| Autor: |
E. Uria Galicia, E. López-López, Esperanza Ortiz-Ordoñez, A. L. Carvajal Hernández, J. P. Maya |
| Rok vydání: |
2006 |
| Předmět: |
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| Zdroj: |
Journal of Applied Ichthyology. 23:40-45 |
| ISSN: |
0175-8659 |
| DOI: |
10.1111/j.1439-0426.2006.00790.x |
| Popis: |
Summary The ovarian cycle was studied in Ameca splendens, a viviparous fish native to western Mexico. Two wild populations living in environments with differential conditions (a small pond adjacent to a reservoir and a spring) were examined to determine whether the conditions these populations are exposed to can elicit differences in the reproductive cycle. The two sites differ from each other with respect to several environmental factors: the spring has clear, oxygen-rich water while the pond has higher levels of conductivity, hardness and inorganic nitrogen. Six stages of gonadal maturation were identified in A. splendens, based on histological and macroscopic characteristics of the gonad. The relative frequency of gonadic stages at both sites showed two reproductive peaks during the year: from March to May and from September to November. Histologically, ovaries exhibit an asynchronous development in both populations, revealing the existence of a multiple reproductive cycle. Relative mean condition shows organisms are in peak condition (K > 1) at age class 1+ as they recruit to reproduction; K was |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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