Summary The ultrastructure of immature and mature spermatozoa, as well the sperm components within oocyte following fertilisation gamete fusion, are investigated in free-living marine nematode, Pontonema vulgare . Immature spermatozoa from testis exhibit a stellate nucleus with nuclear envelope surrounding poorly condensed chromatin. filamentous cytoplasm contains minute mitochondria osmiophilic membranous organelles (MO) vacuolated structure. Mature found uterus amoeboid cells, polarised...

An intracellular bacterium, strain IAS T , was observed to infect several species of the plant-parasitic nematode genus Xiphinema ( astaregiense incertum madeirense pachtaicum parapachydermum and vallense ). The bacterium could not be recovered on axenic medium. 16S rRNA gene sequence found new, being related family Burkholderiaceae, class Betaproteobacteria. Fungal endosymbionts Mycoavidus cysteinexigens B1-EB (92.9 % identity) ‘ Candidatus Glomeribacter gigasporarum’ BEG34 (89.8 are...

Spermatogenesis in testes of the free-living marine nematode Pontonema vulgare was studied with electron microscopy. The nucleus spermatocytes has a large nucleolus; cytoplasm is filled numerous ribosomes, mitochondria, cisternae rough endoplasmic reticulum (RER), Golgi bodies, and flattened osmiophilic cisternae, which are interpreted as modified membranous organelles (MO) spermatozoa other nematodes studied. After completion second meiotic telophase, surrounded by newly formed nuclear...

Abstract Spermatogenesis in two species of free-living marine nematodes from the family Chromadoridae (Panduripharynx pacifica and Euchromadora robusta) was studied electron-microscopically. The spermatogonia both are undifferentiated polygonal cells with a large nucleus surrounded by small amount cytoplasm. In P. cytoplasm spermatocytes contains many Golgi bodies, cisternae RER, ribosomes, mitochondria dense spherical bodies. Filamentous material is accumulated spermatids, which contain...

Abstract The spermatogenesis of the free‐living marine nematode Metachromadora itoi was studied with electron microscopy. Spermatocytes and early spermatids have no cytoplasmic components specific for nematodes, i.e. membranous organelles (MO) fibrous bodies (FB). late are subdivided into residual body main cell a centrally located nucleus devoid nuclear envelope. A pair 9 × 2 centrioles is associated nuclei spermatozoa. mature spermatid surrounded by thick mass radially arranged FB...

Abstract Spermatogenesis in Bursaphelenchus mucronatus, described using TEM, is similar to that of the 'rhabditid' nematodes. The development includes formation complexes fibrous bodies (FB) and membranous organelles (MO) which appear spermatocytes; dissociate spermatids; immature sperm contains separate FB MO transformation continues only after activation female gonoduct. spermatheca mature spermatozoa as bipolar cells subdivided into one large pseudopod a main cell body containing nucleus...

Summary Sperm development and structure in the wood-inhabiting fungal plant-feeding nematode, Bursaphelenchus luxuriosae , were studied using transmission electron microscopy to evaluate interspecific similarities differences of spermatozoa nematodes. In general, spermatogenesis B. fits ‘rhabditid’ pattern supported by morphological phylogenetic analysis order Rhabditida. Spermatocyte includes formation complexes fibrous bodies (FBs) with membranous organelles (MOs), dissociate spermatids...

Abstract A comparative ultrastructural study of the male gametes in entomopathogenic nematodes genus Steinernema (Rhabditida: Steinernematidae) is based on two species producing monomorphic (S. feltiae) and dimorphic tami) spermatozoa. The spermatozoa both are basically same as many other Rhabditida. Immature from testis unpolarised cells containing a nucleus without nuclear envelope, mitochondria membranous organelles (MO), unique component nematode Mature have nucleus, emptied MO, each...

Spermatogenesis in Ditylenchus arachis and D. dipsaci was studied using transmission electron microscopy. includes the formation of complexes fibrous bodies (FB) membranous organelles (MO) spermatocytes, which dissociate separated MO FB spermatids. Immature spermatozoa are unpolarised cells with separate MO. Mature arranged chains. is unique having that have already fused outer membrane immature mature male testis, proving not only insemination plays a role spermiogenesis. Contrary to what...

The distal tip cell (DTC) is a large single located at the apex of nematode gonadal arms.It well investigated in Caenorhabditis elegans Maupas, 1900 and described many other species class Chromadorea.It has been obtained convincing evidence that C. DTC plays an essential role development gonads regulation gametogenesis.We have studied fine structure part testis free living marine nematodes Enoplus.TEM observations revealed absence specialized testes E. michaelseni (Linstow, 1896) brevis...

Abstract - Spermatogenesis of the free-living marine nematode Anticoma possjetica was studied with electron microscopy. The spermatocyte cytoplasm is filled numerous ribosomes, mitochondria, cisternae RER and Golgi bodies. After completion meiosis nucleus spermatids surrounded by a newly formed nuclear envelope. first membranous organelles (MO) appear in early spermatids, late spermatid they, together surround nucleus. bodies are concentrated inside residual body. nuclei immature spermatozoa...

Temereva, E.N., Malakhov, V.V. and Yushin, 2011. Ultrastructural study of oogenesis in Phoronopsis harmeri (Phoronida). —Acta Zoologica (Stockholm) 92: 241–250. The successive stages were examined by electron microscopy methods. During the oogenesis, each oocyte is encircled vasoperitoneal (coelomic) cells forming a follicle. previtellogenic oocytes are small which accumulate ribosomes for future synthesis; their cytoplasm contains characteristic clusters mitochondria osmiophilic particles...

Abstract Spermatogenesis of five rhabditid nematodes was studied using transmission electron microscopy and is described herein. Structure development nematode sperm in all available representatives the extensive order Rhabditida have been analysed main characteristics each infraorder are discussed. The ancestral reconstructed maximum likelihood Bayesian methods based on 44 ultrastructural characters. hypothetical spermatogenesis agrees with previously suggested “rhabditid” pattern appears...

Abstract The structure and development of the dimorphic spermatozoa free-living marine nematode Terschellingia glabricutis (Monhysterida, Linhomoeina, Linhomoeidae) were studied with transmission electron microscope (TEM). linhomoeid pattern includes absence fibrous bodies (FB) in spermatocytes their appearance spermatids as spindle-shaped never associating membranous organelles (MO); presence centrioles near sperm nucleus; occurrence filopodia immature spermatozoa; unpolarised concentric...

The digestive tract of the echinopluteus Echinocardium cordatum consists a tubular oesophagus, spherical stomach, and large hemispherical intestine. oesophagus is constructed from cells one ultrastructural type has subepithelial muscles oriented circumferentially longitudinally. cardiac pyloric sphincters separating stomach intestine, as well anal sphincter, consist myoepithelial muscles. both intestine are able to absorb nutrients phagocytize food. Neuron-like were detected around mouth, in...