Ceratomyxa sparusaurati, n.sp. (Myxosporea: Bivalvulida), a new parasite from cultured gilthead seabream (Sparus aurata L.) (Teleostei: Sparidae): Light and electron microscopic description

Abstract

A new Myxosporea, Ceratomyxa sparusaurati n. sp., was found in the gall bladder and bile of cultured gilthead sea bream (Sparus aurata L.) from different Spanish fish farms. It is clearly different from all the previously reported Ceratomyxa from sparids, and it is distinguished from other members of the genus by the shape and size of the spores. Prevalence of infection was 2.15% in an Atlantic farm, 48.7% in a Mediterranean farm and 28.6% in the facilities of the Instituto de Acuicultura de Torre de la Sal. The cell-in-a-cell pattern was found through all the sporogenesis and the general ultrastructure resembled other Myxosporea. Primary cells with two developing spores, harbored other secondary cells. Disporous sporoblasts contained numerous membrane-bound inclusions, a few lipid droplets and polysaccharides as evidenced by cytochemistry. In mature spores, binucleate sporoplasmic cells contained abundant Thièry-negative sporoplasmosomes.