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

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.

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.

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