Structural Analysis of Embryonic Development of Embryos From the Crossing of Two Species of Siluriform

Based on the need for knowledge about the biology of hybrid fish specimens currently being produced by commercial fish farmers, this study aimed to study the initial ontogenesis up to the fifth day after larval hatching of the Hybrid LP produced by crossing Leiarius marmoratus (♀) and Pseudoplatystoma reticulatum (♂), thus producing important data for fish farming, as well as for ichthyoplankton studies. The embryogenesis of the Hybrid LP was typical of teleosts but with differences and similarities in relation to other species and their parents, such as duration of development and moment of mesoderm segmentation, among others. Five stages of embryonic development were defined, from the moment of fertilization until larval hatching: zygote, cleavage, gastrulation, organogenesis, and hatching. The embryogenesis period was 13 h, at an average temperature of 27.98°C. The embryonic development stages established for the hybrid were like those of its parental species L. marmoratus and P. reticulatum . Thus, through this research, it was possible to conclude that the embryonic development of the Hybrid LP originating from interspecific crosses between females of L. marmoratus with males of P. reticulatum occurred in a development period similar to that found in studies of its parental species as well as for the inverse hybrid (PL), originating from females of P. reticulatum with males of L. marmoratus , under similar temperatures, not being possible to morphologically differentiate the embryos and larvae until the fifth day after hatching, neither of the parental species nor the Hybrid PL.