February 15-18, 2009 Washington State Convention Center Seattle ...

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DETERMINING RIPENESS IN WHITE STURGEON FEMALES: A NONLETHAL METHOD
TO MAXIMIZE YIELD AND QUALITY OF CAVIAR
Anna G. Cavinato and Sarah A. Servid
Department of Chemistry and Biochemistry
Eastern Oregon University
One University Blvd.
La Grande, OR 97850 USA
acavinat@eou.edu,
The long-term goal of this project is to optimize caviar yield and quality from white sturgeon (Acipenser transmontanus) at
harvest. Currently, the only means to assess ripeness and properly time harvest of caviar is measurement of oocyte polarization
index (PI) which requires surgical biopsy.
We report a rapid and non invasive method based on short wavelength near infrared spectroscopy (SW-NIR) that has the ability
to detect the onset of atresia and could possibly replace oocyte PI by providing a less invasive and more reliable predictor of
maturity.
In September 2007 15 late-vitellogenic females were sampled and moved from a warm water site to a cold water site. Fish
were serially sampled in November, January and March. Atresia was induced by moving these females back to warm water.
Abdominal scans were collected non invasively by SW-NIR on anesthetized females using a diffuse reflectance fiber optic
probe. Approximately 200-300 ovarian follicles were then removed by catheter via a 1 cm incision in the abdomen and further
scanned by SW-NIR. Spectral data were analyzed by Soft Independent Modeling of Class Analogy (SIMCA). Best prediction
of onset of atresia through abdominal scans was achieved by building a model on mature fish with 66% of atretic fish correctly
classified. Best prediction of onset of atresia through direct scans of egg follicles was achieved by building a model on atretic
eggs with 80% of atretic eggs correctly identified. Further studies are currently being performed on a larger fish population to
test the predictive ability of these models on new individuals.