Bacteria were isolated from the diseased eggs of two damselfish (Pomacentridae) species, Amphiprion clarkii and Amblyglyphidodon curacao. Healthy A. clarkii eggs were infected separately with four bacterial isolates from the diseased eggs, as well as with Vibrio parahaemolyticus and Listonella anguillarum. Amphiprion clarkii eggs exposed to Cura‐d, an isolate from diseased A. curacao eggs, showed increased mortality compared to uninfected control eggs. The A. curacao eggs were infected separately with the same two isolates from diseased A. curacao eggs, and similarly, eggs exposed to isolate Cura‐d also showed increased mortality compared to uninfected eggs. However, the increase in mortality associated with exposure to isolate Cura‐d was most significant in A. clarkii eggs. A 16S rDNA comparative sequence analysis identified that isolate Cura‐d was most similar to Pseudoalteromonas piscicida, a known fish pathogen. Both Cura‐d and P. piscicida were found to be polarly flagellated, Gram‐negative rods with an oxidative metabolism which grew on d‐mannose, d‐fructose, sucrose and maltose, but not on l‐threonine. Based on these properties, it is proposed that Cura‐d should be classified as P. piscicida strain Cura‐d. It is concluded that the P. piscicida strain cura‐d was associated with the increased mortality observed in A. clarkii eggs.