Marine Leech Infestations - Fish Diseases Caused by Parasites

Marine Leech Infestations

Marine leeches have striated bodies with muscular body wall, with anterior and posterior suckers, usually 8-12 mm long.

CAUSATIVE AGENT:

Zeylanicobdella arugamensis (Fig. 5-16a)

SPECIES AFFECTED:

Grouper, milkfish, tilapia

GROSS SIGNS:

Parasite attaches to the skin, fins (Fig. 5-16b), eyes, nostrils, operculum and inside the mouth. The attachment and feeding sites are hemorrhagic.

EFFECTS ON HOST:

The attachment areas are hemorrhagic. The parasite feeds on the host’s blood and may result to anemia. Leeches act as vectors of viruses, bacteria and protozoan blood parasites.

DIAGNOSIS:

Gross examination of the host fish.

PREVENTION AND CONTROL:

•      Use of filters

•      Mechanical removal

•      Complete drying of facilities

•      50-100 ppm formalin bath for 1 h