Eel sperm cryopreservation: an overview
Juan German
Herranz-Jusdado, Victor Gallego, Marina Morini, Christoffer Rozenfeld, Luz
Pérez, Tamás Müller, Ákos Horváth, Hiromi Ohta, Juan F. Asturiano
Theriogenology 133: 210-215. 2019
https://doi.org/10.1016/j.theriogenology.2019.03.033
Theriogenology 133: 210-215. 2019
https://doi.org/10.1016/j.theriogenology.2019.03.033
Abstract
The eels are teleost
fishes from the order Anguilliformes that includes several species with high commercial
value. Due to the high interest for aquaculture production of some eel species
and for the need to restore eel species that are endangered, several research
groups have directed their research toward developing protocols to cryopreserve
the spermatozoa of Japanese eel (Anguilla
japonica) and European eel (Anguilla
anguilla). In this review, we provide an overview on the different
protocols that have been developed so far. The first developed protocols used
DMSO as cryoprotectant in both species with good success, obtaining sperm
motilities of over 45% in Japanese eel and over 35% in European eel. Moreover,
sperm cryopreserved using DMSO was successfully used in fertilization trials,
although with low fertilization rates. However, recent studies show that DMSO
produce epigenetic changes in eel sperm and therefore, the last developed
protocols used methanol as cryoprotectant instead. Cryopreservation protocols
using methanol as cryoprotectant, showed improved motility values in both
Japanese and European eel. In addition, the latest protocols have been adapted
to cryopreserve larger volumes of sperm of up to 5 mL, which is useful for
larger scale fertilization trials.
The present study
introduces the state of the art and future perspectives of the eel sperm
cryopreservation to be applied in aquaculture and biological conservation
programs.