High degree of non-genetic phenotypic variation in the vascular system of crayfish: a discussion of possible causes and implications

Abstract In this study, the hemolymph vascular system (HVS) in two cambarid crayfishes, i.e. Marbled Crayfish, Procambarus virginalis Lyko, 2017 and Spiny Cheek Faxonius limosus (Rafinesque, 1817), is investigated regard of areas non-genetic phenotypic variation. Despite their genetic identity, specimens P. show variability certain features HVS. Thus, we describe varying branching patterns, sporadic anastomoses, different symmetry states marbled crayfish. We visualize our findings by application classical modern morphological methods, e.g. injection casting resin, micro-computed tomography scanning electron microscopy. By comparing for to vasculature sexually reproducing F. Astacus astacus , discuss variation HVS arthropods general. conclude that constant are hereditary, whereas identified study clonal must be caused factors and, congruent variations A. likely also variations. Both common causal variation, i.e., plasticity stochastic developmental discussed along regarding systems. Further aspects, such as significance phylogenetic interpretations discussed.