Sika Deer Research Articles

DNA barcoding for the identification and authentication of medicinal deer (Cervus sp.) products in China.

Deer products from sika deer (Cervus nippon) and red deer (C. elaphus) are considered genuine and used for Traditional Chinese Medicine (TCM) materials in China. Deer has a very high economic and ornamental value, resulting in the formation of a characteristic deer industry in the prescription preparation of traditional Chinese medicine, health food, cosmetics, and other areas of development and utilization. Due to the high demand for deer products, the products are expensive and have limited production, but the legal use of deer is limited to only two species of sika deer and red deer; other wild deer are prohibited from hunting, so there are numerous cases of mixing and adulteration of counterfeit products and so on. There have been many reports that other animal (pig, cow, sheep, etc.) tissues or organs are often used for adulteration and confusion, resulting in poor efficacy of deer traditional medicine and trade fraud in deer products. To authenticate the deer products in a rapid and effective manner, the analysis used 22 deer products (antler, meat, bone, fetus, penis, tail, skin, and wool) that were in the form of blind samples. Total DNA extraction using a modified protocol successfully yielded DNA from the blind samples that was useful for PCR. Three candidate DNA barcoding loci, cox1, Cyt b, and rrn12, were evaluated for their discrimination strength through BLAST and phylogenetic clustering analyses. For the BLAST analysis, the 22 blind samples obtained 100% match identity across the three gene loci tested. It was revealed that 12 blind samples were correctly labeled for their species of origin, while three blind samples that were thought to originate from red deer were identified as C. nippon, and seven blind samples that were thought to originate from sika deer were identified as C. elaphus, Dama dama, and Rangifer tarandus. DNA barcoding analysis showed that all three gene loci were able to distinguish the two Cervus species and to identify the presence of adulterant species. The DNA barcoding technique was able to provide a useful and sensitive approach in identifying the species of origin in deer products.

Analysis of the Gut Microbiota of Sika Deer (Cervus nippon) Inhabiting the Limited Area of Losiny Ostrov National Park

Analysis of the Gut Microbiota of Sika Deer (Cervus nippon) Inhabiting the Limited Area of Losiny Ostrov National Park

Optimized combination of Cervus nippon (Sika deer), Angelica (Dangui), and Rehmannia (Suk-jihwang) mitigates LPS-induced inflammation: exploring signaling pathways through plasma metabolomics.

The online version contains supplementary material available at 10.1007/s10068-023-01476-x.

AD-YOLOv5: An object detection approach for key parts of sika deer based on deep learning

Accurate and rapid fixation of key parts of sika deer is essential for the mechanized and intelligent collection of both deer blood and velvet antler. To solve the low detection accuracy problem of key parts of deer caused by the diversity of deer farm breeding environment and the rapid movement of deer, this paper proposes an AD-YOLOv5 algorithm for detecting key parts of sika deer based on YOLOv5s. Specifically, a new weighted bidirectional feature pyramid network S-BiFPN is first proposed, which both simplifies the structure and effectively performs skip feature fusion to better capture object information at different scales, so that the adaptive feature fusion capability of the model is optimized. Second, this paper proposes to add a SENet module after the C3 module of the 9th Layer in the backbone part of the network, so that the network can adaptively readjust the channel weights of feature maps to enhance the important features for key parts of sika deer and improve the expression ability of the model for key parts. Furthermore, to make the model more stable in the training process, a novel bounding box regression loss function SIoU is led into, which can better learn the position and size of the bounding box by fusing the orientation information between the ground truth box and the predicted box. The effectiveness of the proposed algorithm is demonstrated through ablation experiments. Experimental results show that the mAP@0.5 of the proposed algorithm reaches 97.30 % for the detection of key parts of sika deer, which is 12.85 %, 9.65 %, 9.18 %, 7.13 %, 3.59 %, 4.6 %, 0.90 % and 0.10 % higher than SSD, EfficientDet, YOLOv3, YOLOv4, Faster R-CNN, YOLOv5s, YOLOv7 and YOLOv8s, respectively. This research provides a new idea for detecting key parts of animals in complex environments and lays a theoretical foundation for the development of intelligent fixation devices for sika deer.

ISCNT embryo culture system for restoration of Cervus nippon hortulorum, presumed to be sika deer in the Korean Peninsula.

Sika deer inhabiting South Korea became extinct when the last individual was captured on Jeju Island in Korea in 1920 owing to the Japanese seawater relief business, but it is believed that the same subspecies (Cervus nippon hortulorum) inhabits North Korea and the Russian Primorskaya state. In our study, mt-DNA was used to analyze the genetic resources of sika deer in the vicinity of the Korean Peninsula to restore the extinct species of continental deer on the Korean Peninsula. In addition, iSCNT was performed using cells to analyze the potential for restoration of extinct species. The somatic cells of sika deer came from tissues of individuals presumed to be Korean Peninsula sika deer inhabiting the neighboring areas of the Primorskaya state and North Korea. After sequencing 5 deer samples through mt-DNA isolation and PCR, BLAST analysis showed high matching rates for Cervus nippon hortulorum. This shows that the sika deer found near the Russian Primorsky Territory, inhabiting the region adjacent to the Korean Peninsula, can be classified as a subspecies of Cervus nippon hortulorum. The method for producing cloned embryos for species restoration confirmed that iSCNT-embryos developed smoothly when using porcine oocytes. In addition, the stimulation of endometrial cells and progesterone in the IVC system expanded the blastocyst cavity and enabled stable development of energy metabolism and morphological changes in the blastocyst. Our results confirmed that the individual presumed to be a continental deer in the Korean Peninsula had the same genotype as Cervus nippon hortulorum, and securing the individual's cell-line could restore the species through replication and produce a stable iSCNT embryo.

Mammal inventory using camera traps in the Central Forest State Nature Reserve (West of European Russia)

A mammal species inventory by estimating their richness is the first and necessary task of any mammal monitoring programme. This paper presents estimates of species richness of mammals (mostly medium and large body-sized) in the Central Forest State Nature Reserve (European Russia). Based on data collected in 2023 from 55 camera trap locations (19 676 camera days), 59 035 images of wild mammals were obtained. A total of 18 species were recorded. Of these, ten species were representatives of the Carnivora, four – Artiodactyla, two – Rodentia, one – Erinaceomorpha, and one – Lagomorpha. This amounted to 84% of all potentially camera-trapped mammals observed in the Central Forest State Nature Reserve. The relative abundance index (RAI) and naïve occupancy (ψnaive) were calculated for all species. The most common and frequently recorded were Meles meles (RAI = 4.95; ψnaive = 0.96), followed by Ursus arctos (RAI = 4.39; ψnaive = 1) and Lepus timidus (RAI = 4.08; ψnaive = 1), while the most rarely recorded species were Castor fiber (RAI = 0.01; ψnaive = 0.02), Erinaceus europaeus (RAI = 0.02; ψnaive = 0.04), and Lutra lutra (RAI = 0.03; ψnaive = 0.07). Large and medium-sized carnivorous and omnivorous mammal communities were the fastest and most completely captured. According to the constructed single-season multispecies occupancy model with Markov chains Monte Carlo, camera traps failed to record 4–5 more possible species. These species are likely to be Mustela lutreola, M. erminea, and Mustela nivalis, as well as two invasive species, Cervus nippon and Capreolus pygargus. All the captured species were recorded in total in a short period of time, namely from the end of March to the beginning of May during 1869 camera-days. Two of them (Castor fiber and Erinaceus europaeus) were recorded exclusively at this time, and they were not captured further until the end of the year. This emphasises the importance of conducting mammal inventory, with inclusion of the spring season.

Comparison of physiologically functional compounds in Sika deer Cervus nippon meats obtained from different regions in Japan.

In Japan, the promotion of effective use of many wild deer as food resource has been conducted. However, they are not necessarily utilized effectively. Thus, we focused physiologically functional compounds to find characteristics of Sika deer meats (commercially available) obtained from different regions such as Hokkaido, Wakayama, Tokushima, and Miyazaki prefectures in Japan, making it a valuable resource for future studies and applications. The amount of carnosine, anserine, and balenine in muscle of deer from Wakayama prefecture was significantly lower than that in muscle of deer from other prefectures. The differences of amount of imidazole dipeptides in different prefectures seems to be caused by feed, rearing environment, and breed. The amount of carnitine in deer meat from Hokkaido was significantly lower than that in muscle of deer from other prefectures, while the amount of acetyl-carnitine in deer meat from Miyazaki prefectures was significantly higher than that from other prefectures. The amounts of glutamine, ornithine, and 3-methylhistidine in muscles of deer from Wakayama prefectures were significantly higher than those in muscle of deer from other prefectures. These results might be caused by differences in feeding habits, habitat, the muscle types, and subspecies of deer obtained from four regions in Japan.

Genetic investigation of glycosylphosphatidylinositol (GPI) anchored Bd37 orthologs in Babesia divergens group and potential use of recombinant protein for ecological survey in deer.

The Babesia divergens/B. capreoli group includes parasites with confirmed or possible zoonotic potential to cause human babesiosis. Currently, diagnostic antigen of the group has not been established. In this study, we investigated the ortholog of Bd37, a (GPI)-anchored major merozoite surface protein of B. divergens sensu stricto, in the Asia lineage of the group. From two genomic isolates from sporozoites/sporoblasts stage, three Bd37 gene variants, namely Bd37 JP-A, JP-B, and JP-C, were isolated with 62.3-64.1% amino acid sequences identity. Discriminative blood direct PCR revealed that Bd37 JP-A was encoded in all parasites infecting wild sika deer examined (n=22). While Bd37 JP-B and JP-C genes were randomly detected in 12 and 11 specimens, respectively. Sequencing of all JP-A variants revealed that the gene was polymorphic with low ratio of non-synonymous to synonymous substitutions (dN/dS) and that a highly polymorphic region was not related to predicted B-cell epitopes. A recombinant JP-A-based ELISA showed an overall positive rate of 13.9% in sika deer in Japan from north (Hokkaido) to south (Kyushu island) across 24 prefectures (n=360). This positive rate was twice as high as that examined by 18S rRNA-based PCR (6.8%). The geographical trends in infection rates were consistent. This study demonstrated that direct examination was informative for revealing genetic background and selecting antigen candidates. Bd37 orthologs may serve diagnostic purposes in combination with indirect fluorescence assay, which requires biological isolates.

Summer Diet of South China Sika Deer (Cervus nippon kopschi) in Taohongling based on High-Throughput Sequencing and Metabarcoding trnL

Summer Diet of South China Sika Deer (Cervus nippon kopschi) in Taohongling based on High-Throughput Sequencing and Metabarcoding trnL

Isolation and characterization of tannin-degrading bacteria from the rumen of wild Hokkaido sika deer (Cervus nippon yezoensis).

We isolated tannin-degrading bacteria from the rumen of wild Hokkaido sika deer and characterized their phylogeny and tannase activity in relation to sample sources. The condensed tannin level was higher in all deer rumen samples (n = 20) than in forage-fed cattle rumen samples (n = 6), whereas no hydrolyzable tannins were detected in any of the rumen samples. Rumen bacteria were enumerated on nonselective brain heart infusion (BHI) agar medium and then transferred onto tannic acid-containing BHI agar plates to screen for bacteria only showing growth (tannin-resistant bacteria) and those showing both growth and a clear zone (tannin-degrading bacteria). Summer samples provided only tannin-resistant bacteria, none of which showed tannin-degrading activity. Although winter samples also provided tannin-resistant bacteria, most isolates exhibited tannin-degrading activity. A total of 70 isolates exhibiting tannin-degrading activity were classified as Streptococcus bovis group based on 16S rRNA gene sequencing and further classified into two groups, either group A or group B. Group A consisted of isolates showing weak tannase activity, whereas group B included a majority of the isolates exhibiting high tannase activity. These results suggest that wild Hokkaido sika deer develop tannin-degrading Streptococcus in the rumen during winter, which allows access to woody food materials rich in tannins.

Morphological differences according to uterine tissue remodeling during estrus between sika deer and water deer

Morphological differences according to uterine tissue remodeling during estrus between sika deer and water deer

Дикі та свійські копитні степових регіонів України: оцінки для Луганщини на початок 21 століття

This article deals with the analysis of abundance and distribution of wild and domestic ungulates in Luhansk Oblast (eastern Ukraine). Descriptions of 10 ungulate species are given, including one species of the family Suidae (Sus scrofa), five species of Cervidae (Cervus elaphus, Cervus nippon, Dama dama, Capreolus capreolus, and Alces alces), three species of Bovidae (Bos taurus, Capra hircus, and Ovis aries), and one species of Equidae (Equus caballus). It shows the decline of populations of many ungulate species, including a 73.8% reduction in the number of cattle and a corresponding 23.4% reduction in the area of major crops in the region. In order to save the lands that have never been ploughed before, and to restore the steppe, we propose to increase the abundance of horses.

Чужорідні види ссавців району природного заповідника «Дніпровсько-Орільський»

The paper provides information on alien mammal species occurring in the territory of the Dnipro–Oril Nature Reserve. The data were collected during annual mammal surveys and by compiling the data provided in the Chronicles of Nature of previous years (1991–2022) within the framework of the scientific topic ‘Study of biodiver-sity, structure and dynamics of natural complexes of the Dnipro–Oril Nature Re-serve.’ Since the creation of the reserve, 44 species of mammals belonging to six orders (Leporiformes, Muriformes, Soriciformes, Vespertilioniformes, Caniformes, and Cerviformes) have been recorded in its territory. The species diversity of mammals of the reserve corresponds to 71% of the mammal fauna of Dniprope-trovsk Oblast and 34% of the mammal fauna of Ukraine. Most of the mammal species found in the reserve are indigenous but the raccoon dog Nyctereutes procy-onoides, muskrat Ondatra zibethicus, and sika deer Cervus nippon, which are arti-ficially introduced species. In addition, the brown rat Rattus norvegicus and the house mouse Mus musculus are distant invaders. The beech marten Martes foina, Blyth’s pipistrelle Pipistrellus lepidus, and serotine bat Eptesicus serotinus are close invaders. Alien species make up 18% of the mammal fauna of the reserve, being represented by a total of eight species. However, there are also species with fluctuating ranges in the studied area: European roe deer Capreolus capreolus, elk Alces alces, Eurasian otter Lutra lutra, Eurasian badger Meles meles, and wild boar Sus scrofa. The periodic contraction and expansion of their ranges within the region makes them similar to introduced species. The presence of the majority of adventive species was registered during the first inventory of the fauna of the described territory during the establishment of the reserve in 1991. However, the first sighting of serotine bat occurred in March 2013 in the floodplain part of the reserve, and the sighting of Blyth’s pipistrelle in the reserve was recorded in the spring of 2016. The article describes the specifics of the existence of alien mammal species in the reserve. The dynamics of abundance, population structure, diet, and environmental impact are presented. Other adventive species that could possibly be found in this territory in the near future are the American mink Neogale vison and golden jackal Canis aureus. A case of visual observation of the coypu Myocastor coypus in the vicinity of the reserve is also presented.

Чужорідні види ссавців у колекції зоологічного музею Луганського національного університету імені Тараса Шевченка

This paper presents a review of information on the specimens of the theriological part of the stock and exhibition collections of the Zoological Museum of Luhansk Taras Shevchenko National University in Luhansk as of 2014. Specimens of species and subspecies belonging to the group of alien mammals were taken into account. The review included both introductions, invaders, and animals belonging to the group of regional invaders (expanded their range within the region), reintroductions and alien species that occur naturally but do not form stable natural populations. Information on specimens of such invasive alien species as Lutra lutra, Nyctereutes procyonoides, Neogale vison, Ondatra zibethicus provide useful data for analysing the distribution and abundance of alien species in certain regions of the Siverskyi Donets basin. The majority of these species occurred in the main channel of the Donets and its immediate tributaries, which once again underlines the important role of river basins in the distribution of mammalian amphibians. The collections of a number of other alien species and subspecies are small, represented only by single specimens of rodents (Sciurus vulgaris exalbidus, Myocastor coypus) and ungulates (Cervus nippon, Dama dama, Bison bonasus, Saiga tatarica) originating from other regions of Ukraine or without information on the place of occurrence. The collections of such species as Castor fiber and Rattus norvegicus, which comprise 4 and 5 specimens respectively, contain specimens from Luhansk region, but information on their distribution is incomplete or insufficient for analysis or comparison. All the specimens listed in the text are valuable for the study of geographical distribution, craniological and morphological studies of alien species from the territory of Luhansk region and other regions of Ukraine, in particular from Poltava (Lutra lutra), Crimea (Sciurus vulgaris exalbidus) and Kherson (Dama dama).

Positive effects of biomass of unpalatable neighborhoods on palatable plants in a grassland community under heavy grazing pressure by sika deer

AbstractThe intensity of grazing on palatable species can vary depending on the neighboring plants in plant communities. We aimed to search for species whose biomass can have a positive effect on palatable plants near them in a grassland under grazing pressure by sika deer. We selected Iris sanguinea Hornem. as an indicator species of ease of being grazed because it is a palatable and past dominant species before the increase in deer density. We estimated the effects of the biomass of neighboring plant species, soil water content, and distance from the forest edge on the height of I. sanguinea. The height was remarkably and positively affected by the biomass of four graminoid species with larger biomass and slightly positively affected by the biomass of a toxic species. This study suggests that the biomass of less‐palatable species may have an important influence on the size of palatable species under grazing pressure by deer.

Hunting of sika deer over six decades does not restore forest regeneration

Abstract High densities of native and introduced deer hamper the regeneration of temperate forests worldwide. Sport hunting is often the sole means of deer control, but whether it can restore forest regeneration remains uncertain. We assessed the potential to restore forest regeneration using unrestricted sport hunting alongside commercial harvesting and government‐funded culling of introduced sika deer (Cervus nippon) across a 594 km2 landscape in North Island, New Zealand. We used six decades of repeated measurements of forest regeneration and deer presence, alongside monitoring of tagged stems in a 20‐year paired exclosure experiment, to determine whether deer control restored regeneration. In our exclosure experiment, mountain beech (Fuscospora cliffortioides) seedling and sapling density, growth and survival were variable but consistently higher when deer were excluded by fencing. Sapling counts in unfenced plots were ≈3–10 times lower after 60 years of deer control compared with unfenced plots, before sika colonisation and other mountain beech forests without sika deer. This result suggests canopy replacement remains at risk despite government‐funded culling and encouragement of sport hunting. Individual‐based demographic models show that mountain beech is unlikely to regenerate following canopy gap formation in our study landscape unless deer impacts are reduced from current levels. These demographic models predicted present‐day forest regeneration far better than two widely used proxies of deer impact: plot‐based counts of saplings and estimates of deer densities from faecal pellet counts. Synthesis and applications. Here, we show that intensive culling beyond that achievable by sport hunting is needed to reduce deer densities enough to assure canopy regeneration. These interventions will be necessary in the many places worldwide where sport hunting is being relied upon to protect forests but appears to be failing. Given the controversy associated with deer culling, and the need for clear evidence to justify its implementation, we suggest managers could strengthen the evidence base for their interventions by collecting data to build demographic models.

Food Habits of Raccoon Dogs at An Agricultural Area in Shikoku, Western Japan.

The diet of raccoon dogs, which live in close proximity to agricultural fields in Matsuyama, western Japan, was studied throughout the year by the fecal analysis method (n = 114). Fruits were most important, accounting for 30-40% of the diet except in winter. Crops were next in importance, accounting for 10-30%. It was characteristic that the proportion of crops was greater and more stable than in other "satoyama" or rural areas in Japan. Crops included rice (Oryza sativa), wheat, sesame (Sesamum indicum), strawberries (Fragaria × ananassa), kiwi fruit (Actinidia chinensis var. deliciosa), ginkgo nuts (Ginkgo biloba), and persimmon (Diospyros kaki). Crops were important as the food for the raccoon dogs, but the use was not regarded as causing serious damage. Although wild boars (Sus scrofa), sika deer (Cervus nippon), and Japanese macaques (Macaca fuscata) were culled for pest control in the area, raccoon dogs were not culled. This may be a reason why the raccoon dog has coexisted with people in Japan.

Changes in forest structure over 23 years under disturbances in a warm temperate rain forest on Yakushima Island, Japan

AbstractClarifying the influence of disturbances by biotic and abiotic agents on long‐term changes in forest structure and demographic rates is an important task of forest ecology. Here, we investigated changes in forest structure and demographic rates and the effects of biotic and abiotic factors (sika deer, ambrosia beetle, neighborhood trees, and indices of strong wind and wetness) in a 4‐ha long‐term ecological study plot in a lowland warm temperate rain forest on Yakushima Island, Japan, from 1996 to 2019 for three regeneration groups related to gap dynamics (gap demander: GD, light shade tolerant: LS, and strong shade tolerant: SS). GD had relatively lower recruitment and survival than LS and/or SS. Changes in demographic rates were not significantly correlated with those in the index of strong wind in any regeneration group. The effects of sika deer on demographic rates did not differ among groups. Stems of Fagaceae species belonging to LS attacked by ambrosia beetles recorded in 2013 did not significantly differ in RGR and survival rates. Our results indicate that despite the relatively long monitoring period of 23 years, we did not detect significant effects of strong winds on demographic rates among regeneration groups, and shade‐tolerant species (LS and SS) showed better demographic performance than light‐demanding species (GD) and an increase in total basal area over time. We need longer monitoring of forest dynamics to understand forest responses to disturbances considering several factors, including the time lag of demographic responses to disturbances and the long‐term effects of disturbances.

Redescription, molecular characterisation and Wolbachia endosymbionts of Mansonella (Tupainema) dunni (Mullin & Orihel, 1972) (Spirurida: Onchocercidae) from the common treeshrew Tupaia glis Diard & Duvaucel (Mammalia: Scandentia) in Peninsular Malaysia

The genus Mansonella Faust, 1929 includes 29 species, mainly parasites of platyrrhine monkeys in South America and anthropoid apes in Africa. In Malaysia, Mansonella (Tupainema) dunni (Mullin & Orihel, 1972) was described from the common treeshrew Tupaia glis Diard & Duvaucel (Scandentia). In a recent classification of the genus Mansonella, seven subgenera were proposed, with M. (Tup.) dunni as a monotypic species in the subgenus Tupainema. In this study, we collected new material of M. (Tup.) dunni from common treeshrews in Peninsular Malaysia and redescribed the morphological features of this species. We found that M. (Tup.) dunni differs from M. (Cutifilaria) perforata Uni et al., 2004 from sika deer Cervus nippon (Cetartiodactyla) in Japan, with regards to morphological features and predilection sites in their respective hosts. Based on multi-locus sequence analyses, we examined the molecular phylogeny of M. (Tup.) dunni and its Wolbachia genotype. Species of the genus Mansonella grouped monophyletically in clade ONC5 and M. (Tup.) dunni was placed in the most derived position within this genus. Mansonella (Tup.) dunni was closely related to M. (M.) ozzardi (Manson, 1897) from humans in Central and South America, and most distant from M. (C.) perforata. The calculated p-distances between the cox1 gene sequences for M. (Tup.) dunni and its congeners were 13.09% for M. (M.) ozzardi and 15.6–16.15% for M. (C.) perforata. The molecular phylogeny of Mansonella spp. thus corroborates their morphological differences. We determined that M. (Tup.) dunni harbours Wolbachia endosymbionts of the supergroup F genotype, in keeping with all other Mansonella species screened to date.

Experimental Evidence of the Diarrheal Activity of Sarcocystis sp. in Sika Deer (Cervus nippon).

Recently, the wild deer population has been increasing in Japan, causing serious feeding-related damage to the agricultural and forestry industries. In conjunction with the government's promotion of hunting for population control, the effective utilization of resources and promotion of the game meat industry as a sixth sector of industrialization are desired by local governments. However, several cases in which patients showed intestinal symptoms such as diarrhea due to the consumption of sika deer meat infected with protozoan Sarcocystis spp. have been reported, and the pathogenic microorganisms found in wild deer should be investigated. In this study, Sarcocystis sp. parasitized Kyushu sika deer (Cervus nippon nippon) in Nagasaki Prefecture, Japan, was examined for its enterotoxicity. A phylogenetic analysis based on the sequence of the 18S rRNA gene and cox1 showed that the species was highly homologous to Sarcocystis japonica and/or Sarcocystis sp. HM050622. We attempted to confirm the diarrhea-evoking toxicity of Sarcocystis sp. in sika deer meat, which has been previously reported in human case reports. A mouse ileal loop assay showed that Sarcocystis sp. in sika deer meat induced significant fluid accumulation in the loop at doses of ∼5 × 106 bradyzoites. Western blotting showed that these Sarcocystis parasites possess actin-depolymerizing factor, a diarrhea-evoking factor, similar to Sarcocystis fayeri, which exists in horsemeat. However, the pathogenic conditions of the ileal loop were different from those of similar experiments with S. fayeri. This study suggests that S. japonica parasitizing C. n. nippon may cause diarrhea via a different mechanism from that of S. fayeri.