Fish diagnostic services available at SEAFDEC

Alarmed by the diseases decimating the shrimp and fish species in your fishponds?

Then seek the diagnostic services of the Southeast Asian Fisheries Development Center-Aquaculture Department (SEAFDEC AQD) in Tigbauan, Iloilo.

The Fish Health Section of SEAFDEC AQD is now accepting samples of shrimp larvae, juveniles and adults for detection of the destructive white spot syndrome virus (WSSV).

Similarly, samples of grouper (lapu-lapu), seabass (apahap), milkfish (bangus), red snapper (maya-maya) and other marine finfish are now accepted for detection of viral nervous necrosis (VNN) and iridovirus.

The WSSV, whose causative agent is a baculovirus, affects various stages of shrimp development (postlarva, juvenile, adult and broodstock or breeder).

Its manifestation include presence of white cuticular spots at the exoskeleton and epidermis of the shrimp, red discoloration, loose cuticle and reduction in food consumption. It has a high mortality rate of up to 100 percent in three to 10 days.

The VNN, with the causative agent nodavirus, affects a number of fishes such as grouper, seabass, red sea bream, sea bream, European bass, parrot fish, striped jack and others.

The gross signs include lethargy of larvae and juveniles, pale color, loss of appetite and equilibrium and corkscrew swimming. The disease can cause mortality rates of 50 to 95 percent.

The iridovirus, which affects groupers, can cause up to 60 percent mortality rates. Among the signs shown by an afflicted grouper are swimming in circles, anemia, loss of weight and lethargy.

The same type of disease also seriously damages stocks of several kinds of cultured marine fish such as yellowtail, seabass and Japanese parrotfish.