Baby bloom in the deep sea: Survival strategies from the seafloor to the ocean surface and back HD

Deep-sea animals have adapted a variety of ways to promote the survival of their young. The babies often come in unusual shapes and sizes, exhibiting features not seen in the adult form. Surprisingly, many larval and juvenile stages of bottom-dwelling species develop in the open ocean; they may disperse long distances along coastlines to decrease resource competition with adult populations or to keep far out of the reach of hungry seafloor predators. Deep-sea babies can look and live very differently from their parents to enhance their chance of survival and may even journey from the seafloor to the surface and back again. Animals in order of appearance: - A mother squid (family Gonatidae) cradles an egg case in her arms as she glides through the midnight zone waters. Carrying the growing embryos inhibits her ability to feed, and she will likely die soon after the babies hatch. - The deep-sea lobster larva, family Polychelidae (1,000 meters/3,300 feet deep), has been called a giant because its size (four to six centimeters/roughly two inches) at this young age is huge compared to other crustacean larvae. Scientists do not know how long they drift in open ocean waters before settling to the muddy seafloor—it could be many months or perhaps even years. - Juvenile rockfishes (500 meters/1,650 feet deep) may travel in ocean currents along coastlines for hundreds of miles away from their parents before settling to rocky or muddy seafloor habitats. Rockfishes are a popular recreational fishing target, but because they are slow-growing and reproduce late in life, they are vulnerable to overfishing. - Dancing bristle worms, family Tomopteridae, allocate energy for building gelatinous egg cases to house developing larvae rather than simply dispersing them into the water column to fend for themselves. The tiny worms have the protection of a large egg case that may also provide nutrition as they grow (400 meters/1,320 feet deep). Both the juveniles and adults have transparent bodies allowing them to blend into the surrounding water and avoid predators. - Larval flatfishes often have spots or transparent bodies to help camouflage them in upper sunlit waters where there is nowhere to hide (400 meters/1,320 feet deep). They feed on plankton in the open waters before transforming to darker colors more appropriate for blending in on the seafloor. The mature flatfishes feed on small clams, worms, and snails on the bottom. -Juvenile red octopuses, Octopus rubescens, form schools of fast, agile swimmers (45 meters/150 feet deep). They feed in the productive, upper ocean waters in a chaotic, swift-moving mass to confuse potential predators and protect them from harm. The adults are solitary and can change color to match their seafloor surroundings as they stealthily hunt for prey. - Baby rattail fishes, family Macrouridae (500 meters/1,650 meters deep), live up off the bottom, in the open waters of the midnight zone, to avoid being eaten by seafloor predato