# Genomic Resources for Imperiled Caribbean Reef‐Forming Corals (Hexacorallia: Scleractinia): Complete Mitochondrial Genomes of Dichocoenia stokesii, Diploria labyrinthiformis, Oculina patagonica, and Stephanocoenia intersepta

## TL;DR

This paper reports the first sequencing of mitochondrial genomes for four imperiled Caribbean reef-forming corals, providing resources for conservation and monitoring.

## Contribution

The study provides the first mitochondrial genome sequences for four coral species, including novel intron structures and phylogenetic insights.

## Key findings

- Mitochondrial genomes of four coral species were sequenced, revealing intron structures in key genes.
- Phylogenetic analysis based on protein-coding genes was conducted for the newly sequenced corals.
- The study identified unique intron insertions in the nad5 and cox1 genes in some species.

## Abstract

Coral reefs provide a wide variety of services essential to both marine ecosystems and human societies yet reef‐forming corals are currently facing a multitude of global and local environmental stressors. Long‐term monitoring of reef‐forming corals is of utmost importance for understanding the response of declining coral populations to environmental insult, and for their restoration. This study is a part of a greater long‐term goal that aims at generating genomic resources for imperiled corals in the greater Caribbean basin. To support the future monitoring of coral reefs using non‐intrusive eDNA strategies, we have sequenced for the first time the mitochondrial genome of four species of corals, three of them inhabiting the greater Caribbean basin: Dichocoenia stokesii,
Diploria labyrinthiformis
,
Oculina patagonica
, and
Stephanocoenia intersepta
and examined their phylogenetic placement. The mitochondrial genomes of Dicho. stokesii, Diplo. labyrinthiformis,
O. patagonica
, and
S. intersepta
are 17,171, 16,905, 14,856, and 19,461 bp in length respectively. All four studied coral mitochondrial genomes contain 13 protein coding genes (PCGs), 2 transfer RNA genes (tRNA), and 2 ribosomal RNA genes (rrnS and rrnL). In all four studied mitochondrial genomes, a long group I intron bisected the nad5 gene. Additionally,
S. intersepta
has a second group I intron 942 bp in length that bisected the cox1 gene, overlapping the nad5 group I intron. The rrL gene in the mitochondrial genome of
S. intersepta
is also bisected by a 7259 bp intron. The phylogenetic position of the species with newly assembled mitochondrial genomes was examined using a Maximum Likelihood phylogenetic analysis based on PCGs. These newly developed genomic resources (mitochondrial genomes) will support eDNA biomonitoring of reef‐forming coral inhabiting the greater Caribbean basin.

Mitochondrial genomes of imperiled Caribbean corals are sequenced. These genomic resources will support conservation initiatives.