Article,
Occurrence of Anguillicola crassus (Nematoda: Dracunculoidea) in Japanese eels Anguilla japonica from a river and an aquaculture unit in SW Taiwan
Diseases of Aquatic Organisms, 71 (2): 101--8 (July 2006)
DOI: 16956057
Abstract
The infection by swimbladder nematodes of the
genus Anguillicola (Dracunculoidea:
Anguillicolidae) was examined in 2 populations of
the Japanese eel Anguilla japonica in SW
Taiwan. Wild eels from the Kao-Ping river were
compared with cultured eels from an adjacent
aquaculture unit. Only the cosmopolitan species
Anguillicola crassus was present. Among wild eels,
prevalence of infection varied between 21 and 62\%,
and mean intensity between 1.7 and 2.7 for adult
worms. Similar intensity values (1.3 to 2.8) were
recorded for the larvae. In cultured eels,
prevalence as well as mean intensities were
higher. In the cultured hosts, mean larval
intensities exceeded those of adult worms 2-fold,
and maximum larval intensities were 4- to 5-fold
higher than in eels from the river. In cultured
eels, dead larvae were also more abundant than in
wild eels. We conclude that infrapopulations of
A. crassus in Japanese eels are regulated by the
defense system of this host, intraspecific
density-dependent regulation being less likely as
the major regulatory mechanism. No influence of the
parasite on eel condition was found in either wild
or cultured eels, indicating a low or moderate
pathogenic effect of A. crassus on this host. This
study shows that A. crassus is moderately common in
cultured and wild Japanese eels in Taiwan, where the
parasite is endemic.
Tags
- air
- {diseases,fisheries,larva,male,prevalence,rivers,seasons,spirurida}
- {infections,taiwan}
- {sacs,anguilla,animals,animals,}
- {size,dracunculoidea,female,fish}
- {wild,body}
