chapter 3 - RiuNet

OBJECTIVES
The chapters presented below have a primary objective in common: the
development and improvement of different techniques and protocols with
the aim of increasing the knowledge about European eel and pufferfish
sperm biology, thereby improving their reproductive performance and the
control of their reproduction in captivity. The specific objectives were:
To standardize European eel sperm quality assessment by a CASA
system in terms of procedural and biological settings, with the aim
of defining a standard method to make accurate comparisons in
aquaculture/aqualcultural reproductive matters possible.
To study the effects on the reproductive performance of three
thermal regimes and three hormonal treatments as alternative
maturation induction methods of male European eels.
To test the changes to the main ions involved in European eel
sperm activation, evaluating the spermtozoa intracellular
concentrations of Ca 2+ , K + , and pH by flow cytometry, and
establishing the first hypothesis about the role of these ions in the
sperm motility activation of this species.
To develop a simple chilled storage method able to preserve the
pufferfish sperm quality parameters over a short-term period.
To evaluate the effects of the composition and osmolality of the
sperm activation medium on the motility characteristics of
pufferfish spermatozoa, as well as to measure the intracellular
concentrations of the main ions involved in its sperm activation.
To study the correlations between all the pufferfish sperm
parameters provided by a CASA system and the fertilization and
hatching rates. Moreover, the effect of the sperm/egg ratio will be
analyzed in relation to these parameters in order to estimate the
optimum dosage to use in reproductive matters in aquaculture.
27