Morphometric characterization of the first blastomeres of rainbow trout (Oncorhynchus mykiss)
- Valdebenito Isler, Iván - Sanchez, Ruben R. - Effer Roldan, Brian - Ubilla Madrid, Andrea
- Datos de publicación:
- Asymmetrical - Early stage - First blastomeres - Rainbow trout - Symmetrical
- Migración Web of Science 
- In the following investigation the morphometric characteristics of the first two blastomeres of rainbow trout (Oncorhynchus mykiss) were determined. Embryos were incubated at 9 degrees C and then fixed in a Stockard solution every 30 min starting from 8.5 to 12.5 h of incubation post fertilization. Embryonic discs were extracted and microphotographs were taken with Q Capture Pro 5.0 software using a stereomicroscope Olympus SZX7. The average size of the blastodiscs was 941.22 +/- 160.42 mu m. The first cleavage finished after approximately 12 h of incubation. The first two blastomeres were regularly symmetrical in their morphology. Blastomere 1 had an average length (L) of 942.68 +/- 105.56 mu m and width (W) of 467.34 +/- 64.33 mu m. Blastomere 2 had an average length of 887.60 +/- 101.65 and width of 454.49 +/- 47.25 mu m (n = 91). Significant differences were found between the length and width of blastomeres 1 and 2. The proportion between the length of blastomeres 1 and 2 was 0.94 +/- 0.07 (n = 91); between the width of blastomeres 1 and 2 it was 0.88 +/- 0.11 (n = 91); and the width/length ratio was 0.51 +/- 0.09 (n = 182). It was concluded that rainbow trout blastomeres tend to be asymmetrical in length with a higher dispersion of widths.