The Difference between Pygmy Seahorses

Pygmy Seahorses and Their Unique Characteristics

by Hafid, AMD-B’s 2025 Divemaster Intern

Pygmy seahorses are among the most fascinating and elusive creatures of the underwater world. With their tiny size and remarkable camouflage, they have intrigued marine enthusiasts and scientists alike. Found primarily in the coral reefs of the Indo-Pacific, these seahorses have adapted to blend seamlessly into their surroundings, making them difficult to spot even by the most experienced divers. Below is a detailed exploration of popular species of pygmy seahorses and their distinctive features.

Hippocampus bargibanti

Hippocampus bargibanti is one of the most well-known pygmy seahorse species, first discovered in the waters of Indonesia. It has a minuscule size, measuring only about 2.5cm in length. This species is frequently found hiding within red or orange sponges, which provide perfect camouflage. Its unique ability to blend into its habitat makes it incredibly difficult to spot, despite its relatively abundant population.

Pygmy-Seahorses-Hippocampus-bargibanti

Bargibant’s Pygmy Seahorse (Hippocampus bargibanti)

Hippocampus satomiae

This species was discovered in the waters around Halmahera Island in Indonesia. It is tiny, measuring around 2cm, and often resides in brightly coloured sponges. H. satomiae is known for its body texture and colouration, which closely resemble the sponges they inhabit, providing excellent protection from predators.

Hippocampus denise

Known as Denise’s Pygmy Seahorse, this species is even smaller than H. bargibanti, with a length of about 1.5cm. They are typically found in smaller sponges or coral reefs, often with vibrant colours like pink or orange. Found at depths between 10 and 50 meters, they have a slim, textured body, giving them a distinct appearance compared to other seahorses.

Pygmy-Seahorses-Hippocampus-denise

Denise’s Pygmy Seahorse (Hippocampus denise)

Hippocampus colemani

Found in the waters around Australia and Papua New Guinea, H. colemani is a slightly larger and fatter pygmy seahorse species. With lighter colours, they often hide in contrastively coloured sponges or corals. These seahorses prefer deeper waters, usually between 30 to 40 meters in depth.

Hippocampus pontohi

One of the smallest pygmy seahorses, H. pontohi has a body length of just 1cm. They are typically found hiding in brightly coloured sponges, particularly pink ones. Their exceptional camouflage makes them incredibly difficult to spot, even in areas frequented by divers.

Also, Hippocampus severnsi known as Severn’s seahorse is a small, rare species found in the Indo-Pacific region. Known for its distinctive appearance, it typically inhabits shallow coral reefs and seagrass beds. Like other seahorses, it feeds on small invertebrates. The H. severnsi was considered a separate species but is now recognised as a variation of the Pontohi.

Hippocampus-severnsi

Severn’s Pygmy Seahorse (Hippocampus severnsi)

The Importance of Pygmy Seahorses

Pygmy seahorses are fascinating not only for their size and camouflage but also for their role in coral reef health. All species rely on coral reefs and the shelter provided by sponges and other marine structures. Their small size and sensitivity to environmental changes make them important indicators of reef conditions.

As pygmy seahorses depend on healthy, undisturbed reefs, their presence or absence signals the reef’s overall health. With coral reefs threatened by acidification, habitat destruction, and climate change, protecting pygmy seahorse habitats is crucial for maintaining marine biodiversity. In short, pygmy seahorses are not only marvels of nature but also vital to the conservation of coral reefs and the broader marine ecosystem.

Manta Rays

Manta Rays: Their Life Cycle and Why They are Vulnerable

by Fahmi, AMD-B’s 2024 Divemaster Intern

Manta rays have a unique but slow reproductive process. Female manta rays give birth to live pups after a pregnancy lasting about a year. What makes them vulnerable is that they typically produce only one pup at a time and may take two to five years before reproducing again. Once born, the pup is left to survive on its own and spends nearly a decade growing and maturing. This slow reproduction rate means manta populations struggle to recover when their numbers are reduced.

Manta rays are highly migratory creatures, travelling vast distances in search of food and suitable habitats. While this behaviour is essential for their survival, it increases their exposure to various threats. Overfishing, entanglement in fishing gear, and habitat destruction—such as the loss of coral reefs that serve as feeding or cleaning stations—pose significant risks. Climate change and pollution also impact the plankton populations that mantas depend on for food, making their survival even more challenging.

Manta-Rays-Life

Why Manta Rays Matter

Although manta rays do not have a massive ecological role compared to species like sharks or corals, they contribute to marine tourism in a significant way. Destinations like Nusa Penida and Raja Ampat attract divers and snorkellers eager to witness these majestic animals. The revenue from manta ray tourism supports local economies and often funds conservation projects, creating a positive cycle of benefits for both humans and the environment.

Manta-Rays-Matter

The Importance of Protecting Manta Rays

Manta rays are not just symbols of marine biodiversity; they are also indicators of ocean health. Their vulnerability reminds us of the delicate balance in marine ecosystems. Protecting manta rays is not only about saving a species—it’s about safeguarding the health of our oceans, promoting sustainable tourism, and respecting the interconnectedness of life underwater.

Protecting-Manta-Rays

Nudibranchs

Nudibranch

When it comes to shapes and colours, the variations found in nudibranchs never ceases to impress underwater photographers – and the rest of us!

There are over 3,000 species of nudibranchs worldwide, with new ones being identified regularly. These fascinating creatures are hermaphrodites, meaning they can mate with any individual of their species. Another intriguing fact is that nudibranchs are carnivorous, with diets that go beyond corals, algae, anemones, and sponges—they may even consume other nudibranchs.

Nudibranchs in Indonesia

To help you get started, here are five fantastic nudibranchs to look out for in Indonesia:

Nudi-Hypselodoris-Bullocki

Hypselodoris bullocki – This species, found in Bali, Lembeh, Triton Bay, Wakatobi, and Ambon, is famous for its lavender hue and dark spots. It’s a beautiful find for those who appreciate subtle but striking patterns.

Nudi-Chromodoris-Magnifica

Chromodoris magnifica – As its name suggests, Chromodoris magnifica truly stands out. You can find this bold nudibranch in places like Raja Ampat, Ambon, Halmahera, Lembeh, and Bali. Its eye-catching combination of orange, white, and black makes it a favorite for underwater photographers.

Nudi-Nembrotha-Kubaryana

Nembrotha kubaryana – Known for its dramatic blend of black, green, and orange, Nembrotha kubaryana is another species divers love to spot in Wakatobi, Bali, Lembeh, Raja Ampat, and Alor.

Nudibranch-Doto-Greenamyori

Doto greenamyori – This unique species has earned the nickname “Doughnut Doto” because of its shape. Doto greenamyori can be found in Tulamben, Wakatobi, and Misool, often hiding among hydroids and other small organisms.

Nudi-Thecacera-Pacifica

Thecacera pacifica – With its bright yellow color and black markings, this nudibranch resembles the famous character Pikachu! You can find it in Bali, Triton Bay, and Alor.

Please note: The above are the areas which offer a high chance of seeing these particular nudis. This being Indonesia, you can find the most unexpected species far outside their known range, for example:
– While diving with AMD-B, Dr Richard Smith (Ocean Realm Images) found displaying male McCosker’s flasher wrasses 2,500km east of their previously recorded range
– Okenia liklik nudis in Tulamben Bay, Bali (previously only recorded in Papua New Guinea and Luzon).

There are many other super-rare nudis that are scattered throughout the ocean so, who knows, maybe YOU will be lucky enough to find a new species and contribute to naming it 🙂