Reinvestigation of vitellogenesis in Caryophyllaeus laticeps (Pallas, 1781) (Cestoda, Caryophyllidea, Caryophyllaeidae), monozoic tapeworm of Abramis brama (Pisces, Teleostei)

Abstract

Reinvestigation of vitellogenesis in the caryophyllidean cestode Caryophyllaeus laticeps (Pallas, 1781) has been performed using light microscope (LM) and transmission electron microscopy (TEM), and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) for glycogen. Vitellogenesis is generally similar to that reported in the past, however, some new observations were made. The present study reveals the first evidence of: (i) interstitial tissue in the vitelline follicles, (ii) lipid droplets in maturing and mature vitellocytes from vitelline follicles, and (iii) lamellar bodies in vitellocytes from the vitelloduct in C. laticeps. Projections of interstitial tissue surround each vitellocyte and the follicle periphery. The perinuclear cytoplasm of the interstitial tissue contains granular endoplasmic reticulum and vesicles of various size and density. Cytoplasmic osmiophobic lipid droplets and lamellar bodies, previously believed to be absent in most caryophyllid cestodes, are readily apparent in vitellocytes of C. laticeps. The origin and presumed function of these inclusions are discussed. On the other hand, the formation and storage of massive amounts of glycogen in the nucleus and large amounts in the cytoplasm of mature vitelline cells are similar to the condition found in other caryophyllids. Results are compared and contrasted with previous studies on vitellogenesis in other monopleuroid cestodes (Amphilinidea and Gyrocotylidea) as well as polypleuroid cestodes (Spathebothriidea) and the remaining strobilated Eucestoda.

Functional ultrastructure and cytochemistry of vitellogenesis and mature vitellocytes of the digenean Cainocreadium labracis (Dujardin, 1845), parasite of Dicentrarchus labrax (L., 1758)

“…Vitellogenesis like that described in our study has been observed in lower cestodes as follows: in gyrocotylids by Xylander (1987), amphilinids by Xylander (1988), caryophyllidids by Bruňanská et al (2012, 2013a, 2013b), bothriocephalids by Świderski and Mokhtar (1974) and Levron et al (2007), and spathebothriids by Bruňanská et al (2005) and Poddubnaya et al (2005, 2006). Common to these cestodes is a similar egg type, with a thin shell and operculated, resembling the eggs of most trematodes.…”

Ultrastructural study of vitellogenesis of Ligula intestinalis (Diphyllobothriidea) reveals the presence of cytoplasmic-like cell death in cestodes

“…The same structures were also observed in the egg-enclosing vitellocytes of the caryophyllidean cestodes W. virilis and K. sinensis and those in the vitelloduct of another caryophyllidean from freshwater teleosts, Caryophyllaeus laticeps (Pallas, 1781) [ 17 , 23 , 25 ]. The role of GER-bodies in mature vitellocytes has not been fully investigated.…”

Vitellogenesis of diphyllobothriidean cestodes (Platyhelminthes)

“…General pattern of vitellogenesis of the diphyllobothriidean cestodes [7,present study] proceeds in a way commonly found in representatives of other lower bothriate eucestodes, i.e. Caryophyllidea, Spathebothriidea, Diphyllidea, and Trypanorhyncha [9][10][11][12][13][14][15][18][19][20][21][22][23].…”

“…Among the basal bothriate eucestodes, vitellogenesis was studied in several species of the Caryophyllidea, but with most data limited to the parasites of cyprinids in the Palearctic Region (e.g. [9][10][11]), in three species of the relictual order Spathebothriidea [12,13] from freshwater and marine teleosts, in one species of the order Diphyllidea [14] and several species of the marine order Trypanorhyncha, parasites of elasmobranchs (e.g., [15]). Therefore, the ultrastructural data on vitellogenesis are available for all but one (Haplobothriidea) orders considered representing the most basal bothriate eucestode lineages.…”