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1.
Zootaxa ; 4949(2): zootaxa.4949.2.7, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33903347

RESUMO

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 first SSU and D2-D3 of LSU sequences for Aegialoalaimus, Manganonema, Metasphaerolaimus constrictus and Daptonema amphorum. Aegialoalaimus tereticauda n. sp. is characterised by body length 755-864 µm, cephalic sensilla papilliform ( 1 µm long), excretory pore located slightly anterior to posterior bulb in males and slightly anterior to nerve ring in females, arcuate spicules 18-22 µm long, gubernaculum present, precloacal supplements absent, and cylindrical tail 58-64 µm long with rounded tip. Relationships between Aegialoalaimus and Chromadorean orders could not be elucidated based on our SSU analysis; no link could be found with the Plectida, where the Aegialoalaimidae is currently placed, or with the Isolamiida or Cylindrolaimus (Areaolaimida), which share a similar and unusual buccal and pharynx morphology. Our SSU phylogenetic analysis confirms the placement of Manganonema within the Xyalidae, although relationships with other xyalid genera remain unclear. The Sphaerolaimidae formed a clade together with the Monhysteridae, which contradicts the current classification where the Sphaerolaimidae and Xyalidae are classified together into the superfamily Sphaerolaimoidea and the Monhysteridae into the Monhysteroidea. Although limited research has been conducted on the nematode diversity in Kermadec Trench to date, the available data show that half of all invertebrate species known from the trench are nematodes, which highlights the importance of conducting further taxonomic research on this group in hadal environments.

3.
PeerJ ; 8: e9923, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32974107

RESUMO

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 anterior end, lateral alae originating from middle of buccal cavity length, female without supplements, male with precloacal and postcloacal pairs of subventral setae, nine tubular supplements (alveolar supplements absent), tubular supplements weakly S-shaped with pointed tip, spicules arcuate 24 microns or 1.4 cloacal body diameters long and dorsal gubernacular apophyses. Lavareda iramscotti sp. nov. is characterised by adult body length 3,023-3,121 microns long, eight longitudinal rows of body pores each with short papilla, cephalic setae 4-5 microns long, tail 146-165 microns long, male with spicules 54 microns long, gubernaculum with triangular apophyses, 20 precloacal supplements with bifid distal tips arranged in 9 + 1 + 10 pattern, female with vulva at 55% of body length from anterior and cuticularisation perpendicular to vagina at level of vulva. The present study provides the first record of a Leptolaimus species from the New Zealand region and the first description of a female specimen of the genus Lavareda.

4.
PeerJ ; 8: e9233, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32518732

RESUMO

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 anchored in Wellington, North Island of New Zealand. It is characterized by body length 763-1,086 µm, and pore of secretory-excretory system located at or near level of teeth. Males have spicules with rounded capitulum followed by a narrower shaft and blade tapered distally, a gubernaculum as long as the spicules, and three cup-shaped precloacal supplements, and females are characterized by a cuticularized prevulvar pad, vagina located at 46-48% of body length from anterior, and vagina anteriorly directed. Chromadorina tangaroa sp. nov. is the first species of the genus to be described from New Zealand, but it is unclear whether it is native to the region because it may have dispersed as part of ship hull biofouling communities. Long-distance transport of nematodes through ship hull biofouling may be a common occurrence, but too little is known about the occurrence of nematodes on ship hulls to gauge the potential effect of shipping on nematode species distributions.

5.
Zootaxa ; 4608(3): zootaxa.4608.3.2, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31717131

RESUMO

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 curved spicules, and 12-16 tubular precloacal supplements. Dorylaimopsis boucheri sp. n. is characterized by lateral differentiation consisting of 3-4 longitudinal rows of larger dots in males and 4-6 rows in females, beginning about 30 µm posterior to amphids and terminating at the conical portion of the tail, 13-16 tubular precloacal supplements, and distal part of tail cylindrical without terminal setae. Dorylaimopsis jinyuei sp. n. is characterized by cuticle with lateral differentiation in the form of longitudinal rows of larger dots in two separate regions, not along entire body. One region is from posterior edge of amphid to anterior of intestine or anterior border of pharyngeal bulb in some females (4-7 longitudinal rows), the other is the tail region (5-7 longitudinal rows). In this paper, Dorylaimopsis metatypica Chitwood, 1936 is transferred to Hopperia because it is characterized by lateral differentiation consisting of larger, irregularly-distributed coarse dots (as in Hopperia), and Hopperia communis Gagarin Nguyen, 2006 is transferred to Dorylaimopsis based on the presence of longitudinal rows of coarse dots and a cylindrical buccal cavity in most specimens of this species. A dichotomous key to valid species of Dorylaimopsis Ditlevsen, 1918 is provided.


Assuntos
Nematoides , Animais , China , Cromadoria , Feminino , Masculino
6.
Mol Phylogenet Evol ; 132: 177-182, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30528082

RESUMO

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 Trophomera cf. marionensis in the Kermadec Trench with existing Trophomera sequences to determine the phylogenetic position of benthimermithids. Our SSU analyses showed Trophomera to be most closely-related to the order Plectida, subclass Chromadorea. Trophomera sequences formed a well-supported monophyletic clade placed within the Plectida, however relationships with other taxa within the order could not be resolved. Based on the result of these analyses, we propose that the family Benthimermithidae be moved to the order Plectida, however, future research on the classification of the family should focus on the benthimermithid genera Bathynema and Adenodelphis, for which no molecular sequences are yet available. We could not confirm a relationship between Trophomera and the family Camacolaimidae, which are both characterised by the presence of a stylet or stylet-like structure in the buccal cavity. Stylets are a common feature of parasitic nematodes, and its presence in a free-living benthimermithid ancestor perhaps similar to present-day camacolaimids could have facilitated a transition to a parasitic lifestyle. Our SSU phylogenetic analyses show that some features of benthimermithids, including the trophosome and a parasitic life cycle where the adults mate outside the host, have evolved independently in different groups of parasitic nematodes.


Assuntos
Nematoides/classificação , Animais , Teorema de Bayes , DNA Ribossômico/classificação , DNA Ribossômico/genética , Funções Verossimilhança , Filogenia
7.
Mol Phylogenet Evol ; 122: 29-36, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29409906

RESUMO

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 SSU and D2-D3 of LSU rDNA sequences of Rhaptothyerus typicus specimens obtained from the continental slope of New Zealand. Molecular sequences of three adults and a late stage juvenile were identical, confirming that they belong to the same species despite pronounced morphological differences. We observed the presence of the rare nucleotide transition A → G and transversion G → Y in the loops of Hairpin 35 and 48 regions, which is consistent with the placement of R. typicus within the order Enoplida. Rhaptothyreus typicus was consistently recovered as a long branch clade in SSU and D2-D3 of LSU analyses, which can have a destabilising effect on tree topology. After Gblocks were used to remove sites of questionable alignment, R. typicus was placed in a clade comprising Trissonchulus, Dolicholaimus and Ironus sequences (family Ironidae, order Enoplida) in both Bayesian and Maximum Likelihood SSU topologies. Depending on which alignment algorithm was used, analyses of LSU sequences focusing on enoplid taxa either suggested a relationship between R. typicus and Halalaimus (family Oxystominidae) or did not identify any clear relationships. Overall, our results provide strong evidence for placing R. typicus and the family Rhaptothyreidae within the order Enoplida, although further work is required to clarify relationships between rhaptothyreids and other enoplid taxa. A parasitic lifestyle could explain the unique morphology of this group, their highly divergent SSU and LSU rDNA molecular sequences, and the marked morphological differences between late juveniles and adults. Further molecular investigations targeting both free-living and parasitic early juvenile life stages in potential deep-sea hosts are needed to better understand the evolution of this unusual nematode taxon.


Assuntos
Nematoides/classificação , Animais , Teorema de Bayes , DNA Ribossômico/química , DNA Ribossômico/classificação , DNA Ribossômico/genética , Nematoides/genética , Nova Zelândia , Filogenia , Subunidades Ribossômicas/química , Subunidades Ribossômicas/classificação , Subunidades Ribossômicas/genética , Análise de Sequência de DNA
8.
PeerJ ; 5: e3309, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28507822

RESUMO

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 contribution of infaunal organisms to benthic respiration, particularly large burrowing organisms, is likely to be indirect and mainly driven by processes such as feeding and bioturbation that stimulate bacterial metabolism and promote the chemical oxidation of reduced solutes. Here, we estimate the direct and indirect contributions of burrowing shrimp (Eucalastacus cf. torbeni) to sediment community oxygen consumption based on incubations of sediment cores from 490 m depth on the continental slope of New Zealand. Results indicate that the presence of one shrimp in the sediment is responsible for an oxygen uptake rate of about 40 µmol d-1, only 1% of which is estimated to be due to shrimp respiration. We estimate that the presence of ten burrowing shrimp m-2 of seabed would lead to an oxygen uptake comparable to current estimates of macro-infaunal community respiration on Chatham Rise based on allometric equations, and would increase total sediment community oxygen uptake by 14% compared to sediment without shrimp. Our findings suggest that oxygen consumption mediated by burrowing shrimp may be substantial in continental slope ecosystems.

9.
Zootaxa ; 4237(2): zootaxa.4237.2.2, 2017 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-28264289

RESUMO

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 Zone. Pararaeolaimus megaloamphidus Timm, 1961, Diplopeltula mollis Bussau, 1993 and Diplopeltula peruensis Bussau, 1993 are considered species inquirendae due to the incomplete nature of the original descriptions. Southerniella amblynema Bussau, 1993, Southerniella lympha Bussau, 1993, and Southerniella nojii Jensen, 1991 are transferred to the genus Intasia Tchesunov & Miljutina, 2008 due to the presence of a single anterior outsretched ovary. A key to valid Southerniella species is provided.


Assuntos
Nematoides , Adenofórios , Animais , Ecossistema , Feminino , Nova Zelândia
10.
PeerJ ; 4: e2154, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27441114

RESUMO

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 community structure). Here, we investigated meiofaunal community attributes in slope, canyon, seamount, and seep habitats in two regions on the continental slope of New Zealand (Hikurangi Margin and Bay of Plenty) at four water depths (700, 1,000, 1,200 and 1,500 m). We found that patterns were not the same for each community attribute. Significant differences in abundance were consistent across regions, habitats, water and sediment depths, while diversity and community structure only differed between sediment depths. Abundance was higher in canyon and seep habitats compared with other habitats, while between sediment layer, abundance and diversity were higher at the sediment surface. Our findings suggest that meiofaunal community attributes are affected by environmental factors that operate on micro- (cm) to meso- (0.1-10 km), and regional scales (> 100 km). We also found a weak, but significant, correlation between trawling intensity and surface sediment diversity. Overall, our results indicate that variability in meiofaunal communities was greater at small scale than at habitat or regional scale. These findings provide new insights into the factors controlling meiofauna in these deep-sea habitats and their potential vulnerability to anthropogenic activities.

11.
Zootaxa ; 4132(1): 59-76, 2016 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-27395652

RESUMO

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., Halichoanolaimus anisospermus n. sp., and Bendiella longicauda n. sp.) and two known selachinematid species (Pseudocheironchus ingluviosus Leduc, 2013 and Synonchiella rotundicauda Leduc, 2013) from shelf and upper slope environments off northeastern New Zealand. Cheironchus haurakiensis n. sp. is characterised by having a multispiral amphideal fovea with five turns, lateroventral mandibles with central arm curved distally and bearing 4-5 pointed projections, and each palm bearing 4-5 pointed projections, ten precloacal supplements in a 1 + 9 arrangement, spicules 78 µm long, and blunt conical tail with thickened cuticle. Halichoanolaimus anisospermus n. sp. is characterised by having an amphideal fovea with 5-6 turns, anterior portion of buccal cavity with cuticularised rhabdions terminating in three sets of seven pairs of teeth (denticles), with the central pair of each set positioned above the other six, dimorphism in size of sperm cells between anterior and posterior testes, gubernaculum consisting of two detached lateral pieces (crurae) tapering distally, three small precloacal supplements consisting of slightly thickened and raised cuticle, and a conicocylindrical tail with conical portion 32-38% of total tail length. Bendiella longicauda n. sp. is characterised by having two dorsosublateral rows of pores from midbody to level of cloaca, amphideal fovea with 4.5 turns, posterior rhabdions with numerous small denticles, spicules 2.1 cloacal body diameters long, a conicocylindrical tail 13.3 cloacal body diameters long and with conical portion 8% of tail length. Preliminary phylogenetic analyses for the family Selachinematidae do not provide evidence of clustering according to depth (intertidal/subtidal vs shelf/upper slope) or geographical location (New Zealand vs Northern Hemisphere). The number of available Selachinematidae sequences, however, remains limited and comprehensive analyses based on larger number of sequences will be necessary to provide more solid conclusions.


Assuntos
Nematoides/classificação , Nematoides/genética , Animais , DNA Ribossômico/genética , Feminino , Sedimentos Geológicos , Masculino , Nematoides/fisiologia , Nova Zelândia , Oceano Pacífico , RNA de Helmintos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
12.
Zootaxa ; 4079(2): 255-71, 2016 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-27396004

RESUMO

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 tooth and right subventral tooth situated anteriorly relative to left subventral tooth, slender spicules 4.4 cloacal body diameters long, and gubernaculum 1.2 cloacal body diameters long with laterally curved distal end and swollen proximal end. Bolbolaimus tongaensis n. sp. is characterised by annulated cuticle with longitudinal bars, oval amphideal aperture and cryptocircular amphideal fovea situated between cephalic setae and only partially surrounded by cuticle annulations, and short spicules cuticularised along dorsal edge and at proximal end and with swollen portion near proximal end. Maragnopsia n. gen. is characterised by a minute, non-cuticularised mouth cavity without teeth, an elongated posterior pharyngeal bulb more than twice as long as it is wide, a single outstretched testis, and a conico-cylindrical tail 13-16 anal body diameters long. A list of all 83 valid Microlaimus species is provided. The present study provides the first microlaimid species records from deep-sea habitats (> 200 m depth) in the Southwest Pacific and Ross Sea. The presence of M. korari n. sp. on both the continental slope of New Zealand and Ross Sea abyssal plain suggests that this species has a wide geographical and depth distribution. However, molecular analyses will be required to confirm the identity of these two geographically disparate populations.


Assuntos
Adenofórios/classificação , Água do Mar/parasitologia , Adenofórios/anatomia & histologia , Adenofórios/crescimento & desenvolvimento , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Ecossistema , Feminino , Masculino , Nova Zelândia , Oceanos e Mares , Tamanho do Órgão , Oceano Pacífico
13.
Parasitol Res ; 115(4): 1675-82, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26779924

RESUMO

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, the benthimermithid Trophomera cf. marionensis was discovered in the body cavity of the lysianassoid amphipod Hirondellea dubia sampled between 7018 and 10,005 m depths in the Kermadec Trench. The nematode specimens, which could be readily observed through the transparent exoskeleton of freshly caught amphipods, were up to twice the length of T. marionensis specimens described from the Atlantic and East Pacific Oceans but were otherwise morphologically identical. Because of its wide geographical and water depth distribution (almost 10,000 m), T. marionensis likely consists of several cryptic species. The prevalence of Trophomera parasites among the host population was estimated to be substantially less than 1 %; such a low proportion of parasitised hosts could help explain why so few Trophomera specimens have been obtained from their host so far. The present study demonstrates that parasites can occur throughout the entire ocean depth and that they likely occur in other hadal trenches where H. dubia and other lysianassoid amphipods also dominate.


Assuntos
Anfípodes/parasitologia , Nematoides/fisiologia , Animais , Geografia , Interações Hospedeiro-Parasita , Oceano Pacífico
14.
Zootaxa ; 3964(5): 501-25, 2015 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-26249462

RESUMO

Little is known about the diversity and systematics of nematodes in hadal trenches (>6000 m depth). The analysis of core samples recently obtained from Tonga (10810 m) and Kermadec Trenches (8081 m) reveals the presence of a diverse nematode community in these extreme environments, and provides the deepest record for the phylum. Here, one new genus and five new species of the family Xyalidae are described. Lamyronema n. gen. is characterised by a large, tripartite buccal cavity and can be distinguished from other genera with similar buccal cavities mainly by the pharyngeal tissue almost completely surrounding the buccal cavity and by the presence of sub-cephalic setae positioned anteriorly to the amphideal fovea. Lamyronema horizonensis n. gen. n. sp. is characterised by the presence of 16-22 sub-cephalic setae, pronounced sexual dimorphism in the size of the amphideal fovea, and short, straight spicules. Daptonema amphorum n. sp. is characterised by short somatic setae, narrow head region, amphideal fovea relatively far from anterior body extremity, thin gubernaculum without apophyses, and cuticularised prevulvar uterine sac with two conspicuous rims. Manganonema kitasatoi n. sp., M. rowdeni n. sp., and M. majusculum n. sp. share traits that set them apart from other species of the genus, i.e., large body size (1100-2080 µm), presence of one pair of short setae posterior to the amphideal fovea, and male reproductive system with two testes. The latter trait necessitates amendments to the genus diagnosis.


Assuntos
Adenofórios/anatomia & histologia , Adenofórios/classificação , Água do Mar/parasitologia , Adenofórios/crescimento & desenvolvimento , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Ecossistema , Feminino , Masculino , Tamanho do Órgão , Oceano Pacífico , Água do Mar/química
15.
Zootaxa ; 3900(4): 505-25, 2014 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-25543753

RESUMO

We describe two new species and provide one new species record of the family Comesomatidae from a submarine canyon habitat on the Southern Hikurangi margin, New Zealand. Vasostoma hexodontium n. sp. is characterized by having an amphideal fovea with three turns, buccal cavity with six teeth and gubernaculum with long and straight caudal apophyses. Sabatieria dispunctata n. sp. is characterized by the absence of cuticle punctations, large amphideal fovea with 4.5 turns, pharynx with posterior bulb, absence of pre-cloacal supplements, strongly arcuate and cuticularized spicules, simple gubernaculum with short caudal apophyses, and vulva opening directed posteriorly. Laimella subterminata Chen & Vincx, 2000, which was originally described from the Beagle Channel and the Magellan Strait (Chile), is recorded from the Southwest Pacific for the first time. 


Assuntos
Adenofórios/classificação , Adenofórios/anatomia & histologia , Adenofórios/crescimento & desenvolvimento , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Ecossistema , Feminino , Masculino , Nova Zelândia , Tamanho do Órgão
16.
Zootaxa ; (3814): 478-94, 2014 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-24943443

RESUMO

Four new Paramphimonhystrella species are described from the continental slope of New Zealand. P. glossalga n. sp. is characterised by presence of twelve lips, large buccal cavity, males with short, heavily cuticularised spicules joined distally, and females with large postvulvar sac and hammer-shaped cuticularised piece immediately posterior to vagina. P. barbula n. sp. is characterised by narrow buccal cavity, oval-shaped amphids, conico-cylindrical tail with swollen appearance due to conspicuously enlarged caudal gland, and males with long slender spicules and small gubernaculum. P. scutula n. sp. is characterised by a lozenge-shaped buccal cavity, males with scythe-shaped spicules, females with vulva at almost two thirds of body length from anterior, and a hammer-shaped cuticularised piece immediately posterior to vagina. P. echinocauda n. sp. is characterised by buccal cavity with cylindrical anterior portion and funnel-shaped posterior portion, distal tip of slender spicules with three pointed projections, thin gubernaculum, and tail with several long setae in middle portion, two lateral setae near tail tip and one terminal seta. The presence of a hammer-shaped cuticularised piece in two species of the genus is recorded for the first time; the function of this structure is unknown. The genus diagnosis is emended and a key to all known Paramphimonhystrella species (seven in total) is provided. The present study provides the first record of the genus outside the type locality (Yellow Sea) and extends its depth distribution from <150 m to 1350 m.


Assuntos
Nematoides/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Animais , Ecossistema , Feminino , Masculino , Nematoides/anatomia & histologia , Nova Zelândia
17.
Zootaxa ; 3682: 351-70, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-25243291

RESUMO

Three new free-living nematode species belonging to the genus Mudwigglus gen. n. are described from the continental slope of New Zealand. The new genus is characterised by four short cephalic setae, fovea amphidialis in the shape of an elongated loop, narrow mouth opening, small, lightly cuticularised buccal cavity, pharynx with oval-shaped basal bulb, and secretory-excretory pore (if present) at level of pharyngeal bulb or slightly anterior. Mudwigglus gen. et sp. n. differs from other genera of the family Diplopeltidae in the combination of the following traits: presence of reflexed ovaries, male reproductive system with both testes directed anteriorly and reflexed posterior testis, and presence of tubular pre-cloacal supplements and pre-cloacal seta. Mudwigglus patumuka gen. et sp. n. is characterised by gubernaculum with dorso-caudal apophyses, vagina directed posteriorly, and short conical tail with three terminal setae. M. macramphidum gen. et sp. n. is characterised by long fovea amphidialis, cylindrical buccal cavity, gubernaculum without apophyses, vagina at right angle to body surface, and conico-cylindrical tail without terminal setae. M. plebeius gen. et sp. n. is characterised by cylindrical buccal cavity with cuticularised ring, gubernaculum with dorso-caudal apophyses, females with vagina directed posteriorly, and conico-cylindrical tail with two terminal setae. Diplopeluta nellyae Vinex and Gourbault, 1992 is transferred to Mudwigglus gen. n. based on observations of paratypes from New Caledonia, and of specimens from the New Zealand continental slope, which both show the presence of two testes facing anteriorly. M. macramphidum gen. et sp. n. was restricted to a single site on Chatham Rise crest (350 m water depth), whereas M. patumuka gen. et sp. was recorded from six sites on western Chatham Rise (350-2800 m). M. plebeius gen. et sp. n. was recorded from 13 sites on Chatham Rise and two sites on Challenger Plateau (264-2300 m). Mudwigglus nellyae comb. n. was restricted to two Challenger Plateau sites. All Mudwigglus gen. n. species appear to be restricted to subsurface sediments.


Assuntos
Adenofórios/anatomia & histologia , Adenofórios/classificação , Adenofórios/fisiologia , Distribuição Animal , Animais , Feminino , Masculino , Nova Zelândia , Oceano Pacífico , Especificidade da Espécie
18.
Zootaxa ; 3609: 274-90, 2013 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-24699590

RESUMO

One new genus and two new species of the family Desmodoridae are described from the upper continental slope of New Zealand, at 350-1240 m water depths. Onepunema gen. n. is characterised by a striated head capsule, small buccal cavity without teeth, and presence of two testes. Onepunema gen. n. can be differentiated from all other genera of the family by the presence of two testes, which is an exception to the holapomorphic character (i.e. monorchic males) of the Desmodoroidea. Onepunema enigmaticum gen. et sp. n. shares characters typical of the subfamilies Spiriniinae (small buccal cavity without distinct teeth) and Desmodorinae (presence of head capsule). Onepunema gen. n. is placed within the Desmodorinae based on the latter trait, which is never found within the Spiriniinae. The type species, Onepunema enigmaticum gen. et sp. n., is characterised by the presence of two laterodorsal and two lateroventral rows of pores with conspicuous ducts, slender pharynx with rounded terminal bulb, presence of two types of cells in intestinal epithelium, and presence of four or five pre-cloacal supplements consisting of thickened areas of cuticle in males. The genus Pseudonchus is recorded for the first time from the deep sea (1240 m water depth) and from the New Zealand region. Pseudonchus virginiae sp. n. is characterised by its stout body, short cephalic setae, monospiral amphideal fovea, short arcuate spicules with capitulum, five regularly-spaced precloacal setae, and short conical tail. A key to all known valid species of the genus Pseudonchus is provided.


Assuntos
Nematoides/anatomia & histologia , Nematoides/classificação , Animais , Ecossistema , Feminino , Masculino , Nova Zelândia , Oceano Pacífico
19.
Zootaxa ; 3722: 483-92, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26171538

RESUMO

Deontostoma tridentum n. sp. is described from epibenthic (Brenke) sledge samples obtained from the continental slope of New Zealand at 570 and 1007 m water depths, and details of the ultrastructure are investigated using scanning electron microscopy (SEM). D. tridentum n. sp. is characterised by having a large buccal cavity with greatly reduced or inconspicuous odontia, one large dorsal onchium and two smaller subventral onchia, cephalic capsule without interlobar incisions with posteriorly-directed arms, ventral pre-cloacal supplement situated 200-215 µm anterior to cloaca, and gubernaculum with triangular crurae and curved proximal portion. Deontostoma tridentum n. sp. can be differentiated from all species of the genus based on the presence of two subventral onchia in the buccal cavity (absent in all other species). It is most similar to D. coptochilus in the presence of a large buccal cavity with a prominent dorsal onchium, structure of the cephalic capsule, and structure of the microlabia (i.e., subventral microlabia completely divided by mandibular ridge and dorsal microlabium not completely divided by mandibular ridge). D. tridentum n. sp. differs from the latter in the presence of crurae (absent in D. coptochilus), absence of ocelli (present in D. coptochilus), and in the position and structure of the ventral pre-cloacal supplement.


Assuntos
Nematoides/classificação , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Feminino , Masculino , Nematoides/anatomia & histologia , Nematoides/crescimento & desenvolvimento , Nova Zelândia , Tamanho do Órgão
20.
Zootaxa ; 3693: 1-35, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26185831

RESUMO

Sabatieria is the most abundant nematode genus on the upper continental slope of New Zealand but no Sabatieria species have yet been recorded/described from the region's deep-sea habitats. The present study describes seven new and one known species of this genus from the continental margin of New Zealand. S. bitumen Botelho et al. 2007 was originally described from the South Atlantic Ocean, and is recorded from the first time in the Pacific Ocean. Sabatieria challengerensis sp. n. is characterised by a combination of short cephalic setae, large fovea amphidialis with 3 turns, short arcuate spicules without distal hook, and short tail with cylindrical proximal portion and blunt, rounded distal portion. Sabatieria parapraedatrix sp. n. is characterised by having a slender body, cuticle with striations resulting from fusion of every second lateral row of dots,fovea amphidialis with 2.0-2.5 turns, spicules with distal hook, and short conico-cylindrical tail. Sabatieria bubulba sp. n. is characterised by the presence of a large muscular pharyngeal bulb, secretory-excretory system with large ventral gland at level of intestine and with cuticularised pore opening. Sabatieria exculta sp. n. is characterised by having a slender body, cuticle with faint annulations resulting from fusion of every second or third lateral row of dots, short cephalic setae, a large ventral gland, and long, narrow gubernacular apophyses. Sabatieria balbutiens sp. n. is characterised by having a dorsally-directed mouth opening and assymetrical mouth cavity and spicules with small distal hook. Sabatieria pumila sp. n. is characterised by the combination of short body length, short cephalic setae, spicules with distal hook and short distal lamella, and 8-9 precloacal supplements. Sabatieria bathycopia sp. n. is characterised by having a stout body, short cephalic setae, curved gubernaculum, and spicules with swollen, lightly cuticularised distal tip.


Assuntos
Distribuição Animal/fisiologia , Nematoides/anatomia & histologia , Nematoides/classificação , Animais , Feminino , Masculino , Nematoides/fisiologia , Nova Zelândia , Oceano Pacífico , Especificidade da Espécie
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