From the sex lives of pygmy seahorses to parasites living in fish nostrils: these photos tell extraordinary ocean stories

By Nell Lewis, CNN

(CNN) — Pygmy seahorses, about the size of a fingernail, are some of the smallest vertebrates in the world. First discovered in 1969, little was known about the creatures. But in the early 2000s, British marine biologist Richard Smith decided to focus his PhD research on Denise’s pygmy seahorse, a species found in Sulawesi, Indonesia. It was then that he made an extraordinary discovery.

Seahorses are renowned for mating for life, with the male carrying the eggs. But after following three male pygmies and one female for weeks, Smith discovered that the sex lives of the smaller variety can be much more colorful.

After flirting with one male, the female would impregnate him, before he went off to brood the eggs for 12 days. Around six days later, another male would come along and she would impregnate him too. The third male, who never got the chance to mate with the female, took to attacking his more successful rivals, attempting to strangle them with his tail.

This story and others are collated in Smith’s book “The World Beneath: The Life and Times of Unknown Sea Creatures and Coral Reefs,” published in November in the US and January in the UK. It showcases the ocean’s little-known creatures with more than 300 images taken during Smith’s research dives in over 23 countries.

There are photographs of flasher wrasses, which Smith calls the “peacocks of the sea” for seducing the females with their kaleidoscope of color. There is the Banggai cardinal fish, found only in Indonesia, which keeps its eggs and newly hatched babies in its mouth for two weeks. Then, there are gruesome parasites, his latest obsession.

“I’ve always liked weird and wonderful creatures, whether it’s on land or underwater,” he told CNN. “But underwater, so little is known about so much.”

Patience is key

Surprisingly, photography came as something of an afterthought to Smith. He started capturing images purely to aid scientific identification and to demonstrate the scale of some of the tiny species he was studying. Gradually, he realized the power of communicating species’ behavior through images and raising awareness of the increasing threats marine fauna face.

“I started to realize that if I wanted to communicate the stories of animals in danger, a beautiful image makes a huge difference,” he says.

During his PhD, after locating the group of four pygmies living in gorgonian (sea fan) corals in Sulawesi, Smith would spend four or five hours a day diving and observing their reproductive and social behavior. “I would study them from dawn until dusk,” he says fondly, and he gave them names: Josephine was the heroine, and her male suitors were called Tom, Dick and Harry.

“I think anthropomorphism has a really useful role in people relating to animals and their behaviors. The pygmy seahorse is so tiny, yet it has this elaborate social behavior,” he says.

Smith photographed them using a digital SLR camera with a macro lens inside waterproof housing. “You have to have a lot of patience,” he says. “I’m keen not to disturb the animals for photos, so I would never poke it or move it to a better background or anything. I just wait and watch.”

He was the first to document an example of polygamy in the seahorse family, and the imagery showed the process in minute detail, even capturing the stretch marks around the belly of the male pygmy once it had released its offspring.

More recently, the object of his fascination has turned to parasites. It’s the stuff of horror films: Smith recalls one that lives in the nostril of a crocodile fish. Another attacks the anemonefish (also known as the clownfish, featured in the animated movie “Finding Nemo”), climbing through its gill arch as a tiny larva and then settling in the mouth, eating away its tongue, and staring out ominously with two black specks for eyes.

Then there’s a parasitoid worm that Smith photographed curled inside a shrimp, like spaghetti: “It starts off infecting the shrimp and then it grows, eating the least important organs to start with, until it eventually becomes a zombie shrimp that just feeds and fuels the growth of the parasite,” he explains. “Ultimately, the parasite will explode out and infect others and kill the host, making it a parasitoid.”

“A beacon of positivity”

Smith is intent on uncovering behaviors never seen before, whether brutal or awe-inspiring. He believes that gathering new information on these little-known species can help build an understanding of ocean ecosystems and ultimately aid their conservation.

He is the focal lead for pygmy seahorses for the International Union of Conservation of Nature (IUCN), the world’s most comprehensive information source on the extinction risk status of plant and animal species. Recently, he led the assessment of the Walea soft coral pygmy seahorse, which was listed as the first critically endangered seahorse.

Walea pygmies, along with many other marine species, are threatened by destructive fishing practices and temperature extremes caused by climate change. Coral bleaching events are becoming more frequent and widespread, causing whole ecosystems to collapse.

Smith hopes that his book will “inspire and educate people about coral reefs.” But while he communicates the threats, his main aim is to shine a light on the incredible animals that are out there.

“We hear so much doom and gloom about the environment, and while I think it’s important to realize this is happening, the best starting point is to teach people what is there … The more people know about these animals and the ecosystem, the more they want to protect it,” he says.

Smith wants to take readers on a journey of discovery and exploration. “There’s so much that’s still to be discovered, we keep finding new things,” he adds. “That’s a beacon of positivity. There are things out there to save and we can still do that.”

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