In the current study, a total of 102 common Todarodes pacificus squid caught in the East Sea were investigated for parasitological research. The results revealed that 33 (32.35%) out of 102 squid were infected by Nybelinia surmenicola, the mean intensity was 5.58 parasites per squid, and the maximum abundance was 11. Morphological analysis using a field emission scanning electron microscope showed the characteristic features of N. surmenicola. Molecular identification based on the 28S rRNA gene confirmed the isolated parasite as N. surmenicola, while phylogenetic analysis revealed that N. surmenicola isolated in this study was clustered with N. surmenicola isolated from Japan. This is the first report of phylogenetic characterization of N. surmenicola isolated from Korea.

Colletotrichum acutatum J. H. Simmonds is an important fungal pathogen that causes anthracnose disease in crops. In this study, 59 C. acutatum isolates from regions in South Korea were collected and phenotypically compared. The average colony diameters of isolates from Gyeongsangbuk-do, Chungcheongbuk-do, and Gangwon-do were 4.36 cm, 4.24 cm, and 4.38 cm, respectively, following 6 days of growth on V8 juice agar. The average conidium concentrations of the isolates from each province were 14.43, 12.83, and 10.17 × 104/mL after 7 days of growth on V8A. Amplified fragment length polymorphism(AFLP) analysis using three primer pairs identified 5 polymorphic bands and 56 monomorphic bands. Two polymorphic bands were identified using the E-ACC/M-CTT primer pair, one polymorphic band was identified using the E-ACG/M-CTG primer pair, and two polymorphic bands were identified using the E-ACG/M-CTT primer pair. A dendrogram was constructed using the AFLP data, and four clusters were identified.

The squid Todarodes pacificus is a commercially important fishery species in East Asia. As East Asians consume raw or lightly cooked squids, there has been growing concern about parasitic infections associated with squid consumption. In the current study, five squids caught in the East Sea were sampled for parasitological research from the biggest fishery market in Seoul, Republic of Korea. They were dissected and examined for parasites using a light microscope. Proteocephalus sp. was isolated and identified using field emission scanning electron microscopy, PCR, and sequencing. Given that Proteocephalus spp. can be affected by water temperature and geographical characteristics, further research on Proteocephalus spp. with respect to changes in water temperature in the East Sea is important.