Science and the Sea The goal of Science and the Sea is to convey an understanding of the sea and its myriad life forms to everyone, so that they, too, can fully appreciate this amazing resource. en-US Science & Medicine Science and the Sea 144 144 2014 Drupal 720 Sat, 07 Sep 2019 00:00:00 -0500 Sat, 07 Sep 2019 00:10:00 -0500 Science and the Sea podcast The goal of Science and the Sea is to convey this understanding of the sea and its myriad life forms to everyone, so that they, too, can fully appreciate this amazing resource. marine science, oceanography, marine biology The University of Texas Marine Science Institute no Deep Diving Devil Rays /articles/deep-diving-devil-rays <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="360" height="202" alt="" /> </div> <p>Devil rays, and their cousins manta rays, are known for putting on spectacular acrobatic shows, jumping and twisting in the air. They grow up to 13 feet across and typically live offshore throughout the world at latitudes where the surface waters are warm. But scientists have learned that devil rays don’t always stay in the warm shallow waters. Besides leaping toward the sky, these rays also regularly descend very deep into the ocean.</p><p>Biologists tracked 15 Chilean devil rays by attaching satellite tags, which gathered data on water temperature, depth and light levels for up to nine months. The depth logs revealed a surprising behavior: Devil rays are champion divers, often venturing more than a mile deep in waters barely above freezing.</p><p>Most likely, these creatures dive to feed on the plentiful fish and invertebrates found in these dark, cold waters, but it’s no small journey for a smorgasbord. About once a day, the devil rays plunge over a mile straight down in less than 30 minutes and then gradually ascend over an hour and a half. Or, they drop down half as deep and hang out there for up to 11 hours at a time.</p><p>Either way, temperatures at those depths range from 35° to 37° F, so it’s no surprise that the rays take the chill off by spending a lot of time in shallow, warm waters, especially just before and after a dive. Gliding through these shallow waters makes for a spectacular show when the rays leap, twist and turn in the air, more than a mile above where they lunched a few hours earlier.</p> Sat, 7 Sep 2019 00:00:00 -0500 Science and the Sea What Fuels Hagfish Hearts? /articles/what-fuels-hagfish-hearts <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="360" height="202" alt="" /> </div> <p>After just an hour or so without oxygen, your heart develops permanent damage. Shortly afterward, it stops beating entirely. Not so with the resilient hagfish, a slimy eel-like creature that feeds on dead marine animals that fall to the ocean floor. In fact, the hagfish’s heart continues beating and supporting normal activity for up 36 hours without any oxygen at all. What scientists haven’t understood is how or why.</p><p>Now they have a partial answer to the first question. Canadian researchers from the University of Guelph conducted an experiment to discover what fuel the hagfish heart uses to keep beating with no oxygen to power it. Past research revealed that the heart first uses the carbohydrate glycogen when oxygen is not available, but then the glycogen runs out.</p><p>The researchers removed hearts from hagfish and observed the muscles for 12 hours, some exposed to normal oxygen levels and others denied oxygen. Within each group, the hearts received saline (salt water) with glucose and glycerol — two types of carbohydrate fuel — or no fuel source at all. All the organs kept beating, “like zombie hearts,” as one scientist described it.</p><p>But the hearts that received glycerol in oxygen-deprived conditions beat more effectively, with stronger contractions and relaxations, than the other hearts denied any fuel or provided glucose. Though it didn’t explain how the other oxygen-deprived hearts kept beating, these findings suggest that glycerol is an important fuel source when oxygen runs out. The next question is where the glycerol comes from — possibly the liver — and why hearts use it. The answers might give scientists clues about how to prevent damage to human hearts when denied oxygen during a heart attack or transplant.</p> Thu, 1 Aug 2019 00:00:00 -0500 Science and the Sea A One of a Kind Ocopus…For Now /articles/one-kind-ocopus%E2%80%A6-now <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="360" height="244" alt="" /> </div> <p>Most octopus species hunt by probing holes or lunging at prey with all eight arms. But the larger Pacific striped octopus is not like most octopuses. This large species is more subtle—and sly. When it spots prey, the octopus shrinks itself and sneaks up to its mark. Then the cephalopod simply reaches out and… well actually, it gently taps its prey. The prey is so startled that it jumps into the octopus’s waiting arms, or the octopus uses the moment to grab dinner.</p><p>And that’s not the only way this species differs from its brethren. The Pacific striped octopus is also quite social. Most octopuses are loners, but scientists have found several dozen Pacific striped octopuses hanging together in the Pacific near Nicaragua and Panama.</p><p>These striped beauties aren’t afraid of romantic entanglements either. Unlike the brief, arm’s-length transfer of sperm most octopus species use during mating, a male and female Pacific striped octopus spend time together, sometimes sharing meals beak-to-beak and staying attached to each other for several days.</p><p>After the female lays a clutch of eggs, she mates again, and again, and again over several months. Most octopus mothers lay a single clutch of eggs, brood them until they hatch and die shortly after, but Pacific striped mothers go on hunting, mating and laying more eggs even after multiple hatchings.</p><p>When a Panamanian biologist first observed these behaviors in the 1970s, other scientists rejected them as too bizarre to be true, until recently, when others saw these behaviors for themselves. But it’s possible the Pacific striped octopus isn’t all that unusual. So few octopus species have been closely studied that biologists may yet discover even stranger lifestyles among others.</p> Mon, 1 Jul 2019 00:00:00 -0500 Science and the Sea The Goddess of Love… in the Twilight Zone /articles/goddess-love%E2%80%A6-twilight-zone <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="370" height="208" alt="" /> </div> <p>As much as people have learned about the oceans and the animals within them, nearly 2,000 new marine species are discovered every year. One of those newcomers so enchanted the scientists who discovered it that they named the small reef fish after Aphrodite, the Greek goddess of love in classical mythology.</p><p>In the gleam of an underwater flashlight, the bright fluorescent yellow of Tosanoides aphrodite and its hot pink stripes are hard to miss, but the pink actually helps protect this brilliantly colored fish. When a pair of biologists found it, T. aphrodite was hiding in the rock crevices of a reef 400 feet deep. That’s in the ocean’s twilight zone, where very little light— and no red light at all—reaches. Without any red light, the Aphrodite fish’s pink stripes help it disappear into the darkness, shielding it from the eyes of passing predators. Only the males display flamboyant pink stripes. Females are solid blood-orange, which similarly helps them vanish into the twilight zone’s darkness.</p><p>So far, the deep waters below St. Paul’s Rocks, a remote, unpopulated archipelago off the coast of Brazil, remain this new species’ only known home. But, the ocean’s twilight zone is an underexplored area because it’s too deep for recreational scuba diving, but shallower than the pitch black midnight zone where submarines and remotely operated underwater vehicles typically gather data. Now that they have started to explore the twilight zone, scientists have been discovering rich communities of marine creatures there, and they may find other populations of this species as well as species yet to be discovered.</p> Sat, 1 Jun 2019 00:00:00 -0500 Science and the Sea Why Mantis Shrimp Shack Up for Life /articles/why-mantis-shrimp-shack-life <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="370" height="279" alt="" /> </div> <p>Many birds and some primates and other mammals mate with one partner for life, but such monogamy is rare in the animal kingdom. Most animals, including nearly all sea creatures, lead more promiscuous lives, trying to have as many offspring as possible. Having lots of offspring with different mates increases the likelihood of long-term survival for an individual’s genes and its species.</p><p>But some mantis shrimp species buck this trend, instead settling down in male-female pairs further away from coral reefs—where their main food sources live—than biologists might normally expect. But why? One common reason for animal monogamy is the greater chances for offspring survival if parents care for their young together, even if they have fewer babies overall. Another is avoiding predators. Spending time looking for a mate may put an animal at greater risk of being caught by a predator. And mantis shrimp shells aren’t as hard as other crustaceans’ more protective exoskeletons.</p><p>A timeline that approximates when different mantis shrimp traits evolved indicates that mantis shrimp began living away from nearby reefs around the same time they had begun pairing up for life. Only later did they start co-parenting. That discovery suggests their monogamy probably evolved from a need to avoid predators. Evolutionary science is inexact, so other pressures could have influenced mantis shrimp monogamy. But not becoming a meal is a pretty good reason to settle down with a lifetime partner—and ensure your genes make it into the next generation.</p> Wed, 1 May 2019 00:00:00 -0500 Science and the Sea Baby Sharks Hang Out Off Long Island /articles/baby-sharks-hang-out-long-island <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="380" height="227" alt="" /> </div> <p>If you’re a baby white shark, could Long Island be your summer refuge? That’s the question a team of scientists asked after they noticed a concentration of baby sharks spending time in the New York Bight. They suspected the bight, which is the stretch of the Atlantic Ocean between Cape May, New Jersey and the eastern tip of Long Island, was a white shark nursery because young sharks had been frequently spotted there for several years. But to confirm it, they needed to know the sharks actually stayed there for lengthy periods.</p><p>The scientists attached satellite and acoustic tags to ten sharks under a year old found swimming near Long Island. The tags monitored the locations of each shark and revealed that they spent several months in that area from August to October, probably because the shallower waters near the shore offer shelter from predators, including other sharks. The scientists also learned that the baby sharks headed south in late fall to shallow waters off the Carolinas. The sharks remained there for winter and returned to Long Island in the spring.</p><p>The tags have now given the scientists a clear map of where these little sharks hang out, when and where they move and the routes they take. For white shark populations to recover from years of overfishing, baby sharks need to grow up and produce their own baby sharks. This information can aid in conservation efforts to ensure the babies of this vulnerable species reach full maturity.</p> Mon, 1 Apr 2019 00:00:00 -0500 Science and the Sea The Spiny Lobster Musician /articles/spiny-lobster-musician <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="370" height="236" alt="" /> </div> <p>If you’re a Disney fan, you’re probably familiar with Sebastian, the lobster who sings “Under the Sea” in The Little Mermaid. Of course, lobsters don’t sing in real life—but some of them do appear to play a violin of sorts. The spiny lobster does not scuttle around with an actual tiny fiddle, but it makes sounds using a mechanism similar to pulling a soft bow across strings. S</p><p>piny lobsters have a structure called a “file” located near their eyes. It is similar to the file crickets use to make their chirps. By moving its antennae, the lobster rubs a piece of soft tissue, known as a plectrum, across the file. The friction creates sound. The scientist who discovered this behavior used a tiny microphone and a motion detector attached to the plectrum to gather data to learn how the lobster made its sound.</p><p>The sound they produce is not especially melodic. It is more like the screechy whine produced by rubbing a moist finger on a balloon. Lobsters appear to use the sound primarily to startle predators for a brief moment, giving the lobster time to scurry away to safety. Such a strategy can be particularly helpful when spiny lobsters molt. Then, their shell is too soft to protect them. So, even at their most vulnerable, spiny lobsters can use “music” to protect themselves.</p> Fri, 1 Mar 2019 00:00:00 -0600 Science and the Sea Purple, Pink and Blue—and They’re All New /articles/purple-pink-and-blue%E2%80%94and-they%E2%80%99re-all-new <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="370" height="197" alt="" /> </div> <p>One is purple, one is pink, and one is blue, and it took 40 scientists from 17 countries to find them, more than 4 miles below the ocean’s surface. They are three new species of snailfish discovered in one of the deepest places on earth, the bottom of the Atacama Trench off the coast of Peru and Chile.</p><p>A team led by researchers at Newcastle University in England has been exploring the deepest parts of the ocean with specialized landers fitted with HD cameras and traps. The landers free-fall to the ocean floor, in this case 24,600 feet below the surface, take photographic and video images, and collect samples. The devices collect data for up to 24 hours before the researchers send an acoustic signal that releases weights in the lander, allowing it to float to the surface so the researchers can collect their scientific booty.</p><p>This research group has already deployed such devices more than 250 times and discovered new snailfish species at the bottom of the Mariana Trench. The Atacama snailfish they found are translucent, eellike fish that lack scales and feed on invertebrates in the trench. Their body tissue is almost entirely gelatinous, well adapted for the extreme conditions at such depths.</p><p>But since they depend on the high pressure and low temperature to stay in one piece, it is extremely difficult for scientists to bring these fragile fish to the surface without them nearly melting away. Nevertheless, researchers managed to bring a live purple Atacama snailfish safely aboard, giving scientists the opportunity to observe and learn from this new species.</p> Fri, 1 Feb 2019 00:00:00 -0600 Science and the Sea Christmas Tree Worms Stay Spirited All Year /articles/christmas-tree-worms-stay-spirited-all-year <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="360" height="221" alt="" /> </div> <p>Families that celebrate Christmas will likely have a colorful tree lighting up their living room right now. But under the sea, millions of Christmas tree worms remain festive all year. Christmas tree worms, whose scientific name is Spirobranchus giganteus, have two spiraled crowns on their back that each resemble a tiny colorful Christmas tree.</p><p>These “trees” can be a single solid color but are also often multi-toned, with a second color gracing the outer tips of their spirals like garland. And these worms don’t restrict themselves to red and green. Some are a brilliant blue or bright yellow, while others might be white with orange tips, ruby with white tips, gold with maroon and white tips or any number of other combinations.</p><p>These colorful spirals help the worm breathe and catch food. The worms anchor themselves to coral and use the feather-like tentacles protruding from their spirals to catch tiny prey from the surrounding water and move it to the worm’s mouth. If the worm is startled, it retreats into burrows in the coral to hide from possible predators.</p><p>Over time, these burrows in the coral can reach 10 inches in length, providing a roomy hiding place for a critter that lives up to 30 years. These worms also help coral recover more quickly from bleaching events and protect it from predators. In fact, in perhaps a bit of an ironic twist, scientists have seen Christmas tree worms literally push away the feet of predatory crown of thorns starfish.</p> Fri, 21 Dec 2018 00:00:00 -0600 Science and the Sea Kidnapping Pays Off…for the Captor /articles/kidnapping-pays-%E2%80%A6-captor <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="360" height="269" alt="" /> </div> <p>When two unrelated species help each other, their relationship is symbiotic, or mutually beneficial. When one species feeds off another, the feeder is a parasite. But some species find a different way to take advantage of another without consent: kidnapping.</p><p>Scientists have recently learned that amphipods, small crustaceans popularly called scuds or sideswimmers, will do whatever it takes to avoid becoming a predator’s meal—even abducting another species for use as their own personal defense weapons. Several amphipods have been found toting around tiny sea snails, called pteropods, like backpacks, apparently because predators don’t find the sea snails very tasty.</p><p>Amphipods range in size from one millimeter to one foot, though most are less than half an inch long. They look a little like a cross between a shrimp and a flea, and most are scavengers that are the prey of birds and fish. Pteropods are less than a quarter inch long and emit unpleasant chemicals to deter predators. Amphipods have no such secret weapon, so they exploit pteropods by carrying them around. As a result, cod icefish pass them by for meals.</p><p>But this isn’t a symbiotic relationship where the pteropod benefits from palling around with an amphipod. In fact, the pteropod likely starves to death while the amphipod holds it hostage, preventing the pteropod from hunting. Scientists have identified two different amphipod– pteropod species pairings, but they don’t yet know if these are typical pairings or how many amphipod or pteropod species end up in these arrangements. They also don’t know if predators other than cod icefish avoid the pteropod-carrying amphipods—or whether an amphipod would accept a ransom to release a pteropod.</p> Sat, 1 Dec 2018 00:00:00 -0600 Science and the Sea Hogfish and their Amazing Technicolor Skin /articles/hogfish-and-their-amazing-technicolor-skin <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="360" height="234" alt="" /> </div> <p>Camouflage is one of the best evolutionary strategies there is for evading predators, and hogfish are masters of it. These pointy-nosed reef dwellers change skin color so rapidly to match their surroundings — literally in milliseconds — that it seems impossible for them to rely only on their eyes to perceive those surroundings.</p><p>As it turns out, they don’t only use their eyes. Hogfish skin can “see” too. Scientists recently analyzed hogfish DNA and learned how this skin vision, called dermal photoreception, works. Hogfish skin cells include chromatophores, which contain a pigment that’s sensitive to light. When these cells sense light patterns, they can mimic those patterns by manipulating the distribution of their pigment, spreading it thin or clustering it together.</p><p>But scientists also wanted to understand how hogfish skin detects light in the first place. Octopus and cuttlefish also rapidly change skin color to blend into their environments. Their skin uses the same basic mechanism that their eyes use. But that’s not how hogfish skin works. Duke University biologists compared genetic material in hogfish skin to genetic material in its retina, the sensory membrane at the back of the eye. They found the fish’s skin and eyes use different genes to detect light.</p><p>Researchers are still studying the molecular chain reaction involved in this newly discovered form of dermal photoreception. They also want to learn how the hogfish combines visual information from the skin and eyes to match its coloration to the environment so quickly. As they learn more, they hope to discover whether this skin-sensing superpower helps hogfish in other ways too. Hogfish and their Amazing Technicolor Skin Hogfish</p> Thu, 1 Nov 2018 00:00:00 -0500 Science and the Sea Sea Serpent…or Surreptitious Shark? /articles/sea-serpent%E2%80%A6or-surreptitious-shark <div class="field field-name-field-image field-type-image field-label-hidden"> <img typeof="foaf:Image" src="" width="360" height="199" alt="" /> </div> <p>Sailors’ lore about the ocean has captured popular imagination for centuries, from mermaids and sirens to the mythical Kraken. But often these stories are rooted in a case of mistaken identity. Tales of frightening sea serpents, for example, may have arisen in part from rare sightings of the elusive frilled shark, a long, slender fish that usually lives 400 to 4,200 feet below the surface.</p><p>In fact, in the earliest existing written description of this bizarre creature, Pennsylvania zoologist Samuel Garman wrote in 1884, “its appearance in the forward portion of the body, particularly in the head, brings vividly to mind the triangular heads, deep-cleft mouths, and fierce looks of many of our most dreaded snakes.” The shark’s discovery led Garman to suggest that people should not dismiss too easily the possibility that a “serpent-like monster of the oceans” might actually exist.</p><p>What makes these sharks so fierce are the 300 teeth that are arranged in 25 diagonal rows along its gaping mouth. The teeth all face backward, making it impossible for prey to back out of the shark’s jaws once snagged. Examinations of stomach contents suggest that squid and other cephalopods make up more than half the frilled shark diet. But scientists know almost nothing about their hunting habits.</p><p>There is one problem, however, in blaming these serpentine predators for supposed sea serpent sightings. Although frilled sharks can grow as long as 6 feet, they more typically reach only 3 to 5 feet long, hardly the massive monster that superstitious sailors might fear. Are frilled sharks responsible for myths about sea serpents, or is that possibility a myth itself?</p> Mon, 1 Oct 2018 00:00:00 -0500 Science and the Sea