DSV Alvin
Scientists in the submersible DSV Alvin at a depth of 3,088 metres at the Alaskan continental margin in the Gulf of Alaska collected a spatangoid urchin, "Cystochinus loveni", about 5 cm diameter, which was wearing a cloak consisting of over 1,000 protists and other creatures, including 245 living xenophyophores, mainly "Psammina" species, each 3–6 mm. The fragility of the xenophyophores suggests that the urchin either very carefully collected them, or that they settled and grew there. Among several possible explanations for the urchin's behaviour, perhaps the most likely are chemical camouflage and weighing itself down to avoid being moved in currents.