Rafaela Amaro - Academia.edu (original) (raw)

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Papers by Rafaela Amaro

Research paper thumbnail of Growth models and longevity of freshwater pearl mussels ( Margaritifera margaritifera ) in Spain

Canadian Journal of Zoology, 2004

Growth rates of populations of the freshwater pearl mussel, Margaritifera margaritifera (L., 1758... more Growth rates of populations of the freshwater pearl mussel, Margaritifera margaritifera (L., 1758), in northwestern Spain were analysed based on measurements of annual annuli and using two nonlinear functions for length-atage data sets: von Bertalanffy's growth model and a hyperbolic function. These populations reach the smallest maximum shell length (90.5 mm) and have the shortest life-span (35 years) and the highest growth rate (k in von Bertalanffy's model >0.1·year -1 , on average) known for this species. The two models were similar in performance and were well fitted (around 99%) to shell-length-at-age data, although the hyperbolic function appears to be applicable only from 6 years of age. The growth rate (either k or k′ from the hyperbolic function) showed a large and significant variation across populations, both among and within drainages.

Research paper thumbnail of Synaptonemal complex analysis in oocytes and spermatocytes of threespine stickleback Gasterosteus aculeatus (Teleostei, Gasterosteidae)

Genetica, 2002

A surface-spreading synaptonemal complex (SC) technique was employed to analyze spermatocytes and... more A surface-spreading synaptonemal complex (SC) technique was employed to analyze spermatocytes and oocytes of stickleback, Gasterosteus aculeatus, in order to visualize the process of chromosome synapsis. The mean SC length was 150 +/- 18 microm in three males and 143 +/- 12 microm in one female analyzed. A representative SC karyotype with 21 bivalents was also presented. Each SC had lateral elements of equal length. No bivalent displaying the atypical synaptic behaviour which is often associated with heteromorphic sex chromosomes was observed neither in males nor in the female analyzed.

Research paper thumbnail of Growth models and longevity of freshwater pearl mussels ( Margaritifera margaritifera ) in Spain

Canadian Journal of Zoology, 2004

Growth rates of populations of the freshwater pearl mussel, Margaritifera margaritifera (L., 1758... more Growth rates of populations of the freshwater pearl mussel, Margaritifera margaritifera (L., 1758), in northwestern Spain were analysed based on measurements of annual annuli and using two nonlinear functions for length-atage data sets: von Bertalanffy's growth model and a hyperbolic function. These populations reach the smallest maximum shell length (90.5 mm) and have the shortest life-span (35 years) and the highest growth rate (k in von Bertalanffy's model >0.1·year -1 , on average) known for this species. The two models were similar in performance and were well fitted (around 99%) to shell-length-at-age data, although the hyperbolic function appears to be applicable only from 6 years of age. The growth rate (either k or k′ from the hyperbolic function) showed a large and significant variation across populations, both among and within drainages.

Research paper thumbnail of Synaptonemal complex analysis in oocytes and spermatocytes of threespine stickleback Gasterosteus aculeatus (Teleostei, Gasterosteidae)

Genetica, 2002

A surface-spreading synaptonemal complex (SC) technique was employed to analyze spermatocytes and... more A surface-spreading synaptonemal complex (SC) technique was employed to analyze spermatocytes and oocytes of stickleback, Gasterosteus aculeatus, in order to visualize the process of chromosome synapsis. The mean SC length was 150 +/- 18 microm in three males and 143 +/- 12 microm in one female analyzed. A representative SC karyotype with 21 bivalents was also presented. Each SC had lateral elements of equal length. No bivalent displaying the atypical synaptic behaviour which is often associated with heteromorphic sex chromosomes was observed neither in males nor in the female analyzed.

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