The Experts below are selected from a list of 2250 Experts worldwide ranked by ideXlab platform

Takashi Wada - One of the best experts on this subject based on the ideXlab platform.

  • cold tolerance of invasive freshwater snails Pomacea canaliculata p maculata and their hybrids helps explain their different distributions
    Freshwater Biology, 2016
    Co-Authors: Keiichiro Matsukura, Kazuhiro Yoshida, Yohei Izumi, Takashi Wada
    Abstract:

    Summary Pomacea canaliculata and P. maculata are invasive freshwater snails originating from South America. The limits of the distributions of the two snails in East and South-East Asia differ. This study verified a role of cold tolerance in range expansion of the snails and the significance of hybridisation between the two species by comparing overwintering ability and cold tolerance among P. canaliculata, P. maculata and their hybrids. Field observations, laboratory tests and chemical analyses of glucose and glycerol contents in the snails’ organs demonstrated that P. maculata cannot colonise temperate regions because it lacks adequate cold tolerance. The hybrids between P. maculata and P. canaliculata exhibited intermediate cold tolerance that is reflected in their current intermediate distribution between the two species in the invaded areas. This indicates a risk of further spread of the hybrid snails into the temperate regions of the invaded area.

  • linkage of cold hardiness with desiccation tolerance in the invasive freshwater apple snail Pomacea canaliculata caenogastropoda ampullariidae
    Journal of Molluscan Studies, 2011
    Co-Authors: Takashi Wada, Keiichiro Matsukura
    Abstract:

    Linkage between cold hardiness and desiccation tolerance was examined in an invasive freshwater apple snail, Pomacea canaliculata, collected from locations in three different climatic zones. Snails collected from temperate Kyushu, Japan, showed enhanced cold hardiness after cold acclimation, and cold-tolerant snails survived longer after exposure to desiccation than cold-intolerant snails without cold acclimation. Progenies of tropical snails collected from Luzon and Mindanao, the Philippines, which had never experienced cold weather revealed the same response as Japanese snails to cold stress: enhancement of cold hardiness after cold acclimation. Cold-tolerant snails from tropical populations also attained better survivorship under desiccation conditions. Thus, linkage of tolerance between cold weather and desiccation appears to be a general feature of P. canaliculata. Cold hardiness of snails before and after cold acclimation, respectively, did not differ among the three populations from temperate and tropical regions. A trend was found for snails from Mindanao, in the tropical rainforest climatic zone (having a milder dry season), to be less desiccation-tolerant than snails from Kyushu and Luzon, having a colder or more severe dry season.

  • life cycle of the apple snail Pomacea canaliculata caenogastropoda ampullariidae inhabiting japanese paddy fields
    Applied Entomology and Zoology, 2009
    Co-Authors: Kazuhiro Yoshida, Takashi Wada, Kazuo Hoshikawa, Yoichi Yusa
    Abstract:

    The life cycle of the apple snail Pomacea canaliculata was monitored over 2- and 1-year periods in Nara (cold district) and Kumamoto (warm district), respectively. The life cycles were similar in both districts: most hatchlings appeared after August, and although some had grown to ≥20 mm by autumn, the majority of juveniles remained <20 mm. The survival rate over winter was very low (<1%) in Nara, and moderately low (9%) in Kumamoto. After winter, survivors grew rapidly with low mortality, reproduced actively in summer, and most died during the following winter. The survival rate during mid-term drying (drying of fields for about 2 weeks in summer) in Nara was high (ca. 90%) in both years. In Nara, snail density after winter decreased to 1/43 of that in Kumamoto, but survivors in Nara grew larger and laid more eggs. Due to these effects, egg density in July, and also snail density in September, in Nara recovered to ca. 1/3 of that in Kumamoto.

  • physiological response to low temperature in the freshwater apple snail Pomacea canaliculata gastropoda ampullariidae
    The Journal of Experimental Biology, 2009
    Co-Authors: Keiichiro Matsukura, Hisaaki Tsumuki, Yohei Izumi, Takashi Wada
    Abstract:

    SUMMARY Cold hardiness of the freshwater apple snail, Pomacea canaliculata , varies seasonally. We investigated lethal factors and physiological changes arising from exposure of P. canaliculata to low temperatures. Snails did not survive freezing. The supercooling point of cold-acclimated (cold tolerant) snails (–6.6±0.8°C) did not differ significantly from that of non-acclimated ones (–7.1±1.5°C) under laboratory conditions. Furthermore, snails died even under more moderately low temperatures approaching 0°C. These results indicate that indirect chilling injury is a factor in the death of P. canaliculata at low temperatures. Regardless of whether the snails were acclimated to low temperatures, all of the dead, and even some of the snails still alive at 0°C, had injured mantles, indicating that the mantle may be the organ most susceptible to the effects of low temperatures. The concentration of glucose in the posterior chamber of the kidney and concentration of glycerol in the digestive gland were significantly higher in cold-acclimated snails than in non-acclimated ones, suggesting carbohydrate metabolic pathways are altered in snails during cold acclimation.

  • seasonal changes in cold hardiness of the invasive freshwater apple snail Pomacea canaliculata lamarck gastropoda ampullariidae
    Malacologia, 2007
    Co-Authors: Takashi Wada, Keiichiro Matsukura
    Abstract:

    We investigated the cold hardiness of a South American freshwater apple snail, Pomacea canaliculata, which began to invade Japanese paddy fields in the early 1980s. Pomacea canaliculata exhibited apparent seasonal fluctuation in its cold hardiness. Snails collected from submerged paddy fields in summer were less tolerant to cold, and none survived exposure to 0°C for five days. With decreasing temperature, together with drainage of its habitat in autumn, P. canaliculata developed cold hardiness, attaining almost 100% survivorship after exposure to 0°C for five days in December. The snails resting in drained fields were approximately nine times more cold tolerant than those collected from submerged fields, based on the time to 50% mortality at 0°C. Snails overwintering in aquatic conditions also acquired cold hardiness.

Marcos Sebastian Dreon - One of the best experts on this subject based on the ideXlab platform.

  • hemocyanin of the caenogastropod Pomacea canaliculata exhibits evolutionary differences among gastropod clades
    PLOS ONE, 2020
    Co-Authors: Ignacio Rafael Chiumiento, Santiago Ituarte, Jin Sun, Jianwen Qiu, Horacio Heras, Marcos Sebastian Dreon
    Abstract:

    Structural knowledge of gastropod hemocyanins is scarce. To better understand their evolution and diversity we studied the hemocyanin of a caenogastropod, Pomacea canaliculata (PcH). Through a proteomic and genomic approach, we identified 4 PcH subunit isoforms, in contrast with other gastropods that usually have 2 or 3. Each isoform has the typical Keyhole limpet-type hemocyanin architecture, comprising a string of eight globular functional units (FUs). Correspondingly, genes are organized in eight FUs coding regions. All FUs in the 4 genes are encoded by more than one exon, a feature not found in non- caenogastropods. Transmission electron microscopy images of PcH showed a cylindrical structure organized in di, tri and tetra-decamers with an internal collar structure, being the di and tri-decameric cylinders the most abundant ones. PcH is N-glycosylated with high mannose and hybrid-type structures, and complex-type N-linked glycans, with absence of sialic acid. Terminal β-N-GlcNAc residues and nonreducing terminal α-GalNAc are also present. The molecule lacks O-linked glycosylation but presents the T-antigen (Gal-β1,3-GalNAc). Using an anti-PcH polyclonal antibody, no cross-immunoreactivity was observed against other gastropod hemocyanins, highlighting the presence of clade-specific structural differences among gastropod hemocyanins. This is, to the best of our knowledge, the first gene structure study of a Caenogastropoda hemocyanin.

Muhammad Masrur Ma’ruf 2061411035) - One of the best experts on this subject based on the ideXlab platform.

  • Performa reproduksi ikan betok (anabas testudineus) betina dengan pemberian pakan buatan berbahan baku tepung keong mas (Pomacea canaliculata)
    2019
    Co-Authors: Muhammad Masrur Ma’ruf 2061411035)
    Abstract:

    Ikan betok (Anabas testudineus) merupakan salah satu spesies ikan betok yang potensial untuk dibudidayakan. Tujuan penelitian ini untuk mengkaji dan mengevaluasi pengaruh pemberian pakan berbahan baku keong mas (Pomacea canaliculata) terhadap tingkat kematangan gonad. Penelitian dilakukan pada bulan Juli – Agustus 2018. Ikan betok (A. testudineus) berasal dari tangkapan alam di perairan persawahan desa Rias Kecamatan Toboali Kabupaten Bangka Selatan. Ikan vetook yang digunakan sebanyak 150 ekor dengan bobot 2 ± 10 gram. Perlakuan yang diberikan pakan buatan yang berbahan baku keong mas (P. canaliculata) dengan kandungan protein pada pakan 32%, 34%, 36%, 38% dan kontrol menggunakan pakan komersil dengan kandungan protein 31 – 33%. Hasil penelitian menunjukkan nilai Indeks Kematangan Gonad (IKG) dengan bobot gonad pada awal penelitian sebesar 0,5 gram. Setelah dilakukan perlakuan dengan pemberian pakan buatan berbahan baku tepung keong mas (P. canaliculata), hasil uji statistik menunjukkan bahwa kontrol berbeda nyata dengan perlakuan pada pengamatan GSI dengan kisaran nilai 16% ± 0.02 pada perlakuan P.38%, HSI dengan kisaran nilai 8% ± 0.01 pada perlakuan P.38%. Fekunditas ikan betok (A. testudineus) yang didapatkan pada hasil penelitian dengan kisaran 509 – 4.686 butir. Perkembangan tingkat kematangan gonad (TKG) awal penelitian (TKG II) setelah diberi pakan buatan berbahan baku keong mas (P. canaliculata) meningkat dengan tingkat kematangan gonad mencapai tahap I

Yoichi Yusa - One of the best experts on this subject based on the ideXlab platform.

  • predator driven biotic resistance and propagule pressure regulate the invasive apple snail Pomacea canaliculata in japan
    Biological Invasions, 2012
    Co-Authors: Yoko Yamanishi, Kazuhiro Yoshida, Noriomi Fujimori, Yoichi Yusa
    Abstract:

    Species richness in local communities has been considered an important factor determining the success of invasion by exotic species (the biotic resistance hypothesis). However, the detailed mechanisms, especially the role of predator communities, are not well understood. We studied biotic resistance to an invasive freshwater snail, Pomacea canaliculata, at 31 sites in an urban river basin (the Yamatogawa) in western Japan. First, we studied the relationship between the richness of local animal species and the abundance of P. canaliculata, demonstrating a negative relationship, which suggests that the intensity of biotic resistance regulates local snail populations. This pattern was due to the richness of native predator communities rather than that of introduced species or non-predators (mainly competitors of the apple snail). Local snail abundance was also affected by immigration of snails from nearby rice fields (i.e. propagule pressure), where few predators occur. Second, we assessed short-term predation pressure on the snail by means of a tethering experiment. Predation pressure was positively correlated with the number of individual predators and negatively correlated with snail abundance. The introduced crayfish Procambarus clarkii was responsible for the variance in predation pressure. These results indicate that the predator community, composed of both native and introduced species, is responsible for resistance to a novel invader even in a polluted urban river.

  • life cycle of the apple snail Pomacea canaliculata caenogastropoda ampullariidae inhabiting japanese paddy fields
    Applied Entomology and Zoology, 2009
    Co-Authors: Kazuhiro Yoshida, Takashi Wada, Kazuo Hoshikawa, Yoichi Yusa
    Abstract:

    The life cycle of the apple snail Pomacea canaliculata was monitored over 2- and 1-year periods in Nara (cold district) and Kumamoto (warm district), respectively. The life cycles were similar in both districts: most hatchlings appeared after August, and although some had grown to ≥20 mm by autumn, the majority of juveniles remained <20 mm. The survival rate over winter was very low (<1%) in Nara, and moderately low (9%) in Kumamoto. After winter, survivors grew rapidly with low mortality, reproduced actively in summer, and most died during the following winter. The survival rate during mid-term drying (drying of fields for about 2 weeks in summer) in Nara was high (ca. 90%) in both years. In Nara, snail density after winter decreased to 1/43 of that in Kumamoto, but survivors in Nara grew larger and laid more eggs. Due to these effects, egg density in July, and also snail density in September, in Nara recovered to ca. 1/3 of that in Kumamoto.

  • a water borne sex pheromone and trail following in the apple snail Pomacea canaliculata
    Journal of Molluscan Studies, 2007
    Co-Authors: Mari Takeichi, Yoshio Hirai, Yoichi Yusa
    Abstract:

    We investigated whether individuals of the apple snail Pomacea canaliculata were attracted by conspecifics or follow mucus trails of other individuals. The snails’ behaviour was studied by a series of choice experiments in a T-maze and in Petri dishes. Both males and females chose the side with a snail of the opposite sex significantly more frequently than the control side without a snail. Males were attracted by water conditioned with females more frequently than unconditioned water, whereas females did not show a preference for male-conditioned water. Moreover, juveniles were not attracted by water conditioned with a male, a female and a juvenile. These data indicate that males were attracted by female odour, which contains one or more water-borne sex pheromones. In addition, both males and females follow mucus trails of snails of the opposite sex. Since females also followed trails of females, the function of trail following is not necessarily related to reproduction. In these experiments P. canaliculata did not distinguish the direction of the trail.

  • nuclear sex determining genes cause large sex ratio variation in the apple snail Pomacea canaliculata
    Genetics, 2007
    Co-Authors: Yoichi Yusa
    Abstract:

    Evolutionary maintenance of genetic sex-ratio variation is enigmatic since genes for biased sex ratios are disadvantageous in finite populations (the “Verner effect”). However, such variation could be maintained if a small number of nuclear sex-determining genes were responsible, although this has not been fully demonstrated experimentally. Brood sex ratios of the freshwater snail Pomacea canaliculata are highly variable among parents, but population sex ratios are near unity. In this study, the effect of each parent on the brood sex ratio was investigated by exchanging partners among mating pairs. There were positive correlations between sex ratios of half-sib broods of the common mother (r = 0.42) or of the common father (r = 0.47). Moreover, the correlation between full-sib broods was very high (r = 0.92). Thus, both parents contributed equally to the sex-ratio variation, which indicates that nuclear genes are involved and their effects are additive. Since the half-sib correlations were much stronger than the parent–offspring regressions previously obtained, the variation was caused by zygotic sex-determining genes rather than by parental sex-ratio genes. The number of relevant genes appears to be small.

  • effects of dormant duration body size self burial and water condition on the long term survival of the apple snail Pomacea canaliculata gastropoda ampullariidae
    Applied Entomology and Zoology, 2006
    Co-Authors: Yoichi Yusa, Takashi Wada, Satoshi Takahashi
    Abstract:

    We investigated factors influencing the survival of the apple snail, Pomacea canaliculata during dormancy in the laboratory at 20–26°C. We placed snails of three size classes in small pots with soil and water, drained the water to induce self-burial, and subsequently checked the snails' survival at intervals. The duration of the dormant period, body size and the success of self-burial all affected the survival of the snails. The effects of water conditions (dry or moist) affected the survival of the snails through interactions with body size and duration. The longest duration of survival under dry conditions was 11 months, and a small proportion of medium-sized and large snails survived the entire experimental period of 29 months under moist conditions.

Ma'ruf, Muhammad Masrur - One of the best experts on this subject based on the ideXlab platform.

  • PERFORMA REPRODUKSI IKAN BETOK (Anabas testudineus) BETINA DENGAN PEMBERIAN PAKAN BUATAN BERBAHAN BAKU TEPUNG KEONG MAS (Pomacea canaliculata)
    'Universitas Mataram', 2019
    Co-Authors: Ma'ruf, Muhammad Masrur
    Abstract:

    Abstract: Climbing perch (Anabas testudineus) is one of the potential local fish species to be cultivated. The purpose of this study was to learn and evaluate the effect of feeding made from golden snail (Pomacea canaliculata) on the level of gonad maturity. The study was conducted in July - August 2018. The climbing perch (A. testudineus) originated from natural catchments in the rice fields of Rias village, Toboali Subdistrict, South Bangka Regency. The used fish are 150 fish with a weight of 2 ± 10 grams. The treatment given by artificial feed made from golden snail (P. canaliculata) with protein content in feed was 32%, 34%, 36%, 38% and control using commercial feed with a protein content of 31 - 33%. The results showed the value of the Gonad Maturity Index (IKG) with gonad weight at the start of the study at 0.5 gram. After treatment with artificial feed made from golden snail (P. canaliculata) flour, the results of statistical tests showed that the control was significantly different from the treatment in the GSI observation with a range of values ​​of 16% ± 0.02 in treatment P.38%, HSI with a value of 8% ± 0.01 in treatment P.38%. Fecundity of climbing perch (A. testudineus) obtained in the results of the study with a range of 509 ± 4,686 items. The development of the initial gonad maturity (TKG) of the study (TKG II) after being given artificial feed made from golden snails (P. canaliculata) increased with the level of gonad  maturity reaching stage IV. Keywords: Anabas testudineus, Pomacea canaliculata,  gonad maturity, IKG, fecundity, TKG.Abstrak: Ikan betok (Anabas testudineus) merupakan salah satu spesies ikan lokal yang potensial untuk dibudidayakan. Tujuan penelitian ini untuk mengkaji dan mengevaluasi pengaruh pemberian pakan berbahan baku keong mas (Pomacea canaliculata) terhadap tingkat kematangan gonad. Penelitian dilakukan pada bulan Juli – Agustus 2018. Ikan betok (A. testudineus) berasal dari tangkapan alam di perairan persawahan desa Rias Kecamatan Toboali Kabupaten Bangka Selatan. Ikan betok yang digunakan sebanyak 150 ekor dengan bobot 2 ± 10 gram. Perlakuan yang diberikan pakan buatan yang berbahan baku keong mas (P. canaliculata) dengan kandungan protein pada pakan 32%, 34%, 36%, 38% dan kontrol menggunakan pakan komersil dengan kandungan protein 31 – 33%. Hasil penelitian menunjukkan nilai Indeks Kematangan Gonad (IKG) dengan bobot gonad pada awal penelitian sebesar 0,5 gram. Setelah dilakukan perlakuan dengan pemberian pakan buatan berbahan baku tepung keong mas (P. canaliculata), hasil uji statistik menunjukkan bawa kontrol berbeda nyata dengan perlakuan pada pengamatan GSI dengan kisaran nilai 16% ± 0.02 pada perlakuan P.38%, HSI dengan kisaran nilai 8% ± 0.01 pada perlakuan P.38%. Fekunditas ikan betok (A. testudineus) yang didapatkan pada hasil penelitian dengan kisaran 509 - 4.686 butir. Perkembangan tingkat kematangan gonad (TKG) awal penelitian (TKG II) setelah diberi pakan buatan berbahan baku keong mas (P. canaliculata) meningkat dengan tingkat kematangan gonad mencapai tahap IV. Kata Kunci : Ikan betok, keong mas, pematangan gonad, IKG, fekunditas, TKG