Ultrastructure of spermiogenesis and spermatozoa ofPolylabroides australis(Platyhelminthes, Monogenea, Polyopisthocotylea, Microcotyudae)

Spermiogenesis and spermatozoon ultrastructure in basal polyopisthocotylean monogeneans, Hexabothriidae and Chimaericolidae, and their significance for the phylogeny of the Monogenea

Sperm ultrastructure provides morphological characters useful for understanding phylogeny; no study was available for two basal branches of the Polyopisthocotylea, the Chimaericolidea and Diclybothriidea. We describe here spermiogenesis and sperm in Chimaericola leptogaster (Chimaericolidae) and Rajonchocotyle emarginata (Hexabothriidae), and sperm in Callorhynchocotyle callorhynchi (Hexabothri...

Sperm ultrastructure and spermiogenesis of Coniopterygidae (Neuroptera, Insecta).

The spermiogenesis and the sperm ultrastructure of several species of Coniopterygidae have been examined. The spermatozoa consist of a three-layered acrosome, an elongated elliptical nucleus, a long flagellum provided with a 9+9+3 axoneme and two mitochondrial derivatives. No accessory bodies were observed. The axoneme exhibits accessory microtubules provided with 13, rather than 16, protofilam...

Ultrastructure of spermiogenesis and the spermatozoon in cyclophyllidean cestodes

The usefulness of the ultrastructural characters of spermiogenesis and of the spermatozoon in the interpretation of relationships in the Platyhelminthes has been widely demonstrated. The present paper provides a review and an update on the ultrastructural knowledge on spermiogenesis and on the spermatozoon in cyclophyllidean cestodes. For each family of cyclophyllideans the pattern of spermioge...

Microhabitat selection of Discocotyle sagittata (Monogenea: Polyopisthocotylea) in farmed rainbow trout.

Microhabitat preference of the monogenean Discocotyle sagittata (Leuckart, 1842) was determined in late spring and late autumn in rainbow trout, Oncorhynchus mykiss (Walbaum), reared in the Isle of Man, U.K. Discocotyle sagittata exhibits a preference for attachment to anterior gill arches: 29% of all worms occurred on gill arch I, 28% on II, 25% on III and 18% on IV. This distribution pattern ...

First record of Amphipolycotyle chloroscombrus Hargis , 1957 ( Monogenea , Polyopisthocotylea , Gastrocotylidae ) in the South Atlantic Ocean