Morphological Comparison of Two Northwest Atlantic Redfishes, Sebastes fasciatus and S. mentella, and Techniques for Their Identification

1986 ◽  
Vol 43 (4) ◽  
pp. 781-787 ◽  
Author(s):  
T. J. Kenchington
Keyword(s):  
Rapid Method ◽  
Morphological Data ◽  
Multivariate Techniques ◽  
Scotian Shelf ◽  
Morphological Comparison ◽  
Large Samples ◽  
Fin Ray ◽  
Field Identification ◽  
Rational Management ◽  
Electrophoretic Techniques

A knowledge of the taxonomy of the Atlantic redfishes, Sebastes spp., and techniques for their field identification are essential prerequisites for rational management of their fishery, but both remain poorly known. Through analysis of a set of morphological data for Sebastes fasciatus and S. mentella of the Scotian Shelf, using multivariate techniques, I examined the potential of 15 characters as field identifiers. Although the species are significantly different, they cannot be fully separated using these characters. I suggest that electrophoretic techniques are needed for precise identifications, although a rapid method for determining the species compositions of large samples, using anal fin ray counts, could be developed.

scholarly journals Monophyly of Heterandriini (Teleostei: Poeciliidae) revisited: a critical review of the data

2012 ◽  
Vol 10 (1) ◽  
pp. 19-44 ◽  
Author(s):  
Alfy Morales-Cazan ◽  
James S. Albert
Keyword(s):  
Biological Sciences ◽  
Morphological Characters ◽  
Model Systems ◽  
Morphological Data ◽  
Maximum Parsimony Analysis ◽  
Fin Ray ◽  
Outgroup Species ◽  
Tree Topologies ◽  
Tree Resolution ◽  
Shape Morphometrics

The systematics and taxonomy of poeciliid fishes (guppies and allies) remain poorly understood despite the relative importance of these species as model systems in the biological sciences. This study focuses on testing the monophyly of the nominal poeciliine tribe Heterandriini and the genus Heterandria, through examination of the morphological characters on which the current classification is based. These characters include aspects of body shape (morphometrics), scale and fin-ray counts (meristics), pigmentation, the cephalic laterosensory system, and osteological features of the neurocranium, oral jaws and suspensorium, branchial basket, pectoral girdle, and the gonopodium and its supports. A Maximum Parsimony analysis was conducted of 150 characters coded for 56 poeciliid and outgroup species, including 22 of 45 heterandriin species (from the accounted in Parenti & Rauchenberger, 1989), or seven of nine heterandriin species (from the accounted in Lucinda & Reis, 2005). Multistate characters were analyzed as both unordered and ordered, and iterative a posteriori weighting was used to improve tree resolution. Tree topologies obtained from these analyses support the monophyly of the Middle American species of "Heterandria," which based on available phylogenetic information, are herein reassigned to the genus Pseudoxiphophorus. None of the characters used in previous studies to characterize the nominal taxon Heterandriini are found to be unambiguously diagnostic. Some of these characters are shared with species in other poeciliid tribes, and others are reversed within the Heterandriini. These results support the hypothesis that Pseudoxiphophorus is monophyletic, and that this clade is not the closest relative of H. formosa (the type species) from southeastern North America. Available morphological data are not sufficient to assess the phylogenetic relationships of H. formosa with respect to other members of the Heterandriini. The results further suggest that most tribe-level taxa of the Poeciliinae are not monophyletic, and that further work remains to resolve the evolutionary relationships of this group.

scholarly journals A revised taxonomy of Asian snail-eating snakes Pareas (Squamata, Pareidae): evidence from morphological comparison and molecular phylogeny

ZooKeys ◽  
2020 ◽  
Vol 939 ◽  
pp. 45-64
Author(s):  
Ping Wang ◽  
Jing Che ◽  
Qin Liu ◽  
Ke Li ◽  
Jie Qiong Jin ◽  
...  
Keyword(s):  
New Species ◽  
Bayesian Inference ◽  
Molecular Phylogeny ◽  
Morphological Data ◽  
Multivariate Morphometrics ◽  
Cryptic Diversity ◽  
Cyt B ◽  
Morphological Comparison ◽  
The Family ◽  
Two New Species

The Asian snail-eating snakes Pareas is the largest genus of the family Pareidae (formerly Pareatidae), and widely distributed in Southeast Asia. However, potential diversity remains poorly explored due to their highly conserved morphology and incomplete samples. Here, on basis of more extensive sampling, interspecific phylogenetic relationships of the genus Pareas were reconstructed using two mitochondrial fragments (cyt b and ND4) and two nuclear genes (c-mos and Rag1), and multivariate morphometrics conducted for external morphological data. Both Bayesian Inference and Maximum Likelihood analyses consistently showed that the genus Pareas was comprised of two distinct, monophyletic lineages with moderate to low support values. Based on evidences from molecular phylogeny and morphological data, cryptic diversity of this genus was uncovered and two new species were described. In additional, the validity of P. macularius is confirmed.

Species circumscription of the Caltha leptosepala polyploid complex (Ranunculaceae) based on molecular and morphological data

Phytotaxa ◽  
2017 ◽  
Vol 316 (3) ◽  
pp. 201 ◽  
Author(s):  
KEIR M. WEFFERLING ◽  
SARA B. HOOT
Keyword(s):  
Species Complex ◽  
Morphological Characters ◽  
Title Page ◽  
Morphological Data ◽  
Polyploid Complex ◽  
Species Circumscription ◽  
Dichotomous Key ◽  
Field Identification ◽  
Geographic Data

The Caltha leptosepala species complex (Ranunculaceae) is taxonomically unresolved, with authors of various regional floras recognizing different names and numbers of species. Integrating molecular, morphological, cytological, and geographic data, we describe three species in the complex, restoring two species names, C. biflora and C. chionophila, in addition to recognizing C. leptosepala. Based on chloroplast and nuclear ribosomal phylogenies, we illustrate key morphological synapomorphies for the three Caltha species, assess the usefulness of previously used morphological characters, and provide a dichotomous key for their field identification. A neotype is designated for C. leptosepala var. howellii because the originals were lost or destroyed.

A morphological comparison of muskrats (Ondatra zibethicus) from Newfoundland and New Brunswick

1982 ◽  
Vol 60 (9) ◽  
pp. 2235-2238 ◽  
Author(s):  
Michael D. Rigby ◽  
William Threlfall
Keyword(s):  
New Brunswick ◽  
Multivariate Techniques ◽  
Ondatra Zibethicus ◽  
Morphological Comparison ◽  
Skull Measurements ◽  
Valid Taxon

Adult muskrats (Ondatra zibethicus) from Newfoundland (N = 44) and New Brunswick (N = 21) were measured and data obtained were analyzed using multivariate techniques. On the basis of skull measurements it was possible to accurately predict (P < 0.01) the site of origin of individual animals. Size differences were related to the availability of preferred foodstuffs. Ondatra zibethicus obscurus is considered a valid taxon for the Newfoundland muskrat.

scholarly journals Brachymelecta Linsley, 1939, previously the rarest North American bee genus, was described from an aberrant specimen and is the senior synonym for Xeromelecta Linsley, 1939

2021 ◽  
Vol 754 ◽  
pp. 1-51
Author(s):  
Thomas M. Onuferko ◽  
Laurence Packer ◽  
Julio A. Genaro
Keyword(s):  
Morphological Variation ◽  
Original Description ◽  
Identification Key ◽  
Morphological Data ◽  
Single Specimen ◽  
Morphological Comparison ◽  
Taxonomic Rank ◽  
Widespread Species ◽  
Senior Synonym ◽  
First Time

The bee genus Brachymelecta Linsley, 1939 has until now been represented by a single specimen, which has puzzled melittologists since its original description as Melecta? mucida Cresson, 1879. Through detailed morphological comparison and images, we show that the holotype is no more than an unusual specimen of a widespread species, most recently known as Xeromelecta californica (Cresson, 1878). We demonstrate that the diagnostic generic features for Brachymelecta fall within the range of morphological variation observed within X. californica. Although the names Brachymelecta and Xeromelecta Linsley, 1939 were published simultaneously, the former was proposed as a genus whereas the latter was proposed as a subgenus of Melecta Latreille, 1802. Thus, the following synonymies are proposed: Xeromelecta syn. nov. under Brachymelecta (since precedence must be given to the name that originally had the higher taxonomic rank) and M.? mucida syn. nov. under B. californica. Additionally, we present updated taxon concepts for and an identification key to the six known species now in Brachymelecta — B. alayoi (Michener, 1988), B. californica, B. haitensis (Michener, 1948), B. interrupta (Cresson, 1872), B. larreae (Cockerell, 1900), and B. tibialis (Fabricius, 1793) — along with redescriptions and a diagnosis for the genus. The male of B. alayoi and females of B. haitensis and B. tibialis are described for the first time. Furthermore, a phylogeny based on combined molecular and morphological data is proposed for Brachymelecta, and the evolution of the genus is explored in a historical biogeographic context.

scholarly journals A morphological comparison of Arceuthobium abietinum and A. campylopodum (Viscaceae) and nomenclatural changes for A. abietinum

2019 ◽  
Vol 13 (1) ◽  
pp. 83-101
Author(s):  
Robert L. Mathiasen ◽  
Shawn C. Kenaley
Keyword(s):  
Pacific Northwest ◽  
Statistical Tests ◽  
Morphological Data ◽  
Dwarf Mistletoe ◽  
Multivariate Statistical ◽  
Morphological Comparison ◽  
Separate Species ◽  
Geographic Ranges ◽  
The Pacific ◽  
High Degree

Fir dwarf mistletoe (Arceuthobium abietinum, Viscaceae) parasitizes true firs (Abies spp.) in the Pacific Northwest through California, the Southwest, and into northern Mexico. At present, fir dwarf mistletoe consists of two special forms (formae speciales, f. sp.) and one subspecies that are morphologically similar, but exhibit a high degree of host specificity. However, A. abietinum has been treated as a subspecies of A. campylopodum or conspecific with it in some taxonomic treatments. Therefore, we undertook this study to compare the morphologies of these dwarf mistletoes; collecting morphological data from nearly 100 A. abietinum and 60 A. campylopodum populations collected across most of their geographic ranges and analyzing these data using univariate and multivariate statistical tests. Our results demonstrated that the special forms and subspecies of A. abietinum are morphologically distinct from A. campylopodum, thereby, supporting the continued recognition of A. abietinum as a separate species. Furthermore, our analysis found significant differences for several of the characters we examined between the special forms of A. abietinum. Therefore, we recombined the special forms as subspecies: A. abietinum subsp. abietinum (formerly f. sp. concoloris) and A. abietinum subsp. magnificae (formerly f. sp. magnificae). The previously described A. abietinum subsp. wiensii was morphologically distinct from subsp. abietinum and subsp. magnificae. The distinctiveness of these taxa was supported by their host affinities as well.

Temporal data in phylogenetic systematics: an example from the mammalian fossil record

1992 ◽  
Vol 66 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J. G. M. Thewissen
Keyword(s):  
Cladistic Analysis ◽  
Phylogenetic Inference ◽  
Morphological Data ◽  
Phylogenetic Systematics ◽  
Temporal Data ◽  
Large Samples ◽  
Geographically Dispersed ◽  
Additional Input ◽  
Character Matrix ◽  
Mammalian Fossil

A method of phylogenetic inference is proposed for taxa that are known from large samples spaced closely in time. The method employs elements of cladistic and stratophenetic methods, and consists of four steps. 1) Morphologically homogeneous clusters are recognized within temporally and geographically constrained samples. 2) Temporally disjunct and geographically dispersed taxa are recognized, and their anagenetic evolution and geographic variation documented. 3) A character matrix is constructed for the taxa and analyzed cladistically. 4) Resulting cladograms are used to construct a phylogenetic tree with additional input from temporal, morphological, ecological, and geographical data. This method supplements the use of cladistically analyzed morphological data with data that are not suited for cladistic analysis, and thus reduces the amount of unused data.

scholarly journals Disentangling the Taxonomic History of the Widespread and Overlooked Centric Diatom Stephanodiscus makarovae and Its Transfer to Cyclostephanos

Taxonomy ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 425-437
Author(s):  
Konrad Schultz ◽  
Thomas Hübener ◽  
Mirko Dreßler ◽  
Olivier Jacques ◽  
Marcus Frank ◽  
...  
Keyword(s):  
Original Description ◽  
Molecular Data ◽  
Russian Language ◽  
Morphological Data ◽  
Centric Diatom ◽  
Morphological Comparison ◽  
History Of ◽  
Key Features ◽  
Morphological And Molecular Data ◽  
The Russian Language

Stephanodiscus makarovae, a taxon originally described from Russia, is morphologically similar to several other taxa within Cyclostephanos, namely C. invisitatus, C. delicatus and C. tholiformis. However, it has not yet been transferred into Cyclostephanos, perhaps due to the difficulty in identifying it, as its original description is available only in the Russian language. To investigate its morphology, a detailed morphological comparison of S. makarovae and C. invisitatus was done from 286 SEM micrographs of 12 monoclonal strains. We performed a three-gene phylogenetic analysis with strains from eight additional taxa to independently confirm the position of S. makarovae. The morphology of S. makarovae shows key features of the genus Cyclostephanos and this attribution is supported by the phylogeny. Here we propose the transfer of the taxon S. makarovae to Cyclostephanos, considering the morphological and molecular data. According to both the molecular and morphological data, C. delicatus has a unique position within the genus; S. makarovae and C. invisitatus are morphologically very similar but genetically distinct. Furthermore, based upon the results, it was possible to reassign the authority of the transfer of S. delicatus into Cyclostephanos.

Scanning electron microscopy of freeze-fractured prescapular lymph node of caprine

1984 ◽  
Vol 42 ◽  
pp. 244-245
Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer
Keyword(s):  
Lymph Node ◽  
Lymph Nodes ◽  
Lymphatic System ◽  
Three Dimensional ◽  
Meat Products ◽  
The Body ◽  
Morphological Data ◽  
The World ◽  
Cellular Constituent ◽  
Scanning Electron

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.

Ultrastructure and Morphology of the Neurospora Crassa Cell Wall Mutants, Slime And Slime X, Using Tem and Sem

1976 ◽  
Vol 34 ◽  
pp. 54-55
Author(s):  
Karen S. Howard ◽  
H. D. Braymer ◽  
M. D. Socolofsky ◽  
S. A. Milligan
Keyword(s):  
Cell Wall ◽  
Neurospora Crassa ◽  
Wild Type ◽  
Morphological Comparison ◽  
Small Areas ◽  
Solid Media ◽  
Thin Sectioning ◽  
X Cells ◽  
Mutant Cells ◽  
Isolated Cell

The recently isolated cell wall mutant slime X of Neurospora crassa was prepared for ultrastructural and morphological comparison with the cell wall mutant slime. The purpose of this article is to discuss the methods of preparation for TEM and SEM observations, as well as to make a preliminary comparison of the two mutants.TEM: Cells of the slime mutant were prepared for thin sectioning by the method of Bigger, et al. Slime X cells were prepared in the same manner with the following two exceptions: the cells were embedded in 3% agar prior to fixation and the buffered solutions contained 5% sucrose throughout the procedure.SEM: Two methods were used to prepare mutant and wild type Neurospora for the SEM. First, single colonies of mutant cells and small areas of wild type hyphae were cut from solid media and fixed with OSO4 vapors similar to the procedure used by Harris, et al. with one alteration. The cell-containing agar blocks were dehydrated by immersion in 2,2-dimethoxypropane (DMP).

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