species concept
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2023 ◽  
Vol 83 ◽  
Author(s):  
S. Aziz ◽  
J. Altaf ◽  
A. Ramzan ◽  
Z. Ahmed ◽  
S. U. R. Qamar ◽  
...  

Abstract Physids belong to Class Gastropoda; Phylum Mollusca have important position in food web and act as bio indicators, pests and intermediate host. Being resistant these are called cockroaches of malacology. Physid snails were collected from different water bodies of Faisalabad (Punjab) and were identified up to species using morphological markers. The morphometry of the specimens was carried out with the help of a digital Vernier caliper in millimeters (mm) using linear measurement of shell characters. Linear regression analysis of the AL/SW ratio vs AL and SL/SW ratio vs AL indicated that allometric growth exists only in Physa acuta when compared with P.gyrina and P. fontinalis. This study will lead to assess the status of the Physid species in Central Punjab. The Principal component analysis shows that the Component 1 (Shell Length) and component 2 (Shell Width) are the most prolific components and nearly 80 percent of the identification. The distance between P. acuta and P. fontinalis is 5.4699, P. acuta and P. gyrina is 7.6411, P. fontinalis and P. gyrina is 16.6080 showing that P. acuta resembles with P. fontinalis, and both these specimens donot resemble with P. gyrina. P.acuta is an invasive species and shows bioactivity making it a potent candidate for bioactive substances.


2022 ◽  
pp. 7-8
Author(s):  
Richard A. I. Drew ◽  
Meredith C. Romig

Abstract This chapter discusses two species models, which are diametrically opposed. The first, often called the 'biological species concept', defines species in terms of 'reproductive isolation', convinced that species arise when subsets of a population are split off and remain geographically isolated over evolutionary time. If and when such new species are reunited with their founder population, interbreeding does not occur, or if it does, infertile progeny result. Hence, from the biological species concept, natural selection is a primary agent of change and directly selects for new species. In this sense, species are the direct products of natural selection and they are therefore 'adaptive devices'. When applying this species concept, it has been impossible to separate some sibling species of fruit flies in the genus Bactrocera where distinct morphological species can be similar in molecular analyses of certain DNA sequences, while similar species morphologically are distinct in the same molecular characters. A radically different model, the 'recognition concept of species', relies heavily on a knowledge of species ecology and behaviour, particularly in their natural habitat. The principal points in this concept are given. In contrast to the now-outdated biological species concept that leads one to depend on laboratory-based research to define species, the recognition concept requires workers to undertake extensive field research in the habitat of the taxon under investigation. In translating this approach to research in the insect family Tephritidae, particularly the Dacinae, some 35 years of field surveys have been undertaken throughout the Indian subcontinent, South-east Asia and the South Pacific region. These surveys included trapping using male lure traps and host fruit collections of commercial/edible fruits. The results of this work have included the provision of specimens of almost all known species for morphological descriptions (c.800 species), material for male pheromone chemistry, and data on host fruit relationships and biogeographical studies.


Diversity ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 5
Author(s):  
Jason E. Bond ◽  
Rebecca L. Godwin ◽  
Jordan D. Colby ◽  
Lacie G. Newton ◽  
Xavier J. Zahnle ◽  
...  

Planetary extinction of biodiversity underscores the need for taxonomy. Here, we scrutinize spider taxonomy over the last decade (2008–2018), compiling 2083 published accounts of newly described species. We evaluated what type of data were used to delineate species, whether data were made freely available, whether an explicit species hypothesis was stated, what types of media were used, the sample sizes, and the degree to which species constructs were integrative. The findings we report reveal that taxonomy remains largely descriptive, not integrative, and provides no explicit conceptual framework. Less than 4% of accounts explicitly stated a species concept and over one-third of all new species described were based on 1–2 specimens or only one sex. Only ~5% of studies made data freely available, and only ~14% of all newly described species employed more than one line of evidence, with molecular data used in ~6% of the studies. These same trends have been discovered in other animal groups, and therefore we find it logical that taxonomists face an uphill challenge when justifying the scientific rigor of their field and securing the needed resources. To move taxonomy forward, we make recommendations that, if implemented, will enhance its rigor, repeatability, and scientific standards.


2021 ◽  
Vol 5 (2) ◽  
pp. 53-58
Author(s):  
Haidar Salim Anan

The present study deals with the paleontology, stratigraphy, paleogeography and paleoenvironment of the sixteen representatives of the Paleogene agglutinated benthic foraminifer Monothalamana of eight genera: Bathysiphon Sars, Orbulinelloides Saidova, Repmanina Suleymanov, Miliammina Heron-Allen & Earland, Agglutinella El-Nakhal, Dentostomina Cushman, Ammomassilina Cushman, Psammolingulina Silvestri. One species Orbulinelloides kaminskii is believed here to be new. As a whole these faunae are rarely described in the micropaleontological literatures, that’s why this study is detected. The recorded species are distributed on both sides of the Northern Tethys (Hungary, France), Southern Tethys (Egypt, UAE, Pakistan), Pacific and Atlantic Ocean. It seems that the changes in paleoceanographic conditions should accentuate the benthic faunal changes. Some of the recorded species are mostly confined to that mention localities in the Atlantic and Pacific Ocean, Northern and Southern Tethys, and it was recorded by a few authors. The deeper water species have smooth tests, while the shallow water specimens are coarser grained. The number differences of the recorded species between the different localities in the Tethys may be due to one or more parameters: the deficiency of available literatures, differences in ecological or environmental conditions (depth, salinity, water temperature, dissolved oxygen, nutrient, land barrier) and not homogeneity in the generic or species concept according to different authors.


2021 ◽  
Vol 8 (2) ◽  
pp. 65-74
Author(s):  
Pekka Niemelä ◽  
Timo Vuorisalo ◽  
Simo Örmä

Emperor Frederick II’s early thirteenth-century book on falconry, De arte venandi cum avibus, is probably the most famous single source for scholars who survey the state-of-the-art in natural sciences in medieval times. Most of the research on his book has focused on the marginal illustrations featuring about 80 bird species. However, the book contains a large amount of ethological, ecological, morphological and faunistic knowledge about bird fauna. Frederick was also one of the first to conduct experiments with birds. Here, we describe the ornithological experiments and observations of Frederick and evaluate them from the perspective of modern ecology. In many contexts, Frederick expressed criticism of Aristotle and his work Liber Animalium. Frederick’s observation upon the geographical variation of species was partially in contrast to the Aristotelian typological or essentialist species concept. This is an important finding from the point of view of the western history of biology. De arte venandi cum avibus demonstrates Frederick’s deep knowledge of the ecology, morphology and behaviour of birds. This knowledge he gained via his long practice with falconry. The love of falconry made Frederick an early proponent of empiricism, and De arte venandi cum avibus was actually the most important achievement of empirical zoology in the thirteenth century.


Turczaninowia ◽  
2021 ◽  
Vol 24 (3) ◽  
pp. 111-128
Author(s):  
Dmitry A. German

Results of taxonomic revision of Middle Asian violet- and orange-flowered wallflowers are presented. Five (vs. eight as traditionally considered) species are recognised. Thus, A. Polatschek’s four-species concept introduced in 2010 is generally supported in terms of lower species diversity of the group in question, though nomenclature is updated in various details including the newly proposed assignment of E. jodonyx to synonymy of E. samarkandicum. Lectotypes are designated for the names E. cyaneum, E. epikeimenum, E. franchetii, E. purpureum var. turkestanicum, E. samarkandicum, E. tianschanicum and E. violascens var. tschimganicum; typification of E. franchetii established on the taxonomically heterogenous material is done in agreement with its existing usage as a synonym of E. samarkandicum (not E. violascens). Redundancy of lectotypification of E. alaicum for which the holotype is extant is demonstrated. Further aspects of systematics, nomenclature, morphology and geography of the treated species are briefly discussed as well.


2021 ◽  
Author(s):  
Kerstin Voigt ◽  
Timothy Y. James ◽  
Paul M. Kirk ◽  
André L. C. M. de A. Santiago ◽  
Bruce Waldman ◽  
...  

AbstractThe increasing number of new fungal species described from all over the world along with the use of genetics to define taxa, has dramatically changed the classification system of early-diverging fungi over the past several decades. The number of phyla established for non-Dikarya fungi has increased from 2 to 17. However, to date, both the classification and phylogeny of the basal fungi are still unresolved. In this article, we review the recent taxonomy of the basal fungi and re-evaluate the relationships among early-diverging lineages of fungal phyla. We also provide information on the ecology and distribution in Mucoromycota and highlight the impact of chytrids on amphibian populations. Species concepts in Chytridiomycota, Aphelidiomycota, Rozellomycota, Neocallimastigomycota are discussed in this paper. To preserve the current application of the genus Nephridiophaga (Chytridiomycota: Nephridiophagales), a new type species, Nephridiophaga blattellae, is proposed.


2021 ◽  
Author(s):  
Maria J.A. Creighton ◽  
Alice Q. Luo ◽  
Simon M. Reader ◽  
Arne Ø. Mooers

ABSTRACTSpecies are the main unit used to measure biodiversity, but different preferred diagnostic criteria can lead to very different delineations. For instance, named primate species have more than doubled since 1982. Such increases have been termed “taxonomic inflation” and have been attributed to the widespread adoption of the ‘phylogenetic species concept’ (PSC) in preference to the previously popular ‘biological species concept’ (BSC). Criticisms of the PSC have suggested taxonomic inflation may be biased toward particular taxa and have unfavourable consequences for conservation. Here, we explore predictors of taxonomic inflation across primate taxa since the initial application of the PSC nearly 40 years ago. We do not find evidence that diversification rate, the rate of lineage formation over evolutionary time, is linked to inflation, contrary to expectations if the PSC identifies incipient species. We also do not find evidence of research effort in fields where work has been suggested to motivate splitting being associated with increases in species numbers among genera. To test the suggestion that splitting groups is likely to increase their perceived risk of extinction, we test whether genera that have undergone more splitting have also observed a greater increase in their proportion of threatened species since the introduction of the PSC. We find no cohesive signal of inflation leading to higher threat probabilities across primate genera. Overall, this analysis sends a positive message that threat statuses of primate species are not being overwhelmingly affected by splitting in line with what has recently been reported for birds. Regardless, we echo warnings that it is unwise for conservation to be reliant on taxonomic stability. Species (however defined) are not independent from one another, thus, monitoring and managing them as such may not meet the overarching goal of conserving biodiversity.


Zootaxa ◽  
2021 ◽  
Vol 5023 (3) ◽  
pp. 335-365
Author(s):  
LAURA RENGIFO-CORREA ◽  
JUAN LUIS x JUAN LUIS TÉLLEZ-RENDÓN ◽  
LYDA ESTEBAN ◽  
HERÓN HUERTA ◽  
JUAN J. MORRONE

The Triatoma phyllosoma species group includes 17 species of kissing bugs, most of them implicated in the transmission of Chagas disease in the Americas. The species of this group are T. bassolsae Alejandre-Aguilar, Nogueda-Torres, Cortéz-Jímenez, Jurberg, Galvão & Carcavallo, 1999, T. brailovskyi Martínez, Carcavallo & Pelaez, 1984, T. dimidiata (Latreille, 1811), T. gerstaeckeri (Stål, 1859), T. gomeznunezi Martínez, Carcavallo & Juberg, 1994, T. hegneri Mazzotti, 1940, T. huehuetenanguensis Lima-Cordón, Monroy, Stevens, Rodas, Rodas, Dorn & Justi, 2019, T. indictiva Neiva, 1912, T. longipennis Usinger, 1939, T. mazzottii Usinger, 1941, T. mexicana (Herrich-Schaeffer, 1848), T. mopan Dorn, Justi, Dale, Stevens, Galvão, Lima-Cordón & Monroy, 2018, T. pallidipennis (Stål, 1872), T. phyllosoma (Burmeister, 1835), T. picturata Usinger, 1939, T. recurva (Stål, 1868), and T. sanguisuga (LeConte, 1855). The validity of some species of the group was uncertain, because of both cryptic species and hybrid occurrence. Species exhibiting these particularities were formerly classified in the T. dimidiata and T. phyllosoma complexes. Although we recognize the historical value of these species complexes, we do not recommend their further use. Instead, we recognize the T. phyllosoma species group here reviewed, considering the current knowledge of the systematics and reproductive behavior of the group. We implement the cohesion species concept, validating the species status of T. bassolsae, T. longipennis, T. mazzottii, T. pallidipennis, T. phyllosoma, and T. picturata. We also provide diagnoses, photographs and a taxonomic key including the recently described species.  


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