Drs. Erika C. Johnston & Scott C. Burgess, USA
Info
The two scientists, Dr. Erika C Johnston of the Hawaii Institute of Marine Biology and Dr. Scott C Burgess of Florida State University, were able to achieve a particularly significant success in 2023. They managed to describe a new Pocillopora species based on mitochondrial and nuclear genomic data , genetic data on algal symbionts, geographic isolation and a distribution pattern within reefs, to describe a new Pocillopora species that differs from other sympatric Pocillopora species.
Mitochondrial and nuclear genome data show that Pocillopora tuahiniensis is a distinct species related to Pocillopora verrucosa and belonging to a different clade than Pocillopora meandrina. However, the rough appearance of Pocillopora tuahiniensis colonies in situ is not easily distinguished from that of Pocillopora verrucosa or Pocillopora meandrina in Moorea.
Sequencing the mtORF region easily distinguishes Pocillopora tuahiniensis from other Pocillopora species.
Pocillopora tuahiniensis has been found in French Polynesia, Ducie Island and Rapa Nui.
On the Moorea fringing reef, Pocillopora tuahiniensis is very abundant at depths ≥10 m and is one of the most abundant Pocillopora species at these depths.
It is also found at lower depths in the shallow water of the fore reef and in the lagoon of the back reef.
At the same site where the scientists observed spawning of Pocillopora meandrina and Pocillopora verrucosa, we also observed spawning of Pocillopora tuahiniensis.
Pocillopora verrucosa and Pocillopora tuahiniensis are sister species and overlap in their distribution in Moorea in different habitats and depths.
Pocillopora verrucosa has a much wider geographic distribution throughout the Indo-Pacific compared to Pocillopora tuahiniensis, although the latter also occurs in part of the Pocillopora tuahiniensis range (French Polynesia, the Isle of Ducie and on Rapa Nui (Easter Island).
The close phylogenetic relationship between P. tuahiniensis and P. verrucosa and the overlap in their geographic ranges indicate that the temporal separation in gamete release, both in terms of day after new moon and minutes after sunrise on intersecting moon days, provides a mechanism for maintaining species boundaries (preventing gene flow) between these species.
Sister species Pocillopora verrucosa and Pocillopora tuahiniensis had similar niche widths and harbored the same specialized symbiont species (mostly Cladocopium pacificum), but the former was more abundant in the back reef and the latter was more abundant deeper in the front reef.
The holotype was 19 cm long, 16 cm wide and 15 cm high.
Color and pigmentation of the living colony:
Colonies can be brown, pink, or pale yellow, and like many Pocillopora species, pigment is concentrated in the mouth opening of the polyps, forming a dark ring.
The more colorful morphs can be seen in the original description, which can be found at the link below, on page 120 (Figs. C and D).
Habitat and biology:
On the Moorea fore reef, Pocillopora tuahiniensis is very common at depths of ≥10 m and is the most common Pocillopora species at these depths.
It is also found at much lower abundances at 5 and 10 m on the fore reef and in the lagoon on the back reef.
Reproduction: It is assumed that reproduction occurs via mass spawning, based on the mass spawning observed in the sister lineages, P. cf. verrucosa in the Red Sea and Pocillopora meandrina Dana 1846 and Pocillopora grandis Dana 1846 on the Great Barrier Reef.
Etymology:
The species name is derived from the Tahitian word for sister, tuahine.
Genomic data indicate that Pocillopora tuahiniensis is a sister species of Pocillopora verrucosa (mtorF haplotypes 3a, 3b, 3f, 3h) in French Polynesia.
The species name Pocillopora verrucosa is assigned to the mtorF haplotypes 3b, 3d, 3f, 3g from the Great Barrier Reef.
Since Pocillopora tuahiniensis was until recently only found in French Polynesia, the etymology of its name, i.e. Tahitian, reflects this geographic location, where it was first identified as a unique species using genomics.
We would like to express our particular gratitude to Dr. Erika C Johnston, who kindly provided us with a number of photos of the new Pocillopora species upon request.
Mitochondrial and nuclear genome data show that Pocillopora tuahiniensis is a distinct species related to Pocillopora verrucosa and belonging to a different clade than Pocillopora meandrina. However, the rough appearance of Pocillopora tuahiniensis colonies in situ is not easily distinguished from that of Pocillopora verrucosa or Pocillopora meandrina in Moorea.
Sequencing the mtORF region easily distinguishes Pocillopora tuahiniensis from other Pocillopora species.
Pocillopora tuahiniensis has been found in French Polynesia, Ducie Island and Rapa Nui.
On the Moorea fringing reef, Pocillopora tuahiniensis is very abundant at depths ≥10 m and is one of the most abundant Pocillopora species at these depths.
It is also found at lower depths in the shallow water of the fore reef and in the lagoon of the back reef.
At the same site where the scientists observed spawning of Pocillopora meandrina and Pocillopora verrucosa, we also observed spawning of Pocillopora tuahiniensis.
Pocillopora verrucosa and Pocillopora tuahiniensis are sister species and overlap in their distribution in Moorea in different habitats and depths.
Pocillopora verrucosa has a much wider geographic distribution throughout the Indo-Pacific compared to Pocillopora tuahiniensis, although the latter also occurs in part of the Pocillopora tuahiniensis range (French Polynesia, the Isle of Ducie and on Rapa Nui (Easter Island).
The close phylogenetic relationship between P. tuahiniensis and P. verrucosa and the overlap in their geographic ranges indicate that the temporal separation in gamete release, both in terms of day after new moon and minutes after sunrise on intersecting moon days, provides a mechanism for maintaining species boundaries (preventing gene flow) between these species.
Sister species Pocillopora verrucosa and Pocillopora tuahiniensis had similar niche widths and harbored the same specialized symbiont species (mostly Cladocopium pacificum), but the former was more abundant in the back reef and the latter was more abundant deeper in the front reef.
The holotype was 19 cm long, 16 cm wide and 15 cm high.
Color and pigmentation of the living colony:
Colonies can be brown, pink, or pale yellow, and like many Pocillopora species, pigment is concentrated in the mouth opening of the polyps, forming a dark ring.
The more colorful morphs can be seen in the original description, which can be found at the link below, on page 120 (Figs. C and D).
Habitat and biology:
On the Moorea fore reef, Pocillopora tuahiniensis is very common at depths of ≥10 m and is the most common Pocillopora species at these depths.
It is also found at much lower abundances at 5 and 10 m on the fore reef and in the lagoon on the back reef.
Reproduction: It is assumed that reproduction occurs via mass spawning, based on the mass spawning observed in the sister lineages, P. cf. verrucosa in the Red Sea and Pocillopora meandrina Dana 1846 and Pocillopora grandis Dana 1846 on the Great Barrier Reef.
Etymology:
The species name is derived from the Tahitian word for sister, tuahine.
Genomic data indicate that Pocillopora tuahiniensis is a sister species of Pocillopora verrucosa (mtorF haplotypes 3a, 3b, 3f, 3h) in French Polynesia.
The species name Pocillopora verrucosa is assigned to the mtorF haplotypes 3b, 3d, 3f, 3g from the Great Barrier Reef.
Since Pocillopora tuahiniensis was until recently only found in French Polynesia, the etymology of its name, i.e. Tahitian, reflects this geographic location, where it was first identified as a unique species using genomics.
We would like to express our particular gratitude to Dr. Erika C Johnston, who kindly provided us with a number of photos of the new Pocillopora species upon request.
