A royal wedding, a Black Panther, a Winter Olympics—
These are some of the big events of 2018… up on land. But this was a momentous year beneath the waves, too. Here are the top five saltiest, sexiest science discoveries of 2018
5. Secret Shark Nursery Revealed
This summer, two thousands feet beneath the surface and approximately 200 miles off Ireland’s coast, the ROV SeaRover discovered thousands of small leathery black pouches strewn across a bone-white coral rubble field. Known as “mermaid’s purses,” these are egg cases of Blackmouth catsharks (Galeus melastomus), a species of small shark. Video from the ROV revealed hundreds of adult catsharks swimming just off the seafloor, guarding their precious, developing eggs. Rising up like a frozen jungle nearby the nursery was a thriving cold water coral reef, a perfect habitat for newly hatched shark pups. The nursery was discovered within one of six offshore Special Areas of Conservation (SACs) in Irish waters, reinforcing the importance of protection of these rare deep-sea habitats.
4. Robot-assisted Reproduction for Corals
Devastated by unprecedented bleaching events in the last few years, corals on the Great Barrier Reef are struggling to repopulate the hardest hit areas. Enter the LarvalBot. Filled with up to 100,000 baby corals collected from healthy reef’s during this year’s mass spawning, this autonomous underwater vehicle (AUV) glides across the seafloor and gently releases the delicate larvae—like a cropduster dropping fertilizer on a field, says Professor Matthew Dunbabin from QUT (Queensland University of Technology). Scientists are monitoring the results of this pilot program with the hopes of scaling up in years to come.
3. Sneaker Male Squid Even Sneakier Than Realized
This year, scientists in Brazil discovered that sneaky male squid are even sneakier than we thought. Not only do they rush in and slap a spermatophore onto a female at any time, but, it turns out, that spermatophore may work to block the female from accessing any previously stored sperm from prior matings. Such sticky tactics force females to use only the most recently deposited sperm- potentially limiting the diversity and amount of sperm a female can draw upon to fertilize her eggs.
2. Anglerfish Sex Tape
Video of a female anglerfish (Caulophryne jordani) and her dwarf, parasitic male lover goes public—the first time we’ve ever been able to witness these animals in the act. Originally filmed in 2016 by two deepsea explorers, the mesmerizing, haunting, and ethereal footage was released this year.
1. Shark Embryos Go the Distance to Devour Their Siblings
Shark sex is extremely diverse and particularly wacky, including well-known intra-uterine cannibalism in sand tiger sharks. In this species, the biggest embryo in each uterus will kill its siblings and eat them for lunch—leaving two victorious pups (one in each uterus). Now, thanks to an underwater ultrasound device, researchers have shown pregnant tawny nurse sharks (Nebrius ferrugineus) house embryos that not only kill their siblings in utero, but will swim back and forth between uteri to do so. Published in early December, it’s a mighty awesome way to wrap the top discoveries for Sex in the Sea 2018.