Parasitologia En Peces

Report about fish parasitic diseases
P. Alvárez-Pellitero CSIC (Consejo Superior de Investigaciones Científicas) Instituto de Acuicultura Torre de la Sal Ribera de Cabanes, 12595 Castellón, Spain

About diagnostic laboratories for parasitic diseases in the region
Most laboratories participating in the survey (48 out 54) from 13 Mediterranean countries stated that they perform diagnosis offish parasitic diseases. Of the 48 laboratories that declared to work on the diagnosis of fish parasitic diseases, 41 stated that they worked with seabream and seabass and 32 with trout. Other species they worked with were eels (13), carps (12), turbot (9) and salmon (9). Many (31 laboratories) stated to also work with other fish species, such as tilapia, mullets, other sparids (Dentex dentex,Puntazzo puntazzo, etc.) and other marine species. This is coherent with available fish production information for the region, and as is the case for the diagnosis of viral and bacterial diseases, most diagnosis is performed on finfish species produced intensively in Mediterranean countries. The different techniques available in the laboratories performing diagnosis of fish parasitic diseases (Table 1)show that most laboratories based their diagnosis partly or totally on simple techniques, such as observation of clinical signs, macroscopical examination of fish and examination of fresh samples (wet mounts, smears). Less laboratories (26 out 48) can perform histopathology studies, and even less (15 or 16) can perform more specialised techniques such as PCR or immunohistochemistry. Table 1.Available techniques in the laboratories performing diagnosis of fish parasitic diseases Diagnostic methods Clinical signs Microscopical examination of fresh samples Macroscopical examination Histopathology Haematological examination Fluorescent antibody technique PCR Immunohistochemistry Transmission electron microscopy DNA probes Available 48 47 46 30 26 15 16 15 9 4

The above mentioned capability(available techniques) explains why, as indicated below, for most parasitic diseases the diagnosis is just based on simple techniques (clinical signs, macroscopical examination, examination of fresh samples) and also histopathology. Thus, the possibility of overlooking or misidentification of some parasites cannot be discarded. Efforts should be done to improve the technical level of diagnosticlaboratories, in order to obtain more accurate diagnosis and the detection of asymptomatic carriers.

Main reported parasites and diseases
A summary about the incidence (based on answers received) of the different parasites and

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diseases found in the laboratories participating in the survey is presented in Table 2. There were reports of about 35 different parasitic diseases, which issignificantly higher than reports stated for fish viral diseases (9) and fish bacterial diseases (15). Table 2. Overview of the fish parasitic diseases covered in the survey
Disease AMOEBOZOANS Amebiasis Diagnosed by 6 laboratories from 2 countries (Spain and Greece) from marine fish (turbot, seabass, seabream and salmon) in routine studies and in occasional examinations, sometimes in fishsuffering mortalities. Diagnosed in 8 laboratories from 7 countries in seabass and seabream, with mortalities frequently reported in juvenile fish. Status based on survey

DINOFLAGELLATES Amyloodiniosis FLAGELLATES Ectoparasitic flagellates Costiasis One of the parasites most frequently reported, in 13 laboratories and 8 countries in different freshwater and marine fish species. Found in routineexaminations and with mortalities in hatcheries. Some cases were stated in 3 laboratories from 3 countries, mainly in marine fish. Only reported by 1 laboratory (Croatia) in different freshwater fish. Diagnosed only in 2 laboratories of 2 countries (Croatia and Spain) in salmonid, cyprinids, Scardinius and exotic fish. Stated by 6 laboratories in 4 countries (Croatia, France, Greece, and Spain) in...