Nicholas Wei Liang Yap
Tropical Marine Science Institute, National University of Singapore, S2S Building, 18 Kent Ridge Road, Singapore 119227
St. John’s Island National Marine Laboratory, c/o Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, Singapore 119227.
Michela Lee Mitchell
Biodiversity and Geosciences, Museum of Tropical Queensland, 70-102 Flinders Street, Townsville, Queensland, Australia.
Zheng Bin Randolph Quek
Department of Biological Sciences, National University of Singapore, Block S3 Level 4, 16 Science Drive 4, Singapore 117558.
Ria Tan
c/o Lee Kong Chian Natural History Museum, National University of Singapore, 2 Conservatory Drive, Singapore 117377.
Koh Siang Tan
Tropical Marine Science Institute, National University of Singapore, S2S Building, 18 Kent Ridge Road, Singapore 119227
St. John’s Island National Marine Laboratory, c/o Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, Singapore 119227.
Danwei Huang
Tropical Marine Science Institute, National University of Singapore, S2S Building, 18 Kent Ridge Road, Singapore 119227
Department of Biological Sciences, National University of Singapore, Block S3 Level 4, 16 Science Drive 4, Singapore 117558
c/o Lee Kong Chian Natural History Museum, National University of Singapore, 2 Conservatory Drive, Singapore 117377.
Communicated by James D. Reimer
Sea anemones (Cnidaria, Actiniaria) are a successful group of marine invertebrates found in a diverse range of environments globally. In spite of their ubiquity, identities for many sea anemones remain unverified, especially those from the Indo-West Pacific region. Here, we clarify the taxonomy of the poorly known Macrodactyla aspera, a shallow-water species first described from the Torres Straits in northern Australia. We re-describe M. aspera based on new morphological and molecular data gathered from the type specimen, other museum vouchers, and from fresh material collected from Singapore. We tested the monophyly of Macrodactyla using three mitochondrial (12S, 16S and cox3) and one nuclear (28S) marker based on three congeners, recovering this genus to be polyphyletic. As a consequence, we transferred M. doreensis to the genus Heteractis, and describe a new species, Macrodactyla fautinae sp. nov. While both M. aspera and M. fautinae sp. nov. share the same arrangement and number of complete mesenteries, a similar distribution of cnidae, and are not symbiotically associated with any other biota, M. fautinae sp. nov. has perforated, lobe-like verrucae on its column, and lacks nematocyst batteries on its tentacles, unlike M. aspera. These two species also occur in similar habitats in Singapore. Finally, because M. aspera strongly resembles Dofleinia armata, the latter species flagged as a danger to public health due to its ability to inflict painful stings, we tested the relationship between these species and found them not to be closely related. However, tentacles of M. aspera, like D. armata, are densely covered with nematocyst batteries and harbour large nematocysts; we infer that M. aspera may also be capable of delivering stings that endanger public health. This study builds upon a growing number of studies that aim to ascertain identities and systematics of sea anemones historically reported from the Indo-West Pacific. Our findings will facilitate accurate species identification, which is crucial for advancing research, formulating conservationmeasures, and protecting public health.
Supplementary materials
Map of Singapore where specimens of both
Macrodactyla aspera (Haddon & Shackleton, 1893) and
Macrodactyla fautinae sp.
nov.
were collected for this study: 1, Pulau Ubin OBS Camp (1°25'07.7"N, 103°55'44.3"E); 2, Pasir Ris (1°22'56.45"N, 103°57'3.88"E); 3, Changi Region beaches [this area encompass the following localities that are in very close proximity to each other: Changi beach, Changi beach near Carpark 4; Changi Point beaches; Changi Point SAF Chalet beach; Changi Point Ferry Terminal beach] (1°23'33.34"N, 103°59'20.94"E); 4, Pulau Sekudu (1°24'19"N, 103°59'17"E); 5, Chek Jawa (1°24'25"N, 103°59'23"E); 6, Beting Bronok (1°26'13.00"N, 104°02'58.00"E); 7, Changi beach near Carpark 7 (1°22'26.03"N, 104°0'24.79"E); 8, Changi East next to Changi water Reclamation Plant (1°18'45"N, 104°00'31"E); 9, Cyrene Reef (Terumbu Pandan) (1°15'28"N, 103°45'19"E). White circles represent
M. aspera, while stars (both black and white) denote the occurrences of
M. fautinae sp. nov., with the single black star indicating the type locality of this new species. Numbers not accompanied by any symbols indicate the presence of both species occurring at the same site. See main-text for full details.
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Distribution of
Macrodactyla aspera (Haddon & Shackleton, 1893) and
Macrodactyla fautinae sp. nov. 1. Murray Islands, Torres Straits. 2. Noumea, New Caledonia. 3. Perth, Western Australia. 4. Singapore. 5. Eilat, Israel. Symbols beside each number represent the occurrence of the sea anemones: circles being
M. aspera, stars represents
M. fautinae. Symbols that are coloured black denote the type locality of the species they represent. See main-text for full details.
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Maximum likelihood phylogram (RAxML) of concatenated dataset (
i.e., 12S, 16S, 28S and
cox3). Bootstrap resampling values under ML, and posterior probability values of Bayesian inference (BI), are indicated at the branches as ML/BI. Only bootstrap values > 50 and posterior probability > 0.8 are shown, values less than these limits are denoted by a dash (-).
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Maximum likelihood phylogram (RAxML) of 12S sequences. Bootstrap values (≥ 50) are indicated on branches.
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Maximum likelihood phylogram (RAxML) of 16S sequences. Bootstrap values (≥ 50) are indicated on branches.
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Maximum likelihood phylogram (RAxML) of 28S sequences. Bootstrap values (≥ 50) are indicated on branches.
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Maximum likelihood phylogram (RAxML) of cox3 sequences. Bootstrap values (≥ 50) are indicated on branches.
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Sea anemones species included in our phylogenetic analyses. Information on voucher specimens and associated museum catalogue numbers are provided here, if available. Dashes denote that such information is absent. Accession numbers in
bold denotes new sequences to this study. Abbreviations: AMNH, American Museum of Natural History, New York; CAS, California Academy of Sciences, San Francisco; Cat. nos., Catalogue numbers; KUNHM, University of Kansas Natural History Museum; ZRC, Zoological Records Collection, Lee Kong Chian Natural History Museum, Singapore.
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