Complete Mitochondrial Genome of Decametra tigrina (A.H. Clark, 1907) (Crinoidea, Comatulida, Colobometridae) and Phylogenetic Analysis

The mitochondrial genome of Decametra tigrina (A.H. Clark, 1907) was fully sequenced and characterized. This circular, double-stranded genome spans 15,794 bp and encompasses 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes. The arrangement of genes remains conserved, matching those of Cenometra bella and the MW405444 (submitted to GenBank as Oligometra serripinna). The base composition consists of 24.6% A, 47.6% T, 16.2% G, and 11.6% C. Most PCGs use ‘ATG’ as the initiation codon, with NADH4L and NADH5 initiating with ‘GTG’. Each PCG terminates with a complete stop codon (‘TAA’ or ‘TAG’). Twelve tRNA genes, three NADH genes, and two rRNA genes are located on the L strand, while the remaining genes reside on the H strand. Phylogenetic analysis utilizing all 13 PCGs demonstrated that D. tigrina forms a clade with MW405444 (submitted to GenBank as O. serripinna, reassessed here as D. tigrina) and Florometra sp. (MN883538). Decametra tigrina forms a sister group with C. bella; together, they cluster with Stephanometra indica (Mariametridae) and Zygometra comata (Zygometridae) in the ML tree.