Characterization of Bottlenose Dolphin (Tursiops truncatus) Sperm Based on Morphometric Traits

Abstract

Bottlenose dolphin (Tursiops truncatus) males follow many reproductive strategies to ensure their paternity. However, little is known about the sperm traits, including morphometric features, that contribute to their reproductive success. Our aim was to study dolphin sperm morphometry (a total of 13 parameters) in two adult males to evaluate (i) presumptive sperm subpopulations, (ii) the correlation of sperm morphometry with testosterone levels and (iii) the effect of refrigerated storage on the sperm morphometry. Sperm populations were classified into four principal components (PCs) based on morphometry (>94% of cumulative variance). The PCs clustered into two different sperm subpopulations, which differed between males. Furthermore, the levels of serum testosterone were positively correlated with the length of the midpiece but negatively correlated with head width and the principal piece, flagellum and total sperm lengths. Most of the sperm morphometric parameters changed during the storage period (day 1 vs. day 7), but only the principal piece length was affected by the storage temperature (5 °C vs. 15 °C). This is the first study to identify dolphin sperm subpopulations based on morphometry and the influence of serum testosterone and refrigeration on sperm morphometry.

Effects of fixatives and storage duration on avian sperm morphology

“…This is also true for birds. Recent advances in this field, in combination with better phylogenetic reconstructions, have shown how sperm size and components may evolve at different rates in different clades and lineages (Omotoriogun et al 2016;Supriya et al 2016), and that the risk of sperm competition can be an important driver in the evolution of sperm traits (Eberhard 1996;Briskie et al 1997;Immler et al 2012; van der Horst and Maree 2014; Rowe et al 2015;Durrant et al 2020). Phenotypic divergences in sperm traits have been indicated as playing a role in speciation processes (Cramer et al 2016(Cramer et al , 2021 and in the delimitation of species (Lifjeld et al 2016).…”

Completion of Maize Stripe Virus Genome Sequence and Analysis of Diverse Isolates

“…MSpV is serologically related to the tenuivirus species Rice stripe virus ( Gingery et al, 1983 ), which is vectored by the small brown planthopper Laodelphax striatellus Fallén. There are reports of rice stripe virus (RSV) infecting maize ( Gingery et al, 1983 ; Bradfute and Tsai, 1990 ), although its infamy comes from its epidemics on japonica cultivars of rice ( Oryza sativa L.) in Eastern Asia ( Wang et al, 2008 ; Otuka et al, 2010 ). Both MSpV and RSV are grouped in the genus Tenuivirus in the family Phenuiviridae ( Abudurexiti et al, 2019 ).…”

The Importance of Studying Factors That Affect the In Vitro Evaluation of Semen Quality to Predict Potential Fertility in Males

“…In the first work under this heading, Fuentes-Albero et al [5] present a novel complete description of sperm morphometry and morphometric subpopulations in the bottlenose dolphin (Tursiops truncatus) and the influence of blood testosterone and refrigeration on the sperm morphometry. Two different sperm subpopulations, which differed between males, were described.…”