The fine structure of Gastromermis sp. (Nematoda: Mermithidae) sperm

The development and morphology of the sperm of the mermithid nematode, Gastromermis sp. appears to be different than that reported for any other nematode sperm. The mature sperm of Gastromermis are elongate with membranous organelles surrounding an apical nuclear region. The mitochondria are arranged in parallel rows and form an elongate sheath. Spermatozoa contain dense tubular structures which have not been seen in other nematodes. Spermatids lack fibrous bodies. The pseudopodia of the spermatozoa are filled with microtubules. Centrioles seen throughout sperm development are composed of 9 doublets.