Species have shown their habital variations in responding to climate change, especially during the spring and summer spawning seasons. The species distribution model (SDM) is considered the most favorable tool to study the potential effects of climate change on species distribution. Therefore, we developed the ensemble SDM to predict the changes in species distribution of Portunus trituberculatus among different seasons in 2050 and 2100 under the climate scenarios RCP4.5 and RCP8.5. The results of SDM indicate that the distribution of this species will move northward and have obviouse seasonal variations. Meanwhile, the suitable habitat for the species will be significantly reduced in summer, with loses rates ranging from 45.23% (RCP4.5) to 88.26% (RCP.8.5) by 2100s. Habitat reduction will mainly occur in the East China Sea and southern part of the Yellow Sea, while there will be a small increase in the northern Bohai Sea. These findings will be important to manage the ecosystem and fishery, provide an information forecast of this species in the future, and maintain species diversity if the seawater temperature rises.

Our understanding of phylogenetic relationships among Gadiformes fish is obtained through the analysis of a small number of genes, but uncertainty remains around critical nodes. A series of phylogenetic controversial exists at the suborder, family, subfamily, and species levels. A total of 1105 orthologous exon sequences and translated amino acid sequences from 36 genomes and 12 transcriptomes covering 33 species were applied to investigate the phylogenetic relationships within Gadiformes and address these problems. Phylogenetic trees reconstructed with the amino acid data set using different tree-building methods (RAxML and MrBayes) showed consistent topology. The monophyly of Gadifromes was confirmed in our study. However, the three suborders Muraenolepidoidei, Macrouroidei, and Gadoidei were not well recovered by our phy-logenomic study, rejecting the validity of suborder Muraenolepidoidei. Four major lineages were revealed in this study. The family Bregmacerotidae forming clade I was the basal lineage of Gadiformes. The family Merluciidae formed clade II. Clade III contained families Melanonidae, Muraenolepididae, Macrouridae (with subfamilies Trachyrincinae, Macrourinae, and Bathygadinae), and Moridae. Clade IV contained at least three families of suborder Gadoidei, i.e., Gadidae, Phycidae, and Ranicipitidae. The subspecies of Lota lota from Amur River were confirmed, indicating that exon markers were a valid high-resolution method for delimiting subspecies or distinct lineages within species level. The PSMC analysis of different populations of L. lota suggests a continuous decline since 2 Myr.