrubbing pads that allow you to clean without getting your hands dirty. These cleaners work like a magnetic sandwich: Put one on either side of the glass, and you can then scrub from outside the tank without touching any water. Although these scrubbers do relieve you of much of the hassle of cleaning algae, they can end up scratching your tank: According to Cho, even one grain of sand accidentally wedged between the scrubbers can leave a zigzag of gouges before you even notice the damage.

We also looked at traditional scrapers, such as the Penn-Plax WZ20 Wizard Aquarium Scraper and Scrubber Combo Kit. But the stainless steel scraper looks unnecessarily harsh for normal algal growth, and some owners report that the head falls apart after some scrubbing.

The API Algae Pad for Glass Aquariums was particularly cheap, but we preferred scrubbers with handles so you don't have to worry about sticking your whole arm into dirty aquarium water.

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