scholarly journals Complex factors shape phenotypic variation in deep-sea limpets

2019 ◽  
Vol 15 (10) ◽  
pp. 20190504 ◽  
Author(s):  
Chong Chen ◽  
Hiromi Kayama Watanabe ◽  
Yukiko Nagai ◽  
Takashi Toyofuku ◽  
Ting Xu ◽  
...  
Keyword(s):  
Phenotypic Variation ◽  
Deep Sea ◽  
Genetic Factors ◽  
Molecular Data ◽  
Morphological Trait ◽  
Cold Seeps ◽  
Phenotypic Characters ◽  
Evolutionary Lineage ◽  
Chemosynthetic Ecosystems ◽  
First Time

Pectinodontid limpets are important members of deep-sea hot vents and cold seeps as can be seen by their conspicuous presence in both extant and extinct systems. They have traditionally been classified into different genera and species based on shell and radula characteristics; the reliability of these characters has been questioned but not tested thoroughly. Here, for the first time in taxa endemic to deep-sea chemosynthetic ecosystems, we combine substrate translocation with molecular data to assess the plasticity and variability of key phenotypic characters. Molecular data revealed that several ‘species’ of extant vent/seep pectinodontids actually represent intergrading morphotypes of a single, highly plastic, evolutionary lineage, with each morphological trait being possibly influenced differently by environmental and genetic factors. Our results challenge previous interpretations of paleoecology at fossil chemosynthetic ecosystems and highlight the importance of modern analogues in understanding fossil systems.

scholarly journals Chiridota heheva—the cosmopolitan holothurian

2020 ◽  
Vol 50 (6) ◽  
Author(s):  
Elin A. Thomas ◽  
Ruoyu Liu ◽  
Diva Amon ◽  
Jon T. Copley ◽  
Adrian G. Glover ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Deep Sea ◽  
Species Complex ◽  
Hydrothermal Vents ◽  
Novel Species ◽  
Cold Seeps ◽  
Ecological Studies ◽  
Chemosynthetic Ecosystems ◽  
Relationship Of ◽  
The Relationship

AbstractChemosynthetic ecosystems have long been acknowledged as key areas of enrichment for deep-sea life, supporting hundreds of endemic species. Echinoderms are among the most common taxa inhabiting the periphery of chemosynthetic environments, and of these, chiridotid holothurians are often the most frequently observed. Yet, published records of chiridotids in these habitats are often noted only as supplemental information to larger ecological studies and several remain taxonomically unverified. This study therefore aimed to collate and review all known records attributed to Chiridota Eschscholtz, 1829, and to conduct the first phylogenetic analysis into the relationship of these chiridotid holothurians across global chemosynthetic habitats. We show that Chiridota heheva Pawson & Vance, 2004 is a globally widespread, cosmopolitan holothurian that occupies all three types of deep-sea chemosynthetic ecosystem—hydrothermal vents, cold seeps and organic falls—as an organic-enrichment opportunist. Furthermore, we hypothesise that C. heheva may be synonymous with another vent-endemic chiridotid, Chiridota hydrothermica Smirnov et al., 2000, owing to the strong morphological, ecological and biogeographical parallels between the two species, and predict that any chiridotid holothurians subsequently discovered at global reducing environments will belong to this novel species complex. This study highlights the importance of understudied, peripheral taxa, such as holothurians, to provide insights to biogeography, connectivity and speciation at insular deep-sea habitats.

scholarly journals Some thecate hydroids (Cnidaria: Hydrozoa) from off New Caledonia collected during KANACONO and KANADEEP expeditions of the French Tropical Deep-Sea Benthos Program

2019 ◽  
Author(s):  
Horia R. Galea ◽  
Peter Schuchert
Keyword(s):  
Deep Water ◽  
Deep Sea ◽  
New Genus ◽  
New Records ◽  
New Caledonia ◽  
Molecular Data ◽  
Systematic Position ◽  
Male And Female ◽  
The Family ◽  
First Time

Thirty-six species of various thecate hydroids occur in two recent, deep-water collections from off New Caledonia. Of these, nine are new, namely Solenoscyphus subtilis Galea, sp. nov., Hincksella immersa Galea, sp. nov., Synthecium rectangulatum Galea, sp. nov., Diphasia alternata Galea, sp. nov., Dynamena opposita Galea, sp. nov., Hydrallmania clavaformis Galea, sp. nov., Symplectoscyphus acutustriatus Galea, sp. nov., Symplectoscyphus elongatulus Galea, sp. nov. and Zygophylax niger Galea, sp. nov. The male and female gonothecae of Caledoniana decussata Galea, 2015, the female gonothecae of Caledoniana microgona Galea, 2015, as well as the gonothecae of both sexes of Solenoscyphus striatus Galea, 2015 are described for the first time. The systematic position of the genera Solenoscyphus Galea, 2015 and Caledoniana Galea, 2015 is discussed on both morphological and molecular grounds, and both are confidently placed within the family Staurothecidae Maronna et al., 2016. In light of the molecular data, the genera Billardia Totton, 1930 and Dictyocladium Allman, 1888 are assigned to the families Syntheciidae Marktanner-Turneretscher, 1890 and Symplectoscyphidae Maronna et al. , 2016, respectively. The previously undescribed gonothecae of Hincksella neocaledonica Galea, 2015, and the male gonothecae of Sertularella tronconica Galea, 2016, were found. Thyroscyphus scorpioides Vervoort, 1993, a peculiar hydroid with putative stem nematothecae, is redescribed and assigned to the new genus Tuberocaulus Galea, gen. nov. Noteworthy new records from the study area are: Tasmanaria edentula (Bale, 1924), Hincksella sibogae Billard, 1918, Dictyocladium reticulatum (Kirchenpauer, 1884), Salacia sinuosa (Bale, 1888) and Billardia hyalina Vervoort & Watson, 2003. Most species are illustrated to facilitate their identification, and the morphology of the new ones is compared to that of their related congeners.

scholarly journals High degree of non-genetic phenotypic variation in the vascular system of crayfish: a discussion of possible causes and implications

Zoomorphology ◽  
2021 ◽  
Author(s):  
Stephan Scholz ◽  
Torben Göpel ◽  
Stefan Richter ◽  
Christian S. Wirkner
Keyword(s):  
Phenotypic Variation ◽  
Genetic Factors ◽  
Vascular System ◽  
Micro Computed Tomography ◽  
Causal Factors ◽  
Developmental Variation ◽  
Branching Patterns ◽  
Phenotypic Variations ◽  
Marbled Crayfish ◽  
High Degree

AbstractIn this study, the hemolymph vascular system (HVS) in two cambarid crayfishes, i.e. the Marbled Crayfish, Procambarus virginalis Lyko, 2017 and the Spiny Cheek Crayfish, Faxonius limosus (Rafinesque, 1817), is investigated in regard of areas of non-genetic phenotypic variation. Despite their genetic identity, specimens of P. virginalis show variability in certain features of the HVS. Thus, we describe varying branching patterns, sporadic anastomoses, and different symmetry states in the vascular system of the marbled crayfish. We visualize our findings by application of classical and modern morphological methods, e.g. injection of casting resin, micro-computed tomography and scanning electron microscopy. By comparing our findings for P. virginalis to the vasculature in sexually reproducing crayfishes, i.e. F. limosus and Astacus astacus, we discuss phenotypic variation of the HVS in arthropods in general. We conclude that constant features of the HVS are hereditary, whereas varying states identified by study of the clonal P. virginalis must be caused by non-genetic factors and, that congruent variations in sexually reproducing F. limosus and A. astacus are likely also non-genetic phenotypic variations. Both common causal factors for non-genetic phenotypic variation, i.e., phenotypic plasticity and stochastic developmental variation are discussed along our findings regarding the vascular systems. Further aspects, such as the significance of non-genetic phenotypic variation for phylogenetic interpretations are discussed.

scholarly journals Corallimorpharians (Anthozoa: Corallimorpharia) from the Argentinean Sea

Zootaxa ◽  
2019 ◽  
Vol 4688 (2) ◽  
pp. 249-263
Author(s):  
DANIEL LAURETTA ◽  
MARIANO I. MARTINEZ
Keyword(s):  
Deep Sea ◽  
Submarine Canyon ◽  
Sister Group ◽  
Southwestern Atlantic ◽  
Sea Anemones ◽  
Northern Patagonia ◽  
Stony Corals ◽  
Internal Morphology ◽  
Southwestern Atlantic Ocean ◽  
First Time

Corallimorpharians are a relative small group of anthozoan cnidarians, also known as jewel sea anemones. They resemble actiniarian sea anemones in lacking a skeleton and being solitary, but resemble scleractinian corals in external and internal morphology, and they are considered to be the sister group of the stony corals. Corynactis carnea (=Sphincteractis sanmatiensis) is a small, common and eye catching species that inhabits the shallow water of northern Patagonia and the Argentinean shelf up to 200 m depth. Corallimorphus rigidus is registered for the first time from the southwestern Atlantic Ocean. It is a rather big and rare species that inhabits only the deep sea. Only two specimens were found at 2934 m depth in Mar del Plata submarine canyon, in an area under the influence of the Malvinas current, which may explain its occurrence. These two species are the only two known jewel sea anemones in the Argentinean sea and are reported and described herein. 

scholarly journals De Novo Genome Assembly of Limpet Bathyacmaea lactea (Gastropoda: Pectinodontidae): The First Reference Genome of a Deep-Sea Gastropod Endemic to Cold Seeps

2020 ◽  
Vol 12 (6) ◽  
pp. 905-910 ◽  
Author(s):  
Ruoyu Liu ◽  
Kun Wang ◽  
Jun Liu ◽  
Wenjie Xu ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Deep Sea ◽  
Metal Ion ◽  
De Novo ◽  
Demographic History ◽  
Gene Families ◽  
Phylogenetic Position ◽  
Cold Seeps ◽  
Nitrogen And Phosphorus ◽  
De Novo Genome Assembly ◽  
A Genome

Abstract Cold seeps, characterized by the methane, hydrogen sulfide, and other hydrocarbon chemicals, foster one of the most widespread chemosynthetic ecosystems in deep sea that are densely populated by specialized benthos. However, scarce genomic resources severely limit our knowledge about the origin and adaptation of life in this unique ecosystem. Here, we present a genome of a deep-sea limpet Bathyacmaea lactea, a common species associated with the dominant mussel beds in cold seeps. We yielded 54.6 gigabases (Gb) of Nanopore reads and 77.9-Gb BGI-seq raw reads, respectively. Assembly harvested a 754.3-Mb genome for B. lactea, with 3,720 contigs and a contig N50 of 1.57 Mb, covering 94.3% of metazoan Benchmarking Universal Single-Copy Orthologs. In total, 23,574 protein-coding genes and 463.4 Mb of repetitive elements were identified. We analyzed the phylogenetic position, substitution rate, demographic history, and TE activity of B. lactea. We also identified 80 expanded gene families and 87 rapidly evolving Gene Ontology categories in the B. lactea genome. Many of these genes were associated with heterocyclic compound metabolism, membrane-bounded organelle, metal ion binding, and nitrogen and phosphorus metabolism. The high-quality assembly and in-depth characterization suggest the B. lactea genome will serve as an essential resource for understanding the origin and adaptation of life in the cold seeps.

Intraspecific variability of morphological characters in the species-rich deep-sea genus Acantholaimus Allgén, 1933 (Nematoda: Chromadoridae)

Nematology ◽  
2016 ◽  
Vol 18 (4) ◽  
pp. 455-473 ◽  
Author(s):  
Dmitry M. Miljutin ◽  
Maria A. Miljutina
Keyword(s):  
Deep Sea ◽  
Intraspecific Variability ◽  
Morphological Characters ◽  
Molecular Data ◽  
Species Discrimination ◽  
Species Differentiation ◽  
Lateral Field ◽  
Operational Taxonomic Units ◽  
General Arrangement ◽  
Taxonomic Approach

Acantholaimusis a species-rich genus of deep-sea nematodes, often with dozens of species found at the same locality but each represented by single or few individuals. Species discrimination by morphological characters in this genus is therefore often difficult due to transitional forms that may be referred to several species because of lack of data on intraspecific variability. The aim of this study was to evaluate the intraspecific variability of morphological characters that are most often used inAcantholaimustaxonomy, in order to distinguish those which are most informative for species differentiation. A reverse taxonomic approach was applied for initial species discrimination. Two loci, one each from small and large subunits of rRNA, were sequenced for 59Acantholaimusspecimens from two deep-sea locations. Twenty-seven Molecular Operational Taxonomic Units (MOTU) were identified, of which 12 were represented by more than one individual. These were then analysed for intraspecific variability in morphological characters. Some of the examined characters showed high intraspecific variability; specifically: length of cephalic setae; distance from anterior end to amphid; shape of anterior setae; position and arrangement of cervical setae. In the absence of genetic data, these characters should be used with caution for differential diagnoses or species discrimination. Other characters were more conservative within the same MOTU: body proportions; length of outer labial setae; amphidial diam.; appearance of lateral field; general arrangement of cervical setae; and shape of tail. These characters may be successfully used for species discrimination in the absence of molecular data.

scholarly journals Deep-sea ophiuroids (Echinodermata) from reducing and non-reducing environments in the North Atlantic Ocean

2005 ◽  
Vol 85 (2) ◽  
pp. 383-402 ◽  
Author(s):  
Sabine Stöhr ◽  
Michel Segonzac
Keyword(s):  
South Carolina ◽  
Gulf Of Mexico ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Cold Seep ◽  
Chemical Compositions ◽  
Cold Seeps ◽  
Additional Species ◽  
Blake Ridge ◽  
Reducing Environment

The animal communities associated with the deep-sea reducing environment have been studied for almost 30 years, but until now only a single species of ophiuroid, Ophioctenella acies, has been found at both hydrothermal vents and methane cold seeps. Since the faunal overlap between vent and seep communities is small and many endemic species have been found among other taxa (e.g. Mollusca, Crustacea), additional species of ophiuroids were expected at previously unstudied sites. Chemical compositions at reducing sites differ greatly from the nearby bathyal environment. Generally, species adapted to chemosynthetic environments are not found in non-chemosynthetic habitats, but occasional visitors of other bathyal species to vent and seep sites have been recorded among many taxa except ophiuroids. This paper presents an analysis of the ophiuroid fauna found at hydrothermal vents and non-reducing nearby sites on the Mid-Atlantic Ridge and on methane cold seeps in the Gulf of Mexico, at Blake Ridge off South Carolina and south of Barbados. In addition to O. acies, four species were found at vents, Ophiactis tyleri sp. nov., Ophiocten centobi, Ophiomitra spinea and Ophiotreta valenciennesi rufescens. While Ophioctenella acies appears to be restricted to chemosynthetic areas, the other four species were also found in other bathyal habitats. They also occur in low numbers (mostly single individuals), whereas species adapted to hydrothermal areas typically occur in large numbers. Ophioscolex tripapillatus sp. nov. and Ophiophyllum atlanticum sp. nov. are described from nearby non-chemosynthetic sites. In a cold seep south of Barbados, three species of ophiuroids were found, including Ophioctenella acies, Amphiura sp., Ophiacantha longispina sp. nov. and Ophioplinthaca chelys. From the cold seeps at Blake Ridge and the Gulf of Mexico, Ophienigma spinilimbatum gen. et sp. nov. is described, likely restricted to the reducing environment. Ophiotreta valenciennesi rufescens occurred abundantly among Lophelia corals in the Gulf of Mexico seeps, which is the first record of this species from the West Atlantic. Habitat descriptions complement the taxonomic considerations, and the distribution of the animals in reducing environments is discussed.

scholarly journals Phylogeny and character evolution in the Dacrymycetes, and systematics of Unilacrymaceae and Dacryonaemataceae fam. nov.

2020 ◽  
Vol 44 (1) ◽  
pp. 161-205
Author(s):  
J.C. Zamora ◽  
S. Ekman
Keyword(s):  
Species Level ◽  
Single Locus ◽  
Phenotypic Characters ◽  
New Family ◽  
Multispecies Coalescent ◽  
Morphometric Analyses ◽  
Methodological Approaches ◽  
First Time ◽  
A New Species ◽  
Multilocus Phylogeny

We present a multilocus phylogeny of the class Dacrymycetes, based on data from the 18S, ITS, 28S, RPB1, RPB2, TEF-1α, 12S, and ATP6 DNA regions, with c. 90 species including the types of most currently accepted genera. A variety of methodological approaches was used to infer phylogenetic relationships among the Dacrymycetes, from a supermatrix strategy using maximum likelihood and Bayesian inference on a concatenated dataset, to coalescence-based calculations, such as quartet-based summary methods of independent single-locus trees, and Bayesian integration of single-locus trees into a species tree under the multispecies coalescent. We evaluate for the first time the taxonomic usefulness of some cytological phenotypic characters, i.e., vacuolar contents (vacuolar bodies and lipid bodies), number of nuclei of recently discharged basidiospores, and pigments, with especial emphasis on carotenoids. These characters, along with several others traditionally used for the taxonomy of this group (basidium shape, presence and morphology of clamp connections, morphology of the terminal cells of cortical/marginal hyphae, presence and degree of ramification of the hyphidia), are mapped on the resulting phylogenies and their evolution through the class Dacrymycetes discussed. Our analyses reveal five lineages that putatively represent five different families, four of which are accepted and named. Three out of these four lineages correspond to previously circumscribed and published families (Cerinomycetaceae, Dacrymycetaceae, and Unilacrymaceae), and one is proposed as the new family Dacryonaemataceae. Provisionally, only a single order, Dacrymycetales, is accepted with in the class. Furthermore, the systematics of the two smallest families, Dacryonaemataceae and Unilacrymaceae, are investigated to the species level, using coalescence-based species delimitation on multilocus DNA data, and a detailed morphological study including morphometric analyses of the basidiospores. Three species are accepted in Dacryonaema, the type, Da. rufum, the newly combined Da. macnabbii (basionym Dacrymyces macnabbii), and a new species named Da. macrosporum. Two species are accepted in Unilacryma, the new U. bispora, and the type, U. unispora, the latter treated in a broad sense pending improved sampling across the Holarctic.

Clathrosporium retortum, a novel aeroaquatic fungus in the Sordariomycetidae (Ascomycota) from Brazil

Phytotaxa ◽  
2015 ◽  
Vol 239 (1) ◽  
pp. 17
Author(s):  
Larissa Bernardino Moro ◽  
Gregorio Delgado ◽  
Iracema Helena SCHOENLEIN-CRUSIUS
Keyword(s):  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Type Specimen ◽  
Molecular Data ◽  
Sao Paulo ◽  
São Paulo ◽  
Present Fungus ◽  
Broad Concept ◽  
Morphological And Molecular Data ◽  
First Time

Clathrosporium retortum sp. nov., collected on submerged mixed leaf litter samples at Ilha do Cardoso State Park, São Paulo state, Brazil, is described based on morphological and molecular data. The fungus is characterized by forming whitish, dense, subglobose to irregular propagules, hyaline to subhyaline when young, subhyaline to dark brown at maturity, that are formed by densely interwoven conidial filaments with each conidial cell repeatedly branching bilaterally or occasionally unilaterally. Phylogenetic analyses using partial LSU nrDNA sequence data suggest that C. retortum belongs in the Sordariomycetes (Ascomycota) where it forms a well-supported clade with Clohesia corticola in the Sordariomycetidae, but its ordinal or familial placement remains unresolved. Its phylogenetic placement confirms the polyphyletic nature of aeroaquatic fungi like Clathrosporium, as it was distantly related to one available sequence in GenBank named as C. intricatum, the type species, which is phylogenetically related to the Helotiales (Leotiomycetes). However, due to lack of authenticity of the identity of this sequence with the type specimen of C. intricatum, a broad concept of Clathrosporium is tentatively adopted here to accommodate the present fungus instead of introducing a new genus. Beverwykella clathrata, Helicoön septatissimum and Peyronelina glomerulata are recorded for the first time from Brazil. Cancellidium applanatum and Candelabrum brocchiatum are new records for the state of São Paulo.

Deep-sea hydrothermal vents and cold seeps

2020 ◽  
pp. 238-292 ◽  
Author(s):  
Richard J. Léveillé ◽  
S. Kim Juniper
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vents ◽  
Cold Seeps
Sign in / Sign up

Export Citation Format

Share Document