Early development and life cycle of Contracaecum multipapillatum s.l. from a brown pelican Pelecanus occidentalis in the Gulf of California, Mexico

Diseases of Aquatic Organisms

Isabel Valles-Vega¹ 

关键词: Contracaecum multipapillatum;    Nematoda;    Anisakidae;    Fish parasite;    Genetic identification;    Development;    Aquatic life cycle;    Mullet;    Brown pelican;    Gulf of California;   

DOI  :  10.3354/dao03147

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The initial developmental stages of Contracaecum multipapillatum (von Drasche, 1882) Lucker, 1941 sensu lato were studied using eggs obtained from the uteri of female nematodes (genetically identified) found in a brown pelican Pelecanus occidentalis from Bahía de La Paz (Gulf of California, Mexico). Optical microscopy revealed a smooth or slightly rough surface to the eggs. Egg dimensions were approximately 53 × 43 µm, although after the larvae had developed inside, egg size increased to 66 × 55 µm. Hatching and survival of the larvae were greater at 15°C than at 24°C, and increased salinity resulted in a slight increase in hatching but seemed to reduce survival at 24°C, but not at 15°C. The recently hatched larvae measured 261 × 16 µm within their sheath. When placed in culture medium, the larvae grew within their sheath, and a small percentage (~2%) exsheathed completely (314 × 19 µm). The larvae continued to grow and develop once they had exsheathed, attaining mean dimensions of 333 × 22 µm. Although they did not moult during culture, optical microscopy revealed a morphology typical of third-stage larvae. Finally, the genetic identity between the larval parasites collected from mullet Mugil curema and adult female parasites collected from the brown pelican suggests a life cycle of C. multipapillatum in which the mullet are involved as intermediate/paratenic hosts and the brown pelicans as final hosts in the geographical area of Bahía de La Paz.

【 授权许可】

Unknown