If corals are our life then Acropora are our Religion. So anytime we meet a new species of Acropora it’s always a real treat especially when we find one as characteristic as Acropora halmaherae. This very delicate, highly sculpted, very unique and typical bushy, skiny, branching Acropora is a real feast for the eye.It’s during a coral reef survey in North Sulawesi, in a protected, deep, and murky bay that we got lucky. The shallow part of the reef was completely damaged, probably due to former fish bombing. Not a great news, as it often starts a domino effect but the deeper part was pristine and amazing.
It’s only below 12 m (35ft) that the corals were healthy and fully covering the seafloor. From this point on this particular dive was a coral fanatic paradise. Probably among the most beautiful deep reef dive I’ve ever done, with rolling hills of plating Pachyseris, Echinopora, Echinophyllia, Mycedium, Turbinaria… with small patches of Fimbriaphyllia, Nemenzophyllia… and some quite large patch of the highly localized Acropora halmaherae that we met for the first time, and recorded for the first time in this part of Indonesia.
Acropora halmaherae: A very characteristic species
Acropora halmaherae, is very easy to ID, as its protruding, tubular corallites are very characteristics. Colonies are compact and bushy. They are composed of very thin branches which is not very common. Another characteristic is that the angle between primary and secondary branches is acute.
Axial and radial corallites are both tubular and of similar length down branches.
The wild coloration of Acropora halmaherae is not amazing but still interesting enough. Colonies are brown with light blue tips but deeper living Acropora are always a good surprise when it comes to captivity, often developing remarkable pigments under reef aquarium lighting.
From the heart of the coral triangle
Its name comes from Halmahera island in the North west of Indonesia, in the Mollucca province, the spice island center. This large, H shape island, stuck between Papua and Sulawesi, bathed by flowing pacific ocean water is a coral heaven, in the center of the coral triangle.
The distribution map of Acropora halmaherae from Corals of world, doesn’t include North Sulawesi, so it’s a first record for this area, extending slightly the distribution map. Discovering this unique species proves that there is just so much more to learn about corals we just hope we will have enough time.