scholarly journals Integrative taxonomy revisits the ontogeny and trophic niches of Rimicaris vent shrimps

2020 ◽  
Vol 7 (7) ◽  
pp. 200837 ◽  
Author(s):  
Pierre Methou ◽  
Loïc N. Michel ◽  
Michel Segonzac ◽  
Marie-Anne Cambon-Bonavita ◽  
Florence Pradillon
Keyword(s):  
Early Life ◽  
Morphological Characters ◽  
Integrative Taxonomy ◽  
Trophic Niche ◽  
Rimicaris Exoculata ◽  
Combined Use ◽  
Niche Shifts ◽  
Mid Atlantic Ridge ◽  
Juvenile Stages ◽  
Trophic Niches

Among hydrothermal vent species, Rimicaris exoculata is one of the most emblematic, hosting abundant and diverse ectosymbioses that provide most of its nutrition. Rimicaris exoculata co-occurs in dense aggregates with the much less abundant Rimicaris chacei in many Mid-Atlantic Ridge vent fields. This second shrimp also houses ectosymbiotic microorganisms but has a mixotrophic diet. Recent observations have suggested potential misidentifications between these species at their juvenile stages, which could have led to misinterpretations of their early-life ecology. Here, we confirm erroneous identification of the earliest stages and propose a new set of morphological characters unambiguously identifying juveniles of each species. On the basis of this reassessment, combined use of C, N and S stable isotope ratios reveals distinct ontogenic trophic niche shifts in both species, from photosynthesis-based nutrition before settlement, towards a chemosynthetic diet afterwards. Furthermore, isotopic compositions in the earliest juvenile stages suggest differences in larval histories. Each species thus exhibits specific early-life strategies that would, without our re-examination, have been interpreted as ontogenetic variations. Overall, our results provide a good illustration of the identification issues persisting in deep-sea ecosystems and the importance of integrative taxonomy in providing an accurate view of fundamental aspects of the biology and ecology of species inhabiting these environments.

scholarly journals Population structure and environmental niches of Rimicaris shrimps from the Mid Atlantic Ridge

2021 ◽  
Author(s):  
Pierre Methou ◽  
Ivan Hernandez Avila ◽  
Cecile Cathalot ◽  
Marie-Anne Cambon Bonavita ◽  
Florence Pradillon
Keyword(s):  
Population Structure ◽  
Hydrothermal Vents ◽  
Life Stages ◽  
Population Demographics ◽  
Juvenile Mortality ◽  
Rimicaris Exoculata ◽  
Population Structures ◽  
Mid Atlantic Ridge ◽  
Juvenile Stages ◽  
Potential Factors

Among the endemic and specialized fauna from hydrothermal vents, Rimicaris shrimp surely constitutes one of the most important and emblematic component of these ecosystems. In the Mid Atlantic Ridge, two species affiliated to this genus co-occur: Rimicaris exoculata and Rimicaris chacei that differ by their morphology, their trophic regime as well as by their abundance. The first forms large and dense aggregations on active vent chimney walls in close proximity to vent fluid emissions, whereas the second is recognized as much less conspicuous, living mostly in scattered groups or solitary further away from the fluids. However, the recent revision of Rimicaris juvenile stages from the Mid Atlantic Ridge show that R. chacei abundance would be higher than expected at these early life stages. Here, we describe and compare the population structures of R. exoculata and R. chacei at the Snake Pit and TAG vent fields. We show widely distinct population demographics between the two co-occurring shrimps with a large post settlement collapse in R. chacei population suggesting a large juvenile mortality for this species. We also observe important spatial segregation patterns between the two species and their different life stages. Additionally, our results highlight distinct niches for the earliest juvenile stages of both R. exoculata and R. chacei, compared to all the other life stages. Finally, we discuss the potential factors - predation and competitive interactions among others - that could explain the differences we observe in the population structure of these two species.

scholarly journals The incredible diversity of Labiobaetis Novikova & Kluge in New Guinea revealed by integrative taxonomy (Ephemeroptera, Baetidae)

ZooKeys ◽  
2018 ◽  
Vol 804 ◽  
pp. 1-136 ◽  
Author(s):  
Thomas Kaltenbach ◽  
Jean-Luc Gattolliat
Keyword(s):  
New Species ◽  
Genetic Distance ◽  
Papua New Guinea ◽  
New Guinea ◽  
Morphological Characters ◽  
Integrative Taxonomy ◽  
On This Island

Material collected between 1999 and 2011 in Papua New Guinea and the Papua Province of Indonesia unveiled the enormous diversity ofLabiobaetison this island. Twenty-six new species were identified and delimited by integrative taxonomy using genetic distance (COI, Kimura-2-parameter) and morphology. These new species are described and illustrated based on larvae, augmenting the total number ofLabiobaetisspecies on the island of New Guinea to 32. Seven morpho-groups of species are proposed based on morphological characters and a key to all New Guinea species is provided. The generic attributes of the larvae are summarised and slightly modified based on the examinations of the new species. Results on the genetics of most species (COI) are also provided. The interspecific K2P distances are between 13% and 32%, the intraspecific distances usually between 0% and 2%. Possible reasons for the remarkable richness of this genus in New Guinea are discussed.

Taxonomic changes and description of two new species for the Phyllodactylus lanei complex (Gekkota: Phyllodactylidae) in Mexico

Zootaxa ◽  
2018 ◽  
Vol 4407 (2) ◽  
pp. 151 ◽  
Author(s):  
TONATIUH RAMÍREZ-REYES ◽  
OSCAR FLORES-VILLELA
Keyword(s):  
New Species ◽  
Molecular Phylogeny ◽  
Genetic Distance ◽  
Morphological Characters ◽  
Integrative Taxonomy ◽  
Cryptic Diversity ◽  
Ecological Data ◽  
Temperature And Precipitation ◽  
Two New Species ◽  
Taxonomic Changes

An integrative taxonomy approach was implemented based on analysis of genetic, phylogenetic, morphological and ecological data to identify the cryptic diversity within the Phyllodactylus lanei complex. At least six species can be identified, of which four are currently considered subspecies: Phyllodactylus lanei, Phyllodactylus rupinus, Phyllodactylus isabelae, Phyllodactylus lupitae and two corresponding to undescribed taxa, which are identified and described in this contribution. These differ from other Mexican geckos in several characters: genetic distance (DNAmt), position in molecular phylogeny (concatened data DNAmt+DNAnu), species tree, morphological characters such as snout-vent length, longitudinal scales, tubercles from head to tail, interorbital scales, scales across venter, third labial–snout scales and rows of tubercles across dorsum; there are also differences in their bioclimatic profiles (temperature and precipitation) and geographical distribution. The most recent studies on taxonomy and evolution of Mexican geckos (Phyllodactylus) show that the diversity of this group of reptiles is currently underestimated, suggesting that more research and conservation efforts are should be addressed at these lizards. 

Description of two new species of Rhamphus related to R. oxyacanthae (Curculionidae, Curculioninae, Rhamphini) from Italy based on a morphological study supported by molecular data

Zootaxa ◽  
2021 ◽  
Vol 4995 (1) ◽  
pp. 111-128
Author(s):  
LUCIANO DIOTTI ◽  
ROBERTO CALDARA ◽  
IVO TOŠEVSKI
Keyword(s):  
New Species ◽  
Morphological Study ◽  
Host Plants ◽  
Molecular Study ◽  
Morphological Characters ◽  
Molecular Data ◽  
Integrative Taxonomy ◽  
The Other ◽  
Distribution Data ◽  
Two New Species

Two new species of the weevil genus Rhamphus from Italy are herein described: R. bavierai n. sp. (Sicily) and R. hampsicora n. sp. (Sardinia). Both are morphologically and from a molecular perspective close to R. oxyacanthae (Marsham, 1802) and R. monzinii Pesarini & Diotti, 2012. Aside from a diagnostic description and a synoptic key, distribution data and notes on the host plants of the four species are reported. Whereas R. monzinii can be distinguished by several morphological characters, the other three species are morphologically very similar to each other and separable only by the combination of a few subtle characters. On the contrary, a preliminary molecular study revealed substantial divergences of mtCOI from 6.2 to 14.9% between the species, confirming the importance of an integrative taxonomy.  

Uncovering Neotropical treefrog diversity: integrative taxonomy reveal paraphyly in Boana atlantica (Amphibia, Anura, Hylidae)

2019 ◽  
Vol 40 (4) ◽  
pp. 511-521
Author(s):  
Luana Rodrigues Lima ◽  
Marcos Jorge Matias Dubeux ◽  
Filipe Augusto Cavalcanti do Nascimento ◽  
Daniel Pacheco Bruschi ◽  
Tamí Mott
Keyword(s):  
Strong Support ◽  
Taxonomic Status ◽  
Nucleolar Organizer ◽  
Morphological Characters ◽  
Integrative Taxonomy ◽  
Morphological Data ◽  
Valid Species ◽  
Nucleolar Organizer Regions ◽  
Candidate Species ◽  
Species Being

Abstract Boana atlantica was described based on morphological characters to acommodate populations from Bahia state, Brazil, previously referred to as B. punctata. However, its taxonomic validity is questionable due to inconsistencies in bioacoustic data. Here, we integrate molecular, cytogenetic and morphological data to re-evaluate the taxonomic status of B. atlantica. Molecular analyses provided strong support for the hypothesis that B. atlantica is a valid species, being, however, nominal populations from Bahia state paraphyletic with respect to individuals of B. atlantica collected in Alagoas and Pernambuco states. These populations shown high genetic divergence in the 16S rRNA mitochondrial fragment, and we consider populations from Alagoas and Pernambuco as a putative new candidate species of Boana punctata group. The external and internal morphology of the tadpoles of these lineages were similar, but Nucleolar Organizer Regions (NOR) was sited in different chromosomes. Our results indicate that B. atlantica is paraphyletic and may be a complex of species. Morphological of adult and/or bioacoustical data should be further assessed to find diagnostic characters to tease these lineages apart and name them properly.

scholarly journals Food sources, behaviour, and distribution of hydrothermal vent shrimps at the Mid-Atlantic Ridge

2000 ◽  
Vol 80 (3) ◽  
pp. 485-499 ◽  
Author(s):  
A.V. Gebruk ◽  
E.C. Southward ◽  
H. Kennedy ◽  
A.J. Southward
Keyword(s):  
Hydrothermal Vents ◽  
Food Sources ◽  
Larval Stages ◽  
Rimicaris Exoculata ◽  
Tube Worms ◽  
The Pacific ◽  
Mid Atlantic Ridge ◽  
Menez Gwen ◽  
Juvenile Shrimp ◽  
Supporting Structures

Five species of bresilioid shrimp were investigated at seven hydrothermal sites on the Mid-Atlantic Ridge: Menez Gwen, Lucky Strike, Rainbow, Broken Spur, TAG, Snake Pit and Logatchev. Samples were prepared for analysis of stable isotopes, elemental composition and lipids. Shrimp behaviour was observed from the submersible ‘Alvin’ and in the laboratory aboard RV ‘Atlantis’. The distribution and zonation of the shrimp species was recorded. Juvenile shrimp of all species arrive at the vents carrying reserves of photosynthetic origin, built-up in the pelagic larval stages. These reserves are used while the shrimp metamorphose to the adult form and, in Rimicaris exoculata and Chorocaris chacei, while they develop epibiotic bacteria supporting structures, the modified mouthparts and the inside of the carapace. The main food of adult R. exoculata is filamentous bacteria that grow on these structures. The intermediate sizes of C. chacei also feed on such bacteria, but the final stage gets some food by scavenging or predation. Mirocaris species scavenge diverse sources; they are not trophically dependent on either R. exoculata or mussels. Adults of Alvinocaris markensis are predators of other vent animals, including R. exoculata. The dense swarms of R. exoculata, with their exosymbionts, can be compared to endosymbiont-containing animals such as Bathymodiolus and the vestimentiferan tube-worms of the Pacific vents. Such associations, whether endo- or ectosymbiotic, may be necessary for the development of flourishing communities at hydrothermal vents.

Long-term variation in isotopic baselines and implications for estimating consumer trophic niches

2008 ◽  
Vol 65 (10) ◽  
pp. 2191-2200 ◽  
Author(s):  
Christopher T. Solomon ◽  
Stephen R. Carpenter ◽  
James A. Rusak ◽  
M. Jake Vander Zanden
Keyword(s):  
Stable Isotope ◽  
Food Web ◽  
Isotope Ratios ◽  
Trophic Niche ◽  
Accurate Estimation ◽  
Stable Isotope Ratios ◽  
Turnover Rates ◽  
C And N ◽  
Trophic Niches

Carbon and nitrogen stable isotope ratios are increasingly used to study long-term food web change. Temporal variation at the base of the food web may impact the accuracy of trophic niche estimates, but data describing interannual baseline variation are limited. We quantified baseline variation over a 23-year period in a north-temperate lake and used a simulation model to examine how this variation might affect consumer trophic niche estimates. Interannual variation in C and N stable isotope ratios was significant for both benthic and pelagic primary consumer baselines. Long-term linear trends and shorter-term autoregressive patterns were apparent in the data. There were no correlations among benthic and pelagic C and N baselines. Simulations demonstrated that error in estimated fish trophic niches, but not bias, increased substantially when sampling of baselines was incomplete. Accurate trophic niche estimates depended more on accurate estimation of baseline time series than on accurate estimation of growth and turnover rates. These results highlight the importance of previous and continued efforts to constrain bias and error in long-term stable isotope food web studies.

scholarly journals Trophic niches of benthic crustaceans in the Pechora Sea suggest that the invasive snow crab Chionoecetes opilio could be an important competitor

Polar Biology ◽  
2020 ◽  
Author(s):  
Anna Gebruk ◽  
Anna K. Zalota ◽  
Polina Dgebuadze ◽  
Yulia Ermilova ◽  
Vassily A. Spiridonov ◽  
...  
Keyword(s):  
Invasive Species ◽  
Stable Isotope ◽  
Integrated Approach ◽  
Trophic Niche ◽  
Snow Crab ◽  
Ecosystem Structure ◽  
Spider Crab ◽  
Chionoecetes Opilio ◽  
Trophic Niches ◽  
Prey Items

AbstractExpanding human activities alongside climate change, the introduction of invasive species and water contamination pose multiple threats to the unique marine ecosystems of the Pechora Sea in the Russian Arctic. Baseline data on biodiversity and responses to environmental change are urgently needed. Benthic decapod crustaceans are globally distributed and play an important role in fisheries, yet their roles in food webs are less understood. In this study, we used an integrated approach combining stomach content analysis and stable isotope analyses (δ13C and δ15N) to examine the trophic niches of three decapod species in the Pechora Sea including the invasive snow crab Chionoecetes opilio and two species of native decapods, the spider crab Hyas araneus and the hermit crab Pagurus pubescens. Stomach contents of 75 decapods were analysed (C. opilion = 23; H. araneusn = 9; P. pubescensn = 43), and 20 categories of prey items were identified with the most frequently occurring prey items being bivalve molluscs (Ciliatocardium ciliatum, Ennucula tenuis, Macoma calcarea), polychaetes, crustaceans and plant debris. Bayesian ellipse analyses of stable isotope signatures (n = 40) revealed that C. opilio displays an overlapping trophic niche with the two native decapods, providing direct evidence that the invader likely competes for food resources with both H. araneus and P. pubescens. As such, the presence of this invasive species could hold important consequences for trophic interactions, benthic ecosystem functioning and biodiversity. Microplastics were also found to be a likely stressor on this ecosystem, as 28% of all stomachs contained digested microplastics among other items. Long-term studies of benthic ecosystem structure and functioning are now needed to more fully understand the extent to which this new competitor may alter the future biodiversity of the Pechora Sea alongside the additional stressor of digested plastics.

An example of problems associated with DNA barcoding in tardigrades: a novel method for obtaining voucher specimens

Zootaxa ◽  
2011 ◽  
Vol 3104 (1) ◽  
pp. 42 ◽  
Author(s):  
MICHELE CESARI ◽  
ILARIA GIOVANNINI ◽  
ROBERTO BERTOLANI ◽  
LORENA REBECCHI
Keyword(s):  
Dna Barcoding ◽  
Dna Barcode ◽  
Intraspecific Variability ◽  
Original Description ◽  
Morphological Characters ◽  
Molecular Data ◽  
Integrative Taxonomy ◽  
Type Locality ◽  
Moss Sample ◽  
Voucher Specimens

We have in recent papers revealed that an integrative taxonomy approach helps to solve taxonomic problems in tardigrades. However, whole tardigrades are required for DNA work, which leaves no hologenophore voucher specimens with adult morphology. Using a novel methodology for the Tardigrada, we introduce the practice of collecting high quality maximum magnification light microscopy images of recently thawed animals to act as hologenophore voucher specimens of animals later used for DNA barcode sequencing. Within the framework of a DNA barcoding project on tardigrades, we collected a moss sample from the type locality of Macrobiotus terminalis Bertolani & Rebecchi, 1993 (Castelsantangelo, Central Apennines, Italy), a species of the “Macrobiotus hufelandi group”. Within the moss sample we found several animals and eggs with a morphology that corresponded to the original description of M. terminalis, while others were attributable to Macrobiotus macrocalix Bertolani & Rebecchi, 1993. In this study, molecular (cox1 mtDNA) analyses demonstrated no intraspecific variability in M. terminalis from the type locality but very large interspecific differences when compared with M. macrocalix and GenBank data for other species within the M. “hufelandi group”. There was also a large difference between our M. terminalis sequences and the GenBank data of a specimen attributed to the same species. The GenBank sequence originated from a population in the Northern Apennines, whose morphology appeared to be like that of the specimens of the locus typicus. This confirmed the importance in utilising material from the type locality for linking molecular data to the species’ morphological characters. Our paper underlines the importance of an integrative taxonomy in species diagnoses and demonstrates a scenario where morphological observations alone are not always sufficient. Lastly, this work adds reliable information to the sequence reference library that provides a useful building block for further studies on similar and related tardigrade taxa.

Setal variability of Hydrozetes lemnae and H. thienemanni (Acari: Oribatida: Hydrozetidae)

Biologia ◽  
2008 ◽  
Vol 63 (5) ◽  
Author(s):  
Anna Seniczak ◽  
Stanisław Seniczak
Keyword(s):  
Posterior Part ◽  
Morphological Characters ◽  
The Other ◽  
Juvenile Stages

AbstractSetal variability and the other morphological characters of juvenile stages and adult of Hydrozetes lemnae (Coggi, 1897) and H. thienemanni Strenzke, 1943 were investigated. In the juveniles of both species the length and shape of some setae vary, especially in the gastronotic region, more so in H. lemnae, which is parthenogenetic and reproduces by thelytoky, than in H. thienemanni, which is dioecious. The former species usually has more thick setae in the anterior and medial regions of the gastronotum, especially in the larva, compared to the latter. In the juveniles of H. lemnae the prodorsal setae le and in are longer, and in the nymphs the gastronotal setae of the l-series are usually longer than in H. thienemanni. These species differ distinctly by the number of long setae in the posterior part of the nymphs; in H. lemnae three pairs of long setae occur, while in H. thienemanni only two pairs; the respective juvenile stages of H. lemnae are also smaller than those of H. thienemanni. In the adults the number of c-series setae varies, as seta c 1 is lost, and in some individuals also seta c 3, and only seta c 2 remains.

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