Research regarding the density of the myocytes and the ratio of the main tissue categories from the lateral muscle of the polyodon spathula species

Abstract

Histological samples were taken from the lateral muscle (dorsal epaxial) (ML-ED), from ten four year old sturgeon (Polyodon spathula) male specimens (Ps3+). These samples were processed with the paraffin sectioning technique and 20 slides with transversal sections of the lateral muscle were obtained. The slides where colored according to the HEA method. They were analyzed with an optic microscope (OM), type MC3. Both diameters (long and short) were measured in the microscopic field for the myocytes and the primary muscular fibers (PMB). Also in the microscopic field the myocytes from the PMB were counted. Through calculations, the average diameter, the circumference and the values for the shape and profile index were determined, at the PMB level. Afterwards the myocytes density and the ratio of the two tissue categories (muscle tissue and conjunctive tissue) at PMB and SMB level were determined. The following results were obtained: the average thickness of the PMB, from the 5 secondary muscle bundles (SMB) studied it varied between 318μ and 452.5μ, with a mean of 383.85μ. The average circumference of the PMB was 1206μ, the shape is a cylindroid with a flattening tendency (If=1,768/1)(Ip=59,19%). The PMB myocyte number oscillated between 34.2 and 72.33, the average being 50.76 muscle fibers. The myocyte density varied between 444.282fm/mm² and 489.166fm/mm², with a mean of 467.383fm/mm². The muscle tissue ratio varied between 64.10% and 75.0%, with a mean of 68.72%. The differences between the means of the five SMB, in accordance with the 11 studied parameters, were tested for statistical purposes, ascertaining that 99.09% of them are insignificant.