Entity

Time filter

Source Type

Singapore, Singapore

Jensen K.R.,Universitetsparken 15 | Ong R.S.L.,National Biodiversity Center
Raffles Bulletin of Zoology | Year: 2015

Spawning was observed in the laboratory and documented by video for a specimen of Lobiger viridis Pease, 1863 (Mollusca: Gastropoda: Heterobranchia: Sacoglossa) from Changi East, Singapore. The spawning animal shaped the egg mass with its mouth-area and the anterior rim of its foot. The head moved from side to side, presumably adding secretions, as the egg mass progressed. The egg mass was shaped as a more or less irregular, elongate spiral. It took approximately three hours to complete the first egg mass, and a second fertile egg mass was produced after 24 hours. The eggs were yellow when deposited but turned pale after several days as shelled veliger larvae developed. A single egg mass was estimated to contain more than 20,000 eggs. Preserved egg capsules were approximately 120 × 90 μm, and veligers had distinct statocysts but no eyes when they were ready to hatch. At this stage veliger shells had maximum diameters of about 106 μm. © National University of Singapore. Source


Von Rintelen K.,Humboldt University of Berlin | Page T.J.,Griffith University | Cai Y.,National Biodiversity Center | Roe K.,Iowa State University | And 5 more authors.
Molecular Phylogenetics and Evolution | Year: 2012

Atyid freshwater shrimps are globally distributed and form an important part of freshwater ecosystems, particularly in the tropics and subtropics. Despite their widespread distribution and ecological importance, their phylogenetic relationships are largely unresolved. Here we present the first comprehensive molecular phylogeny of the Atyidae investigating the evolutionary relationships among 32 of the 42 genera using mitochondrial and nuclear markers. Our data indicate that the established classification of the Atyidae is in need of substantial taxonomic revision at all taxonomic levels. We suggest a new suprageneric systematization of atyids and discuss problematic issues at the generic level, particularly in the most speciose genus, Caridina. Molecular clock based divergence time estimates for atyids vary widely, but invariably support the assumption that atyids are an ancient freshwater lineage with an origin in the mid-Cretaceous at the very latest. Atyid distribution patterns are the result of instances of both long-distance dispersal and vicariance, depending largely on the reproductive mode of taxa. From an evolutionary perspective, the high frequency of independent origin of both a complete (landlocked) freshwater life cycle and a cave-dwelling mode of life is remarkable and unparalleled among crustaceans. © 2011 Elsevier Inc. Source


Orr A.G.,Griffith University | Ngiam R.W.J.,National Biodiversity Center
International Journal of Odonatology | Year: 2011

The larva of Heliaeschna uninervulata is described and figured for the first time. Its characters mostly fall within the limits of variation of Gynacantha spp. Comparison of the larval characters of H. filostyla, the only other member of the genus for which the larva is known, suggests that it is not congeneric with H. uninervulata. © 2011 Worldwide Dragonfly Association. Source


Davison G.W.H.,National Biodiversity Center
Raffles Bulletin of Zoology | Year: 2013

Henry Eeles Dresser wrote and published the nine-volume A History of the Birds of Europe (1871-1882, 1895-1896). This drew a definitive line under the binomial system of nomenclature for European birds. It was succeeded by a period of vigorous exchange amongst the whole community of ornithologists on the merits of trinomial (subspecies) nomenclature, in which the social and financial similarities, and the scientific and intellectual differences, of Dresser and of Henry Seebohm were important. These two friends were influential in determining the framework of the debate, in attracting men of science to Britain to work on the issue, and in publishing a series of works that progressively enlarged in scope to cover the whole of the Palaearctic region. Ironically, each provided support that helped to promote the views of the other, Seebohm by helping to secure subscribers for Dresser, and Dresser by facilitating careers for adherents to Seebohm's ideas. History has shown Seebohm to have had the greater vision and breadth of interests, enabling him to generate ideas that helped to mould modern thinking. © National University of Singapore. Source


Tay T.S.,National University of Singapore | Low J.K.Y.,National Biodiversity Center
Raffles Bulletin of Zoology | Year: 2016

Seabed sampling by dredging and trawling in non-coral reef areas off the island of Singapore to depths of 160 m showed that crinoids were present in more than 30% of the 354 subtidal locations sampled. Approximately 1500 specimens were collected, accounting for 26 nominal species. All belonged to the order Comatulida. Six families were recorded, amongst which the dominant families were Comatulidae (73%) and Himerometridae (23%). The majority of specimens were found in the Singapore Strait that serves one of the busiest container ports in the world and where extensive reclamation have been carried out over the last 50 years. Mean species diversity per survey was generally low (2.7 ± 2.2 species) although one survey recorded at least 12 species. Most species occurred over a wide range of depths and some species, including Comatula cf. solaris and Zygometra comata, both of which can be found between depths of 7 m to 130 m. Of the 26 species recorded, 11 had been previously recorded from coral reefs in Singapore. Mean species density was 0.03 ± 0.05 m-2 and was lower than values known from coral reef habitats in the Indo-Pacific region. Maximum density however, was 0.4 individuals m-2, at east of the Singapore Strait. This value is comparable to coral reefs elsewhere in the Indo-Pacific region, showing that non-coral reef habitats can support similar densities of crinoids. This is the first extensive study focusing on the distribution and characterization of crinoids in Singapore’s non-coral reef habitats. While many crinoids can be found in coral reef habitats, non-coral reef habitats with sufficient productivity and water movement appear to be able to support high densities of crinoids despite chronic anthropogenic disturbances caused by shipping and land reclamation. © National University of Singapore. Source

Discover hidden collaborations