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Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article offers information on Zoological Endeavours Inspired by A. Richard Palmer held during the Annual Meeting of the Canadian Society of Zoologists on May 14-16, 2019.

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An introduction to the special issue of the journal is presented which includes information on papers from a symposium entitled "Advances in animal flight studies" which has perspectives on biology of flight of insects, pterosaurs and bats and mentions information of the editor of the issue.

The article informs that the current issue of the journal is comprised of papers presented in the "Crossing boundaries and building bridges: integrative zoology" symposium held in Montréal, Quebec from May 25-29, 2015 along with information on its editors Angela L. Shamchuk and Heath A. MacMillan.

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dr. M. Brock Fenton has been intrigued by the diversity of bats throughout his long career, and has combined his research and photography skills to capture the extensive morphological diversity found across the order Chiroptera. In this paper, we honour Brock's fascination with diversity by conducting a review of the external and internal characteristics of the bat nose, a morphological feature that Brock's photographs have beautifully captured in many bat species. Specifically, we explore variation in form and function of the bat rostrum and its role in respiration, echolocation, and olfaction in bats, with an emphasis on the noseleaves of nasal-emitting echolocators, as well as how turbinate morphology may be impacted by nasophonation. While our review is not an extensive dive into all that is known about bat noses, our goal is to highlight the diversity we see in form across the order Chiroptera while exploring how function has been shaped by selection, particularly in relation to mode of echolocation signal emission. [ABSTRACT FROM AUTHOR]

The article offers information on the annual meeting of Canadian Society of Zoologists on topic "Animal Mitochondria: Evolution, Performance and Plasticity" that was held in University of Guelph, Ontario on May 13-17, 2013.

The authors highlights some of the significant events in the 90-year history of the "Canadian Journal of Zoology" (CJZ), including the first issue of CJZ with the original name of the "Canadian Journal of Research" in May 1929, a system of peer review established by editor William Hoar in 1964, and the affiliation of CJZ with the Canadian Society of Zoologists since its inception.

Bat conservation has become prevalent over the last few decades due to critical population declines worldwide. Our purpose was to assess whether Brock Fenton's research career coincided with increasing bat conservation research in Canada and North America. Fenton has made significant contributions to bat research during a long and productive publishing career accompanied by participation in research organizations like the North American Society for Bat Research and the Natural Sciences and Engineering Research Council. His conservation research as well as efforts to raise public awareness about these animals has coincided with work for the Committee on the Status of Endangered Wildlife in Canada and its equivalent (Committee on the Status of Species at Risk in Ontario) in ON. To assess the impact of his career, we quantified the relative amount of his peer-reviewed publications with a conservation focus and compared this with the level of conservation-related presentations at annual North American Society for Bat Research conferences. In the same manner, we assessed how often conservation-focused applications were funded by the Ecology and Evolution section of the Natural Sciences and Engineering Research Council—Canada Discovery grant program. Although it cannot be said with authority that Fenton actually initiated the increase in bat conservation research, our results indicate that his research efforts coincide with and presumably had considerable influence in driving this area of research. [ABSTRACT FROM AUTHOR]

Brock Fenton has devoted his career to the study of the ecological adaptations of bats and their diversity. In this paper, we describe his interest and research on the subject of bat evolution and how he has used phylogenetic hypotheses to revise our understanding of divergences and convergences of specific traits within this mammalian order. While he has always been fascinated by the evolution of echolocation, he has also written about the evolution of reproductive, morphological, and behavioural traits and his recent methods of documenting diversity incorporates his lifelong love of photography. We describe these and taxonomic attempts to honour his contributions to the study of bat species diversity. Brock has supported hundreds of students and colleagues with his endless enthusiasm and generosity and inspired them with his ongoing research on bats. [ABSTRACT FROM AUTHOR]

The article focuses on the rich contributions of Professor M. Brock Fenton to the field of bat biology in Canada, tracing his early experiences, academic journey, and impactful career, including his role in mentoring students and his continued influence after retirement. Topics include Fenton's bat encounters, academic achievements, research contributions, mentoring legacy, and post-retirement activities, highlighting his multidimensional impact on the field.

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses valuable contributions to our understanding of factors potentially affecting aerial insectivorous bird populations. Most of the papers in this collection were presented as part of the symposium. Topics include the diversity of stressors potentially contributing to aerial insectivore declines at multiple scales and during different parts of the annual cycle.

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An introduction is presented in which the editor discusses articles in the issue on topics including systematics of sessile, irregularly coiled and suspension feeding snails, Biography, and Bibliography.

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An important, but generally overlooked source in intraspecific variability of characters used in tardigrades taxonomy is sexual dimorphism. Dioecious tardigrades species with unisexual or bisexual populations are common, but external sexual dimorphism is rarely observed. The discovery and integrative analysis of a Diploechiniscus species population with high sexual dimorphism from Calvert Island (Canada) has allowed its description as a new species. Diploechiniscus dimorphus n. sp. is characterized by a different chaetotaxy in males and females, and by enlarged cephalic sensory appendages in the males. The discovery of this new species shows that it is important to consider sexual dimorphism as a source of intraspecific variability in tardigrade taxonomy due to its implications on the use of traits commonly used to delineate species such as chaetotaxy. Lastly, the finding of individuals of Diploechiniscus horningi (Schuster and Grigarick, 1971), a species previously synonymized with Diploechiniscus oihonnae (Richters, 1903), allows us to prove that it is genetically a separate species and to reinstate it. [ABSTRACT FROM AUTHOR]

The introduction of non-indigenous species (NIS) to exotic habitats can have tremendous impacts on native biodiversity, food webs, and ecosystem services. One globally distributed aquatic NIS is the hydrozoan Craspedacusta sowerbii Lankester, 1880. The species' northern distribution boundary in North America is situated in British Columbia (BC), Canada. It is thus of paramount interest to understand its ecology in this warming invaded habitat, allowing for insights into other regions. Specimens of the genus Craspedacusta have been reported in 34 freshwater systems since August 1990. These reported locations are generally shallow (<10 m), most often of natural origin, and have a small surface area (<0.1 km2). We observed an exponential trend of medusa observations from 1990 till the end of the 2020s. The first seasonal records are in July and the latest in October, with peak sightings reported in August and September. After 2012, regional temperature anomalies during July and August were mostly positive, which overlaps with the period of the majority of reported C. sowerbii sightings. Until this day, all examined medusae are males. [ABSTRACT FROM AUTHOR]

The capacity to lay eggs inside healthy fruits rather than on decaying plant matter differentiates insect fruit pests from domestic species. This niche differentiation has been previously proposed to be an adaptation to avoid competition. We hypothesize that pest species will be more strongly affected by competition. We compare the impact of larvae density on fitness traits between Drosophila pests (Drosophila suzukii (Matsumura, 1931); Zaprionus indianus Gupta, 1970) and domestic species (Drosophila immigrans Sturtevant, 1921; Drosophila melanogaster Meigen, 1830). We assessed the effect of crowding on adult emergence and development time. Viability decreased gradually with density for D. immigrans and D. suzukii, while for D. melanogaster and Z. indianus it remained high. Development time increased with density; this was stronger on Z. indianus and D. immigrans than on D. suzukii, which had a moderate increase, and D. melanogaster, which did not change. Contrary to expectations, the distinct patterns observed were not related to each species' domestic or pest lifestyle. In fact, patterns consistent with either scramble or contest type of competition were observed on both pest and domestic species, respectively. These findings challenge prior beliefs regarding competition effects among Drosophila pest species and provide information relevant to integrated pest management. [ABSTRACT FROM AUTHOR]

During 17 spring and summer field seasons between 1973 and 1999, we documented 220 bouts of nursing by dependent polar bear (Ursus maritimus Phipps, 1774) cubs at Radstock Bay, Nunavut, Canada. The overall mean duration of nursing bouts for cubs-of-the-year (COY) and yearlings (YRLG) litters was 7.1 min (standard deviation (SD) = 3.3, range = 1–23). Mean nursing bout durations of one- and two-cub litters of COY and YRLG in spring and summer seasons ranged from 6.09 to 7.78 min and from 5.00 to 9.18 min, respectively. The overall mean duration of inter-nursing intervals for COY and YRLG litters was 5.7 h (SD = 4.9, range = 0.0–35.0). The mean inter-nursing interval for one-cub litters was 6.4 h (SD = 4.6, range = 0.0–20.2) and for two-cub litters was 5.1 h (SD = 5.1, range = 0.0–35.0). We found no evidence for effects of season or cub age class on nursing behavior. We found weak evidence that two-cub litters nurse slightly longer than one-cub litters, potentially reflecting reduced nursing efficiency due to sibling rivalry. There was neither evidence for diel patterns in nursing behavior nor a detectable relationship between the cessation of nursing and the onset of hunting or sleeping by the adult female. [ABSTRACT FROM AUTHOR]

Many aerial insects are declining, yet monitoring wildlife in airspace is challenging. Aerial insectivores, which are themselves a declining guild, may be useful indicators for aerial insects. However, their use as indicators may be complicated if they differentially sample prey depending on foraging range, as predicted by central place foraging theory. We measured diet composition of purple martins (Progne subis (Linnaeus, 1758)) in Quebec by deoxyribonucleic acid (DNA) metabarcoding fecal samples collected from adults and nestlings and used GPS biologgers to measure foraging behaviour of the chick-rearing adults. Foraging range did not predict diet or diet diversity. The proportion of individuals with Diptera and Coleoptera detected in their diets was lower in developed and water habitats. Martins fed their nestlings soft-bodied insects (Diptera and Trichoptera) more often than they ate them themselves. As nestlings aged, they were fed more chitinous arthropods and less soft-bodied prey. As the proportion of different prey orders depended on habitat use and age, but not foraging distance, we argue that purple martin diet is a potential indicator of aerial insect community variation across space, but that interpretations may be complex as birds may sample different components of the aerial insect community during different life stages. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents an editorial on the ongoing research work and publications in the field of echolocation in bats. Topics discussed include a brief of the second international symposium on bat echolocation research, a brief about the research publication papers on this field, and researched data on bat echolocation.

Animals benefit from scatterhoarding, storing food around their home range for use during a period of scarcity, by later eating the stored food. Seedlings may be used as cues of belowground food. We investigated whether scatterhoarders such as eastern gray squirrels (Sciurus carolinensis Gmelin, 1788) and eastern chipmunks (Tamias striatus (Linnaeus, 1758)) use characteristics of seedlings and their seeds as physical cues of the value of the seed. We buried 176 germinating seeds (white oak (Quercus alba L.) and northern red oak (Quercus rubra L.)) in a hardwood forest in Alabama, USA. Seeds were recovered faster with longer leaves (rate ratio (RR) = 0.68, 0.58–0.78, 95% confidence limits (C.L.)) and taller stems (RR = 0.91, 0.88–0.93, 95% C.L.) during spring 2022, and with a smaller number (RR = 1.15, 1.04–1.27, 95% C.L.) of longer leaves (RR = 0.81, 0.70–0.93, 95% C.L.) during fall 2022 (both P < 0.0001). For all seeds, we found that longer roots increased the likelihood of seeds being used (rather than ignored; odds ratio = 1.45, 1.00–2.09, 95% C.L., P = 0.05). We found new evidence suggesting that hoarders use aboveground cues from the seedling to dig it up and belowground seedling cues to assess seed value. These findings add to our understanding of assessing food availability for hoarding animals. [ABSTRACT FROM AUTHOR]

The triple threats of climate change, habitat loss, and environmental pollution have stimulated discussion on how urban areas can be modified to mitigate heat increases and provide habitat for wildlife such as insects. The strategy of using trees to reduce temperatures has been adopted by numerous cities. However, the majority of street trees planted around the world are non-native. Studies conducted in non-urban areas have demonstrated in comparison to native plants, non-native plants are less likely to support native insect diversity. Here, we use a database approach to quantify the number of native Lepidoptera species associated with 76 of the most common street tree species planted in Vancouver, Canada. We tested the prediction that compared to non-native trees, native street trees will support a higher diversity and unique community of native Lepidoptera. As predicted, native street trees were associated with five times as many native Lepidoptera species, and the Lepidoptera communities supported by native versus non-native street trees were distinct. There was no difference in native Lepidoptera associations between broadleaf versus coniferous street trees. These results are consistent with studies that have used active sampling techniques to investigate insect richness on a smaller subset of native and non-native tree species. Collectively, these data provide good evidence that planting native instead of non-native trees will help stem the loss of insect diversity in urban areas. [ABSTRACT FROM AUTHOR]

In the present work, we study the effect of different stimuli (living preys, its homogenate, and reduced glutathione (GSH)) on the discharge of desmonemes in the freshwater cnidarian, Hydra plagiodesmica (Dioni, 1968) (Cnidaria: Hydrozoa). Once confirmed their stimulatory effect, we choose GSH to analyze the relevance of Ca2+, the probable identity of the sensory receptor molecule, and the specific signalling pathway driving the discharge mechanism. Our results show that not only mechanical, but also chemical stimuli by itself may stimulate the discharge of desmonemes. Using calcium chelators, we verify that the discharge mechanism triggered by GSH is dependent on calcium. By mean of drugs that inhibit proteins pertaining to canonical signalling pathways, including GPCRs, we show that GSH causes the influx of Ca2+ via L-type voltage sensitive calcium channel (VGCC), and its release by mean of endoplasmic reticulum calcium channels. Moreover, our results suggest that the putative receptor for GSH is a GPCR coupled to Gq, which produces IP3 and Ca2+ as second messengers. Finally, we show that the genome of Hydra vulgaris (Pallas, 1766) predicts the existence of the different subunits of L-type VGCC, showing a high level of conservation when compared with other groups of Metazoa. [ABSTRACT FROM AUTHOR]

A challenge for management of wildlife species is the assessment of the effect of roads on migration. We developed models to estimate the spatial (zone of influence (ZOI)) and temporal (delays in migration) effects of roads, and test whether road closures reduced delays in migration. We analyzed collar (2011–2019) and road survey data from two barren-ground caribou (Rangifer tarandus groenlandicus (Borowski, 1780)) herds to assess the impact of a 171 km mine road that bisects their migration corridor. We estimated ZOIs of 16–17 km prior to crossing the road during 2018 and 2019, and 3.0 km after crossing. Estimates of mean delay were 4.3 and 2.5 days for 2018 and 2019, which were reduced by 28%–68% (1.2–1.7 days) if roads were closed when caribou were within the ZOI. In 2017–2018, when the road was extended 64 km north, caribou were 12% less likely to deflect north around the road, therefore increasing delays. Road surveys indicated aggregation of caribou prior to crossing the road, with few caribou observed after crossing, a finding supported by collar data. Our methods can estimate the spatial and temporal effects of roads for any wildlife species and assess mitigation strategies in reducing delays in migration. [ABSTRACT FROM AUTHOR]

In the context of climate change, it is crucial to understand whether animals that have been domesticated and (or) selected maintain their abilities to adapt to changes in their thermal environment. Here, we tested how selection for absence of early sexual maturation combined with better growth performance may have impacted thermal resistance and gene expression response in the presence of thermal stress in brook charr Salvelinus fontinalis (Mitchill, 1814). We performed temperature challenge tests on brook charr 0+ juveniles and studied the expression of genes involved in the response to oxidative stress, in synthesis of heat shock proteins, or involved in regulation of apoptosis, in heart and liver tissues. Juveniles from the selected lineage had a higher thermal resistance than controls and a loss of equilibrium occurred on average 1 °C above what was observed for the controls. The relative expressions of catalase and HSP70 were significantly higher in juveniles from the selection program. Overall, thermally sensitive fish were characterized by low mass and length and lower relative expressions of genes associated with stress response. Our results indicate that selection for traits of interests may be indirectly related to the significant lineage effect on growth in early stages of development. [ABSTRACT FROM AUTHOR]

Passive acoustic monitoring usually generates large datasets that require machine learning algorithms to scan sound files, although the complexity of developing machine learning algorithms can be a barrier. We assessed the ability and speed of two user-friendly machine learning tools, Kaleidoscope Pro and BirdNET, for detecting the American toad (Anaxyrus americanus (Holbrook, 1836)) in sound recordings. We developed a two-step approach, combining both tools to maximize species detection while minimizing the time needed for output verification. When considered separately, Kaleidoscope Pro successfully detected the American toad in 85.9% of recordings in the validation dataset, while BirdNET detected the species in 58.4% of recordings. Combining the two tools in the two-step approach increased the detection rate to 93.3%. We applied the two-step approach to a large acoustic dataset (n = 6194 recordings). We started by scanning the dataset using Kaleidoscope Pro (species detected in 417 recordings), then we used BirdNET on the remaining recordings without confirmed presence. The two-step approach reduced the scanning time, the time needed for output verification, and added 37 additional species detections in 45 min. Our findings highlight that combining machine learning tools can improve species detectability while minimizing time and effort. [ABSTRACT FROM AUTHOR]

Density-independent and density-dependent population regulation has long been a subject of investigation. We examined density-dependent and density-independent factors on growth rates of pronghorn (Antilocapra americana (Ord, 1815)) using a retrospective analysis of population survey data. Across Idaho, we found that as the proportion of the subpopulation harvested the previous year increased, growth rates increased. Similarly, as fawn recruitment increased, growth rates increased. We also found when the growth rate in the previous year increased, the growth rate the subsequent year decreased. When subpopulations were examined independently, we found that in a low-elevation desert subpopulation, growth rates were influenced by growth the previous year. In an agricultural-dominated site, growth rates were influenced by fawn recruitment in the current year and maximum temperature the previous fall. Growth rates in a mid-elevation shrub–steppe site were influenced by drought severity prior to parturition and the growth rates from the previous year. Growth rates in two mountain valley subpopulations were influenced by measures of vegetative greenness. At the statewide scale, while managers may strive for increased numbers of pronghorn, density dependence will limit the ability for a region-wide numerical response. On the localized scale, drivers of growth were temporally and spatially explicit, and biologists must consider site-specific actions. [ABSTRACT FROM AUTHOR]

Many foraging models assume "perfect information" and "free movement" when describing predator foraging behavior, although this is rare in nature. Here, we quantified predation by brown bears (Ursus arctos Linnaeus, 1758) on adult sockeye salmon (Oncorhynchus nerka (Walbaum, 1792)) in a series of spatially proximate ponds that largely satisfied both assumptions. Salmon abundance varied among years, but pond area and depth were fixed, allowing us to examine interactions between prey abundance and habitat features. We applied versions of two models to 25 years of data on the number and proportion of salmon killed by bears, modifying these models to include habitat features and temporal variability. The functional response model with a year effect fit the data well, indicating bears could take almost all salmon in ponds when salmon were scarce, but bears were sated when salmon were abundant. The proportion of salmon killed by bears was similar across habitats after correcting for pond depth and area. Overall, bears foraged across all habitats but killed higher proportions of salmon in smaller and shallower habitats, consistent with ease of capture. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We describe Argolebias adrianae, a new species of killifish from a small temporary wetland in the Paraná Forest ecoregion with no regular or predictable temporal pattern of water availability. This habitat is in the Lower Iguazú River Basin, known for its high fish endemism, but until now, only two species of Rivulidae were reported from it, but from the Araucarian Forest ecoregion. The genus Argolebias was previously only known from the lower portions of the Paraguay, Paraná, and Uruguay basins and middle Paraná. The new species is distinguished from all congeners by its unique coloration, which includes a conspicuously dark grey anterior third portion of the dorsal fin and the absence of iridescent spots on the basal half of the pectoral fin in live adult males, as well as dark grey spots on the anterocentral portion of the flanks of females. Our phylogenetic analysis shows A. adrianae to be closely related to Argolebias guarani from the adjacent Middle Paraná basin. We also provide data on the ecology, ontogeny of coloration, and chorion ornamentation of this species. Our findings have important implications for understanding the biogeography, ecology, and evolution of mechanisms that enable organisms to thrive in highly stochastic environments like this one. [ABSTRACT FROM AUTHOR]

Nematode communities in natural pristine forests composed of trees aged over 1000 years have not been thoroughly studied. Old-growth forests can provide diverse microhabitats for nematodes such as fallen trees with mossy conditions. This study aimed to characterize the community and trophic compositions of nematodes in relation to different microhabitats in old-growth Japanese cedar (Cryptomeria japonica (L. f.) D. Don) forests in Yakushima Island, Japan. To this aim, nematodes retrieved from four different types of microhabitats were morphologically identified at the family/genus level and divided into five trophic groups. A nonmetric multidimensional scaling scatterplot showed that nematode communities clustered significantly in each microhabitat and their community compositions were significantly affected by C/N ratio. With respect to nematode trophic composition, bacterivorous nematodes dominated decaying barks of fallen trees, with a relative abundance of 45%, while fungivorous nematodes were dominant in living barks of cedar trunks (61%). Predatory–omnivorous nematodes predominated in mosses of fallen trees (51%). These results showed that nematode community and trophic composition were different among microhabitats characterized by nutrient conditions. The predatory–omnivorous nematodes were abundant in mosses with N-rich conditions. In contrast, fungivorous nematodes were abundant in cedar trunks with high C/N conditions. Thus, old-growth natural forests can provide diverse microhabitats where various nematode taxa coexist due to the presence of fallen trees and mosses. [ABSTRACT FROM AUTHOR]

Introgressive hybridization between members of Odocoileus was examined using the mitochondrial cytochrome-b (maternal marker) and paternal sex-determining region Y (Sry) genes. Eight out of 130 free-ranging individuals from the Panhandle and Trans-Pecos regions of Texas were determined to possess the mitochondrial haplotype of mule deer (Odocoileus hemionus (Rafinesque, 1817)) and the paternal haplotype of white-tailed deer (Odocoileus virginianus Rafinesque, 1832). Results indicated that hybridization between deer species in Texas (6.15%) was more broadly distributed than previously reported. Previous studies demonstrated that ancient hybridization events (1.32 mya) involved the capture of the white-tailed deer mitochondrial genome by mule deer, indicating a male mule deer × a female white-tailed deer directionality relevant to hybridization. Alternatively, contemporary hybridization events indicated a reversal in directionality and suggested a cross between a female mule deer × a male white-tailed deer. The Sry gene and species assignment based on morphological characters consistently were in agreement. Further, phylogenetic relationships between Odocoileus virginianus couesi and Odocoileus hemionus eremicus warrant additional investigation as recent hybridization (>200 years) may be a mechanism that allowed these two subspecies to evolve a unique evolutionary trajectory. [ABSTRACT FROM AUTHOR]

Atlantic cod (Gadus morhua Linnaeus, 1758) can experience mortality at sub-zero (<0 °C) temperatures in ice-infested waters, and many populations migrate to deeper and warmer areas during winter. An exception is the resident population in Gilbert Bay, Labrador, which annually experiences 6 months of sub-zero temperatures. We used the VEMCO Positioning System to estimate fish locations to determine depth utilization and seasonal movements of tagged Gilbert Bay cod ranging in size from 43 to 75 cm. This is the first study to directly monitor the movements of adult Atlantic cod for extended periods (months) in sub-zero temperatures. Gilbert Bay cod remained active under an ice-covered surface during the 6 months of sub-zero temperatures. During both warm (>0 °C) and cold (≤0 °C) periods, fish spent similar amounts of time not moving, moving slowly, and moving at medium and fast rates. They tended to utilize shallow depths, <10 m, beneath surface ice during winter, while utilizing deeper depths as well during other times of the year. Surprisingly, fish that resided within our tracking array year-round had greater cumulative swimming distances during sub-zero periods compared to warmer periods. No tracked fish died during winter, further highlighting the cold adaptiveness of this population and its importance to biodiversity conservation. [ABSTRACT FROM AUTHOR]

Snails are often exposed to high variability of ambient temperatures, thus in response to that, they function for prolonged periods in a dormant state. It is known that molecular chaperones (like heat shock proteins (HSPs)) fulfill important functions in maintaining cell homeostasis and the cellular responses to stress, and that they are activated in many different species upon exposition to various environmental stressors. HSPs defend organisms from the harmful consequences of heat shock and potentially alternative stressors too. After thorough consideration, we decided to identify proteins that interact with HSP70 and HSP90 in Helix pomatia Linnaeus, 1758 snails under extreme thermal (low and high) and photoperiod (short and long) conditions and at hypometabolic/active states as a response to environmental stress. Identification of proteins that interact with HSPs can define a new tool in molecular basis of adaptation to temperature stress in snails. After performing co-immunoprecipitation and Western blot, we obtained results showing that HSP70 interacts with hemocyanin alphaN and alphaD, and with other isoforms of hemocyanin–hemocyanin beta as well as with Na+/K+-ATPase, whereas HSP90 interacts with hemocyanin alphaN. It means that the chaperones are likely to affect the most important life-supporting systems of snails like respiration and ionic conductivity. [ABSTRACT FROM AUTHOR]

Anthropogenic influences caused depletion and subsequent recovery of marine predators, but ecological consequences of altered predator abundance are not well understood. Although many methods are used to study predator diets, methodological biases and logistical challenges preclude robust sampling schemes. We aimed to compare two non-invasive methods: metabarcoding scat-derived deoxyribonucleic acid and hard parts analysis of scat for the Northwest Atlantic grey seal (Halichoerus grypus (Fabricius, 1791)), a species that rebounded after near extirpation. We hypothesized that metabarcoding would detect a greater diversity and frequency of prey, and that notable differences in diet will be detected since prior studies. Grey seal scat samples (N = 247) were collected between 2018 and 2019 from Monomoy Island, Massachusetts, USA. Metabarcoding detected greater prey richness on average, with more frequent detections of clupeids (Clupeidae) and flatfish (Pleuronectiformes), whereas hard parts analysis more frequently detected phycid hakes (Urophycis spp. Gill, 1863). Combining methods increased detections of 13 prey taxa, with 32 prey taxa identified overall. Skates (Rajidae), flatfish, clupeids, and sand lance (Ammodytes spp. Linnaeus, 1758) were top-occurring prey. Our study highlights the importance of using multiple methods to characterize generalist predator diets using non-invasive techniques and suggests grey seal diet has changed since the early 2000s. [ABSTRACT FROM AUTHOR]