The importance (or lack thereof) of niche divergence to the maintenance of a northern species complex: the case of the long-toed salamander (Ambystoma macrodactylum Baird)

2015 ◽  
Vol 28 (4) ◽  
pp. 917-930 ◽  
Author(s):  
J. A. Lee-Yaw ◽  
D. E. Irwin
2013 ◽  
Vol 91 (12) ◽  
pp. 883-892 ◽  
Author(s):  
Jessica A. Wooten ◽  
Carlos D. Camp ◽  
Jonathon R. Combs ◽  
Eden Dulka ◽  
Alexandra Reist ◽  
...  

The Woodland Salamander genus Plethodon Tschudi, 1838, consists of terrestrial lungless salamanders, has been cited as an exemplar of a lineage characterized by niche conservatism. This conclusion has contributed to broader hypotheses dealing with the role of niche conservatism in speciation and the maintenance of species diversity. We re-evaluated these salamanders using newly published techniques designed to detect niche conservatism versus niche divergence using computer-based niche modeling and spatial analysis within a phylogenetic framework. We specifically studied parapatric neighbors in the species complex of Plethodon glutinosus (Green, 1818) to determine if there is evidence of a role for niche divergence at speciation or if niche conservatism characterizes the complex as has been reported for the larger genus. We found that new statistical approaches yield different results from earlier work, suggesting that niche divergence has been a much more important player in the speciation process than has heretofore been understood. Although different parts of the overall Plethodon phylogeny may be characterized by different rates of niche evolution, the rapidly burgeoning area of research centered on niche conservatism appears to be in a state of flux with regards to methods that give consistently repeatable results.


2014 ◽  
Vol 25 (1-2) ◽  
pp. 61-68 ◽  
Author(s):  
V. I. Monchenko ◽  
L. P. Gaponova ◽  
V. R. Alekseev

Crossbreeding experiments were used to estimate cryptic species in water bodies of Ukraine and Russia because the most useful criterion in species independence is reproductive isolation. The problem of cryptic species in the genus Eucyclops was examined using interpopulation crosses of populations collected from Baltic Sea basin (pond of Strelka river basin) and Black Sea basin (water-reservoires of Dnieper, Dniester and Danube rivers basins). The results of reciprocal crosses in Eucyclops serrulatus-group are shown that E. serrulatus from different populations but from water bodies belonging to the same river basin crossed each others successfully. The interpopulation crosses of E. serrulatus populations collected from different river basins (Dnipro, Danube and Dniester river basins) were sterile. In this group of experiments we assigned evidence of sterility to four categories: 1) incomplete copulation or absence of copulation; 2) nonviable eggs; 3) absence of egg membranes or egg sacs 4) empty egg membranes. These crossbreeding studies suggest the presence of cryptic species in the E. serrulatus inhabiting ecologically different populations in many parts of its range. The same crossbreeding experiments were carries out between Eucyclops serrulatus and morphological similar species – Eucyclops macruroides from Baltic and Black Sea basins. The reciprocal crossings between these two species were sterile. Thus taxonomic heterogeneity among species of genus Eucyclops lower in E. macruroides than in E. serrulatus. The interpopulation crosses of E. macruroides populations collected from distant part of range were fertile. These crossbreeding studies suggest that E. macruroides species complex was evaluated as more stable than E. serrulatus species complex.


2016 ◽  
Vol 27 (3-4) ◽  
pp. 47-54
Author(s):  
K. K. Holoborodko ◽  
V. O. Makhina ◽  
K. S. Buchnieva ◽  
O. E. Pakhomov

Floodplain valley of the Dnieper river midstream is a unique natural complex, having a great bìogeographical, ecological, environmental, historical and recreational values. In 1990, the Natural reserve «Dniprovsko-Orilsky» was established within the area. The Natural reserve «Dniprovsko-Orilsky» is environmentally protected site within the Dnipropetrovsk region, Dnipropetrovsk oblast, Ukraine. This reserve occupies part of the Dnieper river valley and marshy and reedy banks of Protovch river (existing bed of Oril river). It was created by Regulation of the Council of Ministers of the USSR of 15 September 1990, No. 262, based on common zoological and ornitological Nature reserves «Taromskì plavni» and «Obukhovskie zaplavy». On the territory of the Natural reserve «Dniprovsko-Orilsky», they were registered 32 Lepidoptera species listed in the List of Threatened Species at different categories (5 species in IUCN Red List ; 18 in Red Data Book of Ukraine; 7 in European Red List of plants and animals endangered on a global scale; 31 in Red Book of Dnipropetrovsk oblast). The main scientific materials were author’s collections from area of research and materials of entomological funds, Department of Zoology and Ecology, Oles Honchar Dnipropetrovsk National University (mostly Memorial Collection of V. O. Barsov). Field surveys covered all the ecosystems basic on size and degree of protection. The author’s researches have conducted over the past decade during annual expeditions to the Reserve. Taxonomic structure of the complex is quite diverse, and represented by all the major families of higher millers and rhopalocera, having protectedstatus. In relation to taxonomy, this complex formed by representatives of five superfamilies (Zyganoidea, Noctuoidea, Bombycoidea, Hesperioidea, Papilionoidea) from 11 families (Zygaenidae, Saturniidae, Sphingidae, Noctuidae Arctiidae Hesperiidae, Papilionidae, Pieridae, Nymphalidae, Satyridae, Lycaenidae). High taxonomic diversity can be explained by unique geographical location of the reserve in azonal conditions of the Dnieper river valley. Such location allows to enter different zoogeographic Lepidoptera groups on the reserve territory. Zoogeographic analysis of species protected within the reserve territory selected 7 basic groups. It was found that most of the globally rare species have Mediterranean origin (39 %); species of Palearctic origin are in second place (22 %); Western Palearctic and Ponto-Kazakh types of areas are same of number of species, and come third (11 %); and others come 17 % (European, Euro-Siberian, and Holarctic). This fauna component is specific due to presence of so-called «northern» species that make up 40 % (representatives of Palearctic, Western Palearctic, Euro-Siberian, European and Holarctic groups). Their existence within the reserve territory is only possible due to development of boreal valley ecosystems. High taxonomic diversity can be explained by unique geographical location of the reserve in azonal conditions of the Dnieper river valley. Such location allows to enter different zoogeographic Lepidoptera groups on the reserve territory. Zoogeographic analysis of species protected within the reserve territory selected 7 basic groups. It was found that most of the globally rare species have Mediterranean origin (39 %); species of Palearctic origin are in second place (22 %); Western Palearctic and Ponto-Kazakh types of areas are same of number of species, and come third (11 %); and others come 17 % (European, Euro-Siberian, and Holarctic). This fauna component is specific due to presence of so-called «northern» species that make up 40 % (representatives of Palearctic, Western Palearctic, Euro-Siberian, European and Holarctic groups). Their existence within the reserve territory is only possible due to development of boreal valley ecosystems.


Author(s):  
A. Muntala ◽  
P. M. Norshie ◽  
K. G. Santo ◽  
C. K. S. Saba

A survey was conducted in twenty-five cashew (Anacardium occidentale) orchards in five communities in the Dormaa-Central Municipality of Bono Region of Ghana to assess the incidence and severity of anthracnose, gummosis and die-back diseases on cashew. Cashew diseased samples of leaves, stem, inflorescences, twigs, flowers, nuts and apples showing symptoms (e. g. small, water-soaked, circular or irregular yellow, dark or brown spots or lesions on leaves, fruits and flowers, sunken surface, especially on the apples, blight, gum exudates) were collected for isolation of presumptive causative organism. The pathogen was isolated after disinfecting the excised diseased pieces in 70% ethanol, plated on potato dextrose agar (PDA) and incubated at 28 oC for 3 to 7 days. The identity of the putative pathogen was morphologically and culturally confirmed as belonging to Colletotrichum gloeosporioides species complex using standard mycological identification protocols. The pathogen had varied conidia sizes of between 9-15 up to 20 μm in length and diameter of 3-6 μm. The conidia were straight and cylindrically shaped with rounded or obtuse ends. The septate mycelium was whitish-grey, velvety and cotton-like in appearance from the top. The results confirmed the presence of the pathogen in the orchards with incidence ranging from 6.9% and 14.0% for gummosis and averaged 22.9% for anthracnose infected orchards. The result of the pathogenicity test confirmed the isolates to be pathogenic on inoculated cashew seedlings and were consistently re-isolated, thereby establishing the pathogen as the true causal agent of the said diseases in cashew trees and thus completed the Koch’s postulate.


2014 ◽  
Vol 10 (3) ◽  
pp. 196-200 ◽  
Author(s):  
Monica Scognamiglio ◽  
Rosario Nicoletti ◽  
Severina Pacifico ◽  
Brigida D'Abrosca ◽  
Antonio Fiorentino

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