Isotopic (15 N) relationship of pregnant females and their embryos: Comparing placental and yolk-sac viviparous elasmobranchs.

Nitrogen stable isotopes ratios (15 N) were determined for selected tissues (muscle, liver, blood and yolk) of pregnant females and their embryos of a placental viviparous species, the Pacific sharpnose shark (Rhizoprionodon longurio), and a yolk-sac viviparous species, the speckled guitarfish (Pseudobatos glaucostigmus). The R. longurio embryo tissues were 15 N enriched compared to the same tissues in the pregnant female, using the difference in 15 N (15 N) between embryo and adult. Mean 15 N was 2.17 in muscle, 4.39 in liver and 0.80 in blood. For P. glaucostigmus, embryo liver tissue was significantly 15 N enriched in comparison with liver of the pregnant female (15 N mean = 1.22), whereas embryo muscle was 15 N depleted relative to the muscle of the pregnant female (15 N mean = -1.22). Both species presented a significant positive linear relationship between 15 N and embryo total length (LT ). The results indicated that embryos have different 15 N depending on their reproductive strategy, tissue type analysed and embryo LT .

Bar-Camarasa, I., Marmolejo-Rodrguez, A. J., O'Hara, T. M., Elorriaga-Verplancken, F. R., Trejo-Ramrez, A., Martnez-Rincn, R. O., & Galvn-Magaa, F.

Baró-Camarasa, Isis||Marmolejo-Rodríguez, Ana J||O'Hara, Todd M||Elorriaga-Verplancken, Fernando R||Trejo-Ramírez, Abel||Martínez-Rincón, Raúl O||Galván-Magaña, Felipe

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