Collyricloides massanae (Digenea, Collyriclidae): spermatozoon ultrastructure and phylogenetic importance.

Abdoulaye Jacque Bakhoum,Yann Quilichini,Carlos Feliu,Cheikh Tidiane Bâ,Jordi Miquel,Bernard Marchand

doi:10.1051/parasite/2014061

Abstract

The spermatological characteristics of Collyricloides massanae (Digenea: Collyriclidae), a parasite of Apodemus sylvaticus caught in France, were studied by means of transmission electron microscopy. The mature sperm of C. massanae presents two axonemes of different lengths with the 9 + “1” pattern of the Trepaxonemata, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies, one mitochondrion, a nucleus and granules of glycogen. An analysis of spermatological organisation emphasised some differences between the mature spermatozoon of C. massanae and those reported in the Gorgoderoidea species studied to date, specially belonging to the families Dicrocoeliidae, Paragonimidae and Troglotrematidae. The ultrastructural criteria described in C. massanae such as the morphology of both anterior and posterior spermatozoon extremities, the association “external ornamentation + cortical microtubules”, the type 2 of external ornamentation and the spine-like bodies would allow us to bring closer the Collyriclidae to Microphalloidea. However, further ultrastructural and molecular studies are needed particularly in the unexplored taxa in order to fully resolve the phylogenetic position of the Collyriclidae.

Highlights

The Collyriclidae Ward, 1917 is a small family with two genera and two species namely Collyriclum faba (Bremser in Schmalz, 1831) and Collyricloides massanae (Vaucher, 1969) [56]
An analysis of spermatological organisation emphasised some differences between the mature spermatozoon of C. massanae and those reported in the Gorgoderoidea species studied to date, specially belonging to the families Dicrocoeliidae, Paragonimidae and Troglotrematidae
The ultrastructural criteria described in C. massanae such as the morphology of both anterior and posterior spermatozoon extremities, the association ‘‘external ornamentation + cortical microtubules’’, the type 2 of external ornamentation and the spine-like bodies would allow us to bring closer the Collyriclidae to Microphalloidea

Summary

Introduction

The Collyriclidae Ward, 1917 is a small family with two genera and two species namely Collyriclum faba (Bremser in Schmalz, 1831) and Collyricloides massanae (Vaucher, 1969) [56]. This family is distinguished from other members of the Gorgoderoidea by the location of adults in the host, i.e. cysts in the skin or intestinal wall of birds and mammals [8]. The monotypic genus Collyricloides described by Vaucher [56] was established for a species from cysts in the intestinal wall.

Methods

Results

Conclusion