Developmental stages of the diplozoid monogenean Eudiplozoon nipponicum, comprising oncomiracidium, diporpa, juvenile, and adult, were investigated using light and scanning electron microscopy in conjunction with confocal scanning laser microscopy in order to examine body organization and identify explicit morphological adaptations to the ectoparasitic life in each stage. The parasite exhibits a complex digestive tract well equipped for hematophagous feeding. It consists of a mouth opening with prominent buccal suckers, eversible pharynx with adjacent glandular structures, and a blind-ending gut with cecal lining. Glandulo-muscular organs, located apically and opened into the mouth corner, are considered to be a part of the digestive tract. Based on our observations of pharynx eversion and in light of the presence of several glandular or gland-like structures, we propose a new hypothesis on the possibility of extracorporeal digestion of this parasite. The hindbody bears an attachment apparatus, comprising haptor, lobular extensions, and tegumental folds, responsible for the parasite's firm attachment to the host gills. The possibility of buccal suckers assisting in the parasite's translocation while searching for an optimal niche or their temporary attachment function during feeding is discussed. The body of each compound adult (i.e., permanent copula) is almost completely filled by two complete reproductive tracts comprising the female as well as male organs. Such a reproductive strategy, in which two independent heterogenic individuals fuse into a single hermaphrodite organism without the need to search for mating partner, represents a high specialization of diplozoids to their parasitic life.

Department of Botany and Zoology Faculty of Science Masaryk University Kotlářská 2 611 37 Brno Czech Republic

Zobrazit více v PubMed

Parasitol Int. 2007 Sep;56(3):179-83 PubMed

Parasitology. 2003 Apr;126(Pt 4):349-57 PubMed

Parasitology. 1960 May;50:51-60 PubMed

J Parasitol. 2003 Feb;89(1):198-200 PubMed

Int J Parasitol. 2001 Jun;31(8):783-92 PubMed

Parasitology. 1966 Feb;56(1):63-100 PubMed

J Parasitol. 2004 Aug;90(4):817-22 PubMed

J Ultrastruct Res. 1985 Jul-Aug;92(1-2):47-54 PubMed

An insight into the functional genomics and species classification of Eudiplozoon nipponicum (Monogenea, Diplozoidae), a haematophagous parasite of the common carp Cyprinus carpio

Eudiplozoon nipponicum: morphofunctional adaptations of diplozoid monogeneans for confronting their host

Eudiplozoon nipponicum (Monogenea, Diplozoidae) and its adaptation to haematophagy as revealed by transcriptome and secretome profiling

Identification and partial characterization of a novel serpin from Eudiplozoon nipponicum (Monogenea, Polyopisthocotylea)

Cysteine peptidases of Eudiplozoon nipponicum: a broad repertoire of structurally assorted cathepsins L in contrast to the scarcity of cathepsins B in an invasive species of haematophagous monogenean of common carp

Architecture of Paradiplozoon homoion: A diplozoid monogenean exhibiting highly-developed equipment for ectoparasitism

A novel type I cystatin of parasite origin with atypical legumain-binding domain

An ultrastructural study of the surface and attachment structures of Paradiplozoon homoion (Bychowsky & Nagibina, 1959) (Monogenea: Diplozoidae)

Ultrastructure of the digestive tract of Paradiplozoon homoion (Monogenea)