Environmental and Genetic Contributions to Morphological Differentiation in Ciscoes (Coregoninae) of the Great Lakes

1981 ◽  
Vol 38 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Thomas N. Todd ◽  
Gerald R. Smith ◽  
Louella E. Cable
Keyword(s):  
Great Lakes ◽  
Environmental Effects ◽  
Management Strategies ◽  
Morphological Differentiation ◽  
Single Species ◽  
Genetic Differences ◽  
Morphological Differences ◽  
Genetic Contributions

Laboratory-produced progeny of Coregonus alpenae, C. zenithicus, C. hoyi, and C. kiyi and their wild parents were used to examine the contributions of genotype and environment to morphology. Morphological differences between parents and offspring were generally greater than those between species, indicating strong environmental effects. The phenotypic effects on most characters can probably be attributed to different developmental temperatures and perhaps to stresses in the hatchery not encountered in the Great Lakes. Genetic differences were inferred from morphological differences between offspring of different species raised under identical conditions. Genetic differences were demonstrated between C. hoyi and C. kiyi but not between C. alpenae and C. zenithicus which suggested that our samples of C. alpenae and C. zenithicus represented only a single species. The presence of unique stocks of coregonines in the Great Lakes, as well as of several species, suggests that management strategies should focus on both levels of diversity.Key words: Salmonidae, Coregoninae, Coregonus, morphology, Great Lakes, development, stocks

A new species of Psammophis (Serpentes: Psammophiidae) from the Turpan Basin in northwest China

Zootaxa ◽  
2021 ◽  
Vol 4974 (1) ◽  
pp. 116-134
Author(s):  
MINLI CHEN ◽  
JINLONG LIU ◽  
BO CAI ◽  
JUN LI ◽  
NA WU ◽  
...  
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Northwest China ◽  
Genetic Differences ◽  
Cytb Gene ◽  
Turpan Basin ◽  
Morphological Differences ◽  
A New Species

An adult sand snake specimen was collected during a herpetofaunal survey conducted in the Turpan Basin in northwest China. Phylogenetic analyses revealed that this specimen, along with other snake sloughs and skins collected from different localities in the Turpan Basin formed a clade that is sister to Psammophis lineolatus. This taxon exhibited substantial divergence from its congeners (P. lineolatus and P. condanarus) with uncorrelated p-distances ranging from 11.9 ± 0.9% to 15.8 ± 1.6% for the ND4 gene and from 10.2 ± 0.8% to 13.8 ± 1.1% for the Cytb gene. Given the genetic differences along with morphological differences, we describe the specimen from the Turpan Basin as Psammophis turpanensis sp. nov. We provide detailed morphological descriptions, and compare this specimen with five Asian sand snakes and the Afro-Asian Sand Snake, P. schokari. In addition, we provide brief comments on the biogeography of Psammophis in China. 

Management inferences from a demographic analysis of sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes

2008 ◽  
Vol 65 (2) ◽  
pp. 227-244 ◽  
Author(s):  
Luis Antonio Vélez-Espino ◽  
Robert L McLaughlin ◽  
Thomas C Pratt
Keyword(s):  
Great Lakes ◽  
Life Stage ◽  
Petromyzon Marinus ◽  
Management Strategies ◽  
Sea Lamprey ◽  
Management Plan ◽  
Laurentian Great Lakes ◽  
Alternative Methods ◽  
Vital Rates ◽  
Population Growth Rates

We use matrix models incorporating uncertainty in values of life history traits and density-dependent survival to assess pest management strategies implemented by the Great Lakes Fishery Commission to control nonnative sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes. The primary method of sea lamprey control has been treatment of rearing tributaries with chemical lampricides, but release of sterilized males and deployment of migratory barriers and traps are important components of the management plan. Uncertainties in the effectiveness of alternative control remain, however. Our models demonstrated that the management target of reducing lampricide use by 20% while maintaining current levels of control could be achieved if alternative methods are used to suppress current lake-wide fecundity rates by 49%–65%, assuming equal lampricide efficiency on larvae and metamorphosing individuals, or by 42%–55% when lampricide mortality on larvae is assumed to be half of that on metamorphosing individuals. At current levels of lampricide use, reduction to 72%–88% of current fecundity rates is recommended to ensure long-term control of sea lamprey populations in the face of uncertainty in current estimates of population growth rates. New control options targeting additional vital rates, such as survival of the parasitic life stage, could further reduce reliance on lampricides while maintaining effective sea lamprey control.

scholarly journals STUDY OF SINGLE-SPECIES POPULATION MODELS

2020 ◽  
pp. 161-166
Author(s):  
Marthak Rutu
Keyword(s):  
Spatial Heterogeneity ◽  
Environmental Effects ◽  
Age Structure ◽  
Single Species ◽  
Research Paper ◽  
Population Models ◽  
Deterministic Models ◽  
One Dimensional ◽  
Species Population ◽  
Single Species Population

In this research paper one dimensional population models developed centuries ago shows that growth and/decay of single homogeneous populations But environmental effects spatial heterogeneity or age-structure deterministic models prevailing single species population models.

scholarly journals Three new species of leaflitter frogs from the upper Amazon forests: cryptic diversity within Pristimantis "ockendeni" (Anura: Strabomantidae) in Ecuador

Zootaxa ◽  
2008 ◽  
Vol 1784 (1) ◽  
pp. 11 ◽  
Author(s):  
KATHRYN R. ELMER ◽  
DAVID C. CANNATELLA
Keyword(s):  
New Species ◽  
Dna Sequences ◽  
Amazon Basin ◽  
Single Species ◽  
Cryptic Diversity ◽  
Morphological Differences ◽  
Three New Species ◽  
Multiple Species

We describe three new species of Pristimantis leaflitter frogs from the upper Amazon basin of Ecuador: Pristimantis achuar, Pristimantis altamnis, and Pristimantis kichwarum. Each of these new species was previously considered to be part of a single species, formerly known as Eleutherodactylus ockendeni (Boulenger) morph B. However, analysis of DNA sequences together with examination of the morphology of more than 600 specimens from Ecuador reveals that multiple species were confused under the same name. The morphological differences among the three new species are subtle but consistent: presence or absence of a black canthal stripe and/or supratympanic ridge, snout-vent length, and ventral colouration. The three species are generally allopatric and geographically restricted, although at some localities two of the species occur sympatrically.Describimos tres especies nuevas de ranas del sotobosque de la cuenca Amazónica Ecuatoriana: Pristimantis achuar, Pristimantis altamnis y Pristimantis kichwarum. Estas especies fueron consideradas antes como una sola especie bajo el nombre Eleutherodactylus ockendeni (Boulenger) morfo B. Sin embargo, el análisis de secuencias de ADN y la examinación de la morfología de más que 600 especímenes Ecuatorianos indican que en realidad existen tres especies. Sus diferencias morfológicas son sutiles pero constantes: presencia o ausencia de una raya cantal negra y/o de un pliegue supratimpánico y su coloración ventral. Las tres especies tienen distribuciones alopátricas y distintas aunque en algunas localidades se puede encontrar dos de las tres especies juntas.

A Bayesian spatiotemporal approach to inform management unit appropriateness

2019 ◽  
Vol 76 (2) ◽  
pp. 217-237 ◽  
Author(s):  
Rujia Bi ◽  
Yan Jiao ◽  
Can Zhou ◽  
Eric Hallerman
Keyword(s):  
Great Lakes ◽  
Fisheries Management ◽  
Yellow Perch ◽  
Management Strategies ◽  
Computational Cost ◽  
Bayesian Hierarchical ◽  
Fish Stocks ◽  
Spatiotemporal Correlation ◽  
Management Actions ◽  
Gill Net

One prerequisite for sustainable fisheries management is to match management actions with biological processes. Stocks are fundamental units for fisheries management. Understanding the spatial structure of fish stocks is critical for conducting defensible stock assessments, applying efficient management strategies, and ensuring the sustainability of fish stocks. Yellow perch (Perca flavescens) is an important fishery in the Great Lakes. The appropriateness of its management units (MUs) has been identified as of high concern by the Great Lakes Fisheries Commission. Here we established integrated nested Laplace approximations and stochastic partial differential equations as two powerful tools for modeling spatiotemporal patterns of fish relative biomass. These fast computational approaches were applied to fit a Bayesian hierarchical hurdle model to occurrence and positive mass of yellow perch caught in gill-net surveys. Yellow perch relative biomass index has clear temporal variation and spatial heterogeneity, with the two middle MUs for yellow perch within Lake Erie merging together. The method explicitly models the spatiotemporal correlation structure inherent in biomass survey data at a reasonable computational cost, and the estimated spatiotemporal correlation informs stock structure.

Reproductive potential of South African thermophilic Meloidogyne populations, with special reference to Meloidogyne enterolobii

Nematology ◽  
2019 ◽  
Vol 21 (9) ◽  
pp. 913-921 ◽  
Author(s):  
Milad Rashidifard ◽  
Mariette Marais ◽  
Mieke S. Daneel ◽  
Hendrika Fourie
Keyword(s):  
South African ◽  
Management Strategies ◽  
Reproductive Potential ◽  
Single Species ◽  
Mixed Species ◽  
Initial Experiment ◽  
Meloidogyne Enterolobii ◽  
Species Population ◽  
Rf Values ◽  
Single Species Population

Summary Variability in the reproductive potential of Meloidogyne spp. is crucial to design suitable nematode management strategies. The reproductive potential of nine South African single-species Meloidogyne populations, M. enterolobii (5), M. incognita (2) and M. javanica (2), as well as three mixed-species communities (each containing two of the three species) were determined in glasshouse experiments. A mixed-species community of M. enterolobii and M. javanica had the highest reproductive potential (Rf = 15.7) in the initial experiment. For the repeat experiment, a single-species population of M. javanica was the most injurious (Rf = 19.1). Conversely, a single-species population of M. enterolobii had the lowest Rf values in the initial (Rf = 1.0) and repeat (Rf = 6.1) experiments. Substantial variation existed in terms of the reproductive potential of M. enterolobii single-species populations and mixed-species communities.

Taxonomic identity of the patagonian frog Atelognathus jeinimenensis (Anura: Neobatrachia) as revealed by molecular and morphometric evidence

Zootaxa ◽  
2011 ◽  
Vol 2880 (1) ◽  
pp. 20 ◽  
Author(s):  
HELEN DÍAZ-PÁEZ ◽  
MARCELA A. VIDAL ◽  
JUAN C. ORTIZ ◽  
CARMEN A. ÚBEDA ◽  
NÉSTOR G. BASSO
Keyword(s):  
Genetic Diversity ◽  
Morphological Analysis ◽  
Single Species ◽  
Geographic Pattern ◽  
Chilean Patagonia ◽  
Nucleotide Data ◽  
D Loop ◽  
Low Levels ◽  
Morphological Differences ◽  
Chilean Populations

The frog genus Atelognathus is currently represented by nine species distributed in Argentinean and Chilean Patagonia. It is mainly distributed in Argentina, and there are only three species in Chile (A. ceii, A. grandisonae and A. jeinimenensis). Regarding the morphological relationships among Atelognathus species, Meriggio et al. (2004) suggest that A. jeinimenensis is more related to A. salai than other species. A. salai was described from Laguna Los Gendarmes (Argentina), 90 km air line from the type locality of A. jeinimenensis. This paper presents a morphological analysis and a study of population genetics using mtDNA nucleotide data from Argentinean and Chilean localities to assess the genetic distance between A. salai and A. jenimenensis. We obtained 477 bp-long d-loop sequences from 51 Atelognathus specimens collected in four localities. According to our results, the morphological differences between A. salai and A. jeinimenensis populations are limited to size, and there are no distinctive characteristics that would separate two species, in addition to which a simple geographic pattern of genetic diversity suggests a single species of Atelognathus. Also, the populations from Chile (Cerro Castillo, RN Lago Jeinimeni and Chile Chico) and Argentina (Laguna de Los Gendarmes) have low levels of genetic divergence that may be consistent with glaciations during the Late Pleistocene. We propose Atelognathus jeinimenensis as a junior synonym of A. salai and that the Chilean populations should be assigned to A. salai.

scholarly journals Megadiversity in the Ant Genus Melophorus: The M. rufoniger Heterick, Castalanelli and Shattuck Species Group in the Top End of Australia’s Northern Territory

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 386
Author(s):  
Alan N. Andersen ◽  
Benjamin D. Hoffmann ◽  
Stefanie K. Oberprieler
Keyword(s):  
Morphological Differentiation ◽  
Single Species ◽  
Species Group ◽  
Northern Region ◽  
Northern Territory ◽  
Distributional Analysis ◽  
Additional Species ◽  
Sympatric Distribution ◽  
Total Species ◽  
Eleven Species

This study contributes to an understanding of megadiversity in the arid-adapted ant genus Melophorus by presenting an integrated genetic, morphological and distributional analysis of diversity within the M. rufoniger group in the 400,000 km2 Top End (northern region) of Australia’s Northern Territory. An earlier study of the Top End’s ant fauna lists eleven species from the M. rufoniger group, but a recent revision of Melophorus described the taxon as a single species occurring throughout most of the Australian mainland. CO1 sequences were obtained for 120 Top End specimens of the M. rufoniger group, along with a specimen from just outside the Top End. We recognize a total of 30 species among the sequenced specimens from the Top End, based on marked CO1 divergence (mean > 9%) in association with morphological differentiation and/or sympatric distribution. The sequenced specimen from just outside the Top End represents an additional species. Our unpublished CO1 data from other specimens from elsewhere in monsoonal Australia indicate that all but two of the 30 sequenced Top End species are endemic to the region, and that such diversity and endemism are similar in both the Kimberley region of far northern Western Australia and in North Queensland. The total number of species in the M. rufoniger group is potentially more than the 93 total species of Melophorus recognized in the recent revision. It has previously been estimated that Melophorus contains at least 1000 species, but our findings suggest that this is a conservative estimate.

Differentiation in Coregonus zenithicus in Lake Superior

1980 ◽  
Vol 37 (12) ◽  
pp. 2228-2235 ◽  
Author(s):  
Thomas N. Todd ◽  
Gerald R. Smith
Keyword(s):  
Endangered Species ◽  
Great Lakes ◽  
Lake Superior ◽  
Distinct Species ◽  
Multivariate Morphometrics ◽  
Geographic Isolation ◽  
Allometric Growth ◽  
Spawning Time ◽  
Morphological Differences ◽  
Species Taxonomy

Morphological variation in Coregonus zenithicus has long plagued biologists working on Lake Superior ciscoes. Some of this variation is due to allometric growth; earlier workers incorrectly recognized large C. zenithicus as a distinct species, C. nigripinnis cyanopterus. Coregonus reighardi dymondi is a variant of C. zenithicus in northern bays of Lake Superior and Lake Nipigon. The morphological differences between members of spring and fall spawning populations of C. zenithicus in Lake Superior are no greater than those between geographically separate populations. We conclude that spawning time and geographic isolation act similarly in effecting differentiation of coregonine populations, and that populations with different spawning times do not necessarily represent different species.Key words: Coregonus zenithicus, cisco, Great Lakes, multivariate morphometrics, endangered species, taxonomy

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