External & Internal Signs

Asian Sea Bass that died of streptococcus iniae

Golden snapper - Strepococcus iniae


Visible effects of sea lice on host fish may vary by location and severity. Damage to the host fish is caused by the feeding activity of sea lice. Chalimus stages cause only mild, localized damage although even this may have adverse effects on fish health.

The most damaging stage of L. salmonis tends to be the pre-adults, particularly as these concentrate on the head region which has no protective scales and is therefore more susceptible to damage Although adult female L. salmonis are the largest stage and can cause more damage, once they become gravid the majority tend to move to a position behind the dorsal and anal fins where damage is less severe and not so detrimental to the fish.

Disease reprinted courtesy of OIE Diagnostic Manual for Aquatic Animal Diseases, OIE (World Organisation for Animal Health), Paris, France.