Sex in the Sea

Marah J. Hardt

12 annotations Aug 2023 data

Afterword

  • Just imagine spending your entire adult life in the big city, meeting tons of attractive fellow singles day in and day out, year after year, but having to wait until just before you kick the bucket to have sex. And if that is not torture enough, when you finally get to do it, your only option is to go back to your hometown and lose your virginity with someone from your high school. That's a salmon's sex life in a nutshell.
  • With a long time until they reach maturity (over a decade in some species) and relatively low reproductive rates (in part because females do not breed every year), sea turtles can't withstand intensive harvesting pressure on adults or their eggs. But harvesting is only one of the challenges faced by sea turtles today. Another, more subtle threat also looms—that of warming temperatures. Sea turtles plan their reproductive cycle to coincide with just the right temperature window within which to lay their eggs. This is because the temperature of the sand determines the sex of the hatchling. It's as if instead of X and Y chromosomes, our sex was dictated by the weather. Babies born in summer would be girls, those in winter, boys.
  • As climate change continues to warm the land, the sex ratio of sea turtles is at risk, with the potential for fewer males to be produced. So far, this change has not yet been detected, but researchers are on the lookout. Meanwhile, physical barriers such as seawalls and jetties, meant to protect homes and preserve sand for tourists, can often destroy the habitats female turtles rely on for nesting
  • The long-distance calls of the great whales of the world create an eerie, almost ethereal symphony of sound—some of it audible to us, much of it not. But recent advancements in technology, such as buoys equipped with acoustical listening stations, are helping researchers better comprehend the basin-scale conversations that are occurring. When a whale off Newfoundland may be communicating with a whale off Bermuda, it forces us to rethink the dynamics of whale dating games—and how human activities may be drowning out the conversation.
  • Pee can be a powerful love potion in the sea. Some male fish fake fatherhood to score more fertilizations. Cuttlefish are convincing cross-dressers. In some fish, the smaller the male, the bigger the cojones.
  • In the world of lobster sex, nothing says "let's get it on" like peeing in your lover's face. Males and females rely on the sultry scent of their urine to set the mood and, once engaged, keep potential rivals at bay until a couple has completed their crustacean consummation.
  • But in the lobster world, there's rarely a rematch. Not right away at least. Boston University professor Dr. Jelle Atema has shown in experiments that the losing lobster can remember the smell of his vanquisher's pee and will refuse to engage in another brawl for at least a week. A winning lobster, on the other hand, seems to gain a bit of confidence with each conquest, an attitude that may be reflected in the smell of his urine.
  • In addition to increasing the volume of their pee, winning lobsters likely add a kind of signature to their scent, something that broadcasts their credentials and serves to intimidate rival males. Though he has yet to identify the specific compound, Atema notes that it's likely lobster urine goes beyond just identifying individuals; for dominant males, it may also say "I'm a badass, and I'm going to kick your shelled butt." Such an "eau de confidence" would be mighty attractive to a female lobster.
  • The female's strategy is to be coy and quick. She makes daily and brief visits to her heartthrob's den, flicking her antennules inside to smell him out and then spritzing him quickly in the face with her own pee (those front-facing nozzles come in handy) before getting the hell out of there. At first, each time the female returns, the male may lunge at her, even land a good swat or two. But eventually, her love potion begins to take hold.
  • The male starts to lets loose his own stream of urine, furiously fanning the fin-like appendages called swimmerettes located under a lobster's tail. This action draws her scent inward while flushing a mix of his and her urine out behind him. As most lobster shelters come with a back door for quick escapes, the mixed aroma of the his-and-her lobster pee wafts outward, broadcasting the lovers' intentions widely—lobsters may do it in dens, but they are far from discreet.
  • Eventually, the male calms down enough for the female to make her move and enter his den. She'll stay part time at first and only allow him to get to first or second base: there's lots of heavy petting with antennae and jointed limbs going on, but that's about it. Diane Cowan, senior scientist at The Lobster Conservancy and a former student of Atema's, explains that for females, this part-time moving-in together is a test. The female learns whether the male really controls the shelter or if another male can come kick him out. More than anything, a female lobster needs to know her partner can offer her total protection when it comes time to mate. For the male, it's a chance for him to learn if she is really ripe and ready—something he can likely smell and taste. As lobsters have the equivalent of taste buds on their legs, the constant touching between two courting lobsters is really more of a mutual tasting—they are licking each other with their feet. It's kinky stuff.
  • That's where her love potion comes into such great effect. The scent of a pre-molt female is the ultimate aphrodisiac for a male. Once the male has melted into a more hospitable nature and the female determines he does indeed lord over this shelter, she'll move in full time.