A survey of the parasites of milkfish (Chanos chanos (Forskal)) in the Philippines

• Main Author: Regidor, Simeona Eugenio
• Format: text
• Language: English
• Published: Animo Repository 1989
• Subjects: Milkfish > Parasites
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/1240
• Institution: De La Salle University

A survey of the protozoan and metazoan parasites of milkfish (Chanos chanos (Forskal)) in the Philippines was conducted during May 1986 to January 1988. From the examination of 30 fry, 300 juveniles, 37 sub-adults and 12 adults, 19 different species of parasites were recovered. These include eight Protozoa (Ceratomyxa sp. Cryptobia branchiales Nie in Chen, 1955 Leptotheca sp. Scyphydia sp. Trichodina n. sp. Trichodina sp. Tripartiella n. sp. and Vorticella sp.), six Digenea (Heterophyopsis expectans (Africa and Garcia, 1935) Tubangui and Africa, 1938 metacercaria Isorchis parvus Durio and Manter, 1969 Pseudobunocotyla awa Yamaguti, 1965 Transversotrema laruei Velasquez, 1958 Digenea gen. sp. adult and Digenea gen. spp. metacercaria) one Nematoda (Nematoda gen. sp. larva) one Acanthocephala (Cavisoma magnus (Southwell, 1927) Van Cleave, 1931) one Cestoda (Scolex polymorphus O. F. Muller, 1788 plerocercoid) one Copepoda (Caliqus epidemicus Hewitt, 1971) and one Isopoda (Gnathiidae gen. sp.).Krusadaitrema chanosi Zhukov, 1972 is considered a synonym of Isorchis parvus. A redescription of Cavisoma magnus is included, and two new species of trichodinids are described. Seven of the species identified have not been previously reported from the Philippines (Ceratomyxa sp., Trichodina n. sp., Tripartiella n. sp., I. parvus, P. awa, C. magnus, and S. polymorphus), two species are new to science (Tripartiella n. sp. and Trichodina n. sp.), and three are new reports for Chanos chanos (H. expectans, S. polymorphus, and C. magnus). A comprehensive list of parasites infecting milkfish from the various collection localities including their prevalences and intensities of infection is included. The changes in the parasite fauna of milkfish from fry to marketable size were analyzed. Among the parasites recovered only four showed significant heterogeneity among collections (Trichodina spp., T. laruei, Digenea gen. sp. metacercaria and C. epidemicus). However, of these only one species, T. laruei, showed significant correlation of parasite counts with increased host age.