scholarly journals Revealing their innermost secrets: an evolutionary perspective on the disparity of the organ systems in anomuran crabs (Crustacea: Decapoda: Anomura)

2016 ◽  
Vol 85 (4) ◽  
pp. 361-386 ◽  
Author(s):  
Jonas Keiler ◽  
Stefan Richter ◽  
Christian S. Wirkner
Keyword(s):  
Hydrothermal Vents ◽  
Morphological Changes ◽  
Direct Consequence ◽  
Morphological Characters ◽  
Last Common Ancestor ◽  
Organ Systems ◽  
Freshwater Habitats ◽  
Chemosynthetic Bacteria ◽  
Cladistic Analyses ◽  
Morphological Transformations

The Southern Australian crustacean species Lomis hirta (Lomisoidea: Lomisidae) is a representative of one of the three anomuran taxa which obtained their crab-like habitus independently from each other. This process, the evolutionary transformation into a crab-like form, is termed carcinization. To shed light on the morphological changes which took place during carcinization and to investigate structural dependence (coherence) between external and internal morphological characters, we studied L. hirta and representatives of its putatively most closely related taxa, Aegla cholchol (Aegloidea: Aeglidae) and Kiwa puravida (Chirostyloidea: Kiwaidae). External and internal anatomy was studied using microcomputertomography and computer-aided 3D reconstruction. A. cholchol and K. puravida belong to equally exceptional lineages: Aegla is endemic to South America and lives in freshwater habitats; Kiwa is a deep sea dweller associated to chemosynthetic bacteria found in methane seeps or hydrothermal vents. On the basis of recent cladistic analyses we reconstruct the anatomical ground pattern of the squat lobster-like last common ancestor of the three taxa and trace the morphological transformations that affected inner and outer morphology in the recent forms. Our results show, among other things, that the pleon in Lomis underwent drastic modifications in the context of carcinization, including a reduction of the muscular portion leaving more room for the hepatopancreas and gonads, and a narrowing of the pleonal ganglia which became shifted anteriorly into the cephalothorax and attached to the cephalothoracic ganglion. We interpret these anatomical changes in Lomis to have come about because of the loss of the caridoid escape reaction, which in turn was a direct consequence of the evolution of a strongly bent pleon as part of the crab-like habitus, and of a hidden lifestyle.

scholarly journals Molecular Correlation between Larval, Deutonymph and Adult Stages of the Water Mite Arrenurus (Micruracarus) Novus

Life ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 108
Author(s):  
Pedro María Alarcón-Elbal ◽  
Ricardo García-Jiménez ◽  
María Luisa Peláez ◽  
Jose Luis Horreo ◽  
Antonio G. Valdecasas
Keyword(s):  
Culex Pipiens ◽  
Adult Stage ◽  
Gravid Female ◽  
Morphological Characters ◽  
Species Level ◽  
Life Stages ◽  
Water Mite ◽  
Molecular Correlation ◽  
The Common ◽  
Morphological Transformations

The systematics of many groups of organisms has been based on the adult stage. Morphological transformations that occur during development from the embryonic to the adult stage make it difficult (or impossible) to identify a juvenile (larval) stage in some species. Hydrachnidia (Acari, Actinotrichida, which inhabit mainly continental waters) are characterized by three main active stages—larval, deutonymph and adult—with intermediate dormant stages. Deutonymphs and adults may be identified through diagnostic morphological characters. Larvae that have not been tracked directly from a gravid female are difficult to identify to the species level. In this work, we compared the morphology of five water mite larvae and obtained the molecular sequences of that found on a pupa of the common mosquito Culex (Culex) pipiens with the sequences of 51 adults diagnosed as Arrenurus species and identified the undescribed larvae as Arrenurus (Micruracarus) novus. Further corroborating this finding, adult A. novus was found thriving in the same mosquito habitat. We established the identity of adult and deutonymph A. novus by morphology and by correlating COI and cytB sequences of the water mites at the larval, deutonymph and adult (both male and female) life stages in a particular case of ‘reverse taxonomy’. In addition, we constructed the Arrenuridae phylogeny based on mitochondrial DNA, which supports the idea that three Arrenurus subgenera are ‘natural’: Arrenurus, Megaluracarus and Micruracarus, and the somewhat arbitrary distinction of the species assigned to the subgenus Truncaturus.

scholarly journals Changes in the Gut Microbiome of the Sea Lamprey during Metamorphosis

2012 ◽  
Vol 78 (21) ◽  
pp. 7638-7644 ◽  
Author(s):  
Amanda Tetlock ◽  
Christopher K. Yost ◽  
John Stavrinides ◽  
Richard G. Manzon
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Gut Microbiome ◽  
Morphological Changes ◽  
Sea Lamprey ◽  
Phenotypic Characterization ◽  
Filter Feeding ◽  
Content Type ◽  
Organ Systems ◽  
Feeding Larva

ABSTRACTVertebrate metamorphosis is often marked by dramatic morphological and physiological changes of the alimentary tract, along with major shifts in diet following development from larva to adult. Little is known about how these developmental changes impact the gut microbiome of the host organism. The metamorphosis of the sea lamprey (Petromyzon marinus) from a sedentary filter-feeding larva to a free-swimming sanguivorous parasite is characterized by major physiological and morphological changes to all organ systems. The transformation of the alimentary canal includes closure of the larval esophagus and the physical isolation of the pharynx from the remainder of the gut, which results in a nonfeeding period that can last up to 8 months. To determine how the gut microbiome is affected by metamorphosis, the microbial communities of feeding and nonfeeding larval and parasitic sea lamprey were surveyed using both culture-dependent and -independent methods. Our results show that the gut of the filter-feeding larva contains a greater diversity of bacteria than that of the blood-feeding parasite, with the parasite gut being dominated byAeromonasand, to a lesser extent,CitrobacterandShewanella. Phylogenetic analysis of the culturableAeromonasfrom both the larval and parasitic gut revealed that at least five distinct species were represented. Phenotypic characterization of these isolates revealed that over half were capable of sheep red blood cell hemolysis, but all were capable of trout red blood cell hemolysis. This suggests that the enrichment ofAeromonasthat accompanies metamorphosis is likely related to the sanguivorous lifestyle of the parasitic sea lamprey.

Problems of compensative fisheries: increasing the adaptive potential of broad whitefish Coregonus nasus (Pallas) in early ontogenesis by weak magnetic fields. 1. Morphometric analysis

2020 ◽  
pp. 32-46
Author(s):  
Alexander Germanovich Selyukov ◽  
Ekaterina Vladimirovna Efremova ◽  
Svetlana Aleksandrovna Selyukova ◽  
Leonid Alexandrovich Shuman
Keyword(s):  
Magnetic Fields ◽  
Morphometric Analysis ◽  
Juvenile Fish ◽  
Morphological Characters ◽  
Control Treatment ◽  
Physical Factors ◽  
Morphometric Characters ◽  
Ob River ◽  
Biological Potential ◽  
Organ Systems

The article presents the results of a production experiment with the embryos of Coregonus nasus, delivered at the Sobsk fish hatchery (settlement Kharp, YaNAO). The plant is taking compensatory measures to restore the number of valuable species of whitefishes in the Ob river basin. The purpose of our study was to increase the biological potential of juvenile broad whitefish for their subsequent release to the Ob river. At the last stage of the embryonic period, the embryos were treated with ultra-weak pulsed magnetic fields for several days. In the postembryonic period, the control and experimental juveniles of broad whitefish were fixed for subsequent morphometric and cytological-histological analysis. After conducting a morphometric analysis, we found that already at the early stages of the postembryonic period, the experimental larvae and fry exceeded the control ones in most parameters. Later, these differences persisted. At the same time, the juveniles of the experimental batch showed, as a rule, less variability of morphological characters. Also, the weight of the experimental fry before release to the Ob significantly exceeded the weight of the control fry. We calculated the degree of correlation of morphometric characters in juvenile broad whitefish of both parties in the process of rearing and found that during the first month the correlation of most parameters in the experimental juveniles was lower than in the control. However, with further development, the degree of relationship between the parameters in juveniles in the experiment increased and reached it in the control. Later, the allometric growth of the experimental juveniles began, which caused a decrease in the connection between some characters. We are discussing the features of the development of experimental juvenile fish; activation of its natural mechanisms of autorehabilitation by using weak physical factors. We explain the reasons for the stable, but insignificant differences between the experimental fish fry over the control treatment with an ultra-weak pulsed magnetic field at the last stages of embryogenesis, when the main organ systems are already formed. We conclude that this approach is advisable, starting with fertilization and early embryogenesis.

scholarly journals Towards a phylogeny of the Metazoa: evaluating alternative phylogenetic positions of Platyhelminthes, Nemertea, and Gnathostomulida, with a critical reappraisal of cladistic characters

2004 ◽  
Vol 73 (1-2) ◽  
pp. 3-163 ◽  
Author(s):  
Ronald A. Jenner
Keyword(s):  
Sister Group ◽  
Morphological Characters ◽  
Total Evidence ◽  
Morphological Data ◽  
Future Research ◽  
Sister Group Relationship ◽  
Cladistic Analyses ◽  
Phylogenetic Hypotheses ◽  
Data Matrices

This paper critically assesses all morphological cladistic analyses of the Metazoa that were published during the last one and a half decades. Molecular and total evidence analyses are also critically reviewed. This study focuses on evaluating alternative phylogenetic positions of the ‘acoelomate’ worms: Platyhelminthes, Nemertea, and Gnathostomulida. This paper consists of two parts. In Part I, all recently proposed sister group hypotheses and the supporting synapomorphies for these phyla are evaluated. Discrepancies in the treatment of corresponding characters in different cladistic analyses are identified, and where possible, resolved. In Part II, the overall phylogenetic significance across the Metazoa of all characters relevant for placing the ‘acoelomate’ worms is examined. The coding and scoring of these characters for other phyla are evaluated, and uncertainties in our understanding are pointed out in order to guide future research. The characters discussed in this paper are broadly categorized as follows: epidermis and cuticle, reproduction and sexual condition, development, larval forms, coeloms and mesoderm source, nervous system and sensory organs, nephridia, musculature, digestive system, and miscellaneous characters. Competing phylogenetic hypotheses are compared in terms of several criteria: 1) taxon sampling and the fulfillment of domain of definition for each character; 2) character sampling; 3) character coding; 4) character scoring and quality of primary homology; 5) quality of the proposed diagnostic synapomorphies as secondary homologies. On the basis of this study I conclude that a sister group for the Platyhelminthes has not yet been unambiguously established. A clade minimally composed of Neotrochozoa (Mollusca, Sipuncula, Echiura, Annelida) emerges as the most likely sister group of the Nemertea on the basis of morphological and total evidence analyses. Finally, morphological data currrently favor a sister group relationship of Gnathostomulida and Syndermata (probably plus Micrognathozoa). In contrast, molecular or total evidence analyses have not identified a reliable sister group of Gnathostomulida.Further progress in our understanding of metazoan phylogeny crucially depends on the improvement of the quality of currently adopted cladistic data matrices. A thorough reassessment of many of the more than 70 morphological characters discussed here is necessary. Despite the recent compilation of comprehensive data matrices, the power to test competing hypotheses of higher-level metazoan relationships is critically compromised due to uncritical data selection and poor character study in even the most recently published cladistic analyses.

Phylogeny and biogeography of the South American subgenus Euschistus (Lycipta) Stål (Heteroptera: Pentatomidae: Carpocorini)

2016 ◽  
Vol 47 (4) ◽  
pp. 313-346 ◽  
Author(s):  
Luciana Weiler ◽  
Augusto Ferrari ◽  
Jocelia Grazia
Keyword(s):  
Phylogenetic Analyses ◽  
Morphological Characters ◽  
Data Matrix ◽  
South American ◽  
The South ◽  
Cladistic Analyses ◽  
Heteroptera Pentatomidae ◽  
Definition Of

Phylogenetic analyses of the 13 species of the subgenusLyciptabased on morphological characters were performed under equal and implied weighting, following the method of Mirande (2009). Species fromDichelops,Ladeaschistus,Proxys,Spinalanx,Euschistus(Euschistus) andEuschistus(Mitripus) were included as outgroups, and the tree rooted onCarpocoris. Sixty-five morphological characters were coded in the data matrix. The cladistic analyses did not recover the monophyly of the subgenusLycipta. A clade was supported based on characters of the pygophore and female ectodermal ducts strengthening a new definition ofEuschistus(Lycipta). One species,Euschistus monrosi, was excluded from the subgenus and transferred to the nominal subgenus.Euschistus(Lycipta) species are distributed in two Neotropical subregions: Brazilian (Pará, Rondônia and Yungas provinces) and Chacoan (Pampean, Atlantic, Parana andAraucariaForests and Puna provinces). Biogeographical analyses of spatial vicariance were performed employing different sets of parameters and allowed to identify five disjunctions nodes.

Molecular systematics of subtribe Banksiinae (Banksia and Dryandra; Proteaceae) Based on cpDNA and nrDNA sequence data: Implications for taxonomy and biogeography

1998 ◽  
Vol 11 (4) ◽  
pp. 321 ◽  
Author(s):  
Austin R. Mast
Keyword(s):  
Sequence Data ◽  
Phylogenetic Reconstruction ◽  
Morphological Characters ◽  
Internal Transcribed Spacers ◽  
Nuclear Ribosomal Dna ◽  
Base Substitution ◽  
Trnl Intron ◽  
Single Root ◽  
Cladistic Analyses ◽  
Molecular Characters

Despite considerable research interest in the subtribe Banksiinae (Banksia L.f. and Dryandra R.Br.), no strongly supported phylogenetic hypothesis for the relationship between the genera exists, nor have molecular characters been sampled for phylogenetic reconstruction at any level. In this study, DNA sequence characters were sampled from chloroplast DNA (cpDNA; the trnL intron, the trnL 3′ exon, and the spacer between the trnL 3′ exon and trnF) and nuclear ribosomal DNA (nrDNA; both internal transcribed spacers) of 18 species of Banksia and five of Dryandra, with six outgroup taxa from the subfamily Grevilleoideae. The molecular characters provided the opportunity to code taxa outside of Banksia for cladistic comparison with the genus—an opportunity not previously provided by morphological characters. Cladistic analyses, using parsimony, explored the effects of various weightings of transition to transversion events and base substitution to insertion and deletion events to determine which relationships in the cladograms were robust. The trnL/trnF and ITS characters strongly supported a paraphyletic Banksia with respect to a monophyletic Dryandra. The molecular results supported a single root for Thiele and Ladiges’(1996) unrooted morphological cladogram along the branch between the Isotylis to B. fuscolutea clade and the Grandes to B. tricuspis clade. George’s (1981) subgenus Banksia and section Banksia appeared dramatically non-monophyletic. The distribution of eastern taxa at derived positions on the molecular cladograms suggested considerable cladogenesis in the the genus prior to the formation of the Nullarbor Plain during the Tertiary.

Character evolution and the origin of Caimaninae (Crocodylia) in the New World Tropics: new evidence from the Miocene of Panama and Venezuela

2016 ◽  
Vol 90 (2) ◽  
pp. 317-332 ◽  
Author(s):  
Alexander K. Hastings ◽  
Moritz Reisser ◽  
Torsten M. Scheyer
Keyword(s):  
South America ◽  
New World ◽  
Morphological Characters ◽  
Character Evolution ◽  
Lower Jaw ◽  
Close Relationship ◽  
Cladistic Analyses ◽  
North And South America ◽  
New Evidence ◽  
North And South

AbstractAlligators and caimans share a close relationship, supported by both molecular and morphological characters. The divergence between alligators and caimans has been difficult to discern in the fossil record. Two basal taxa have recently been described from the Miocene of Panama and Venezuela but have not yet been presented in a joint phylogeny. Continued preparation of the type material of the Venezuelan Globidentosuchus brachyrostris Scheyer et al., 2013 has revealed new characters for scoring in a cladistic framework. In addition, the first lower jaw of the Panamanian Centenariosuchus gilmorei Hastings et al., 2013 is described herein, and additional characters were scored. In total, we conducted five cladistic analyses to better understand the character evolution involved in the establishment of Caimaninae. In each case, Globidentosuchus appears as the basal-most of the caimanine lineage, followed by Culebrasuchus mesoamericanus Hastings et al., 2013 from Panama. Stepwise character additions of synapomorphies define progressively more derived caimanines, but stratigraphic context creates ghost lineages extending from the Miocene to Paleocene. The persistence of two basal taxa into the Miocene of northern South America and Central America supports the concept of a relict basal population in this region. This further supports biogeographic hypotheses of dispersals in both directions between North and South America prior to full land connection.

Two new genera and species of chiltoniid amphipods (Crustacea: Amphipoda: Talitroidea) from freshwater mound springs in South Australia

Zootaxa ◽  
2009 ◽  
Vol 2293 (1) ◽  
pp. 35-52 ◽  
Author(s):  
RACHAEL A. KING
Keyword(s):  
South Australia ◽  
Distinct Species ◽  
Morphological Characters ◽  
New Genera ◽  
Molecular Analyses ◽  
Australian Species ◽  
The Family ◽  
Freshwater Habitats ◽  
Australian Freshwater

Amphipods within the family Chiltoniidae are an abundant yet taxonomically poorly known member of Australian freshwater habitats. With only four species known from Australia, the group is inadequately defined and marked by taxonomists as difficult to identify. Recent molecular analyses of chiltoniids from mound springs in South Australia detected several distinct species, prompting a morphological revision of material from the central and southern Lake Eyre region. Clear groups defined by unique combinations of morphological characters (focusing on uropodal, coxal, male gnathopod 2, and antennal morphology) were found that closely correlated with clades found in the molecular analyses. Arabunnachiltonia n. gen. is established for A. murphyi n. sp. from Strangways Springs in South Australia. Wangiannachiltonia n. gen. is established for W. guzikae n. sp. from Davenport Springs in South Australia. The chiltoniid genera are discussed and a key is presented to the known Australian species.

scholarly journals Distribution and evolution of secondary metabolites in Eriocaulaceae, Lythraceae and Velloziaceae from "campos rupestres"

2000 ◽  
Vol 23 (4) ◽  
pp. 931-940 ◽  
Author(s):  
Antonio Salatino ◽  
Maria Luiza Faria Salatino ◽  
Déborah Yara A.C. dos Santos ◽  
Márcia Cristina B. Patrício
Keyword(s):  
Fatty Acids ◽  
Secondary Metabolites ◽  
Salient Feature ◽  
Morphological Characters ◽  
Epicuticular Wax ◽  
Campos Rupestres ◽  
Carbon Chains ◽  
Cladistic Analyses ◽  
Flavonoid Patterns ◽  
Molecular Characters

Hypotheses are presented on the evolution of structural patterns of secondary metabolites (flavonoids and foliar wax alkanes) and fatty acids of families of "campos rupestres". The distribution of fatty acids is given for genera of Lythraceae, with emphasis on Cuphea (supposedly more advanced) and Diplusodon. Compounds with saturated short chains represent a derived condition in Lythraceae although they are probably restricted to Cuphea. It is suggested that evolution selected for more complex flavonoid patterns in Cuphea, with the inclusion of C-glycoflavones and methoxylated flavonols (rhamnetin and isorhamnetin), which are not found in members of Diplusodon and Lafoensia. The supposedly primitive groups of Eriocaulaceae (e.g., Paepalanthus) presented more complex flavonoid patterns characterized by flavones and flavonols, the latter frequently being 6-hydroxylated or methoxylated. More advanced groups of Eriocaulaceae (e.g., Leiothrix and Syngonanthus) apparently possess only flavones, C-glycoflavones are a salient feature of species with smaller habits. In Velloziaceae, members of the primitive subfamily Vellozioideae show distribution of alkanes of foliar epicuticular wax in which C27, C29 or C31 predominate; members of the derived subfamily Barbacenioideae usually show distributions with a predominance of C33 or C35, while species of Pleurostima (Barbacenioideae) have C31 as the main homologue, thus being intermediate between the two subfamilies. It is suggested that the evolution of alkanes in Velloziaceae follows a trend toward elongation of carbon chains. The condition of advanced or primitive chemical patterns is inferred from the results of cladistic analyses based on morphological characters (Eriocaulaceae and Lythraceae), and morphological and molecular characters (Velloziaceae).

Phylogeny of the genus Bryoria

2011 ◽  
Vol 43 (6) ◽  
pp. 617-638 ◽  
Author(s):  
Leena MYLLYS ◽  
Saara VELMALA ◽  
Håkon HOLIEN ◽  
Pekka HALONEN ◽  
Li-Song WANG ◽  
...  
Keyword(s):  
Growth Form ◽  
Sequence Data ◽  
Molecular Study ◽  
Morphological Characters ◽  
Ssu Rdna ◽  
Species Status ◽  
Infrageneric Classification ◽  
Rdna Sequence Data ◽  
Cladistic Analyses ◽  
Current Species

AbstractThe phylogenetic relationships of the genus Bryoria were examined using ITS, partial glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and mitochondrial SSU rDNA sequence data in addition to 20 chemical and morphological characters. This first comprehensive molecular study to assess Bryoria phylogeny includes representatives from all the traditionally recognized four sections. Combined cladistic analyses of 88 Bryoria specimens representing at least 25 species resulted in highly resolved phylogenies. Based on the results, a new infrageneric classification for the genus is proposed. Five sections are recognized, largely corresponding to the existing classification, with the addition of section Americanae. The study shows that while most species with an erect growth-form are clearly monophyletic, current species status of many pendent taxa can be questioned.

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