Biodiversity Data Journal :
Research Article
|
Corresponding author: Danwei Huang (huangdanwei@nus.edu.sg)
Academic editor: Pavel Stoev
Received: 05 Dec 2016 | Accepted: 07 Feb 2017 | Published: 13 Feb 2017
© 2017 Rosa Poquita-Du, Chin Soon Lionel Ng, Jun Bin Loo, Lutfi Afiq-Rosli, Ywee Chieh Tay, Peter Todd, Loke Ming Chou, Danwei Huang
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Poquita-Du R, Ng C, Loo J, Afiq-Rosli L, Tay Y, Todd P, Chou L, Huang D (2017) New evidence shows that Pocillopora‘damicornis-like’ corals in Singapore are actually Pocillopora acuta (Scleractinia: Pocilloporidae). Biodiversity Data Journal 5: e11407. https://doi.org/10.3897/BDJ.5.e11407
|
Molecular sequence data have previously revealed the existence of cryptic species associated with the Pocillopora ‘damicornis-like’ coral. Recently, this species complex has been reclassified into three species including the resurrected P. acuta, which appears to have a wide distribution. Morphological characteristics described for P. acuta are present in corals previously identified as Pocillopora damicornis. To determine if the Pocillopora ‘damicornis-like’ colonies on Singapore’s reefs are P. acuta, P. damicornis, or both, we examined a new collection of Pocillopora using mitochondrial DNA data and morphology. We also compared specimen morphologies from past collections and examined the known regional distributions of both species. Our analyses show that most Pocillopora ‘damicornis-like’ corals in Singapore are P. acuta instead of P. damicornis. Findings here are important for coral diversity records in Singapore and will help clarify distributional limits of morphologically similar Pocillopora species.
biodiversity, cryptic species, distribution, museum specimens, phylogenetic analysis, Pocillopora
Numerous hard coral species exhibit substantial intraspecific morphological variation (
The genus Pocillopora Lamarck, 1816, is of special interest as it is characterised by exceptionally high levels of phenotypic variation (
Recently, P. acuta was re-established as an entirely separate species from P. damicornis based on differences in their mitochondrial open reading frame (ORF) sequences (
The morphological characteristics described for P. acuta are exhibited by corals previously identified as Pocillopora damicornis in Singapore. Based on this observation, we hypothesise that most of the Pocillopora colonies on Singapore’s reefs are likely to be P. acuta and not P. damicornis. Here, we examine a range of P. ‘damicornis-like’ (sensu
Results of this study are important for coral diversity records in Singapore and will also help clarify the geographical range limits of morphologically closely-related Pocillopora species. As one of the most widespread corals on Singapore's reefs (
Sixteen Pocillopora samples were collected from five coral reef sites across the southern offshore islands of Singapore. We focused on a wide range of colony morphologies that, following
Pocillopora specimens examined in this study. In situ appearances (A: HD159, D: HD162, G: HD161, J: HD160, M: HD154), with corresponding images of bleached skeletons (B, E, H, K, N). C, live specimen showing brown ring surrounding each oral opening (image by Jenny). F, I, branches from colonies shown in D and G respectively. L, O, calices and septa from colonies shown in J and M respectively. Scale bars represent 1 cm (B, E, H, K, N) and 1 mm (F, I, L, O) respectively.
Pocillopora specimens previously identified as P. damicornis from the Zoological Reference Collection, Lee Kong Chian Natural History Museum, Singapore (A, B: ZRC.1980.20.133; C, D: ZRC.1991.766; E, F: ZRC.1987.1538; G, H: ZRC.1987.1995; I, J: ZRC.1991.763; K, L: ZRC.1987.1537). A–F, colonies with thick branches; G–L, colonies with thinner branches. Scale bars represent 1 cm.
DNA was extracted by overnight digestion in hexadecyltrimethylammonium bromide (CTAB) and proteinase K, followed by phase separation using phenol: chloroform: isoamyl-alcohol (25:24:1). Polymerase chain reactions primed using FATP6.1 and RORF were performed according to
We compiled in Mesquite 3.10 (
We used RAxML 8.0.9 (
Our phylogenetic analysis of seven Pocillopora species recovers two moderately-supported monophyletic groups of P. meandrina + P. verrucosa (P. damicornis type γ) and ‘Clade 1’, as defined by
The topology and statistical supports within this clade match those obtained by
Pocillopora acuta Lamarck, 1816, p. 274;
Materials examined. MNHN-IK-2010-792 (holotype, Muséum national d’Histoire naturelle de Paris, France; type locality: Indian Ocean); see Table
Specimen no. |
Catalogue no. |
Locality |
Latitude, Longitude |
Date collected |
Collector |
Last identification |
RA1 |
- |
Raffles Lighthouse |
|
Oct 2015 |
R.C. Poquita-Du |
Pocillopora damicornis |
GA1 |
- |
Raffles Lighthouse |
|
Oct 2015 |
R.C. Poquita-Du |
Pocillopora damicornis |
SA1 |
- |
St. John’s Island |
|
Oct 2015 |
R.C. Poquita-Du |
Pocillopora damicornis |
HD154 |
ZRC.CNI.1067 |
Pulau Subar Darat |
|
Oct 2016 |
D. Huang |
Pocillopora acuta |
HD155 |
- |
Pulau Subar Darat |
|
Oct 2016 |
D. Huang |
Pocillopora acuta |
HD156 |
- |
Pulau Subar Darat |
|
Oct 2016 |
Y.C. Tay |
Pocillopora acuta |
HD157 |
ZRC.CNI.1068 |
Pulau Subar Darat |
|
Oct 2016 |
Y.C. Tay |
Pocillopora acuta |
HD158 |
- |
Pulau Subar Darat |
|
Oct 2016 |
Y.C. Tay |
Pocillopora acuta |
KA1 |
- |
Kusu Island |
|
Oct 2015 |
R.C. Poquita-Du |
Pocillopora damicornis |
HD159 |
ZRC.CNI.1069 |
Kusu Island |
|
Oct 2016 |
C.S.L. Ng |
Pocillopora acuta |
HD160 |
ZRC.CNI.1070 |
Kusu Island |
|
Oct 2016 |
C.S.L. Ng |
Pocillopora acuta |
HD161 |
ZRC.CNI.1071 |
Pulau Subar Laut |
|
Oct 2016 |
Y.C. Tay |
Pocillopora acuta |
HD162 |
ZRC.CNI.1072 |
Pulau Subar Laut |
|
Oct 2016 |
Y.C. Tay |
Pocillopora acuta |
HD163 |
- |
Pulau Subar Laut |
|
Oct 2016 |
Y.C. Tay |
Pocillopora acuta |
HD164 |
- |
Pulau Subar Laut |
|
Oct 2016 |
Y.C. Tay |
Pocillopora acuta |
HD165 |
- |
Pulau Subar Laut |
|
Oct 2016 |
Y.C. Tay |
Pocillopora acuta |
- |
ZRC.1980.3.20.133 |
Sentosa |
- |
Sep 1979 |
L.T. Chan |
Pocillopora damicornis |
- |
ZRC.1987.1537 |
Pulau Hantu |
- |
1987 |
L.M. Chou |
Pocillopora damicornis |
- |
ZRC.1987.1538 |
Pulau Hantu |
- |
1987 |
L.M. Chou |
Pocillopora damicornis |
- |
ZRC.1991.763 |
Pulau Hantu |
- |
1991 |
Reef Ecology Study Team |
Pocillopora damicornis |
- |
ZRC.1991.766 |
Singapore |
1991 |
Reef Ecology Study Team |
Pocillopora damicornis |
|
- |
ZRC.1987.1995 |
Singapore |
- |
- |
Reef Ecology Study Team |
Pocillopora damicornis |
Description. Colonial, densely caespitose (Fig.
Remarks. Colonies collected from Singapore’s reefs show great variation in branching morphologies, overlapping with those described for Pocillopora acuta and P. damicornis by
This study contributes to the limited data that have emerged from the South China Sea region on the identity of Pocillopora species. The recently-revived species P. acuta is described to have a wide distribution reaching from the central Pacific to the Indian Ocean (
Although we find no contemporary evidence of P. damicornis on Singapore’s reefs, the variability of colony branch thickness among specimens from past collections held at the LKCNHM (Fig.
The taxonomy of South China Sea Pocillopora remains poorly understood. A previous study has shown that Pocillopora ‘damicornis-like’ types 4 and 5 are present in Taiwan, while the Gulf of Thailand only hosts the latter type (
Broadly, Pocillopora acuta is present in both Taiwan and Gulf of Thailand, but P. damicornis appears to be limited to the northern South China Sea as it has thus far only been confirmed from Taiwan using the mitochondrial ORF. Further north at the Yaeyama Islands, Japan, P. damicornis is present but is likely rare relative to P. acuta (
Thus far ranging from the Central Pacific to the Indian Ocean through Singapore, Taiwan and Hawai’i, further sampling may reveal the presence of P. acuta in more localities in the Central Indo-Pacific. Overall, the emerging picture shows that most ‘damicornis-like’ corals in the southwestern South China Sea region are actually P. acuta instead of P. damicornis.
This study is funded by the National Research Foundation (Singapore) through the Marine Science R&D Programme (R-154-000-A25-281). We thank Bert Hoeksema and an anonymous reviewer for helping to improve the manuscript, and Chua Keng Soon (LKCNHM) for assistance with loans, imaging and cataloguing of specimens.