SURVEY OF HELMINTHS IN CLIMBING PERCH (ANABAS TESTUDINEUS) FROM SAN SAI DISTRICT, CHIANG MAI PROVINCE

Abstract

Abstract. A helminthological study of Anabas testudineus was conducted. Fifty fish were collected from natural water resources in San Sai District, Chiang Mai Province, between July and September 2003. Seven species of helminths were recovered, as follows; one Monogenea species, Trianchoratus sp, was recovered at gill filaments, with a prevalence of 32%. In the intestine, the adult stage Acanthocephala, nematodes, and trematodes were found: Pallisentis sp (22%), Camallanus sp (11%), and Allocreadium sp (2%), respectively. Moreover, metacercarial stages of three species: Stellantchasmus falcatus (88%), Acanthostomum sp (78%), and Centrocestus caninus (70%), were examined in the body portion of the fish (gills, fins, scales, head, and muscles). Two species of metacercarial stage, Centrocestus caninus and Stellantchasmus falcatus, are helminths that can infect humans. plates, and then examined under a compound microscope. The intestine was dissected by needles and the presence of worms was determined using a stereomicroscope. The head and muscles were chopped and digested with crude extract solution of pineapple in a blender. Sequentially, the mixture was transferred into Erlenmeyer flasks, then incubated in a shaking water bath at 37˚C for 2 hours. The metacercariae were isolated using graded sieves and then rinsed with 0.85% sodium chloride solution. The encysted metacercariae were studied and identified with excysted metacercariae under a compound microscope. All of the worms were fixed in 5% formalin, stained with hematoxylin or borax carmine, dehydrated in alcohol series, and mounted with permount. Species identification was carried out by morphological examination, as described by RESULTS Out of 50 climbing perch (Anabas testudineus) collected from natural water sources in San Sai District, 49 were infected with 7 species of helminths. The species with the highest infection rate was Stellantchasmus falcatus (88%) while Acanthostomum sp, Centrocestus caninus, Camallanus sp, Trianchoratus sp, and Pallisentis sp were present in 78, 70, 66, 32, and 22%, respectively. The species with the lowest infection rate was Allocreadium sp (2%), as shown in The result revealed that S. falcatus showed the highest mean intensity, at 59.64 (2,982/50), while Acanthostomum sp and C. caninus were 41 (2,092/50) and 40.82 (2,041/50), respectively. In contrast, the adult stage of the trematode, Allocreadium sp, wa