Complete mitochondrial genome of the hydrothermal vent stalked barnacle Vulcanolepas fijiensis (Cirripedia, Scalpelliforms, Eolepadidae)

The Mitochondrial Genome of the Globally Invasive Barnacle Megabalanus coccopoma Darwin 1854 (Crustacea: Balanomorpha): Rearrangement and Phylogenetic Consideration within Balanomorpha

Megabalanus coccopoma (Darwin, 1854) is a globally invasive species in Balanomorpha (Crustacea). This species is a model organism for studying marine pollution and ecology. However, its mitogenome remains unknown. The mitogenome sequencing of M. coccopoma is completed in the present study. It has a 15,098 bp in length, including 13 protein-coding genes (PCGs), 2 ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), along with a putative regulatory area. A substantial A+T bias was observed in the genome composition (68.2%), along with a negative AT (0.82) and GC (−0.136) skew. Compared to the gene sequence of the ground model of pan-crustacea, 13 gene clusters (or genes), such as 10 tRNAs and 3 PCGs, were observed in a different order. This was in line with the previously observed large-scale gene rearrangements of Balanomorpha. Among the 37 genes, the gene cluster (M-nad2-W-cox1-L2-cox2-D-atp8-atp6-cox3-G- nad3-R-N-A-E-S1) Balanomorpha was conserved. Furthermore, phylogeny analysis indicated that the existing Balanomorpha species family was divided into nine rearrangement patterns, supporting the polyphyly of Balanoidea.

The first mitochondrial genome of Capitulum mitella (Crustacea: Cirripedia) from China: revealed the phylogenetic relationship within Thoracica

Capitulum mitella (Crustacea: Cirripedia) is an important stalked barnacle. The first mitochondrial genome of C. mitella from China was presented, which is a circular molecule of 15,930 bp in length and AT content is 64.4%. It encodes 37 genes, including 13 PCGs, 22 tRNAs, and two rRNAs, which is consistent with most barnacles species reported. There are 15 genes encoded on the light strand and 22 genes encoded on the heavy strand. Identical to most barnacles species reported, srRNA and lrRNA genes are adjacent and separated only by trnV gene. Phylogenetic trees showed that C. mitella clustered with Pollicipes polymerus, indicating Pollicipedidae is monophyletic. However, Scalpelliformes was not monophyletic from the phylogenetic tree. From the level of order, the Lepadiformes was located at the base of the phylogenetic tree, indicating that its divergence time was earlier than Scalpelliformes. The results provided more insights into phylogenetic consideration at the genomic level within superorder Thoracica.