Marine sponges were collected by scuba divers working at
depths between 3 and 15 m from six different locations,
including temperate, subtropical and tropical regions (Table
1). The samples mainly belonged to the subclass Tetractinomorpha
and Ceractinomorpha (Demospongiae). Samples from
Australia, Dominica and Malta were frozen after collection
and stored at ®18 °C, samples from Tenerife were stored in
sterile sea water supplemented with 250 mg l−" of benzylpenicillin
and streptomycin sulphate (Merck) at 4° for 7 days
until examination, whereas samples from Helgoland were
processed immediately after collection.