Investigation on the Adriatic Elasmobranchia liver oils. IV. Biochemical study about oils from the liver and eggs of Centrina salviani Risso

Abstract

      By the comparison of the physical and chemical properties of the different liver oils on the sample Centrina Salviani it is determined that there exist certain differences between fema­les in the different stages of their sexual maturity. These diffe­rences are striking in the specific gravity and the percentage of unsap. matters. It was not possible to fix any differences on other constants.

     The content of oil in fructified and unfructified eggs was investigated and their properties compared with liver oils. Great differences were determined in the specific gravity, refraction index as well as in the content of free, further volatile and in water soluble acids. During the period which passes from the fructification and the formation of the germ a great decrease of the percentage of unsap. matters, total fatty acids, free fatty acids, the saponif. number and the iodine number can be obser­ved on the oil from eggs.

      The chemical properties of fatty acids from the liver oil of the pregnant female and the female with undeveloped ovaries were researched and the results compared with each other. No essential differences were found. The fatty acids from oils of unfructified eggs do not differ much from the former either. The fatty acids from fructified eggs show an increase of the iodine number and a decrease of the neutralization number and the percentage of polybromide.

      A success was attained in the separation of the individual components from the unsap. matters and their quantitative de­termination in the way of chromatographic adsorbtion. Only in one case a greater quantity of hydrocarbon was found, which is not squalene but probably pristan. It is difficult to fix a re­lation between the presence of the exceptional great quantity of hydrocarbon in the liver oil of the pregnant female and the de­velopment of gonads for at other pregnant females only an in­significant quantity of hydrocarbon was found.

      It is further determined that the quantities of cholesterol, selachyl-, batyl and chimyl alcohol are verv variable. In respect of the content of cholesterol and chimyl alcohol in the unsap. yield there exists a difference between pregnant females and fe­males with undeveloped ovaries.

      The chemical composition of unap. matters in oils from eggs is similar to the composition of unsap. matters in liver oils and differs from it only by a much greater content of chole­sterol.

      Basing on these researches it can be concluded that the development of gonads is in a certain connection with the me­tabolism of the fat in the liver. Essential differences are deter­mined in the composition of the fat during the period which passes from the formation of unfructified eggs till their fructi­fication and the development of the germ in the eggs.