Also in the context of the preparatory actions for the project, the morphological analysis of the captured, labeled and photographed individuals was evaluated, from which biological tissue samples (fragment of fat fin) were taken for genetic analysis.
The measurements and the counting of the livery characteristics are done through the ImageJ software. The morphological analysis, which began in September, was crossed with the genetic data of the “rapid” loci, from which 6 hybridization classes were reconstructed. The main morphological and livery characteristics were identified above all to be easily detectable even in field conditions, processed by PCA (Analysis of the main components) by means of the R Project Software: 20 parameters identified and analyzed.
Using the hybridization classes obtained with the so-called “rapid” markers, the following reference phenotypic characteristics were identified for the native trout of Molise:
– 4 vertical dark bands alternating with 3 light bands (in the Volturno specimens all the pure specimens present this characteristic, more or less marked)
– absence of the black line on the first rays of the anal and dorsal fins
– black and red points whose proportion is independent of the degree of purity of the individual
– parr spots (when present, or in the absence of dark vertical bands) always on several rows and in a number greater than 9.
Further analyzes will be carried out in the coming weeks taking into consideration the genetic results obtained through the use of SNPs which provide a more precise picture of the total introgression rates and those of each individual.