Trematode metacercariae of fishes as sentinels for a changing limnological environment

Diseases of Aquatic Organisms

I. Paperna¹  A. Diamant¹  R. Dzikowski¹ 

关键词: Bioindicators;    Fishes;    Cichlidae;    Trematode;    Metacercariae;    Lake Kinneret;    Species richness;    Diversity indices;   

DOI  :  10.3354/dao055145

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Trematode metacercaria populations infecting cichlids in Lake Kinneret (Sea of Galilee) were used as sentinels for the changing limnological environment. Parasitological data from 0+ cichlid fingerlings (Tilapia zillii, Oreochromis aureus,Sarotherodon galilaeus) were collected from the northwest shore of the lake during 1999 to 2001 and compared with data obtained from 1982 to 1984. The results show that the composition of the metacercarial populations changed significantly between the2 samplings periods. The total number of metacercarial species found in the Kinneret cichlids was lower in 1999 to 2001 than in 1982 to 1984. Metacercariae transmitted by the snail Bulinus truncatus (Clinostomum tilapiae, Euclinostomumheterostomum, Bolbophorus levantinus and Neascus-type metacercariae‹black spot and others) that were commonly found in 1982 to 1984 were absent from the fishes sampled during 1999 to 2001. The other trematode metacercariae (Centrocestussp. and Haplorchis sp. transmitted by Melanoides tuberculata, Pygidiopsis genata transmitted by Melanopsis costata, as well as Phagicola longa, Strigeidae sp.1, an unidentified metacercaria typically found in the liver,and glochidia) increased in abundance in fishes sampled during 1999 to 2001. The calculated Œtrue¹ species richness of the habitat, extrapolated as a function of sampling effort, was significantly lower in the 1999 to 2001 versus 1982 to 1984 samples,while significantly fewer fishes needed to be sampled (Œsampling effort¹) during 1999 to 2001 in order to reach the Œtrue¹ species richness. The higher calculated values of species richness and diversity for the 1999 to 2001 samples despite the overalldecline in species number is explained by the overall increase in metacercariae prevalence.

【 授权许可】

Unknown