Ecological opportunity shapes a large Arctic charr species radiation

Ecological opportunity is considered a crucial factor for adaptive radiation. Here, we combine genetic, morphological and ecological data to assess species and ecomorphological diversity of Artic charr in six lakes of a catchment in southernmost Greenland, where only charr and stickleback occur. Because the diversity of habitats and resources increases with lake size, we predict a positive association between lake size and the extent of ecomorphological diversity. The largest lake of the catchment harbours the largest Arctic charr assemblage known today. It consists of six genetically differentiated species belonging to five ecomorphs (anadromous, littoral benthic, profundal dwarf, planktivorous, piscivorous), of which the latter comprises two ecomorphologically extremely similar species. Lakes of intermediate size contain two ecomorphologically and genetically distinct species. Small lakes harbour one genetically homogeneous, yet sometimes ecomorphologically variable population. Supporting our prediction, lake size is positively correlated with the extent of ecomorphological specialization towards profundal, pelagic and piscivorous lifestyle. Furthermore, assemblage-wide morphospace increases sharply when more than one genetic cluster is present. Our data suggest that ecological opportunity and speciation jointly determine phenotypic expansion in this charr radiation.

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Two new species in the Ficinia indica complex (Cyperaceae, tribe Cypereae) from South Africa

Phytotaxa ◽

10.11646/phytotaxa.295.1.4 ◽

2017 ◽

Vol 295 (1) ◽

pp. 49

Author(s):

ALUWANI A. TSHIILA ◽

SAMSON B.M. CHIMPHANGO ◽

JAN-ADRIAAN VILJOEN ◽

A. MUTHAMA MUASYA

Keyword(s):

New Species ◽

Region Growing ◽

Distinct Species ◽

Cape Floristic Region ◽

Morphological Data ◽

Similar Species ◽

Ecological Features ◽

Dichotomous Key ◽

As Species ◽

Two New Species

Unclear boundaries between species hinder identification in the field and in herbaria, especially in species groups that can only be distinguished on the basis of subtle morphological and ecological features. One such taxon is Ficinia indica, widespread in the Greater Cape Floristic Region, growing on deep sandy soils between sea level and 1000 m elevation. Within its range, several phylogenetically related and morphologically similar species co-occur or occupy distinct habitats. Studies in herbaria show species in the Ficinia indica complex to be largely misidentified based on the use of qualitative information. Here, we investigate whether the six taxa recognized, based on one or a few characters, are supported as distinct species based on multivariate analysis of macro-morphological data. Two of the taxa were mostly separated whereas the other four taxa overlapped in multivariate space, but all the taxa could be distinguished using a single or a combination of morphological and ecological characters. We uphold the four previously recognized taxa (Ficinia argyropus, F. elatior, F. indica, F. laevis) as species, describe two new species (F. arnoldii and F. montana), and provide a dichotomous key for their identification.

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Multigene phylogeny and morphology reveal Phaeobotryon rhois sp. nov. (Botryosphaeriales, Ascomycota)

Phytotaxa ◽

10.11646/phytotaxa.205.2.2 ◽

2015 ◽

Vol 205 (2) ◽

pp. 90 ◽

Cited By ~ 4

Author(s):

XIN-LEI FAN ◽

KEVIN D. HYDE ◽

JIAN-KUI LIU ◽

YING-MEI LIANG ◽

CHENG-MING TIAN

Keyword(s):

New Species ◽

Distinct Species ◽

Similar Species ◽

Multigene Phylogeny ◽

Fruiting Bodies ◽

Canker Disease ◽

Multigene Analysis ◽

The Family ◽

Rhus Typhina ◽

A New Species

The family Botryosphaeriaceae encompasses important plant-associated pathogens, endophytes and saprobes with a wide geographical and host distribution. Two dark-spored botryosphaeriaceous taxa associated with Rhus typhina dieback and canker disease were collected from Ningxia Province, in northwestern China. Morphology and multigene analysis (ITS, LSU and EF-1α) clearly distinguished this clade as a distinct species in the genus. Phaeobotryon rhois is introduced and illustrated as a new species in this paper. The species is characterized by its globose, unilocular fruiting bodies and small, brown, 1-septate conidia. It can be distinguished from the similar species P. cercidis, P. cupressi, P. mamane and P. quercicola based on host association and conidial size and colour.

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Genetic diversity of three Aegla species (Decapoda, Anomura) revealed by AFLP and mtDNA markers

Crustaceana ◽

10.1163/15685403-00003873 ◽

2019 ◽

Vol 92 (4) ◽

pp. 445-462

Author(s):

Bianca L. Zimmermann ◽

Jober V. De Vargas Machado ◽

Sandro Santos ◽

Marlise L. Bartholomei-Santos

Keyword(s):

Genetic Diversity ◽

Distinct Species ◽

Genetic Distances ◽

Species Level ◽

Taxonomic Resolution ◽

Similar Species ◽

Southern Brazil ◽

Low Levels ◽

Management And Conservation ◽

Mtdna Markers

Abstract Representatives of the genus Aegla present a conserved morphology; thus, the increased use of molecular markers has raised many taxonomic issues. We used AFLP and mtDNA to investigate the genetic differentiation and phylogenetic relationships of morphologically similar species with overlapping distribution areas in southern Brazil: A. georginae, A. ludwigi, and A. platensis. While A. platensis is widely distributed, the critically endangered A. georginae and A. ludwigi have limited distributions. Although both markers showed populations with low levels of genetic variability, they differed markedly in revealing relationships between populations; according to AFLP, the genetic distances between A. platensis populations were as high as those between distinct species, a result not observed when considering mtDNA data. We emphasize that the use of multiple lines of evidence is necessary for defining correct levels of genetic diversity and a good species-level taxonomic resolution. Such features are essential for the management and conservation of Aegla species.

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Effects of Lake Size on Phytoplankton Nutrient Status

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f94-277 ◽

1994 ◽

Vol 51 (12) ◽

pp. 2769-2783 ◽

Cited By ~ 39

Author(s):

S. J. Guildford ◽

L. L. Hendzel ◽

H. J. Kling ◽

E. J. Fee ◽

G. G. C. Robinson ◽

...

Keyword(s):

Nutrient Status ◽

Canadian Shield ◽

Small Lakes ◽

Large Lakes ◽

P Deficiency ◽

Water Renewal ◽

Mixed Layers ◽

Shield Lakes ◽

Lake Size ◽

Total P

Phytoplankton nutrient status measurements (C/P, C/N, C/chlorophyll, N/P, alkaline phosphatase activity, and N debt) were measured for 6 yr in seven remote Canadian Shield lakes. Lakes Nipigon and Superior were also studied for 2 yr. These lakes varied in surface area from 29 to 8.223 × 10 ha, they all stratified fully during the summer and had water renewal times > 5 yr. All lakes were severely P deficient; however, the large lakes (> 2000 ha) were consistently less P deficient than small lakes. A growth-rate indicator (photosynthesis normalized to particulate C) agreed with nutrient status indicators, in that small lakes had lower rates than large lakes. Total P was a good predictor of chlorophyll, but factors related to lake size (temperature and mixed depth) were equally good or better predictors of nutrient status. Decreasing mean water column light intensity could not explain the lower P deficiency of large lakes. The deeper, more energetic mixed layers in large lakes apparently cause P to be recycled more efficiently. Extrapolation of observations or experimental results from small to large lakes requires recognition that phytoplankton in large lakes are less nutrient deficient and may have higher growth rates.

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A karyological study of the genus Pnigalio Schrank (Hymenoptera: Eulophidae): Assessing the taxonomic utility of chromosomes at the species level

Bulletin of Entomological Research ◽

10.1017/s0007485311000356 ◽

2011 ◽

Vol 102 (1) ◽

pp. 43-50 ◽

Cited By ~ 8

Author(s):

M. Gebiola ◽

M. Giorgini ◽

P. Navone ◽

U. Bernardo

Keyword(s):

Relative Length ◽

Distinct Species ◽

Species Level ◽

Similar Species ◽

Karyological Study ◽

Centromeric Index ◽

Interspecific Variability ◽

Reciprocal Differences ◽

Karyotype Structure

AbstractWe provide a karyological study of 12 species of the genus Pnigalio in an attempt to evaluate the taxonomic utility of karyotypes at the species level. For all species of Pnigalio examined the number of chromosome was 2n=12. Karyotype formulae presented mainly metacentric and submetacentric chromosomes, although a pair of acrocentrics or subtelocentrics, shorter than biarmed chromosomes, was present in some species. The analysis of karyotypes of Pnigalio showed frequent but not general interspecific variability of the chromosome traits. Although most of the studied species revealed concordance between morphological and karyological characters (centromeric index and relative length), two other categories have been identified: morphologically distinct species without reciprocal differences in karyotype structure, and morphologically similar species that strongly differ in chromosomal characters.

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Genetic relationships and variation in the Stylosanthes guianensis species complex assessed by random amplified polymorphic DNA

Genome ◽

10.1139/g93-006 ◽

1993 ◽

Vol 36 (1) ◽

pp. 43-49 ◽

Cited By ~ 38

Author(s):

Kemal Kazan ◽

John M. Manners ◽

Don F. Cameron

Keyword(s):

Species Complex ◽

Genetic Relationships ◽

Random Amplified Polymorphic Dna ◽

Random Sequence ◽

Distinct Species ◽

Similar Species ◽

Protein Patterns ◽

Stylosanthes Guianensis ◽

Taxonomic Groups

Genetic variation in the five taxonomic groups of the Stylosanthes guianensis (Aubl.) Sw. complex was investigated using random amplified polymorphic DNA markers (RAPDs). DNA samples from four plants of each of 45 accessions within the S. guianensis species complex were analyzed using 20 oligonucleotides of random sequence. Little variation was found within each of the 18 accessions (1–7% of total RAPD bands in pairwise comparisons) and none within each of the other 27 accessions. However, higher levels of polymorphisms were observed both within (index of genetic distance = 1 − F = 0.16–0.248) and between (1 − F = 0.254–0.408) the five taxa. This level of differentiation at the DNA level supported an earlier classification of the taxa as distinct species. A phenogram based on band sharing was constructed to show genetic relationships among the taxa studied. This phenogram corroborated the description of relationships based on morphological–agronomic characteristics, seed protein patterns, rhizobial affinities, crossability, and pollen stainability of the hybrids. In this phenogram, the most similar species were S. grandiflora and S. hippocampoides (1 − F = 0.264), with S. acuminata also showing closest similarity to these two species (1 − F = 0.277 and 0.283, respectively). Stylosanthes gracilis accessions showed the closest similarity (1 − F = 0.296) to S. guianensis ssp. guianensis accessions. Lowest similarity values (1 − F = 0.335–0.411) were found between these two species and S. grandiflora, S. acuminata, and S. hippocampoides.Key words: polymerase chain reaction, random amplified polymorphic DNA, Stylosanthes guianensis species complex.

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A comprehensive and integrative re-description of Synchaeta tremula (Müller, 1786) and the newly rediscovered Synchaeta tremuloida Pourriot, 1965 (Rotifera: Synchaetidae)

Zootaxa ◽

10.11646/zootaxa.4276.4.3 ◽

2017 ◽

Vol 4276 (4) ◽

pp. 503 ◽

Cited By ~ 3

Author(s):

TANJA WILKE ◽

WILKO H. AHLRICHS ◽

OLAF R.P. BININDA-EMONDS

Keyword(s):

Taxonomic Status ◽

Morphological Data ◽

Integrative Approach ◽

Similar Species ◽

Ecological Data ◽

Separate Species ◽

Unique Character ◽

Character Set ◽

Initial Description ◽

Scanning Electron

In this paper, we focus on the two morphologically similar species Synchaeta tremula (Müller, 1786) and Synchaeta tremuloida Pourriot, 1965. This study records one of the first detections of the latter species since its initial description and clarifies its uncertain taxonomic status. Using an integrative approach combining morphological data (from light and scanning electron microscopy) with molecular and ecological data, we present re-descriptions of S. tremula and S. tremuloida and confirm their status as separate species. Finally, we also provide a unique character set that can be readily applied to unambiguously identify each species using easily observable features.

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A morphological study of variation in Tyrophagus (Acarina), with particular reference to populations infesting cheese

Bulletin of Entomological Research ◽

10.1017/s0007485300055565 ◽

1961 ◽

Vol 52 (3) ◽

pp. 501-529 ◽

Cited By ~ 6

Author(s):

Phyllis L. Robertson

Keyword(s):

Close Association ◽

Distinct Species ◽

Linear Measurement ◽

Wide Distribution ◽

Ecological Data ◽

Plant Materials ◽

Frequency Distributions ◽

Ecological Zones ◽

Distribution And Ecology ◽

The Many

The difficulty of deciding the systematic status of variations within and between populations of Tyrophagus is considered in relation to the wide distribution of the genus and the many materials it infests.Variation within populations of what was thought to be one species infesting cheese is explained by the isolation of three closely similar forms which it is difficult, if not impossible, to separate by measurement alone. Frequency distributions overlap slightly for four linear measurement ratios on which separation is attempted, but differences between them are emphasised by differences in minute structural characters and they are therefore accepted as distinct species, identified as longior (Gervais, 1844), palmarum Oudemans, 1924, and putrescentiae (Schrank, 1781).Variation between populations attacking plant materials and other stored products in addition to cheese is accounted for to some extent by the recognition of three further Tyrophagus species, oudemansi Robertson, 1959, brevicrinatus Robertson, 1959, and tropicus Robertson, 1959.Within the species recognised, significant differences are recorded in dorsal hair characters and body proportions between populations on cheese produced in different geographical areas, and also between cheese populations and those infesting other materials, and these differences are thought to be at a racial level.T. longior, T. palmarum and T. putrescentiae are found to be distributed around the world, but as cheese pests they occupy somewhat different, although overlapping, geographical zones, since longior is a temperate-to-cool form, palmarum a temperate form and putrescentiae a subtropical or tropical form. The three are also found to occupy different, but overlapping ecological zones, making possible their association in mixed populations.Confusion in ecological data previously published on Tyrophagus is thought to be attributable in part to similarities in the morphology, geographical distribution and ecology of its species, and to their close association.

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The size-distribution of Earth’s lakes

Scientific Reports ◽

10.1038/srep29633 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 36

Author(s):

B. B. Cael ◽

D. A. Seekell

Keyword(s):

Power Law ◽

Theoretical Explanation ◽

Lake Area ◽

Power Law Distribution ◽

Small Lakes ◽

Large Lakes ◽

Lake Ecology ◽

Empirical Distributions ◽

Theoretical Predictions ◽

Lake Size

Abstract Globally, there are millions of small lakes, but a small number of large lakes. Most key ecosystem patterns and processes scale with lake size, thus this asymmetry between area and abundance is a fundamental constraint on broad-scale patterns in lake ecology. Nonetheless, descriptions of lake size-distributions are scarce and empirical distributions are rarely evaluated relative to theoretical predictions. Here we develop expectations for Earth’s lake area-distribution based on percolation theory and evaluate these expectations with data from a global lake census. Lake surface areas ≥0.46 km2 are power-law distributed with a tail exponent (τ = 2.14) and fractal dimension (d = 1.4), similar to theoretical expectations (τ = 2.05; d = 4/3). Lakes <0.46 km2 are not power-law distributed. An independently developed regional lake census exhibits a similar transition and consistency with theoretical predictions. Small lakes deviate from the power-law distribution because smaller lakes are more susceptible to dynamical change and topographic behavior at sub-kilometer scales is not self-similar. Our results provide a robust characterization and theoretical explanation for the lake size-abundance relationship, and form a fundamental basis for understanding and predicting patterns in lake ecology at broad scales.

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Use of habitats by non-volant small mammals in Cerrado in Central Brazil

Brazilian Journal of Biology ◽

10.1590/s1519-69842012000500016 ◽

2012 ◽

Vol 72 (4) ◽

pp. 893-902 ◽

Cited By ~ 5

Author(s):

M. Santos-Filho ◽

F. Frieiro-Costa ◽

ÁRA. Ignácio ◽

MNF. Silva

Keyword(s):

Species Composition ◽

Small Mammals ◽

Distinct Species ◽

Sensu Stricto ◽

Monodelphis Domestica ◽

Similar Species ◽

Gallery Forest ◽

Central Brazil ◽

Small Mammal Community ◽

Forested Areas

Non-volant small mammals are organisms capable of yielding precise information on richness, abundance and species composition variations related to the use of habitats. The aim of this research was to compare these variations in Cerrado sensu stricto, Palm Forest, Gallery Forest and Rocky Field. From May 1999 to February 2000, we surveyed non-volant small mammals (hence small mammals) in Serra das Araras Ecological Station. We captured 218 individuals and recaptured 62 individuals, belonging to 21 taxa, 13 rodents and eight marsupials, in a total of 13200 trap-nights. Capture success was 1.7%. We observed higher richness of small mammals in forested areas (Gallery Forest and Palm Forest) than in open areas (Rocky Field and Cerrado sensu stricto). The Palm Forest had the highest richness of marsupials, possibly due to the quality of a specific niche. The Rocky Field had the smallest richness, but with very high abundance of few species, mainly Thrichomys pachyurus and Monodelphis domestica. Forest habitats had similar species composition. The open habitats, Cerrado sensu stricto and Rocky Field, had a distinct species composition between them, and also when compared to forested areas. Different species are exclusive or showed preference for specific habitats. The protection of horizontally heterogeneous biomes, such as Cerrado, has a fundamental importance to the maintenance of the regional diversity of the small mammal community of Central Brazil.

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