Daniel Leduc

Daniel Leduc
National Institute of Water and Atmospheric Research | NIWA · Oceans Centre

PhD

About

118
Publications
42,362
Reads
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1,780
Citations
Citations since 2017
50 Research Items
1260 Citations
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
Additional affiliations
January 2013 - present
National Institute of Water and Atmospheric Research
Position
  • Researcher
January 2010 - December 2012
University of Otago
Position
  • PostDoc Position
January 2009 - December 2009
University of Otago
Position
  • Research Assistant

Publications

Publications (118)
Article
Full-text available
Relatively little is known about the taxonomy and ecology of deep-sea nematode species inhabiting cold seep habitats. The available data show that cold seep nematode communities are typically characterized by low diversity and are often dominated by a single species, although no nematode taxon appears to have a strong association with methane seepa...
Article
One new Comesoma Bastian, 1865 species and one known Sphaerolaimus species are described from the intertidal areas of a sand beach and mangrove wetland, respectively, in Beihai City, P.R. China (South China Sea) using morphological and molecular data. Comesoma sinica n. sp. is characterised by body length 2366-2925 μ m, long cephalic setae 24-32 μ...
Article
Full-text available
The family Haliplectidae is reported from Iran for the first time and Haliplectus iranicus sp. n., from a mangrove forest in the Persian Gulf, is described. The new species is characterised by one ventromedian supplement near to cloacal aperture and a group of three supplements, 10-15 μ m anterior to cloacal opening, absence of protuberant caudal p...
Article
Full-text available
Hadal trenches are depocenters for organic material, and host intensified benthic microbial activity. The enhanced deposition is presumed to be reflected in elevated meiofaunal standing-stock, but available studies are ambiguous. Here, we investigate the distribution of meiofauna along the Atacama Trench axis and adjacent abyssal and bathyal settin...
Article
Zalonema sesoskoensis n. sp. is described from shallow subtidal sediments of Sesoko Island. The new species is characterised by annulated cuticle with minute spines, male with ventral and lateral alae, circle of eight subcephalic setae between cephalic setae and anterior edge of amphideal fovea, amphideal fovea with 3.5 turns in male and 2.5 turns...
Article
Full-text available
One new nematode species is described and two new species records are provided from the edge (6,080 m depth) and axis (7,132 m) of Kermadec Trench, Southwest Pacific. Leptolaimus hadalis sp. nov. is characterised by medium body 587–741 μm long, labial region not offset from body contour, inconspicuous labial sensilla, amphid located 12–19 μm from a...
Article
Full-text available
Recent work on the taxonomy of nematodes in Southwest Pacific Ocean trenches has led to the discovery of taxa which so far appear to be restricted to the oceans’ deepest environments. Here, Litinium gludi sp. nov. is described based on specimens obtained from a deep basin within the Kermadec Trench at 9540 m water depth. The new species differs fro...
Article
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The Kermadec Trench is the world’s fifth deepest trench and extends from approximately 26 to 36°S near the northeastern tip of New Zealand’s North Island. Here, we describe a new species of Aegialoalaimus, a nematode genus with unusual buccal cavity and pharynx morphology, from a site at 9540 metres water depth in Kermadec Trench, and provide the f...
Article
Full-text available
Turbidity flows – underwater avalanches – are large-scale physical disturbances that are believed to have profound and lasting impacts on benthic communities in the deep sea, with hypothesized effects on both productivity and diversity. In this review we summarize the physical characteristics of turbidity flows and the mechanisms by which they infl...
Article
Full-text available
The Desmodoridae is a diverse and widespread family of free-living nematodes. Here, we provide the first record of the group in the Persian Gulf and describe three new species: Metachromadoroides sinuspersici sp. n., Zalonema iranicum sp. n. and Z. supplementorum sp. n. Metachromadoroides sinuspersici sp. n. is characterised by finely annulated cut...
Article
Full-text available
Human activities alter biodiversity, influencing bottom-up and top-down control on food webs which can affect ecosystem functioning. In marine ecosystems, large bivalves play a critical role in benthic–pelagic coupling including nutrient cycling; however, their influence on the uptake of detrital organic matter by benthic communities is less unders...
Article
Full-text available
The Selachinematidae is a globally distributed family of predatory nematodes found from shallow waters to the abyssal plain. Here, three new species of Halichoanolaimus de Man, 1886 (H. ossilagulus sp. nov., H. funestus sp. nov. and H. pumilus sp. nov.) and one known species (H. ovalis Ditlevsen, 1921) are described from the New Zealand continental...
Article
Full-text available
Recently, Danovaro et al. [1] prioritized deep-sea essential ecological variables (DEEVs), based on opinions from 112 deep-sea experts worldwide, to support development of a global deep-ocean monitoring and conservation strategy. While a set of universally important DEEVs is necessary to ensure appropriate monitoring, we challenge the conclusion th...
Preprint
Full-text available
Turbidity flows – underwater avalanches – are large-scale physical disturbances that are believed to have profound and lasting impacts on benthic communities in the deep sea, with hypothesised effects on both productivity and diversity. In this review we summarize the physical characteristics of turbidity flows and the mechanisms by which they infl...
Article
Full-text available
Two new species of the order Plectida are described from Chatham Rise, New Zealand. Leptolaimus dififtinus sp. nov. is characterised by the short body 319-420 microns long, truncate labial region slightly offset from body contour and bearing conspicuous outer labial papillae, cephalic setae 1.3-1.4 microns long, amphid located 4-9 microns from ante...
Article
Full-text available
Studies have shown the importance of submarine canyons as conduits of land-derived organic carbon beyond the coastal shelf into the deep-sea where a single obvious river source can be identified. When there is more than one river source, identifying which rivers contribute to canyon sediment organic matter is technically challenging. Here, we compa...
Article
Full-text available
We provide a review of the enoplid suborder Trefusiina Siddiqi, 1983, based on morphological considerations and analyses of new and published 18S rDNA sequences. We also describe Halanonchus scintillatulus Leduc sp. nov. from the Hauraki Gulf, northern New Zealand, as well as females of Trefusialaimus idrisi Leduc, 2013 from the continental slope o...
Article
Full-text available
Chromadorina is a globally distributed, largely marine nematode genus frequently found on a variety of organisms, including macro- and microalgae and crustaceans, as well as artificial substrates such as settlement plates and ship hulls. Here, Chromadorina tangaroa sp. nov. is described from filamentous seaweed growing on the hull of RV Tangaroa an...
Article
Full-text available
Synonchium iranicum sp. n. and Richtersia bispinata sp. n. are described from the Persian Gulf and their relationships investigated using SSU phylogenetic analyses. Synonchium iranicum sp. n. is characterised by a buccal cavity with three equally sized mandibles, each with five small teeth, a rounded tail with three distinct caudal glands and disti...
Article
Full-text available
Submarine canyons can facilitate the transfer of land‐derived organic matter to the deep sea. Here, we investigated links between variability in organic matter availability from land and marine sources and infauna communities in two contrasting canyon systems off New Zealand and used stable isotope analyses to identify potential food sources of ben...
Article
Full-text available
Predicting the impacts of anthropogenic disturbance on deep-sea ecosystems requires a thorough understanding of both environmental and faunal drivers of ecosystem function. Studies of deep-sea ecosystems, however, typically consider environmental drivers only and seldom investigate the effects of seabed communities on ecosystem processes. Here, we...
Article
The current nematode classification comprises three primarily marine basal Chromadorean orders: the Microlaimida Leduc et al., 2018; Desmodorida De Coninck, 1965; and Chromadorida Chitwood, 1933. The phylogenetic placement of several taxa within these orders, however, is unclear due to the paucity of taxonomically informative morphological characte...
Poster
Full-text available
Over the last two decades, molecular phylogenetic analyses have greatly improved our understanding of nematode classification and evolution. Since the last comprehensive treatment of the phylum (Schmidt-Rhaesa 2014), phylogenetic analyses based mainly on SSU sequences have led to several major changes in marine nematode classification, and the nema...
Article
Full-text available
Three new species of the free-living marine nematode genus Dorylaimopsis are described from the South China Sea and the Chukchi Sea. Dorylaimopsis longispicula sp. n. is characterized by cuticle with lateral differentiation consisting of four longitudinal rows of larger dots in pharyngeal and tail regions, two rows of larger dots elsewhere, long cu...
Article
One new Sabatieria Rouville, 1903 and one new Hopperia Vitiello, 1969 species are described from Conway Trough off the east coast of New Zealand’s South Island based on light and scanning electron microscope observations and SSU and D2-D3 of LSU molecular sequences. Additional morphological observations and molecular sequence data are also provided...
Article
Full-text available
Benthimermithid nematodes are parasites of invertebrates currently classified within their own order. Relationships between the Benthimermithida and other nematode orders, however, remain unclear due to their relatively simple morphology, their rarity, and paucity of molecular sequence data. Here, we combine molecular sequences obtained from Tropho...
Poster
Full-text available
We used bulk stable isotope and compound-specific isotope analyses to determine the sources of organic matter in sediments of two contrasting canyon systems on either side of the active plate boundary and associated uplifted mountain divide of the South Island off New Zealand (Southwest Pacific): Kaikoura Canyon, a steep canyon close to the shore o...
Article
Full-text available
Spirinia parasitifera is a common nematode species recorded from coastal habitats of the White, North and Barents Seas, the Northwest Atlantic, the Maldives and Australia, and exhibits a high degree of variability in some morphological characters. For these reasons it has been suggested that S. parasitifera is a species complex comprised of several...
Preprint
Full-text available
Research Infrastructures (RIs) are facilities, resources and services used by the scientific community to conduct research and foster innovation. LifeWatch ERIC has developed various virtual research environments, which include many virtual laboratories (vLabs) offering high computational capacity and comprehensive collaborative platforms that supp...
Preprint
Full-text available
Research Infrastructures (RIs) are facilities, resources and services used by the scientific community to conduct research and foster innovation. LifeWatch ERIC has developed various virtual research environments, which include many virtual laboratories (vLabs) offering high computational capacity and comprehensive collaborative platforms that supp...
Article
Tripylella jianjuni sp. n. (Tripylidae) is described from New Zealand. Females are characterised by a relatively long body (1743 (1675-1860) μm in the female and 1747 (1576-1979) μm in the male), outer labial setae (8-9 μm long) and cephalic setae (4-5 μm long) in a single circle, two large subventral teeth in two adjacent stomatal chambers, relati...
Preprint
Full-text available
Research Infrastructures (RIs) are facilities, resources and services used by the scientific community to conduct research and foster innovation. LifeWatch ERIC has developed various virtual research environments, which include many virtual laboratories (vLabs) offering high computational capacity and comprehensive collaborative platforms that supp...
Article
Full-text available
Link to read-only article: http://rdcu.be/rtjd Pollen is ubiquitous in nearshore marine sediments; however, its potential importance for food-limited deep-seabed communities remains unknown. Here we report on the distribution of pollen to depths of 10,800 m in two Southwest Pacific trenches, as well as relationships between pollen concentrations a...
Article
Hadal trenches are characterised by environmental conditions not found in any other deep-sea environment, such as steep topography and periodic disturbance by turbidity flows, which are likely responsible for the distinct nature of benthic communities of hadal trenches relative to those of the abyssal plain. Nematodes are the most abundant metazoan...
Article
The placement of the rare deep-sea nematode order Rhaptothyreida remains unclear due to the unique morphology of this group, an unknown life cycle with morphologically distinct juvenile stages which may or may not be parasitic, and lack of molecular sequences. Here, we investigate the phylogenetic placement and status of the Rhaptothyreida based on...
Article
Full-text available
Because of their relatively simple body plan, the number of morphological characters used to differentiate between closely related nematode genera is often limited. In addition, boundaries among genera sometimes become blurred due to the appearance of new trait combinations as more new species are described. Molecular phylogenetic analyses can addr...
Article
Full-text available
Extreme marine environments cover more than 50% of the Earth’s surface and offer many opportunities for investigating the biological responses and adaptations of organisms to stressful life conditions. Extreme marine environments are sometimes associated with ephemeral and unstable ecosystems, but can host abundant, often endemic and well-adapted m...
Article
Deep-sea community attributes vary at a range of spatial scales. However, identifying the scale at which environmental factors affect variability in deep-sea communities remains difficult, as few studies have been designed in such a way as to allow meaningful comparisons across more than two spatial scales. In the present study, we investigated nem...
Article
Full-text available
free access: https://academic.oup.com/zoolinnean/article/doi/10.1093/zoolinnean/zlx072/4560798/Phylogenetic-position-of-the-Paramicrolaimidae?guestAccessKey=185f89c2-556f-4aea-af93-4dd9b8b2e69c The phylogenetic position of Paramicrolaimidae Lorenzen, 1981, a rare group of marine free-living nematodes, has been the subject of debate due to the uniq...
Article
Full-text available
For full text: http://rdcu.be/wwUh Meiofauna are an important component of deep-sea benthic communities because they are highly abundant and play an important role in the sediment. This review describes trends in the ecology of deep-sea meiofauna based on results from studies published since the review by Soltwedel (2000), with a focus on spatial...
Data
Respiration data Oxygen levels in five cores incubated from Chatham Rise, 490 m depth.
Article
Full-text available
Sediment community oxygen consumption (SCOC) is a proxy for organic matter processing and thus provides a useful proxy of benthic ecosystem function. Oxygen uptake in deep-sea sediments is mainly driven by bacteria, and the direct contribution of benthic macro-and mega-infauna respiration is thought to be relatively modest. However, the main contri...
Article
Full-text available
A new species of the predatory nematode genus Sphaerolaimus is described from the continental shelf off northeastern New Zealand, and an updated list of valid Sphaerolaimus species is provided. Sphaerolaimus haurakiensis n. sp. is characterised by eight longitudinal rows of 10–16 μm long somatic setae becoming gradually sparser posteriorly, six out...
Article
Full-text available
Four new nematode species of the order Araeolaimida are described from the continental slope of New Zealand: Sabatieria megadena sp. n., Pararaeolaimus tetradenus sp. n., Southerniella parasimplex sp. n., and Diplopeltula cuspidiboja sp. n. The present study provides the first record of the genus Pararaeolaimus in the New Zealand Exclusive Economic...
Article
Full-text available
Research on benthic communities in the deep sea has focused largely on habitats in isolation, with few studies considering multiple habitats simultaneously in a comparable manner. The present study aimed to determine the structural differences in benthic communities of continental slope, seamount, canyon, vent, and seep habitats, and assess their r...
Article
Full-text available
Odontophora is a globally distributed marine nematode genus common in intertidal and subtidal sediments. Odontophora is one of the most diverse genus of the family Axonolaimidae with over 30 valid species described to date; however, the last revision of the genus was made over four decades ago. In addition, limited molecular sequence data are avail...
Article
Full-text available
Acanthopharynx dormitata sp. n. and Desmodora bilacinia sp. n. are described from intertidal sediments of Wellington, North Island of New Zealand. Acanthopharynx dormitata sp. n. is characterised by a cephalic capsule with a crown of 14 setae (four cephalic and ten subcephalic setae) and 24 additional subcephalic setae arranged in eight longitudina...
Article
Full-text available
Studies of deep-sea benthic communities have largely focused on particular (macro) habitats in isolation, with few studies considering multiple habitats simultaneously in a comparable manner. Compared to mega-epifauna and macrofauna, much less is known about habitat-related variation in meiofaunal community attributes (abundance, diversity and comm...
Data
Results of PERMANOVA analysis test for the effects of habitat, water depths, sediment depth and their interaction on meiofaunal abundance at the Hikurangi Margin and Bay of Plenty study region.
Data
Results of second-stage analysis for stations from 700, 1,000 and 1,200 m water depth strata showing meiofaunal abundance and diversity between habitats and sediment depths for Hikurangi Margin. [Abundance shown in total meiofauna individuals per 10 cm2; diversity as meiofaunal taxon richness].
Data
Raw data for regional analysis. Data used for PERMANOVA analysis on community attributes between Hikurangi Margin and Bay of Plenty.
Data
List of final environmental variables that were used in the DistLM analysis and the correlated variables that were removed prior to analysis of meiofauna for Hikurangi Margin and Bay of Plenty region. [STD = Standard deviation of depth based on 3, 5, 7, 15 grid cell focal mean, Slope STD = Standard deviation of slope, Vrm = terrain rugosity, range...
Data
Results of PERMANOVA analysis test for the effects of habitat, water depths, sediment depth and their interaction on meiofaunal diversity at the Hikurangi Margin and Bay of Plenty study region. Significant factors at the 5% level are shown in bold. [df = degrees of freedom, SS = sum of squares, MS = mean square, Pseudo-F = Pseudo-F statistic, P = P...
Data
Raw data for DistLM analysis for each region, Hikurangi Margin and Bay of Plenty.
Data
SIMPER analysis results showing environmental variables accounting for regional dissimilarity between the Hikurangi Margin and Bay of Plenty study regions (cut-off applied at 70% contribution). [Av.Value = average environmental variable value, Av.Sq.Dist = average dissimilarity, Sq.Dist/SD = Dissimilarity/Standard Deviation, Contrib% = % contributi...
Data
Results of PERMANOVA analysis test for the effects of habitat, water depths, sediment depth and their interaction on meiofaunal community structure at the Hikurangi Margin and Bay of Plenty study region. The effect of spatial covariates were taken into account for community analysis (result not shown). Significant factors at the 5% level are shown...
Data
Results of PERMANOVA analysis tests on second stage analysis. Results showed the effects of habitat (slope, canyon, seamount and seep), water depths (700 m, 1,000 m, 1,200 m), sediment depth and their interaction on meiofaunal community structure at the Hik. Significant factors at the 5% level are shown in bold. [df = degrees of freedom, SS = sum o...
Data
Raw data for PERMANOVA analysis at each region, Hikurangi Margin and Bay of Plenty. Data used for PERMANOVA analysis on community attributes at each region Hikurangi Margin and Bay of Plenty. Data for second stage analysis at Hikurangi Margin sites also included.
Poster
Full-text available
Nemys, the online nematode biodiversity information system erected from the filing cabinet at Ghent University (Belgium) in 1998, is now integrated into the World Register of Marine Species (WoRMS) hosted at the Flanders Marine Institute (VLIZ). This transfer was accompanied by the appointment of an international editor community consisting of expe...
Article
Full-text available
Limited molecular sequence data are available for selachinematid nematodes, with little or no data from the Southern Hemisphere or habitats beyond the subtidal zone. Here, we provide molecular sequence data for the small subunit (SSU) 18S rDNA gene and D2–D3 region of large subunit (LSU) 28S rDNA gene of three new (Cheironchus haurakiensis n. sp.,...
Article
Full-text available
Parasitic nematodes have evolved to exploit a wide variety of hosts living in a range of marine environments. Benthimermithid nematodes occur deeper than any other nematode parasites (down to 5880 m depth) but are mostly known from free-living adult stages living in the sediments, and parasitic juveniles are seldom encountered. In the present study...
Article
The spread of human activities into the deep sea may pose a high risk to benthic communities and affect ecosystem integrity. The deep sea is characterized by physical and biological heterogeneity and different habitat types are likely to differ in their vulnerability to anthropogenic impacts. However, across-habitat comparisons are rare, and no com...
Article
Three nematode species of the superfamily Desmodoroidea Filipjev, 1922, were isolated from beach sediments in Wellington, New Zealand, for morphological and molecular analyses. Two of these species, Desmodorella verscheldei sp. nov. and Dracograllus ngakei sp. nov., were new to science and are described herein. Epsilonema rugatum Lorenzen, 1973, co...
Article
Full-text available
New deep-sea nematodes of the family Microlaimidae are described from the Southwest Pacific Ocean and Ross Sea. Microlaimus korari n. sp. is characterised by annulated cuticle with longitudinal bars, round amphideal aperture slightly smaller than the cryptospiral amphideal fovea, spacious and heavily cuticularised buccal cavity with large dorsal to...