Evaluation of Neoergasilus japonicus (Ergasilidae) Occurrence on Rudd Scardinius erythrophthalmus Using Fuzzy Logic Approach

N. japonicus is a parasitic copepod from the family Ergasilidae (Copepoda, Poecilostomatoida) and is native to eastern Asia. N. japonicus has spread to many countries via different reasons. The fish host of this parasite in Lake Sapanca is S. erythrophthalmus. This study proposes a decision-support tool that uses a fuzzy-logic model of expert knowledge to assist in multi-criteria decision-making to forecast the existence of N. japonicus on fish according to the fish size and temperature of water by using MATLAB programming language to help the fishery industry to detect environments suitable for procreation of the parasite. The results produced by the software were compared with data obtained by parasitological examination of rudd, S. erythrophthalmus, from Lake Sapanca, Turkey. A total of 122 S. erythrophthalmus, including 64 males and 58 females with a mean length of 24.93 ± 3.65 cm (range: 15.2–34.0 cm), were examined. The findings indicated that although there are variations between examination results and those obtained from fuzzy software, the results are consistent with one another. According to the results, 20.49% of the fish were infected according to the data obtained from the lake. The proposed FLS system predicted that 27.87% would be infected. Hence fuzzy logic based algorithm make it possible to evaluate N. japonicus infectio