Standardization of sperm motility analysis by using CASA-Mot for Atlantic salmon (Salmo salar), European eel (Anguilla anguilla) and Siberian sturgeon (Acipenser baerii)

Carina Caldeira,Sandra Hernández-Ibáñez,Anthony Valverde,Patrick Martin,Juan G Herranz-Jusdado,Víctor Gallego,Juan F Asturiano,Borys Dzyuba,Martin Pšenička,Carles Soler

doi:10.1016/j.aquaculture.2018.12.001

Abstract

It is essential to define an optimized standard method to assess the fish sperm quality to minimize the differences between the results obtained by different laboratories. Only this optimization and standardization can make them useful from academia to industry. This study presents the validation of sperm motility assessment using a CASA-Mot system for three endangered diadromous fish species: European eel (Anguilla anguilla), Atlantic salmon (Salmo salar) and Siberian sturgeon (Acipenser baerii). To attain this goal, different technical and data processing methods were tested: 1) magnification lens (×10 and ×20), 2) Spermtrack® reusable chambers (10 and 20 μm depth) and 3) different frame rates (50 ≥ FR ≤ 250). The results suggested that the sperm motility assessment for eel, salmon and sturgeon should be performed at 200, 250 and 225 frames s−1, respectively. Moreover, to obtain a high number of analysed spermatozoa in less time and a natural movement of the sperm cells, it is recommended to use ×10 objective and 20 μm depth. In conclusion, different technical settings influence sperm kinetic parameters and should be validated for each fish species to allow the comparison of results between laboratories.

Highlights

The marked decline of wild stocks of some diadromous fish species such as European eel (Jacoby and Gollock, 2014), Atlantic salmon (NASCO, 2016) and Sturgeon sp. (Ruban and Bin Zhu, 2010) due to construction of dams, pollution, poaching and overfishing, together with their economic importance and high commercial demand, aroused a great interest in their production in captivity
The aim of this study was to evaluate different technical settings such as frame rate, counting chamber models and lens magnification to define a standard method for the analysis of sperm motility of these three endangered fish species (Anguilla anguilla, Salmo salar, Acipenser baerii) using a CASA system
The most notable difference was registered in the sperm motility traits of each fish species (Figure 1), with the catadromous species (European eel) exhibiting the lowest velocity and straightness of motion of spermatozoa tracks than anadromous species (Atlantic salmon and Siberian sturgeon)

Summary

Introduction

The marked decline of wild stocks of some diadromous fish species such as European eel (Jacoby and Gollock, 2014), Atlantic salmon (NASCO, 2016) and Sturgeon sp. (Ruban and Bin Zhu, 2010) due to construction of dams, pollution, poaching and overfishing, together with their economic importance and high commercial demand, aroused a great interest in their production in captivity. Besides the different CASA-Mot systems can follow the same general principle, each one has specific algorithms which can result in the incompatibility of results (Holt et al, 1994). This common principle consists in the individual measurement of spermatozoa motility based on the detection of spermatozoa head in consecutive images in order to obtain spermatozoa tracks (Mortimer et al, 1997; Bobé et al, 2010; Fauvel et al, 2010). The sperm quality assessment is sensitive to the hardware systems, such as the optical microscope, video camera and counting chambers

Objectives

Methods

Results

Discussion

Conclusion