DAO 45:131-139 (2001)  -  doi:10.3354/dao045131

Fitness of the marine parasitic nematode Anisakis simplex s.str. in temperate waters of the NE Atlantic

Elvira Abollo1, Stefano D¹Amelio2, Santiago Pascual1,*

1Área de Parasitología, Grupo PB2, Facultad de Ciencias, Universidad de Vigo, 36200 Vigo, Spain
2Institute of Parasitology, University of Rome ŒLa Sapienza¹, P. le Aldo Moro, 5, 00185 Rome, Italy
*Corresponding author: E-mail:

ABSTRACT: In temperate waters of the NE Atlantic, third-stage larvae of Anisakis simplex sensu stricto collected from 3 paratenic host species were identified by restriction fragment length polymorphisms. The condition of wild larval infrapopulations was assessed by examining morphometric and growth characteristics. The differentiation patterns and the excretory/secretory products of larvae grown in vitro were also examined. An extensive morphometric, growth and differentiation variability was found between parasite larvae collected from different paratenic host sources. Nematode infrapopulation larvae from the squid comprise those smaller individuals with the lowest values of survival rates and moult success. It may be then concluded that the fitness of A. simplex s.str. larvae is not the best possible in the squid, which impaired the competitiveness of the parasite and its chances of developing into an adult. This suggests that the microenvironments impaired by the paratenic host may provide larval infrapopulations with unique ecological factors probably influencing its recruitment to the final host populations.

KEY WORDS: Anisakis simplex s.str. · Fitness · Recruitment

Full text in pdf format