scholarly journals Invasive snails, parasite spillback, and potential parasite spillover drive parasitic diseases of Hippopotamus amphibius in artificial lakes of Zimbabwe

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ruben Schols ◽  
Hans Carolus ◽  
Cyril Hammoud ◽  
Kudzai C. Muzarabani ◽  
Maxwell Barson ◽  
...  
Keyword(s):  
Habitat Destruction ◽  
Snail Species ◽  
Anthropogenic Pressures ◽  
Large Herbivore ◽  
Bulinus Truncatus ◽  
Artificial Lakes ◽  
Hippopotamus Amphibius ◽  
Parasite Spillback ◽  
The Common ◽  
Trematode Parasites

Abstract Background Humans impose a significant pressure on large herbivore populations, such as hippopotami, through hunting, poaching, and habitat destruction. Anthropogenic pressures can also occur indirectly, such as artificial lake creation and the subsequent introduction of invasive species that alter the ecosystem. These events can lead to drastic changes in parasite diversity and transmission, but generally receive little scientific attention. Results In order to document and identify trematode parasites of the common hippopotamus (Hippopotamus amphibius) in artificial water systems of Zimbabwe, we applied an integrative taxonomic approach, combining molecular diagnostics and morphometrics on archived and new samples. In doing so, we provide DNA reference sequences of the hippopotamus liver fluke Fasciola nyanzae, enabling us to construct the first complete Fasciola phylogeny. We describe parasite spillback of F. nyanzae by the invasive freshwater snail Pseudosuccinea columella, as a consequence of a cascade of biological invasions in Lake Kariba, one of the biggest artificial lakes in the world. Additionally, we report an unknown stomach fluke of the hippopotamus transmitted by the non-endemic snail Radix aff. plicatula, an Asian snail species that has not been found in Africa before, and the stomach fluke Carmyerius cruciformis transmitted by the native snail Bulinus truncatus. Finally, Biomphalaria pfeifferi and two Bulinus species were found as new snail hosts for the poorly documented hippopotamus blood fluke Schistosoma edwardiense. Conclusions Our findings indicate that artificial lakes are breeding grounds for endemic and non-endemic snails that transmit trematode parasites of the common hippopotamus. This has important implications, as existing research links trematode parasite infections combined with other stressors to declining wild herbivore populations. Therefore, we argue that monitoring the anthropogenic impact on parasite transmission should become an integral part of wildlife conservation efforts. Graphical abstract

Population abundance of the common hippopotamus Hippopotamus amphibius in the Haut Niger National Park, Republic of Guinea / Abondance de la population d'hippopotame commun Hippopotamus amphibius dans le Parc National du Haut Niger, République de Guinée

Mammalia ◽  
2006 ◽  
Vol 70 (1-2) ◽  
Author(s):  
David Brugière ◽  
Bakary Magassouba ◽  
Amidou Sylla ◽  
Halimou Diallo ◽  
Mamadou Sow
Keyword(s):  
National Park ◽  
Buffer Zone ◽  
Wet Season ◽  
Republic Of Guinea ◽  
Hippopotamus Amphibius ◽  
The Status ◽  
Grazing Area ◽  
The Common ◽  
The Republic

AbstractThe Republic of Guinea is thought to contain the largest population of common hippopotamus in West Africa. However, no systematic field survey has been carried out recently and the information available is limited to informal observations. To clarify the status of the common hippopotamus in Guinea, we carried out a biannual population survey along the section of the Niger River (the largest river in Guinea) within the Haut Niger National Park. We counted 93 hippopotamuses in 28 groups in the dry season and 77 hippopotamuses in 23 groups in the wet season. Mean group size and number of neonates did not change between the seasons. Hippopotomuses were more numerous along the river sections bordering uncultivated floodplains. This underlines the significance of this habitat (which is used as a grazing area) for conservation of this species. Haut Niger National Park is the most important protected area in Guinea for conservation of the common hippopotamus. Hippopotamus-human and -cattle conflicts in terms of floodplain use in the park's buffer zone should be closely monitored. Floodplain conversion to rice fields represents one of the most important threats to the long-term conservation of hippopotamus populations in Guinea.

scholarly journals Phylogeography of Bulinus truncatus (Audouin, 1827) (Gastropoda: Planorbidae) in Selected African Countries

2018 ◽  
Vol 3 (4) ◽  
pp. 127 ◽  
Author(s):  
Eniola Abe ◽  
Yun-Hai Guo ◽  
Haimo Shen ◽  
Masceline Mutsaka-Makuvaza ◽  
Mohamed Habib ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Haplotype Diversity ◽  
Snail Host ◽  
Snail Species ◽  
African Countries ◽  
Urinary Schistosomiasis ◽  
Bulinus Truncatus ◽  
High Haplotype Diversity ◽  
Gene Coi ◽  
Mitochondrial Cytochrome Oxidase

The transmission of some schistosome parasites is dependent on the planorbid snail hosts. Bulinus truncatus is important in urinary schistosomiasis epidemiology in Africa. Hence, there is a need to define the snails’ phylogeography. This study assessed the population genetic structure of B. truncatus from Giza and Sharkia (Egypt), Barakat (Sudan) and Madziwa, Shamva District (Zimbabwe) using mitochondrial cytochrome oxidase subunit 1 gene (COI) and internal transcribed spacer 1 (ITS 1) markers. COI was sequenced from 94 B. truncatus samples including 38 (Egypt), 36 (Sudan) and 20 (Zimbabwe). However, only 51 ITS 1 sequences were identified from Egypt (28) and Sudan (23) (because of failure in either amplification or sequencing). The unique COI haplotypes of B. truncatus sequences observed were 6, 11, and 6 for Egypt, Sudan, and Zimbabwe, respectively. Also, 3 and 2 unique ITS 1 haplotypes were observed in sequences from Egypt and Sudan respectively. Mitochondrial DNA sequences from Sudan and Zimbabwe indicated high haplotype diversity with 0.768 and 0.784, respectively, while relatively low haplotype diversity was also observed for sequences from Egypt (0.334). The location of populations from Egypt and Sudan on the B. truncatus clade agrees with the location of both countries geographically. The clustering of the Zimbabwe sequences on different locations on the clade can be attributed to individuals with different genotypes within the population. No significant variation was observed within B. truncatus populations from Egypt and Sudan as indicated by the ITS 1 tree. This study investigated the genetic diversity of B. truncatus from Giza and Sharkia (Egypt), Barakat area (Sudan), and Madziwa (Zimbabwe), which is necessary for snail host surveillance in the study areas and also provided genomic data of this important snail species from the sampled countries.

scholarly journals Preventing crop raiding by the Vulnerable common hippopotamus Hippopotamus amphibius in Guinea-Bissau

Oryx ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Luis M. González ◽  
Francisco G. D. Montoto ◽  
Tome Mereck ◽  
Junior Alves ◽  
José Pereira ◽  
...  
Keyword(s):  
Coastal Waters ◽  
Rice Fields ◽  
Crop Damage ◽  
Running Water ◽  
Rice Farmers ◽  
Guinea Bissau ◽  
Hippopotamus Amphibius ◽  
Electric Fencing ◽  
Effective Deterrent ◽  
The Common

AbstractGuinea-Bissau is host to the westernmost subpopulation of the common hippopotamus Hippopotamus amphibius, which is one of only two known populations inhabiting coastal waters. The presence of hippopotamuses causes conflict with rice farmers as a result of crop damage and the absence of effective measures to protect crops. To develop an effective method for protecting rice fields, we studied the patterns of access to flooded and rain-fed rice fields by hippopotamuses and assessed the effect of the installation of electric fences. Hippopotamuses were detected in 54% of the flooded fields (n = 100) and in 31.9% of the rain-fed fields (n = 91). They were detected more frequently in fields on offshore islands than on the mainland, in unfenced than in fenced fields, and in fields closer to running water. Hippopotamuses entered fenced flooded fields less frequently than unfenced, and were detected most frequently at the end of the rainy season and the start of the dry season, and in the period of vegetative stem growth. Electric fences were an effective deterrent and facilitated increased rice production. The maintenance and cost of the electric fencing were acceptable to farmers, and therefore the use of such fencing is recommended to resolve the conflict between hippopotamuses and farmers in Guinea-Bissau and in other areas with similar conditions.

Histological Properties of Main and Accessory Olfactory Bulbs in the Common Hippopotamus

2017 ◽  
Vol 90 (3) ◽  
pp. 224-231 ◽  
Author(s):  
Daisuke Kondoh ◽  
Kenichi Watanabe ◽  
Kaori Nishihara ◽  
Yurie S. Ono ◽  
Kentaro G. Nakamura ◽  
...  
Keyword(s):  
Granule Cell ◽  
Olfactory System ◽  
Olfactory Nerve ◽  
Mitral Cell ◽  
Vomeronasal System ◽  
Olfactory Bulbs ◽  
Hippopotamus Amphibius ◽  
Cell Layers ◽  
The Common ◽  
Tufted Cells

The olfactory system of mammals comprises a main olfactory system that detects hundreds of odorants and a vomeronasal system that detects specific chemicals such as pheromones. The main (MOB) and accessory (AOB) olfactory bulbs are the respective primary centers of the main olfactory and vomeronasal systems. Most mammals including artiodactyls possess a large MOB and a comparatively small AOB, whereas most cetaceans lack olfactory bulbs. The common hippopotamus (Hippopotamus amphibius) is semiaquatic and belongs to the order Cetartiodactyla, family Hippopotamidae, which seems to be the closest extant family to cetaceans. The present study evaluates the significance of the olfactory system in the hippopotamus by histologically analyzing the MOB and AOB of a male common hippopotamus. The MOB comprised six layers (olfactory nerve, glomerular, external plexiform, mitral cell, internal plexiform, and granule cell), and the AOB comprised vomeronasal nerve, glomerular, plexiform, and granule cell layers. The MOB contained mitral cells and tufted cells, and the AOB possessed mitral/tufted cells. These histological features of the MOB and the AOB were similar to those in most artiodactyls. All glomeruli in the AOB were positive for anti-Gαi2, but weakly positive for anti-Gαo, suggesting that the hippopotamus vomeronasal system expresses vomeronasal type 1 receptors with a high affinity for volatile compounds. These findings suggest that the olfactory system of the hippopotamus is as well developed as that of other artiodactyl species and that the hippopotamus might depend on its olfactory system for terrestrial social communication.

scholarly journals Establishment and characterization of fibroblast cultures derived from a female common hippopotamus (Hippopotamus amphibius) skin biopsy

2020 ◽  
Author(s):  
Tao Wang ◽  
Zelong Li ◽  
Jinpu Wei ◽  
Dongmin Zheng ◽  
Chen Wang ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Cultured Cells ◽  
Population Decline ◽  
Fibroblast Cell ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Fibroblast Cultures ◽  
Hippopotamus Amphibius ◽  
The Common

AbstractThe population decline in the common hippopotamus (Hippopotamus amphibius) has necessitated the preservation of their genetic resources for species conservation and research. Of all actions, cryopreservation of fibroblast cell cultures derived from animal biopsy is considered a simple but efficient means. Nevertheless, preserving viable cell cultures of the common hippopotamus has not been achieved to our knowledge. To this end, we detailed a method to establish fibroblast cell cultures from a female common hippopotamus fetus in this study. By combining the classic tissue explant direct culture and enzymatic digestion methods, we isolated a great number of cells with typical fibroblastic morphology and high viability. Characterization of the fibroblast cultures was carried out using different techniques. In short, neither bacteria/fungi nor mycoplasma was detectable in the cell cultures throughout the study. The population doubling time was 23.9 h according to the growth curve. Karyotyping based on Giemsa staining showed that cultured cells were diploid with 36 chromosomes in all, one pair of which was sex chromosomes. Mitochondrial cytochrome C oxidase subunit I gene sequence of the cultured cells was 99.26% identical with the Hippopotamus amphibius complete mitochondrial DNA sequence registered in GenBank, confirming the cells were derived from a common hippopotamus. Flow cytometry and immunofluorescence staining results revealed that the detected cells were positive for fibroblast markers, S100A4 and Vimentin. In conclusion, we isolated and characterized a new fibroblast cell culture from a common hippopotamus skin sample and the cryopreserved cells could be useful genetic materials for the future research.

scholarly journals High prevalence of urinary schistosomiasis in a desert population: results from an exploratory study around the Ounianga lakes in Chad

2022 ◽  
Vol 11 (1) ◽  
Author(s):  
Wendelin Moser ◽  
Annour Adoum Batil ◽  
Rebekka Ott ◽  
Moussa Abderamane ◽  
Ruth Clements ◽  
...  
Keyword(s):  
Intermediate Host ◽  
Exploratory Study ◽  
Health Concern ◽  
Sahara Desert ◽  
Water Contact ◽  
Urinary Schistosomiasis ◽  
Bulinus Truncatus ◽  
Contact Sites ◽  
High Prevalence ◽  
Trematode Parasites

Abstract Background Researching a water-borne disease in the middle of the Sahara desert might not seem the most relevant concern. However, nomadic Sahelian pastoralists health concerns regarding their livestock and anecdotal reports about trematode infections of Fasciola spp. and Schistosoma spp. in desert-raised animals justified an exploratory study focusing on the lakes of Ounianga in Northern Chad. The aim was to test whether trematode parasites such as Schistosoma spp. occur in human populations living around the Sahara desert lakes of Ounianga Kebir and Ounianga Serir in northern Chad. Methods The study was carried out in January 2019 and comprised of three components. First, a cross sectional survey based on a random sample drawn from the population to detect infections with S. haematobium and S. mansoni; second, focus group discussions exploring disease priorities, access to health and health seeking behaviour; and third, surveying water contact sites for intermediate host snails. Samples of trematode parasites and snails were confirmed on species level by molecular genetic methods. For parasitological and malacological surveys descriptive statistics were performed. Qualitative data analysis included the full review of all transcripts, followed by a descriptive and explorative thematic analysis. Results Among 258 participants, the overall S. haematobium prevalence using urine filtration was 39.2% [95% confidence interval (CI): 33.5–45.1%], with 51.5% of the infected suffering from heavy infection. The intermediate host snail of S. haematobium (Bulinus truncatus) occurred at water contact sites near both study villages, revealing the potential for local transmission. Although a positive S. mansoni point-of-care circulating cathodic antigen (POC-CCA) test result was obtained from 8.6% (95% CI 5.7–12.8%) of the samples, no intermediate host snails of S. mansoni were found, and the relevance of S. mansoni remains uncertain. Qualitative findings underline the importance of morbidity caused by urinary schistosomiasis, and the lack of access to diagnostics and treatment as a major health concern. Conclusions This research revealed a high prevalence of urinary schistosomiasis in the population living around the lakes of Ounianga in the Sahara, a United Nations Educational, Scientific and Cultural Organization (UNESCO) world heritage site in Chad. Despite the high public health importance of the associated morbidity expressed by the population, there is no access to diagnostics and treatment. Further work is needed to develop and test a context-adapted intervention. Graphical Abstract

scholarly journals Status of the relict population of the Critically Endangered Madagascar spider tortoise Pyxis arachnoides

Oryx ◽  
2012 ◽  
Vol 46 (3) ◽  
pp. 457-463 ◽  
Author(s):  
Ryan C. J. Walker ◽  
Tsilavo H. Rafeliarisoa
Keyword(s):  
Protected Areas ◽  
Distance Sampling ◽  
Habitat Destruction ◽  
Species Range ◽  
Line Transect ◽  
Anthropogenic Pressures ◽  
Community Based Conservation ◽  
Relict Population ◽  
Distance Model ◽  
C 71

AbstractThe Madagascar spider tortoise Pyxis arachnoides is endemic to the coastal dry forests of south-west Madagascar. In recent years its range has been reduced by c. 71%, with the species now confined to eight fragmented populations occupying a total of 2,464 km2. These remaining populations are facing a significant threat of extinction because of habitat destruction and other anthropogenic pressures. We developed methodology for a line transect distance sampling survey and applied it systematically across the species' range. The resulting distance model estimated a mean density of 226.9 tortoises km−2 (95% confidence interval, CI, 168.1–306.3) and a total population of 664,980 (95% CI 492,680–897,550). Fragmentation of the species’ range suggests the current population could be <30% of the historical population. Of the remaining population 73.5% falls within protected areas. However, nine of these 12 protected areas are designated as IUCN category III, V or VI parks, allowing some extractive activities to be undertaken. The most effective strategy for the conservation of P. arachnoides would be to reduce the threats to this species and its habitat, and to develop and expand the current community-based conservation and poverty alleviation programmes in the region.

100 Reproductive cycle and pregnancy monitoring in the common hippopotamus (Hippopotamus amphibius) through salivary steroid analyses and transabdominal ultrasonography

2019 ◽  
Vol 31 (1) ◽  
pp. 176
Author(s):  
J. Wojtusik ◽  
I. M. C. Brandicourt ◽  
W. Rice ◽  
T. L. Roth
Keyword(s):  
Enzyme Immunoassay ◽  
Reproductive Cycle ◽  
Reproductive Activity ◽  
Botanical Garden ◽  
Ex Situ ◽  
Sample Collection ◽  
Transabdominal Ultrasonography ◽  
Hippopotamus Amphibius ◽  
Steroid Analysis ◽  
The Common

The common hippopotamus (Hippopotamus amphibius) is listed as vulnerable to extinction by the IUCN due to a significant decrease in population size, caused by habitat loss and poaching. Ex situ populations can help ensure against species loss, but careful reproductive management is essential to maintain sustainable populations. Hormone monitoring allows for characterisation of the reproductive cycle and gestation, offering insight into timing of receptivity and conception and facilitating pregnancy diagnosis and estimation of parturition date. Fecal steroid analysis has been validated for measuring progestogens in hippos. However, hippos are often housed in groups and frequently defecate in the water, making sample collection and source identification difficult. Salivary steroid analysis has been employed for monitoring reproductive activity in several species, but has not been tested in hippos. Additionally, transabdominal ultrasonography has proven valuable in diagnosing and monitoring pregnancy in many large mammals, but efficacy in the common hippo is unknown. The goals of this project were to (1) validate the use of an enzyme immunoassay to monitor progestogens in hippo saliva, (2) confirm that salivary progestogen profiles accurately reflect reproductive activity, (3) determine if transabdominal ultrasonography can be used to diagnose pregnancy, and, if so, (4) monitor and characterise fetal development via weekly examinations. Saliva (4-7 per week) and fecal (2-7 per week) samples were collected from 7 adult female hippos housed at 3 USA facilities over 3-7 months. Saliva and fecal samples were extracted in ethanol and extracts diluted (1:2 to 1:10 and 1:25 to 1:500, respectively) before evaluation by enzyme immunoassay (Progesterone mini-kit; Arbor Assays). Parallelism was confirmed between serially diluted fecal (r2=0.993) and saliva (r2=0.990) samples and the standard curve. Inter- and intra-assay coefficients of variation were maintained at &lt;10%. Comparison of fecal and saliva progestogen concentrations revealed a strong correlation between the 2 sample types (r2=0.848) and suggested that saliva offers a comparable alternative. Both fecal and saliva extracts exhibited elevated progestogens during luteal phases and gestation. One nulliparous female housed at the Cincinnati Zoo &amp; Botanical Garden (Cincinnati, OH, USA) was trained for voluntary transabdominal ultrasound exams. An Ibex Pro portable ultrasound machine (E.I. Medical Imaging, Loveland, CO, USA) with curvilinear probe (5-2.5MHz) was used at a scanning depth of 17.8 and 23.4cm. Intrauterine fluid and possible fetal tissue were observed 79 days following the last confirmed mating. Spine, rib cage, and beating heart were clearly visible at ~156 days of gestation. Ultrasound procedures were continued until the premature birth of a calf at ~181 days (normal hippo gestation ~231 days). Salivary progestogen monitoring and transabdominal ultrasonography appear suitable for tracking reproductive activity and diagnosing and monitoring pregnancy in the common hippo.

The occurrence of schistosomin, an antagonist of female gonadotropic hormones, is a general phenomenon in haemolymph of schistosome-infected freshwater snails

Parasitology ◽  
1991 ◽  
Vol 103 (3) ◽  
pp. 371-378 ◽  
Author(s):  
M. De Jong-Brink ◽  
M. Elsaadany ◽  
M. S. Soto
Keyword(s):  
Lymnaea Stagnalis ◽  
Digenetic Trematode ◽  
Freshwater Snails ◽  
Snail Species ◽  
General Phenomenon ◽  
Bulinus Truncatus ◽  
Diplostomum Spathaceum ◽  
Target Organs ◽  
Trichobilharzia Ocellata ◽  
Gonadotropic Hormones

In haemolymph of Lymnaea stagnalis, parasitized with the digenetic trematode parasite Trichobilharzia ocellata, a neuropeptide (schistosomin) occurs which antagonizes female gonadotropic hormones, e.g. calfluxin (CaFl). By means of an ultracytochemical hormone-assay, the CaFl assay, it was demonstrated that the occurrence of schistosomin is a general phenomenon in schistosome-infected freshwater snails. Haemolymph of the schistosomiasis-transmitting snail species Biomphalaria glabrata and B. pfeifferi, parasitized with Schistosoma mansoni, also appeared to contain an antagonizing factor, i.e. schistosomin. In contrast, in haemolymph of L. stagnalis parasitized with Diplostomum spathaceum (Diplostomatidae) no schistosomin could be found. This suggests that schistosomin may only occur in snails infected with parasites belonging to the Schistosomatidae. The effect of schistosomin is rather specific. Haemolymph of B. glabrata parasitized with S. mansoni had not the capacity to inhibit the response to CaFl in the target organs for CaFl, the albumen glands of L. stagnalis and Bulinus truncatus. The same holds true for haemolymph of infected L. stagnalis: it did not inhibit the CaFl response in glands of B. glabrata and B. truncatus and even not in those of a related species (L. ovata). Schistosomins in haemolymph of infected B. glabrata and B. pfeifferi, on the other hand, seem more related. Both appeared to inhibit the hormone response in glands of the two Biomphalaria species studied. The results indicate that schistosomin in haemolymph of schistosome-infected pulmonate snails, although functionally related, may differ structurally.

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