Parasite infections (Trematoda, Digenea) of Sagitta friderici (Chaetognatha) from the southwestern Atlantic Ocean: prevalence and distribution

Diseases of Aquatic Organisms

Alicia A. Gil de Pertierra Mónica A. Palmieri Margarita Ostrowski de Núñez¹  María C. Daponte¹ 

关键词: Chaetognaths;    Derogenes sp.;    Ectenurus sp.;    Monascus filiformis;    Lepocreadiidae;    Argentine Sea;    Zooplankton;   

DOI  :  10.3354/dao071225

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The following chaetognaths were found in the Atlantic Ocean between 34 to 40°S and 52°20’ to 62°00’W: Sagitta friderici, S. tasmanica, S. minima, S. gazellae, and S. enflata (in order of abundance). Of these, only S. friderici was parasitised by unencysted metacercariae of the families Derogenidae (Derogenes sp.), Hemiuridae (Ectenurus sp.) and Fellodistomidae (Monascus filiformis), and encysted metacercariae of Lepocreadiidae. The percentage of infection for each sampling station varied from 0.033 to 0.001 in August and from 0.02 to 0.001 in October 1996, with the highest values occurring at stations closer to the coast. The intensity of infection (worms per host) varied from 1 to 3 for Ectenurus sp. and was 1 for Derogenes sp., Monascus filiformis and Lepocreadiidae. Unencysted metacercariae were found in mature developmental stages of chaetognaths, whereas encysted ones occurred mainly in juveniles. The size and length of the ovaries of parasitised and unparasitised chaetognaths did not differ significantly. This is the first report of encysted Lepocreadiidae metacercariae and a progenetic metacercaria of Ectenurus sp. in Chaetognatha from the SW Atlantic Ocean.

【 授权许可】

Unknown