Cambios histomorfológicos en el ovario del pez capitán, Eremophilus mutisii Humboldt 1805 (Pisces: Trichomyteridae), durante el ciclo reproductivo anual,en la laguna del Muña, sistema río Bogotá, Colombia

The principal aim of this investigation was to study the anual morpho-histological changes in the ovary of the fish capitan, Eremophilus mutisii, in the Rio Bogota basin in Colombia, with regard to the reproductive cycle, size of the mature fishes and seasonal changes in the environment. The fibs material was collected monthly. The gonads were fixed in Bouin's fixative. Subsequently they were washed several times in 70% ethanol. Transversal sections of about 5 cm in length, each of which produced 10 slides with 10 or so sections per slide, were taken from the center to the anterior portion of the right ovary of each fish, since no macroscopic significant differencie was observed in the oogenic process in the anterior, central and posterior portion of the ovary. The sections were dehydrated in tetrahydrofuran and embedded in paraffin. Sections were cut at 6 microns and stained with haematoxylin and eosin (H & E). The gonosomatic index (GSI) or maturity index (MIl was calculated.