Accurate survey methods are required for any wildlife research to yield reliable population data. This constraint finds significance in amphibian research that involves a highly threatened group of animals with a large proportion of cryptic species not easily detected by conventional survey methods. Across a growing spectrum of zoology research, survey outcomes are benefitting from the efficacy of scent detection dogs in assisting with species detection. We investigated the ability of a scent detection dog to locate and identify traces of giant bullfrog, Pyxicephalus adspersus scent and investigate methods of preserving frog scent for use in subsequent conditioning training of dogs. The scent detection dog was able to detect 100,000 times diluted scent with 87% sensitivity and 84% efficacy. High specificity (98,6%) was also achieved while presented with the challenge of detecting P. adspersus scent amid that of other frog species. Detection sensitivity was negatively correlated with scent preservation time but yielded the highest sensitivity for samples that were preserved as skin swabs stored at 4 °C and diluted shortly before use. Conservationists, scientists, and customs officials alike can benefit from scent detection dog detection of amphibians through enhanced sample acquisition rates with reduced collection biases.
Obtaining reliable estimates of population abundance is of utmost importance for wildlife research and management. To this aim, camera-traps are increasingly used, as this method has the advantage of being noninvasive and allows for continuous monitoring. Camera traps can be used to estimate abundance in combination with traditional capture-recapture techniques, as well as with estimators that do not require marked individuals. Here, we investigated the use of camera-based mark-recapture methods applied to an Alpine marmot (Marmota marmota) population in the Paneveggio-Pale di San Martino Natural Park (eastern Italian Alps). We compared abundance estimates derived from a traditional capture-mark-recapture (CMR) framework and camera trap mark-resight (CTMR) over three consecutive years. CMR models estimated a population size of n = 19 individuals (95% CI = 18-27), n = 15 (14-22) and n = 24 (22-32) in 2019, 2020 and 2021 respectively. CTMR returned an estimated population size of n = 24 (95% CI = 18-30), n = 20 (17-24) and n = 22 (21-24) for the same years. The difference between the estimate of these two methods was significant only in 2020, with CMR returning a lower estimate than CTMR (95% CI = –9.4-–0.6). This difference was not significant for 2019 (95% CI = –10.9-0.9) and 2021 (95% CI = –1.8-5.9). Based on our results, the use of CTMR techniques is promising in the estimation of absolute population size of marmots, and the estimator was slightly more precise than CMR. Further studies are needed to evaluate the effectiveness of CTMR with reduced capture effort.
The sicklefin redhorse, Moxostoma sp. (Cypriniformes: Catostomidae), is an innominate imperiled catostomid endemic to the Hiwassee and Little Tennessee river basins, which has been restricted to a few tributaries of these systems by impoundments. During collections to propagate sicklefin redhorse for reintroduction, a myxozoan, described herein, was observed infecting sicklefin redhorse in the Little Tennessee River Basin, North Carolina. Myxobolus naylori Ksepka et Bullard sp. n. infects the stratum spongiosum covering the scales of sicklefin redhorse. Myxospores of the new species differ from all congeners by the combination of having a mucous envelope, intercapsular process, and sutural markings as well as lacking an iodinophilic vacuole in the sporoplasm. and A phylogenetic analysis of the 18S rDNA gene recovered the new species in a polytomy with Myxobolus marumotoi Li et Sato, 2014 and a clade comprised of species of Myxobolus Bütschli, 1882; Thelohanellus Kudo, 1933, and Dicauda Hoffman et Walker, 1973. Histological sections of infected sicklefin redhorse skin revealed myxospores within a plasmodium in the stratum spongiosum dorsal to scales, encapsulated in collagen fibres, and associated with focal erosion of scales directly beneath the plasmodium; in some instances, the scale was perforated by the plasmodium. The specificity of the new species to sicklefin redhorse may make it a useful biological tag to differentiate sicklefin redhorse from morphologically similar species. The new species is the first parasite reported from sicklefin redhorse, a species of concern to the United States Fish and Wildlife Service. No species of Myxobolus has been reported from species of Moxostoma in the Southeast United States. As it was observed that Myxobolus minutus Rosser, Griffin, Quiniou, Alberson, Woodyard, Mischker, Greenway, Wise et Pote, 2016 is a primary junior homonym of Myxobolus minutus Nemeczek, 1911, we propose the replacement name Myxobolus diminutus (Rosser, Griffin, Quiniou, Alberson, Woodyard, Mischker, Greenway, Wise et Pote, 2016).
In the Pyrenees, brown bear population abundance is estimated from non-invasive genetic analyses of scat and hair samples. Although such analyses are highly beneficial for population monitoring and research, it can be especially difficult for humans to locate bear scats in the field. To address this, we have incorporated a dog (trained from an early age to detect bear scats) into these efforts since 2014. Here, we compared the effectiveness of the scat-detection dog/handler and human-only teams to locate bear scats using our work in the Pyrenees as a case study. A species validation was systematically carried out, either genetically or visually using a microscope, based on the presence of bear hair, for all scats collected from 2010 to 2019. From 2014 to 2019, the use of the dog/handler team in addition to human-only teams increased the average number of bear scats collected annually by four times in comparison with the 2010-2013 period when only humans were searching for scats. This temporal augmentation could not be explained by the increase in bear population size. From 2014 to 2019, the annual percentage of outings during which at least one bear scat was found was 17 times higher for the dog than for humans. The use of the dog also resulted indirectly in a better genotyping success and genetic identification of more individuals due to a larger choice of viable samples that could be sent to the molecular laboratory, as well as a larger number of cub scats detected by the dog. We found that even the use of a single scat-detection dog can greatly improve the efficiency of detecting target scats in challenging monitoring conditions.
Cysteine protease is a superfamily of widespread proteolytic enzymes and plays a major role in larval invasion, migration, exsheathing, survival and immune evasion in parasites. In the present study, the gene coding cysteine proteinase of the nematode Trichinella spiralis (Owen, 1835) was cloned into pQE-80L and subsequently expressed in E. coli JM109. The rTsCP was purified and its antigenicity was identified by Western blot and ELISA. Using anti-rTsCP serum the native TsCP was identified in muscle larval crude proteins. The results of quantitative real-time PCR and immunofluorescence test demonstrated that the TsCP was expressed in all stages of T. spiralis and located mainly in cuticle, stichosome and reproductive organs. The immunisation of mice with rTsCP elicited Th2-predominant immune responses. Anti-rTsCP antibodies could partially inhibit the in vitro larval invasion of intestinal epithelial cells and kill the newborn larvae by an antibody-dependent cell-mediated dose-dependent cytotoxicity. The vaccinated mice exhibited a 54% reduction of adults and a 33% reduction of muscle larvae following challenge infection. The results suggested that the TsCP might be an indispensable protein in Trichinella invasion, development and survival of T. spiralis in hosts, and could be a potential vaccine target against infection., Yan Yan Song, Li Ang Wang, Hua Na Ren, Xin Qi, Ge Ge Sun, Ruo Dan Liu, Peng Jiang, Xi Zhang, Jing Cui, Zhong Quan Wang., and Obsahuje bibliografii
Trichodina centrostrigeata Basson, Van As et Paperna, 1983 from Oreochromis mossambicus (Peters) and O. niloticus (Linnaeus) from different host populations from Argentina, Mexico and South Africa was reviewed. Although T. centrostrigeata has a distinct denticle structure that makes morphological taxonomic inferences uncomplicated, variation of the denticles within and among individuals and populations were still observed. While traditional taxonomy of mobilines is heavily reliant on morphometrics, and recently even more so on molecular analysis, this paper proposes the use of geometric morphometry, specifically elliptical Fourier analysis, to address morphological conflicts that arise when comparing different populations. By applying this technique, combined with traditional taxonomy, it was found that T. centrostrigeata in this study can be grouped into two separate morphotypes, the first (type a) from aquaculture farms in Argentina and Mexico and the second (type b) from a natural habitat in Glen Alpine Dam, South Africa. This study supports the validity of geometric morphometry as an additional technique to distinguish not only between species but also evolutionary plasticity of the same species from different localities and habitats.
The Natal multimammate mouse, Mastomys natalensis, occurs throughout sub-Saharan Africa. Mitochondrial phylogenetics indicate this species was fragmented during the Pleistocene, forming six matrilineage phylogroups: A-I, A-II, A-III, B-IV, B-V, B-VI with distinct ranges. All except the A-III lineage are identified as natural reservoirs of mammarenaviruses. M. natalensis A-III is found in western Ethiopia and is the only lineage reported in the country. While screening 203 small mammal samples from Dhati Welel National Park for mammarenaviruses, we detected mammarenavirus RNA in nine samples, eight from M. natalensis and one from M. awashensis. A sequence similarity search and phylogenetic analysis confirmed the M. natalensis mitochondrial DNA belongs to the A-III lineage. We characterised the complete virus genome, which showed typical mammarenavirus organisation. Phylogenetic analysis indicated it clusters with Gairo virus found in M. natalensis B-IV in Tanzania, while showing sufficient divergence from other mammarenaviruses to be considered as a new species, for which we proposed the name Dhati Welel. Additional sampling in the M. natalensis A-III phylogeographic range should help determine whether the detection of the virus in M. awashensis represents a local spill-over or if the virus circulates in both Mastomys species.
Endozoochory is a mutualistic interaction between plants and animals. Such a relationship has rarely been examined in the Eurasian otter Lutra lutra. This study aimed to assess the use and electivity of fruit by this carnivore, along with the viability of ingested seeds. Otter spraints and fruit were collected from the River Bullaque (Guadiana River basin, central Spain) in June and September 2018-2019. A high occurrence of fruit (> 40%) was found in spraints during September. Otters ingested fruit in June from only one plant species: Iberian bushweed Flueggea tinctoria (Phyllanthaceae); whereas seeds ingested in September belonged to four plant species: apple mint Mentha suaveolens (Lamiaceae), common hawthorn Crataegus monogyna, dog rose Rosa canina and elmleaf blackberry Rubus ulmifolius (three Rosaceae species). According to the environmental availability, otters displayed avoidance for mint and rose, neutral selection for hawthorn and preference for blackberry. Germination was unsuccessful for mint seeds, whereas germination was the highest for blackberry (37%; 49% for blackbird Turdus merula, a well-known frugivorous species). Otters appear to display an ecological role as seed dispersers for riparian vegetation in Iberian fresh waters. These findings provide insights into this endozoochorous co-evolution between plants and Carnivora.
Black rats (Rattus rattus) are native to the Indian subcontinent but have now colonized most continents and islands following human movements and international trade. They are involved in the circulation and transmission to humans of many zoonotic agents as well as in massive damage to food stocks and native biodiversity in the regions they have settled. This study investigates the genetic diversity and possible origins of black rats from Benin, West Africa. We sequenced the complete mitochondrial cytochrome b gene in 90 individuals from nine localities in Benin. These sequences were subsequently compared to 390 other cytochrome b haplotypes from individuals from various European, Asian, American and African localities. Nucleotide polymorphism analysis, haplotype network and maximum likelihood phylogenetic tree reconstructions showed low mitochondrial diversity in black rats from Benin. Our results also suggest at least two distinct introduction events: one introduction probably occurred during the spice trade (15th-17th century) through the Indies Road connecting Europe to Asia. Other introduction events could have occurred more recently following the intensification of globalized trade from the eighteenth century, and onwards.
The elastase, which belongs to the serine protease family, hydrolyses various proteins and may be involved in the parasite invasion. In this study, complete sequence of elastase-1 (TsE) the nematode Trichinella spiralis (Owen, 1835) was cloned into the plasmid pcDNA3.1 as TsE DNA vaccine. After intramuscular vaccination, serum anti-Trichinella antibodies (IgG and subclass IgG1/IgG2a, and IgA), total and specific intestinal mucosal sIgA in mice vaccinated with pcDNA3.1/TsE were measured by ELISA. The results showed that vaccination with pcDNA3.1/TsE induced a systemic humoral immune response (high levels of serum IgG and subclass IgG1/IgG2a and IgA) and local intestinal mucosal immune responses (high levels of TsE-specific sIgA). Vaccination of mice with TsE DNA vaccine also triggered a systemic and local concomitant Th1/Th2 response, as demonstrated by significant elevation of Th1 (IFN-γ and IL-2) / Th2 (IL-4 and IL-10) cytokine levels after the spleen, mesenteric lymph node and Peyer's patch cells from vaccinated mice were stimulated with recombinant TsE (rTsE). The vaccination of mice with pcDNA3.1/TsE displayed a 17% reduction of intestinal adult worms and a 39% reduction of muscle larvae. Our results indicated that TsE DNA vaccine elicited a systemic concomitant Th1/Th2 response and an enteral local sIgA response, and produced a partial protection against infection with T. spiralis. The TsE may be regarded as a potential candidate vaccine target against Trichinella infection. The oral polyvalent vaccines should be developed to improve the protective efficacy of anti-Trichinella vaccines.