Abstract
Assessing the genetic diversity and gene flow among populations in combination with ecological data provides valuable insight into the spatial use and genetic structure of wildlife. ...Anthropic impact generates landscape changes that threaten species by favouring their isolation in small patches and limiting their connectivity. However, in some cases, it can increase genetic exchange among wild populations. Here, we used a set of 16 microsatellites to study the genetic diversity, population genetic structure, and historical and current gene flow of coypu (Myocastor coypus) populations, a semi-aquatic rodent that inhabits watercourses of the highly anthropized agroecosystems of the Pampas region. Our results showed moderate to high levels of genetic diversity and revealed the existence of genetic structure among populations. Bayesian analysis showed different patterns of genetic structure among and within sampling sites. Also, the patterns of historical gene flow differed from that seen today. These results, together with previous studies, suggest that anthropic pressure, habitat fragmentation and ephemeral landscapes in a highly modified ecosystem could alter the dispersal patterns of coypus in their native range, which would otherwise be different in an environment with low anthropic impact. The results provide new information that could be used in effective conservation programmes.
Abstract
Anthropization processes confront local wildlife with a new set of conditions that may lead to local extinctions or allow the expansion of some species. This is what happens with the coypu ...(Myocastor coypus) in gated communities in the metropolitan area of Buenos Aires (Argentina), where its rapid population growth results in continuous conflicts with the local inhabitants. The aim of this study was to document the daily and seasonal activity patterns and behavior of the coypu in an urban landscape within their natural distribution range. To achieve this, we conducted a camera-trap survey within areas occupied by the species from February to November 2018. The coypu activity was mainly crepuscular and nocturnal with variations between seasons. We found that the seasons with the greatest activity patterns overlap were winter and autumn (84%), while the least overlap was observed between summer and winter (53%). During the active periods, time spent on foraging behavior was dominant. Time dedicated to vigilance was greater in summer than in winter. This result, alongside an increase in nocturnal activity during summer, shows that coypu in this urban landscape shift its behavior when exposed to an increasing human activity. This study brings up more ecological data of this species, which is key to find alternative control methods within gated communities to lead to a harmonic relationship between inhabitants and the species in its native distribution.
The nutria, (Myocastor coypus), is a semiaquatic rodent native to the subtropical and temperate regions of South America. The species was introduced to South Korea for meat and fur production ...purposes and a wild population has become established. The species subsequently invaded aquatic ecosystems and destroyed aquatic vegetation and cultivated crops. Thus, it is essential to understand their current distribution and future range expansion for effective control and eradication strategies to reduce the risk of colonization into new regions. In this study, we used niche modeling procedure to identify potentially suitable habitats for M. coypus under current and future predicted climate change using the maximum entropy algorithm. We found that the main habitat area of M. coypus is expected to expand under a warming climate from ~ 4069 km
in the southern and southeastern regions of South Korea, to the northern border of the country, with estimated ranges of 21,744 km
, 55,859 km
, and 64,937 km
by 2030, 2050, and 2070, respectively. The findings of the present study assist in identifying the future distribution and potential dispersion routes of M. coypus in South Korea, which is important for informing the government regarding essential management actions plans at regional and local scales.
Abstract
Myocastor coypus is a rodent native to South America that is strongly linked to river systems. Past studies on the coypu in its native distribution range were aimed mainly at its ecology and ...parasitology and genetic studies are very limited. Here, we used sequences of the mitochondrial D-loop control region to study the genetic diversity, population genetic structure and some aspects of historical population dynamics of coypu at the centre of its native range. Our results showed moderate to high levels of genetic diversity and an absence of genetic structure in the study area. Bayesian analysis of population structure (BAPS) showed the existence of two haplogroups distributed in most sampling sites. These results suggest that movement of coypu is independent of the structure of current known river networks and its dispersal patterns are related to flooding events and the presence of lagoons connecting river basins. The demographic expansion patterns in these populations and those of other South American mammals during the Late Pleistocene support the hypothesis that demographic changes in wild populations are related to fluctuations in climate and ecology. The mitochondrial data obtained in this study constitute the first record of these types of sequences in the native range of M. coypus.
Myocastor coypus es un roedor nativo de Sudamérica fuertemente ligado a los sistemas fluviales. En su área de distribución nativa, los estudios llevados a cabo en la especie estuvieron dirigidos principalmente a estudiar su ecología y zoonosis, sin embargo, los estudios genéticos son muy limitados. En el presente trabajo, utilizamos secuencias del d-loop de la Región Control del ADN mitocondrial para estudiar la diversidad genética, la estructura genética de la población y algunos aspectos de la dinámica poblacional histórica del coipo en el centro de su área de distribución. Nuestros resultados develaron niveles moderados y altos de diversidad genética, y ausencia de estructuración genética en el área de estudio. El BAPS exhibió la existencia de dos haplogrupos distribuidos en la mayoría de los sitios de muestreo. Estos resultados sugieren que el movimiento de los coipos sería independiente de la estructura de las redes fluviales actuales conocidas y que sus patrones de dispersión estarían relacionados con eventos de inundación y con la presencia de lagunas que conectan las cuencas fluviales. Los patrones de expansión demográfica observados en esta población de coipos y en otras poblaciones de mamíferos sudamericanos durante el Pleistoceno tardío, apoyan la hipótesis de que las fluctuaciones climáticas y los cambios ecológicos están relacionados con cambios demográficos en las poblaciones silvestres. Los datos mitocondriales obtenidos en este estudio constituyen el primer registro de este tipo de secuencias en el área de distribución nativa de esta especie.
Abstract
The morphological characteristics of the endocrine pancreas of nutria in female and male nutria at the age of 1 day, 2 months, 4.5 months, 7.5 months and 12 months have a number of sex and ...age characteristics and differences. The number of islets in pancreatic lobules at 1 day of age in males is 3–6, and in females – 2–3. At 2 months of age, their number in males decreases to 2–4, and in females it increases to 5–6. From 4.5 months of age, the number of islands in females and males ranges from 2 to 3. At 1 day and 2 months of age, in nutria, islet division is recorded due to the cleavage and formation of new cell groups. The area of endocrine islets in females and males of nutria changes in a wave-like manner with age, having minimum values in 1-day and 4.5 months of age, and the maximum at 12 months of age. The nuclear-cytoplasmic ratio of endocrine islet insulocytes in nutria increases from 1 day to 2 months of life to their maximum values, and in subsequent age periods decrease and by the age of 12 months reaches its minimum.
Abstract Multiple paternity is common in many species. While its benefits for males are obvious, for females they are less clear. Female indirect benefits may include acquiring ‘good genes’ for ...offspring or increasing litter genetic diversity. The nutria ( Myocastor coypus ) is a successful invasive species. In its native habitat, it is polygynous, with larger and more aggressive males monopolizing paternity. Here, using culled nutria we genetically examined multiple paternity in-utero and found a high incidence of multiple paternity and maintenance of the number of fathers throughout gestation. Moreover, male fetuses sired by the prominent male have higher testosterone levels. Despite being retained, male fetuses of ‘rare’ fathers, siring commonly only one of the fetuses in the litter, have lower testosterone levels. Considering the reproductive skew of nutria males, if females are selected for sons with higher future reproductive success, low testosterone male fetuses are expected to be selected against. A possible ultimate explanation for maintaining multiple paternity could be that nutria females select for litter genetic diversity e.g., a bet-hedging strategy, even at the possible cost of reducing the reproductive success of some of their sons. Reproductive strategies that maintain genetic diversity may be especially beneficial for invasive species, as they often invade through a genetic bottleneck.
About the Authors: Eleonora Chinchio * E-mail: eleonora.chinchio@unimi.it Affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy ORCID logo ...http://orcid.org/0000-0002-8104-2063 Matteo Crotta Affiliation: Veterinary Epidemiology, Economics and Public Health Group, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, United Kingdom ORCID logo http://orcid.org/0000-0002-5508-9028 Claudia Romeo Affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy Julian A. Drewe Affiliation: Veterinary Epidemiology, Economics and Public Health Group, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, United Kingdom Javier Guitian Affiliation: Veterinary Epidemiology, Economics and Public Health Group, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, United Kingdom Nicola Ferrari Affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy Citation: Chinchio E, Crotta M, Romeo C, Drewe JA, Guitian J, Ferrari N (2020) Invasive alien species and disease risk: Why we should care about invasive alien species from a health perspective The anthropogenic movement of pathogens into new geographic locations or host species, so-called “pathogen pollution” 1, is one of the main threats to human and animal health in a globalized world. Since the majority of zoonotic emerging diseases originate from wildlife 2, as recent outbreaks like Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), Nipah, or Chikungunya point out, particular attention should be paid to wild animals’ translocations, which represent a potential driver of change in pathogen ecology and distribution 1. Some well-known examples of IAS include the south-American coypu Myocastor coypus, invasive in North America, Europe, and Asia, where it causes both environmental and economic impacts consuming aquatic vegetation and undermining riverbanks 5, and the eastern-Asiatic brown marmorated stink bug Halyomorpha halys, a successful global invader causing severe economic damages to agricultural crops 6. Besides affecting biodiversity conservation and economy, IAS, as translocated species, may promote pathogen pollution in the invaded area leading to the emergence of diseases 1,7–9. To this aim, we provide here an overview of how animal IAS may affect local disease dynamics both directly and indirectly, i.e., acting as pathogen hosts or disrupting the recipient ecosystem structure, through real-case examples from the ecological literature, and, in the last paragraph, we propose future initiatives aimed at improving our capacity for targeted actions toward the IAS most likely to threaten human and animal health, calling for an increased involvement of people working in the fields of animal and public health in a new invasion epidemiology field.
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