Structural abnormalities of common carp Cyprinus carpio spermatozoa

Abstract

Spermatozoa of common carp Cyprinus carpio are typically consist of a primitive head without acrosome, a midpiece with several mitochondria, a centriolar complex (proximal and distal centriole), and one flagellum. During an evaluation of the motility of common carp spermatozoa, we found spermatozoa with more than one flagellum and/or "double head" in three different individuals. This may be related to abnormal spermatogenesis. Ultrastructure and physiological parameters of spermatozoa were examined using light microscopy (dark field with stroboscopic illumination), transmission and scanning electron microscopy, and flow cytometry. The recorded pictures and videos were evaluated using Olympus MicroImage software. All spermatozoa with more than one flagellum had a larger head and shorter flagella. They occasionally demonstrated several cytoplasmic channels separating the flagella from the midpiece. Each flagellum was based upon its own centriolar complex, with the connection of the flagellum to the head always at a constant angle. The flagella always consisted of nine peripheral pairs and one central doublet of microtubules. Sperm exhibited a relative DNA content similar to that found in sperm from normal males, with higher coefficients of variation. Although similar abnormalities have been found in livestock, where they were described as a defect in spermiogenesis, no comparable results have been reported in fish. The frequency at which these abnormalities occurs, the fertilization ability of males with defects in spermiogenesis, the influence of these abnormalities on progeny in terms of ploidy level, and the occurrence of deformities warrant further investigation.

Comparative study on ultrastructure and motility parameters of spermatozoa of tetraploid and hexaploid Siberian sturgeon Acipenser baerii

“…Found double axoneme of sturgeon spermatozoa in this study could indicate a kind of defect in spermiogenesis of 6n male as is similarly described in carp by Pšenička et al. (2009b).…”

Motility, morphology, mitochondria and ATP content of diploid spermatozoa from sex-reversed clonal diploid and neo-tetraploid loach,Misgurnus anguillicaudatus

“…Ultrastructure of the spermatozoa was observed by scanning electron microscope (SEM) and transmission electron microscopy (TEM), according to the procedures in carp sperm (Psenicka et al, 2009). Sperm from evaluated males was fixed with 2.5% glutaraldehyde in 0.1 M phosphate buffer for 2 days at 4°C,following which it was postfixed, washed repeatedly for 2 h at 4°C in 4% osmium tetroxide, and dehydrated through an acetone series.…”

An electron microscopic analysis on the ultra structural abnormalities in sperm of the common carpCyprinus carpio L. inhabiting a polluted lake, Umiam (Meghalaya, India)

“…Matos et al (2002) studied biflagellate spermatozoon structure of the hermaphrodite fish Satanoperca juripari . It is to be noted in this context that despite a large number of published works in the existing literature about sperm ultra structure, very few reports exist on the same topic with reference to environmental stress and pollution (Dey et al,2009a; Psenicka et al,2008). …”