Alex Mustard / Thorny seahorse (Hippocampus histrix) gripping onto a sponge. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Shane Gross / Portrait of a Thorny seahorse (Hippocampus histrix) near Malapascua, Philippines.

Shane Gross / Thorny or spiny seahorse (Hippocampus histrix) portrait made off Anilao, Philippines.

Alex Mustard / Hedgehog seahorse (Hippocampus spinosissimus) female moves over a sandy seabed. Dauin, Negros Island, Philippines. Bohol Sea, tropical west Pacific Ocean.

Jeff Rotman / Thorny Sea Horses (Hippocampus histrix) on Alcyonarian coral (Dendronephthya sp.). Israel, Red Sea.

Georgette Douwma / Thorny seahorse (Hippocamus histrix). Lembeh Strait, North Sulawesi, Indonesia.

Pascal Kobeh / Thorny seahorses (Hippocampus histrix) in coral, Sulu Sea, Philippines.

Pascal Kobeh / Thorny seahorses (Hippocampus histrix) tails coiled round coral, Sulu Sea, Philippines.

Franco Banfi / Thorny / Spiny seahorse (Hippocampus histrix) portrait, Dumaguete, East Negros Island, Central Visayas, Philippines, Pacific Ocean.

Franco Banfi / Thorny / Spiny seahorse (Hippocampus histrix) portrait, Dumaguete, East Negros Island, Central Visayas, Philippines, Pacific Ocean.

Constantinos Petrinos / Longspine seahorse (Hippocampus histrix) with its tail wrapped around a sponge. Lembeh Strait, North Sulawesi, Indonesia.

Constantinos Petrinos / Longspine seahorse (Hippocampus histrix) Lembeh Strait, North Sulawesi, Indonesia.