The Ocean is Queer: Exploring Diversity in Marine Life 🌈
Published on 1/30/25
Written & Presented by Colleen McGaughey (She/Her), Edited & Formatted by Jessica Colla (She/Her)
The ocean is a vast and wonderful world, full of life forms that defy expectations. As we celebrate love and diversity for PRIDE month, it’s the perfect time to dive into the incredible ways marine life expresses affection and reproduction.
In the queer community, we love to break down societal norms … and it turns out the ocean does too! From male pregnancy and gender fluidity to sex change and same-sex pairings, ocean life showcases incredible diversity that challenges traditional binaries and gender roles. Let’s explore how the ocean’s love stories inspire us!
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Gender-Bending Tactics
The ocean is full of surprises, especially when it comes to gender and reproductive behaviors. Many marine species break away from binary expectations, showing us that fluidity and flexibility aren’t just human experiences—they’re part of the natural world too! In the sea, behaviors we might label as “nontraditional” or gender-nonconforming are often the underwater norm!
These gender-expansive tactics aren’t just fascinating—they’re powerful survival strategies. Whether it's shifting roles, adapting physical traits, or ensuring the next generation thrives, marine life reminds us that thriving doesn’t require fitting into a box.
Devoted Dads
Male seahorses carry the eggs in his brood pouch.
While we often think of parenting roles as fixed, the ocean challenges those assumptions in surprising ways. Some species have completely rewritten the script on reproduction—starting with a gender role reversal that gives new meaning to devoted fatherhood: the seahorse.
After an elaborate courtship, the female seahorse lays her eggs into a brood pouch on the male’s belly. He fertilizes the eggs and takes care of them until they’re ready to be born. During this time, he regulates the salinity of the pouch, provides oxygen, and may even supply nutrients—just like pregnancy! When it’s time for the babies to be born, the male goes through contractions resembling mammalian labor.
Seahorses belong to the family Syngnathidae, which includes other species like sea dragons and pipefish. And guess what? They do male pregnancy too! So, next time you see a seahorse, sea dragon or pipefish with a larger belly, you’re likely looking at a devoted father-to-be!
Cuttlefish and The Art of the sneak
“Sneaker” male cuttlefish disguise themselves as females to get past dominant males undetected.
Parenthood isn’t the only place where marine life defies expectations. Even before reproduction takes place, many species use unconventional strategies to ensure their genes are passed on. For some, the key to success isn’t dominance and strength—it’s deception.
For male cuttlefish, size often determines access to mates—larger, more dominant males guard and court females, leaving smaller males at a disadvantage. But rather than accept defeat, some clever males employ a remarkable reproductive strategy: mimicry.
These "sneaker" males disguise themselves as females by altering their skin color, body posture, and behavior to avoid detection. By appearing non-threatening to larger males, they can slip past undisturbed and successfully mate with a female right under the dominant male’s watchful eye.
This strategy is a brilliant example of evolutionary adaptability, proving that success in the animal kingdom isn’t always about strength—sometimes, it’s about strategy. By avoiding direct competition, sneaker males increase their chances of passing on their genes without the risks of aggressive confrontations. It’s a reminder that in nature, gender and behavior can be fluid, shifting as needed for survival and reproductive success.
Love Beyond Binaries
Cuttlefish and seahorses aren’t the only animals embracing adaptability when it comes to reproduction. In fact, some species take this flexibility to the next level—by changing sexes entirely!
More than 500 fish species naturally change their sex as part of their life cycle. This remarkable adaptation has proven invaluable throughout evolutionary history. When a population faces an imbalance in sex ratios—whether due to predation, natural disasters, or just bad luck—the ability to transition between sexes can be a lifesaving strategy.
Here are just a few examples:
Clownfish
Clownfish are a protandric species, characterized by a sequential sex change from males to females.
As an educator at the Seattle Aquarium, I'm frequently asked, “Where is Nemo?” I don’t mind pointing out the Clown Anemonefish (also known as Clownfish); its a wonderful story of adventure and a father's dedication to finding his son. But if I could change just one thing about the film … Marlin ought be Nemo's mother!
For many fish, the ability to switch sexes ensures population stability, allowing groups to adapt to changes in their environment. Clownfish, for example, take a matriarchal approach, with dominant males stepping into female roles when necessary.
These beloved fish, popularized by Disney's Finding Nemo, live in small groups led by a large female who breeds with a group of smaller males. If the female dies or is displaced, the largest and most dominant male transitions to female and becomes the new matriarch. This process, called protandry (transitioning from male to female), demonstrates incredible adaptability and the ocean’s commitment to ensuring the next generation endures.
Parrotfish & Wrasses
This protogynic parrotfish is a colorful “supermale,” which breeds with a harem of females.
But not all sex changes happen in the same direction. While clownfish transition from male to female, other species, like parrotfish and wrasses, do the opposite—starting life as females before transforming into dominant males when the opportunity arises. This process, known as protogyny, is actually more common in the marine world than the reverse (male-to-female transitions).
In most wrasse species, a single dominant male leads a harem of females. If the male dies or disappears, the largest and most dominant female undergoes a complete sex change, transforming into a male to take over the role. This transition ensures that there is always a breeding male available to perpetuate the population.
Parrotfish take this transformation to the next level. Not only do they change from female to male, but they often develop entirely new color patterns (and even body shape) in the process. Individuals undergo dramatic shifts from dull, muted tones to brilliant blues, greens, and yellows, signaling their new status. These vibrant males, known as supermales, control large territories and have exclusive breeding access to groups of females.
Did you know? Non-dominant male parrotfish closely resemble females of their species? This clever disguise allows them to "sneak" past dominant males and mate undetected—just like the stealthy cuttlefish!
Gobies
The yellow pygmy goby is an expert at gender-fluidity!
Some fish push this adaptability even further. While clownfish and wrasses change sex once, gobies take it to the extreme—switching back and forth between male & female multiple times throughout their lives, depending on what their population needs!
This rare phenomenon, known as serial bi-directional sex change, allows gobies to remain highly flexible and resilient in dynamic environments where population structures can shift rapidly. If males become scarce, a female can transition to male and take on a reproductive role. But if more females are needed to ensure steady egg production, a male can revert back to female.
This ability gives gobies a huge survival advantage, allowing them to maintain balanced breeding populations even when environmental pressures, predation, or social dynamics cause shifts in sex ratios.
Nudibranchs
Nudibranchs have both sets of reproductive organs, allowing each individual to fertilize and be fertilized.
There are many marine invertebrates that exemplify diversity in reproduction, but few do it with as much flair as nudibranchs. These flamboyant, soft-bodied sea slugs, found in tropical and temperate waters, take reproductive adaptability to new heights by doing away with seperate sexes altogether!
Unlike species that change sexes over time, nudibranchs can fertilize and be fertilized simultaneously during mating (known as intersex reproduction), ensuring that both individuals can lay eggs. In a vast ocean where encounters with a mate might be challenging, this strategy significantly increases their chances of reproductive success.
Mating among nudibranchs is a fascinating spectacle. When two individuals meet, they align head-to-tail and exchange sperm, engaging in a reciprocal fertilization process. Some species even wield elaborate, spiny reproductive structures that prevent partners from escaping too soon—nudibranch courtship can be intense!
Flying Solo: Love Without a Partner
But what if finding a mate isn’t an option at all? Some marine animals have evolved ways to reproduce without a partner, ensuring their species’ survival in even the most isolated or challenging environments.
Sponges
The parent sponge splits off a “bud” to grow a new organism!
In sponges, asexual reproduction often occurs through fission, where an individual splits into two or more separate organisms. This method is often triggered by environmental stressors or injuries, enabling rapid recovery and colonization of new habitats. Another method is budding, where small outgrowths (buds) form on the parent sponge. These buds can detach and settle elsewhere or remain attached, forming colonies.
Corals & anemones
Coral fragmentation occurs naturally, and can be leveraged to propagate new corals for conservation efforts!
Corals and anemones primarily reproduce asexually through fragmentation, where pieces of the coral colony break off (due to storms or physical disturbances) and reattach to a substrate, growing into new colonies. Another common method is polyp budding, where new polyps emerge from the body of the parent polyp and either remain as part of the colony or establish a new one. The budding anemone is literally named after this amazing feat!
Sea Jellies
The jellyfish lifecycle alternates between sexual and asexual reproduction!
Certain jellyfish species alternate between asexual and sexual reproduction. During the benthic (bottom-dwelling) polyp stage, they reproduce asexually by a process called strobilation, where the polyp generates a stack of tiny, free-swimming organisms called ephyra that are released into the water column to grow into adult jellies. Once they reach adulthood, jellies switch to a form of sexual reproduction called broadcast spawning (more on that later!). This combination of asexual and sexual reproduction ensures genetic diversity while rapidly increasing their numbers when conditions are favorable.
sharks & rays
Multiple stingray species have been documented reproducing through parthenogenesis, or asexual reproduction without a partner in complex vertebrates.
While asexual reproduction is more common in simple invertebrates, some complex vertebrates—including certain sharks and rays—have developed an incredible ability to reproduce by themselves! This rare phenomenon, called parthenogenesis, happens when an egg (or sperm) develops into an embryo without external fertilization.
A recently famous example is Charlotte the round stingray, housed at the public aquarium in North Carolina, who reproduced on her own in early 2024. Charlotte had not been housed with a male stingray for over eight years, making her pregnancy a complete surprise. Aquarium staff discovered that she had developed her own embryos through parthenogenesis, further demonstrating that life finds a way.
A female Indo-Pacific leopard shark chose to reproduce via parthenogenesis despite having access to males!
Another favorite story about parthenogenesis is of an Indo-Pacific leopard shark. A few years ago, she laid a couple of eggs at her home aquarium. This wasn’t unusual—there were two reproductively mature males in the habitat, both of whom had successfully fathered offspring before. Prior to hatching, aquarium staff assumed that one or both of the sharks had fathered her offspring. However, when the aquarium conducted a paternity test, they discovered the pups had no father! Despite having the option to reproduce traditionally, this shark decided to have them (literally) all on her own!
The Many Ways to Mate
While asexual reproduction offers independence, most marine species rely on some form of sexual reproduction—and the ocean has come up with some truly fascinating ways to make it happen! From explosive group spawnings to unexpected hybrid love stories, sexual reproduction in the sea proves that diversity extends far beyond just who mates—it's also about how!
The Big Broadcast
Sea cucumbers partake in synchronized broadcast spawnings, filling the sea with millions of gametes that appear milky-white.
Many marine animals, like salmon, sea cucumbers and mollusks, use a method called broadcast spawning. During specific times of year—often tied to seasons or lunar cycles—huge groups of individuals release eggs and sperm (gametes) into the water column all at once, sometimes in dazzling synchronized displays. With millions of gametes floating freely in the current, fertilization is left to chance. It’s a reproductive strategy that depends on numbers, timing, and a little bit of luck. This method also often involves multiple partners by default, increasing genetic diversity with every mass spawning event.
Multiple mates
Female sea turtles often copulate with several partners, resulting in a genetically diverse egg clutch and higher likelihood of hatchlings reaching adulthood.
Sea turtles take a more direct approach with internal fertilization, but that doesn’t mean they stick to just one partner. In fact, females often mate with multiple males before laying their eggs. The sperm from these various encounters is stored internally and can fertilize eggs from different fathers within a single clutch. This reproductive strategy enhances genetic diversity and improves the odds of successful offspring—especially important for a species that faces so many threats before even hatching.
Timing Is Everything in Seals
Pinnipeds (seals, sea lions & walruses) can delay the implantation of their fertilized embryo, ensuring perfect timing for pupping season!
Some marine mammals, like seals and sea lions, have mastered the art of reproductive timing through a process called delayed implantation. After mating and fertilization, the embryo doesn’t immediately implant into the uterus. Instead, it pauses development for weeks or even months—essentially hitting the snooze button—until environmental conditions are just right.
This strategy ensures that pups are born during the most favorable season, typically when food is abundant and the weather is milder. For pinnipeds who migrate or live in regions with seasonal extremes, delayed implantation helps synchronize birth with the return to breeding colonies or haul-out sites. It’s a brilliant adaptation that gives newborns the best possible start in life, showing that reproductive success isn't just about mating—it's also about perfect timing.
Two Uterus and Built-In Patience
Hammerheads have two uteruses to increase reproductive output (more uteruses = more babies), and reduce likelihood of intra-uterine predation between pups!
Sharks never fail to impress when it comes to reproductive creativity. Many species of sharks, including blue sharks and hammerheads, have two functional uteruses, allowing them to carry multiple developing pups in separate compartments at the same time. This dual-uterus system helps maximize reproductive output while also reducing competition between embryos, especially in species where embryos can be... well, a little aggressive (some even practice intrauterine cannibalism—yikes!).
Even more amazing? Some sharks have been documented delaying their pregnancies when environmental conditions aren’t ideal. If food is scarce, temperatures are off, or stress levels are high, female sharks can pause the development of their embryos until the timing is safer for birth. This remarkable ability allows them to better ensure the survival of their young—demonstrating that shark moms don’t just deliver powerful predators, they do it with strategic precision.
When Species Blur the Lines
Sometimes reproduction even crosses species boundaries, like the Rockhopper and Macaroni penguin chicks (rock-aroni) recently featured in National Geographic’s mini-series Secrets of the Penguins!
In rare but fascinating cases, sexual reproduction crosses species boundaries. In the Caribbean Islands, researchers have documented the hybridization of angelfish (Queen + Blue Angelfish), where individuals from different species successfully reproduce and produce viable offspring. These hybrids often display blended physical traits, like mixed color patterns, and can sometimes be fertile themselves. The same hybridization has been identified between surgeonfish within the Hawaiian Islands (Achilles + White Cheek Surgeonfish).
And it’s not just fish getting creative! In the National Geographic series Secrets of the Penguins, one episode follows an adorable and unusual couple: a rockhopper penguin and a macaroni penguin who formed a monogamous bond, successfully producing “rock-aroni” chicks! Though these two species don’t typically interbreed in the wild, their courtship behaviors and nesting together suggest a potential for interspecies relationships even among more traditionally monogamous animals.
Love Knows No Boundaries
Reproduction is only one part of the story! In many species, relationships and sexual behaviors play important social and evolutionary roles beyond simply producing offspring—challenging the idea that sex is always about reproduction. As it turns out, the animal kingdom is full of creatures that challenge traditional notions of sex and relationships—they’re just queer!
Same-sex sexual behaviors (also known as SSB) are common across a vast array of marine species. In many cases, these behaviors provide real advantages to the population. For example, in social species, SSBs can promote group cohesion, strengthening social bonds within the community. They can also create opportunities for caregiving, such as when same-sex pairs adopt orphaned young without adding strain to their existing responsibilities. That said, there are also plenty of cases where no clear evolutionary or ecological benefit is evident—what I can only assume comes down to individual preference!
The list of marine species exhibiting SSBs is extensive (entire textbooks have been written on the subject), so I’ll highlight just a few examples here:
Southern Resident Orcas
Male resident orcas court & perform mating behavior to reinforce social bonds, practice for future reproductive encounters, and demonstrate personal preference.
Southern Resident Orcas of the Pacific Northwest are highly social animals that rely on deep, lasting relationships within their pods. Among males, same-sex sexual behaviors are common, and researchers estimate between 30-50% of them engage in courtship, mating behaviors and other affectionate activity with other males at least once in their lifetime.
Scientists are still studying why this occurs, but there are a few strong theories:
Social Bonding: Engaging in affectionate behavior and physical touch may reinforce trust and cooperation between males, which is crucial in pod dynamics.
Practice for Reproduction: Young orcas may use these interactions to develop mating skills, ensuring greater success when they eventually mate with females.
Personal Preference: As in many other species, these behaviors may not always serve an obvious evolutionary function—they could simply be a natural expression of preference within their social structure.
Regardless of the reason, these same-sex behaviors highlight the rich complexity of companionship in animals like orca, which goes beyond reproductive necessity.
Atlantic Bottlenose Dolphins
Male bottlenose dolphins form lifelong relationships with other males; the longest social bond in their social structure!
Orca’s aren’t the only marine mammals to form deep, lasting same-sex bonds. Did you know that Atlantic Bottlenose Dolphins form only two types of long-term social bonds? The first is between a mother and her calf. But that relationship has an expiration date—once the calf is old enough to venture off on its own. The other, and the only lifelong bond in dolphins, only occur between males! It’s extremely common for male dolphins to form couples—or even throuples—and stick together for life.
Male dolphins travel, hunt, and play together, and they also mate with each other regularly. While they do mate with females too, these encounters include their male partners and tend to be short-lived. In contrast, the bond between male dolphins lasts for decades, making it one of the most enduring relationships in their social structure.
Puffins & other Seabirds
Puffins form long-term, monogamous, same-sex pairs to nest and rear young together.
Same-sex partnerships aren’t limited to mammals or fish. Female-female pairings are surprisingly common among seabirds, occurring in species like penguins, gulls, albatrosses, and puffins. These bonds often mirror the strong, long-term relationships typically associated with traditional male-female partners. In many cases, they serve important social or reproductive functions within the colony, like cooperative nesting or rearing young.
A particularly delightful example comes from the Seattle Aquarium, where two female tufted puffins, Gill and Gertie, have been a committed pair for about five years. Tufted puffins are known for forming lifelong monogamous relationships, so it’s entirely possible that Gill and Gertie’s partnership could last a lifetime as well.
Whether driven by necessity, social bonding, or individual preference, these relationships showcase the beauty of same-sex partnerships in nature and reminding us that love takes many forms.
The diversity of marine life (and love) in the ocean. 💙
A Celebration of Ocean Love
From male pregnancies to lifelong same-sex partnerships, the ocean’s incredible inhabitants challenge our understanding of gender, reproduction, and love.
This June, let’s celebrate nature and heed its lessons on adaptability, connection and resilience. Because when it comes to love, the ocean proves that diversity is the key to survival.
So next time you look out at the waves, take a moment to appreciate the unique and beautiful ways love flourishes beneath the surface. Happy PRIDE month from the ocean to you!
What's your favorite example of love and diversity in the ocean? Let us know in the comments!
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Discover the diverse and wonderful world of ocean love in this fun dive into marine reproduction and relationships! From sex-changing clownfish to parthenogenic sharks and same-sex puffin pairs, this article celebrates the incredible diversity of life beneath the waves. Perfect for curious minds and ocean lovers alike!