SCOTLAND: The Big Picture / Maiden's salp (Thetys vagina) , west coast of Scotland, UK, July.

Juergen Freund / Salp (Salpidae) colony with diver in the background, North Sulawesi, Indonesia.

David Fleetham / Pelagic tunicate or salp (Salpa aspera) Hawaii.

Doug Perrine / Rover fish (Emmelichthyidae) juvenile sheltering inside a colonial salp at night in surface waters of deep ocean off Kailua Kona, Hawaii, USA.

SCOTLAND: The Big Picture / Amphipods (Amphipoda) living on a salp (Salpidae), Scotland, UK, July.

Tim Laman / Salp (Salpidae) floating on the currents of Cebu island, Philippines.

Richard Herrmann / Salp (Salpidae), San Diego, California

Richard Herrmann / Salp (Cyclosalpa affinis), Nine Mile Bank, San Diego, California

David Shale / Salp chain {Salpidae} Mid-Atlantic Ridge, North Atlantic Ocean

David Shale / Salp chain {Salpidae} Mid-Atlantic Ridge, North Atlantic Ocean

Richard Herrmann / Salp (Pegea sp) chain floating in open sea, San Diego, California

Richard Herrmann / Salp (Pegea sp) chain floating in open sea, San Diego, California

Richard Herrmann / Salp (Pegea sp) chain floating in open sea, San Diego, California

Richard Herrmann / Salp (Pyrosoma sp), San Diego, California

Juergen Freund / Colonial salp {Salpidae}, barrel-shaped, free-floating tunicates, Indo-pacific

Mike Parry / Salema (Salpa sp) portrait underwater, Hawaii

Hiroya Minakuchi / Salp (Salpa thompsoni), planktonic tunicate, Antarctica

Alex Mustard / A small fish, probably a Driftfish (Nomeidae), sheltering inside a Salp (Salpa sp.) in open water as part of the plankton, Bitung, North Sulawesi, Indonesia, Lembeh Strait.

David Fleetham / Pelagic tunicate (Salpa aspera) floating in the open ocean at night, Yap, Micronesia, Pacific Ocean.

Franco Banfi / Salps (Salpidae) drifting in the open ocean, Antarctic Peninsula, Antarctica, Southern Ocean.

Franco Banfi / Salps (Salpidae) drifting over the seabed, Antarctic Peninsula, Antarctica, Southern Ocean.

David Fleetham / Pelagic tunicate / Salp (Salpa aspera) close up at night, Yap, Micronesia, Pacific Ocean.

Doug Perrine / Colonial salp chain (Salpidae), with tiny (about 1cm) Cephalopod sheltering inside one of the blastozooids, probably a male or immature female Argonaut / Paper nautilus (Argonauta sp.), drifting in su...

Magnus Lundgren / Colony of common salps (Salpa fusiformis) Balayan Bay, off Anilao, Batangas, Philippines, Pacific Ocean

Magnus Lundgren / Colony of common salps (Salpa fusiformis) Balayan Bay, off Anilao, Batangas, Philippines, Pacific Ocean

Magnus Lundgren / Common salp (Salpa fusiformis) with parasites such as sea lice and others, Balayan Bay, off Anilao, Batangas, Philippines, Pacific Ocean

Magnus Lundgren / Tiny shrimp sitting in a colony of common salp, (Salpa fusiformis), the most widespread species of salp, Balayan Bay, off Anilao, Batangas, Philippines, Pacific Ocean.

Magnus Lundgren / Young fish inside a drifting salp, photographed at night, Balayan Bay, Luzon, Philippines. Magnus