Spermiogenesis and spermatozoon ultrastructure of Hunterella nodulosa (Cestoda: Caryophyllidea), a monozoic parasite of suckers (Catostomidae) in North America

Abstract

spermiogenesis and ultrastructure of mature spermatozoon of the caryophyllidean cestode Hunterella nodulosa, a parasite of suckers (Catostomidae), have been studied by transmission electron microscopy. This monozoic tapeworm is unique in its mode of attachment and represents the second North american species studied. the process of spermiogenesis of H. nodulosa follows the general pattern already described in other caryophyllideans. the most characteristic feature is the presence of a slight rotation of the flagellar bud, which seems to be a typical character of spermiogenesis in this cestode group. The mature spermatozoon of H. nodulosa is characterized by the presence of one axoneme of 9 + "1" type of the trepaxonematan flatworms surrounded by a semi-arc of cortical microtubules in its anterior extremity, parallel nucleus and cortical microtubules arranged in a parallel pattern, which corresponds to the Type III pattern of cestode spermatozoa according to Levron et al. (2010). Comparison of the present data with those available for other caryophyllideans did not reveal substantial differences, even though they belong to different families, infect different hosts (catostomid, cyprinid and siluriform fishes) and occur in distant zoogeographical regions. This indicates uniformity of the process of sperm formation and spermatozoon ultrastructure in one of the evolutionarily most ancient groups of tapeworms.

New data on spermiogenesis and trepaxonematan axoneme in basal tapeworms (Cestoda, Caryophyllidea, Lytocestidae) parasitizing cyprinid fishes

“…Electron-dense material in the apical region of the zone of differentiation in the early stages of spermiogenesis has been observed in lytocestid tapeworm Khawia armeniaca 12 for the first time within the order Caryophyllidea. Subsequently, this material was detected in other caryophyllidean species: Wenyonia virilis 21,22 , Khawia sinensis 13 , Breviscolex orientalis 23 , Lytocestus indicus 14 , Hunterella nodulosa 24 , Caryophyllaeus laticeps 25 , Caryophyllaeides fennica 11 , and K . rossittensis (present study).…”

Ultrastructure and cytochemistry of the mature spermatozoon of Khawia armeniaca (Cholodkovsky, 1915) (Caryophyllidea: Lytocestidae), a parasite of Capoeta capoeta sevangi (De Filippi, 1865) (Teleostei, Cyprinidae)

“…Glycogen is the major carbohydrate storage form in animals and represents the major energy store of the spermatozoa in the Eucestoda (Euzet et al, 1981). The presence of glycogen was detected using Thiéry method (1967) in the spermatozoa of the Caryophyllidea (Bruňanská, 2009;Yoneva et al, 2011;Bruňan ská & Kostič, 2012;Matoušková et al, 2018;Bruňanská et al, 2019; present study), and in male gametes of other cestodes, e.g. Diphyllobothriidea, Bothriocephalidea, Haplobothriidea, Di phyllidea, Trypanorhyncha, Tetraphyllidea, Proteocephalidea, and Tetrabothriidea (Levron et al, 2010).…”

Ultrastructure of the sperm of Adelobothrium sp. (Cestoda: Lecanicephalidea)

“…The focus of much of this work has been on members of the orders Bothriocephalidea, Caryophyllidea, and Cyclophyllidea (see e.g., Yoneva et al. , , ; Miquel et al. ; Bruňanská & Kostič ; Marigo et al.…”

“…There have been a few concerted efforts to study spermatozoan morphology for members of all known families within an individual order, for example, in the Caryophyllidea (see Yoneva et al. , ,b). However, it is likely that the known families are not representative of the actual number of major lineages in the order (Olson et al.…”

“…Although data on spermatozoan ultrastructure for members of most cyclophyllidean families are present in the literature, a mere 2% of the total species diversity within this very species-rich order (~3000 described species; Caira & Littlewood 2013) has been studied. There have been a few concerted efforts to study spermatozoan morphology for members of all known families within an individual order, for example, in the Caryophyllidea (see Yoneva et al 2011Yoneva et al , 2012a. However, it is likely that the known families are not representative of the actual number of major lineages in the order (Olson et al 2001;Oros et al 2008).…”