In addition to the metabolites previously reported, a new natural product 2,5,6-tribromo-N-methylindole-3-carbaldehyde [1] has been isolated from the marine bryozoan Zoobotryon verticillatum collected in two different locations of the Spanish coast. Its structure was elucidated by interpretations of spectral data and chemical interconversions. Compound 1 delays the metamorphosis in fertilized sea urchin eggs at low concentrations.