Effects of developmental mode on genome size in shrimps (Dendrobranchiata and Caridea)

Abstract

Abstract Studies on genome size (GS) aim to quantify the amount of DNA in an organism’s genome. Crustaceans are an excellent group in which to study GS from an evolutionary perspective since they are ubiquitous in almost all environments and show substantial variation in genome size. We evaluated the range of GS across two shrimp groups (Decapoda), focusing on differences in GS with different reproductive and developmental backgrounds. We also mapped GS as related to phylogeny to examine how nuclear DNA content changes in these two major groups of decapods. The most basal group, the Dendrobranchiata (represented by the superfamily Penaeoidea, with 14 species evaluated) had low GS values ranging 1.56–5.23 picograms. This group also has the most ancestral development mode, hatching as nauplius and following and extended pattern in what we refer to as “regular development.” By contrast, Pleocyemata, represented by the most derived shrimp taxa from infraorder Caridea (77 species evaluated), exhibits a variable set of GS values, ranging 3.71–22.40 picograms. This group undergoes a more advanced, shortened developmental mode, hatching as a zoea or even as an advanced zoea. We propose a relationship between the type of development, phylogenetic position, and genome size, where the basal group exhibiting the most wide-ranging type of development, showing lower GS values. More derived groups, which tend to have a shorter developmental mode, exhibit more plastic GS values and higher genome sizes reported in the literature.