Green abalone, Haliotis fulgens, is one of the five species along the coasts of Baja California, Mexico, that has become economically important. Nonetheless, nonregulated fishing activities and anthropogenic impacts have contributed to the decline of its populations, increasing the interest in abalone conservation; therefore, habitat restoration and stocking of native species need to be considered .
Cryopreservation of sperm of aquatic species can be helpful in such programs to protect endangered species in natural disasters or accidents that can affect wild populations. Additionally, the aquaculture industry can also benefit from artificial insemination, reducing the risk of disease transmission, creating new lines with favorable traits, conserving stocks, and transporting good quality gametes between farms. Developing a cryopreservation protocol for green abalone would aid in such restoration efforts, providing an alternative breeding option for this aquaculture industry that is not entirely established.
This work aimed to develop cryopreservation protocols for sperm of H. fulgens. In this study, three commonly used cryoprotectants (CPAs) were chosen: Dimethyl sulfoxide (DMSO), glycerol, and methanol. Four different CPAs concentrations (5%, 10%, 15%, and 20 %) and four equilibration times (5, 10, 15, and 20 min) were evaluated in a manually controlled cooling Styrofoam chamber.
Thawed sperm quality was evaluated by estimating the percentages of sperm motility and plasma membrane integrity (PMI) using a dual staining technique. Results suggested that 15% DMSO was the best among the CPAs evaluated, resulting in higher motility (48%) and PMI (58%) (Fig. 1).