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Miadlikowska J.,Duke University | Richardson D.,Saint Mary's University, Halifax | Magain N.,Duke University | Magain N.,University of Liège | And 6 more authors.
American Journal of Botany | Year: 2014

Premise of this study: Aquatic cyanolichens from the genus Peltigera section Hydrothyriae are subject to anthropogenic threats and, therefore, are considered endangered. In this study we addressed the phylogenetic placement of section Hydrothyriae within Peltigera. We delimited species within the section and identified their symbiotic cyanobacteria. Methods: Species delimitation and population structure were explored using monophyly as a grouping criterion (RAxML) and Structurama based on three protein-coding genes in combination with two nuclear ribosomal loci. The 16S and rbcLX sequences for the cyanobionts were analyzed in the broad phylogenetic context of free-living and symbiotic cyanobacteria. Key results: We confirm with high confidence the placement of section Hydrothyriae within the monophyletic genus Peltigera; however, its phylogenetic position within the genus remains unsettled. We recovered three distinct monophyletic groups corresponding to three species: P. hydrothyria, P. gowardii s.s., and P. aquatica Miadl. & Lendemer, the latter being formally introduced here. Each species was associated with an exclusive set of Nostoc haplotypes. Conclusions: The ITS region alone provides sufficient genetic information to distinguish the three morphologically cryptic species within section Hydrothyriae. Section Hydrothyriae seems to be associated with a monophyletic lineage of Nostoc, that has not been found in symbiotic association with other members of Peltigera. Capsosira lowei should be transferred to the genus Nostoc. Potential threats to P. aquatica should be re-examined based on the recognition of two aquatic species in western North America. © 2014 Botanical Society of America.


PubMed | Environment Canada, Saint Mary's University, Halifax, New York Botanical Garden, Nova Scotia Museum of Natural History and 3 more.
Type: Journal Article | Journal: American journal of botany | Year: 2014

Premise of this study: Aquatic cyanolichens from the genus Peltigera section Hydrothyriae are subject to anthropogenic threats and, therefore, are considered endangered. In this study we addressed the phylogenetic placement of section Hydrothyriae within Peltigera. We delimited species within the section and identified their symbiotic cyanobacteria. Methods: Species delimitation and population structure were explored using monophyly as a grouping criterion (RAxML) and Structurama based on three protein-coding genes in combination with two nuclear ribosomal loci. The 16S and rbcLX sequences for the cyanobionts were analyzed in the broad phylogenetic context of free-living and symbiotic cyanobacteria. Key results: We confirm with high confidence the placement of section Hydrothyriae within the monophyletic genus Peltigera; however, its phylogenetic position within the genus remains unsettled. We recovered three distinct monophyletic groups corresponding to three species: P. hydrothyria, P. gowardii s.s., and P. aquatica Miadl. & Lendemer, the latter being formally introduced here. Each species was associated with an exclusive set of Nostoc haplotypes. Conclusions: The ITS region alone provides sufficient genetic information to distinguish the three morphologically cryptic species within section Hydrothyriae. Section Hydrothyriae seems to be associated with a monophyletic lineage of Nostoc, that has not been found in symbiotic association with other members of Peltigera. Capsosira lowei should be transferred to the genus Nostoc. Potential threats to P. aquatica should be re-examined based on the recognition of two aquatic species in western North America.


Abolit D.,1051 Cooks Brook Road | Gilhen J.,Nova Scotia Museum of Natural History
Canadian Field-Naturalist | Year: 2011

Sciurids are often seen eating carrion on roads but are rarely seen attacking live prey.We report a rare incident of an Eastern Chipmunk, Tamias striatus, attacking (but not eating) a Maritime Garter Snake, Thamnophis sirtalis pallidulus, at Cooks Lake, Halifax County, Nova Scotia, Canada, on 29 September 2009 at 1315 h.


Moore J.-D.,Foret Quebec | Gilhen J.,Nova Scotia Museum of Natural History
Canadian Field-Naturalist | Year: 2011

Three colour morphs of the Eastern Red-backed Salamander, Plethodon cinereus, are known in eastern Canada: red-backed, lead-backed, and erythristic. Anomalies, including two albino and four leucistic individuals, are also known from eastern Canada.We report the first salamander individuals exhibiting amelanism, which is a lack of black skin pigment, but with black eyes, one from Quebec and one from Nova Scotia, Canada.


McLeod B.A.,Saint Mary's University, Halifax | Frasier T.R.,Saint Mary's University, Halifax | Lucas Z.,Nova Scotia Museum of Natural History
PLoS ONE | Year: 2014

Species biogeography is a result of complex events and factors associated with climate change, ecological interactions, anthropogenic impacts, physical geography, and evolution. To understand the contemporary biogeography of a species, it is necessary to understand its history. Specimens from areas of localized extinction are important, as extirpation of species from these areas may represent the loss of unique adaptations and a distinctive evolutionary trajectory. The walrus (Odobenus rosmarus) has a discontinuous circumpolar distribution in the arctic and subarctic that once included the southeastern Canadian Maritimes region. However, exploitation of the Maritimes population during the 16th-18th centuries led to extirpation, and the species has not inhabited areas south of 55°N for ∼250 years. We examined genetic and morphological characteristics of specimens from the Maritimes, Atlantic (O. r. rosmarus) and Pacific (O. r. divergens) populations to test the hypothesis that the first group was distinctive. Analysis of Atlantic and Maritimes specimens indicated that most skull and mandibular measurements were significantly different between the Maritimes and Atlantic groups and discriminant analysis of principal components confirmed them as distinctive groups, with complete isolation of skull features. The Maritimes walrus appear to have been larger animals, with larger and more robust tusks, skulls and mandibles. The mtDNA control region haplotypes identified in Maritimes specimens were unique to the region and a greater average number of nucleotide differences were found between the regions (Atlantic and Maritimes) than within either group. Levels of diversity (h and π) were lower in the Maritimes, consistent with other studies of species at range margins. Our data suggest that the Maritimes walrus was a morphologically and genetically distinctive group that was on a different evolutionary path from other walrus found in the north Atlantic. © 2014 McLeod et al.


Gilhen J.,Nova Scotia Museum of Natural History | Russell R.W.,Saint Mary's University, Halifax
Canadian Field-Naturalist | Year: 2015

We report three records of a rare blue American Bullfrog, Lithobates catesbeianus, from Nova Scotia, Canada.


Gilhen J.,Nova Scotia Museum of Natural History | Scott F.,Nova Scotia Museum of Natural History
Canadian Field-Naturalist | Year: 2014

We describe an unusual diversity of melanistic conditions in populations of the Maritime Gartersnake, Thamnophis sirtalis pallidulus, in Nova Scotia: pure melanism, melanism, nigrismus (predominantly melanistic), abundismus (mosaic melanism). This variability is widespread in Nova Scotia, and it includes coastal islands.


Gilhen J.,Nova Scotia Museum of Natural History | Caswell G.,Nova Scotia Museum of Natural History | Drake C.,Nova Scotia Museum of Natural History | MacDonald M.,Nova Scotia Museum of Natural History | McKinnonramshaw H.,Nova Scotia Museum of Natural History
Canadian Field-Naturalist | Year: 2012

On 10 June 2012 a sample of seven gravid female Northern Ring-necked Snakes (Diadophis punctatus edwardsii), from Big Tancook Island, Lunenburg County, Nova Scotia, was selected for a seasonal live display at the Nova Scotia Museum of Natural History in Halifax. A total of 13 eggs was removed from the display in late June 2012 and incubated for public viewing. The eggs began hatching on 22 August 2012. One of the hatchlings was partial albino (with zanthophores or amelanistic). This is the first record of an albinistic Northern Ring-necked Snake in Nova Scotia.


Gilhen J.,Nova Scotia Museum of Natural History
Canadian Field-Naturalist | Year: 2010

The Maritime Garter Snake, Thamnophis sirtalis pallidulus, is highly variable in pattern and colour. Although this subspecies is largely defined on the basis of colour, four colour morphs have previously been described for the subspecies, including a melanistic form. Based on specimens from Nova Scotia, Canada, a fifth, uncommon erythristic variant is added to the complex colour variation known for the Maritime Garter Snake.


Gilhen J.,Nova Scotia Museum of Natural History
Canadian Field-Naturalist | Year: 2011

I describe a brown morph of the Northern Ringneck Snakes (Diadophis punctatus edwardsii) that occurs in a population on Big Tancook Island, Mahone Bay, Lunenburg County, Nova Scotia, Canada.

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