Experimental manipulation of perceived predation risk alters survival, cause of death, and demographic patterns in juvenile snowshoe hares
Canadian Journal of Zoology, Ahead of Print. Perceived predation risk alters prey behaviour and physiology, but few studies have examined downstream consequences on prey demography in wild populations. Perceived predation risk could alter adult reproductive performance via reduced investment in offspring quality and post-birth care. We manipulated perceived predation risk in snowshoe hare (Lepus americanus Erxleben, 1777) by exposing pregnant mothers to chases by a domestic dog (Canis familiaris Linnaeus, 1758). Litter size was comparable between risk-augmented and control groups, but treated females had more stillbirths...
Source: Canadian Journal of Zoology - September 26, 2023 Category: Zoology Authors: Jacob L. Seguin Melanie R. Boudreau Sophia Lavergne Ryan Lamoureux Charles J. Krebs Rudy Boonstra Source Type: research
Two large structure-forming sponges from opposite North American coasts: a taxonomic review of Arctic –Pacific Mycale (Mycale) loveni and the description of a new Arctic–Atlantic Mycale
Canadian Journal of Zoology,Volume 101, Issue 9, Page 807-823, September 2023. Mycale (Mycale) loveni (Fristedt, 1887) is a very large structure-forming sponge that has previously been reported in the North Pacific, North Atlantic, and Arctic oceans. Through morphological and molecular examination, North Atlantic and Eastern Canadian Arctic specimens are now described as a new species, Mycale (Mycale) lorea sp. nov. The two species have similar external morphology; however, the spicules that make up their skeletons differ in size and shape, and the species are also separated phylogenetically by multiple genetic markers. (S...
Source: Canadian Journal of Zoology - September 1, 2023 Category: Zoology Authors: Curtis Dinn Bruce Ott Mari ève Bouchard Marmen Royce Steeves Genevi ève Côté Vonda Hayes Claude Noz ères Meredith V. Everett Abigail Powell Jackson W.F. Chu Source Type: research
Taxonomic revision of the sexually dimorphic flies of the Neotropical genus Euepalpus Townsend, 1908 (Diptera: Tachinidae), with notes on sexual patches in Tachinini
Canadian Journal of Zoology, Ahead of Print. Euepalpus Townsend, 1908 is a small Neotropical genus of bristle flies (Diptera: Tachinidae: Tachinini), which includes two valid species whose taxonomy is unclear, mainly because males and females are sexually dimorphic. Males exhibit a pair of sexual patches on the dorsal surface of abdominal tergite 5, an unusual feature in Tachinidae. Here, the genus is revised, including a key to species and detailed descriptions and illustrations of the type material and males and females of each species. The male and female terminalia of Euepalpus species are described for the first time....
Source: Canadian Journal of Zoology - August 24, 2023 Category: Zoology Authors: Filipe Macedo Gudin Source Type: research
Standard metabolic rate differs between rainbow trout (Oncorhynchus mykiss) growth forms
Canadian Journal of Zoology, Ahead of Print. In variable environments, repeatable phenotypic differences between individuals provide the variation required for natural selection. The pace-of-life syndrome (POLS) provides a conceptual framework linking individual physiology and life histories to behaviour, where rapidly growing individuals demonstrate higher rates of resting or “standard” metabolic rate (SMR). If differences in SMR are consistent between fast- and slow-growing individuals, these differences may be important to capture in bioenergetic relationships used to describe their growth, energy acquisition, and a...
Source: Canadian Journal of Zoology - August 3, 2023 Category: Zoology Authors: B. Greenaway C. Veneruzzo M.D. Rennie Source Type: research
Running overnight and struggling to find sea ice: long-distance movement by an Arctic fox (Vulpes lagopus) from Russia
Canadian Journal of Zoology, Ahead of Print. Given the scale, speed, and complexity of recent changes in the Arctic, our understanding of their multiple implications for Arctic biota is still limited. We detail for the first time in the vast Russian Arctic the long-distance movement of an Arctic fox (Vulpes lagopus (Linnaeus, 1758)) tracked with a GPS/iridium collar providing considerably high precision (several meters) and frequency of locations (every 4 h). Revealed diurnal activity patterns of the Arctic fox indicate that it ran greater distances in night hours and shortest in day hours during the most intense moveme...
Source: Canadian Journal of Zoology - August 3, 2023 Category: Zoology Authors: N. Sokolova K. Shklyar I. Fufachev V. Filippova A. Sokolov Source Type: research
The first consolidation of morphological, molecular, and phylogeographic data for the finely differentiated genus Diaphoreolis (Nudibranchia: Trinchesiidae)
Canadian Journal of Zoology,Volume 101, Issue 8, Page 635-657, August 2023. We demonstrate the application of the multilevel organismal diversity approach using the example of the nudibranch trinchesiid genus Diaphoreolis. For the first time, fine-scale morphological, genetic, and phylogeographic data are presented for all known species of the genus Diaphoreolis. One of the significant results of the present study and analysis is that the species D. stipata (Alder and Hancock, 1843) comb. nov., originally described from the North Atlantic and reinstated here, is revealed to be a sister species to the new NW Pacific species...
Source: Canadian Journal of Zoology - August 1, 2023 Category: Zoology Authors: Tatiana Korshunova Karin Fletcher Torkild Bakken Alexander Martynov Source Type: research
Environmental drivers of juvenile dispersal and adult non-breeding movements in Ambystoma salamanders
Canadian Journal of Zoology, Ahead of Print. Understanding the environmental drivers of species ’ dispersal and migration patterns is needed to accurately predict climate change impacts on populations. For pond-breeding amphibians, adult movements associated with the breeding period are well studied but major gaps exist in our knowledge of the drivers of adult and juvenile non-breeding movem ents. Here, we assess environmental drivers of adult and juvenile Ambystoma maculatum (Shaw, 1802), Ambystoma jeffersonianum (Green, 1827), and their unisexual dependants’ (Ambystoma laterale–jeffersonianum (Uzzell, 1964)) summer...
Source: Canadian Journal of Zoology - July 31, 2023 Category: Zoology Authors: S.G. Van Drunen J.E. Linton J.P. Bogart D.R. Norris Source Type: research
Differential digestive and metabolic profile of juveniles and adults of the estuarine-dependent marine fish Mugil liza (Mugilidae) cohabiting inside a southwestern Atlantic coastal lagoon
This study was carried on juveniles and adults of Mugil liza Valenciennes, 1836 inhabiting inside Mar Chiquita Coastal Lagoon (Argentina). Both stages exhibited amylase, maltase, sucrase, lipase, trypsin, and aminopeptidase-N activities in the intestine, which were active over a wide range of pH and temperatures and exhibited Michaelis –Menten kinetics. Adults exhibited higher intestinal coefficient (31%), higher amylase (32%), and lower maltase (82%) and lipase activities (38%). Glycogen concentration in liver and muscle was similar, while free glucose concentration was higher in adults (772% and 400%, respectively). In...
Source: Canadian Journal of Zoology - July 28, 2023 Category: Zoology Authors: C. Albanesi M. Gonz ález-Castro A. L ópez-Mañanes Source Type: research
Regulation of feed intake, digestive enzyme activity, and growth in response to live feed and prepared diet during early rearing of Labeo rohita
Canadian Journal of Zoology, Ahead of Print. A 35 day feeding trial in a replicate of five was conducted to evaluate the impact of partial and total replacement of live feed (LF) with nanoparticulate-prepared diet (ND) on early rearing of rohu (Labeo rohita (Hamilton, 1822)). Larvae 3 days after hatching (DAH) were evenly distributed into three groups; T1 was reared exclusively on LF, T2 was on ND, and T3 was co-fed both LF and ND (1:1). All groups showed a feed-dependent increase in growth and the expression of genes involved in feed intake and growth with age DAH. The T3 group showed significantly higher weight gain, ...
Source: Canadian Journal of Zoology - July 26, 2023 Category: Zoology Authors: Mashooq Ali Amina Zuberi Muhammad Ahmad Naima Younus Source Type: research
Differences in thermal energetics of the cave myotis (Myotis velifer) from a cool and a warm environment of central Mexico
Canadian Journal of Zoology, Ahead of Print. Endotherm homeotherms deal with the energetic cost of maintaining a stable body temperature (Tb) in ecosystems differing in ambient temperature (Ta). In response, animals adjust some of their thermal energetics to meet the energy requirements of thermoregulation. Bats are small mammals with a geographical distribution that may include environments with different Ta. Therefore, these animals should adjust their thermal energetics depending on the environmental characteristics of the habitats where they live. Using open-flow respirometry, we measured basal metabolic rate (BMR), th...
Source: Canadian Journal of Zoology - July 13, 2023 Category: Zoology Authors: Kevin I. Medina-Bello Carmen Lorena Orozco-Lugo Jorge Ayala-Berdon Source Type: research
Neuroendocrinology of the vase tunicate, Ciona intestinalis: consideration of the practical applications for the control of this invasive species
Canadian Journal of Zoology, Ahead of Print. The vase tunicate, Ciona intestinalis (Linnaeus, 1767), is a social but non-colonial ascidian that is implicated in biofouling of aquatic structures and destruction of the shellfish industry through competition for planktonic nutrients and substrate settling habitats. The sequencing of the C. intestinalis genome has provided insight into the phylogenetic origins of this species, indicating that this lineage and its allies represent a sister taxon to the chordates. Although the practical use of this genomic information at controlling this invasive species is equivocal, a number o...
Source: Canadian Journal of Zoology - July 4, 2023 Category: Zoology Authors: Sabine R. Lovejoy Source Type: research
Transport-related enzymes and osmo-ionic regulation in a euryhaline freshwater shrimp after transfer to saline media
Canadian Journal of Zoology, Ahead of Print. To understand the response of freshwater organisms to rising environmental salinity, it is essential to investigate their osmo-ionic regulatory physiology. Our laboratory experiment investigated the transfer of Palaemon argentinus (Nobili, 1901) from 2 ‰ (control condition) to concentrated salinity (15 and 25‰) for short- (6 h), medium- (48 h), and long-term (>504 h) acclimation periods. We measured relevant parameters in the shrimp’s haemolymph, the time course of the response of branchial V–H+–ATPase (VHA), Na+, K+–ATPase (NKA), carbonic anhydrase (CA) activ...
Source: Canadian Journal of Zoology - June 30, 2023 Category: Zoology Authors: Antonela Asaro Silvina A. Pinoni Catherine Lorin-Nebel Romina B. Ituarte Source Type: research
Differences between thermal preference and thermal performance in a wintry spider Mecicobothrium thorelli: are the spiders under evolutionary pressures on their seasonal activity?
In this study, we assessed the thermal preference and locomotor performance of the spider Mecicobothrium thorelli Holmberg, 1882, a wintry mygalomorph spider endemic to the native mountainous grasslands of central Argentina and Uruguay. The preferred temperatures of the 72.4% of the individuals were in the range of 10 –20 °C. The highest frequencies of preferred temperatures were 10–15 °C in males and 15–20 °C in females. The sprint speed showed significant differences between all the temperatures evaluated and showed the highest speeds at 25 °C and the lowest at 3 °C. The optimal temperature was 26.09...
Source: Canadian Journal of Zoology - June 29, 2023 Category: Zoology Authors: Justina Panchuk Leonela Schwerdt Nelson Ferretti Source Type: research
Assessment of family-derived metabolic traits for the conservation of an ancient fish
In this study, a series of physiological indices were used to assess the variability that exists among progeny of lake sturgeon (Acipenser fulvescens Rafinesque, 1817) produced from eight different families. We designed a controlled experiment aimed to evaluate metabolic performance of age-0 lake sturgeon where growth, energy density, survival, metabolic rate, volitional swimming performance, and critical thermal maxima were quantified for fish reared under the same environmental conditions. We found a strong family effect for most metrics that were quantified and primarily influenced by the female. Furthermore, poor growt...
Source: Canadian Journal of Zoology - June 26, 2023 Category: Zoology Authors: David Deslauriers Gwangseok R. Yoon Kari J. McClellan Cheryl N. Klassen W. Gary Anderson Source Type: research
Metabolic and transcriptomic response of two juvenile anadromous brook charr (Salvelinus fontinalis) genetic lines towards a chronic thermal stress
Canadian Journal of Zoology, Ahead of Print. Many salmonid species are particularly susceptible to chronic and acute temperature changes caused by global warming. We aimed to study the differences in metabolic and transcriptomic responses of a chronic heat stress on a control and selected (absence of early sexual maturation and growth) line of brook charr Salvelinus fontinalis (Mitchill, 1814). We exposed individuals to different temperatures for 35 days (15, 17, and 19 °C). High temperature reduced the growth rate (in length) and the Fulton condition factor. Both maximal metabolic rate and the aerobic scope were hig...
Source: Canadian Journal of Zoology - June 26, 2023 Category: Zoology Authors: Christophe Jourdain-Bonneau David Deslauriers Cl émence Gourtay Kenneth M. Jeffries C. Audet Source Type: research
