Alex Mustard / 2020VISION / Phosphorescent Seapen (Pennatula phosphorea) extends out of the muddy seabed in the calm waters of the upper reaches of a Scottish sea loch. Loch Duich, Ross and Cromarty, Scotland, UK, April

SCOTLAND: The Big Picture / Phosphorescent sea pen (Pennatula phosphorea) at night, taken with flash, Loch Duich, Scotland, UK, January.

SCOTLAND: The Big Picture / Phosphorescent sea pen (Pennatula phosphorea), Loch Duich, Highlands, Scotland, UK, January.

Alex Mustard / Pink-purple Phosphorescent seapen (Pennatula phosphorea) growing on a muddy seabed, Loch Linnhe, The Highlands, Scotland, UK.

Alex Mustard / Long-legged spider crab (Macropodia sp) climbs on a phosphorescent seapen (Pennatula phosphorea) grows on a muddy seabed. Glencoe, Ballachulish, Lochaber, The Highlands, Scotland, United Kingdom. Loch...

Alex Mustard / Common hermit crab (Pagurus bernhardus) scuttles past a phosphorescent seapen (Pennatula phosphorea) grows on a muddy seabed. Glencoe, Ballachulish, Lochaber, The Highlands, Scotland, United Kingdom....

Alex Mustard / Pink-purple phosphorescent seapen (Pennatula phosphorea) grows on a muddy seabed. Glencoe, Ballachulish, Lochaber, The Highlands, Scotland, United Kingdom. Loch Leven, Loch Linnhe, North East Atlantic...

Franco Banfi / Sea pen (Pennatula phosphorea) Puolo Bay, Punta Campanella Marine Protected Area, Costa Amalfitana, Italy, Tyrrhenian Sea, Mediterranean.