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An investigation into the morphological and behavioral adaptations of the aquatic larvae of Aquatica leii (Coleoptera: Lampyridae) to prey upon freshwater snails that serve as intermediate hosts for the liver fluke
... Liver flukes can cause huge losses to livestock industries and affect the health of humans where fascioliasis is an important human disease (Walker et al., 2011 andFürst et al., 2012). In their general distributio n, freshwater pulmonate snails are benthic anima ls living in the shallower water of lakes, ponds, marches, rivers, streams and ditches (Rondelaud et al., 2011 andFu &Meyer-Rochow, 2012). Snail control strategies are considered a priority for the reduction of transmission. ...
... Liver flukes can cause huge losses to livestock industries and affect the health of humans where fascioliasis is an important human disease (Walker et al., 2011 andFürst et al., 2012). In their general distributio n, freshwater pulmonate snails are benthic anima ls living in the shallower water of lakes, ponds, marches, rivers, streams and ditches (Rondelaud et al., 2011 andFu &Meyer-Rochow, 2012). Snail control strategies are considered a priority for the reduction of transmission. ...
The water bug Sphaerodema urinator Duforas (Hemiptera: Belostomatidae), inhabits lakes, ponds, marches and rice fields, was found to predate on a wide range of other aquatic organisms like insects and snails. To evaluate the predatory potential on the Fasciola intermediate host, Lymnaea natalensis Krauss snail, laboratory studies involved searching; encounter, consumption and prey preference were achieved. Obtained results indicated that the searching time of the predator ranged between 3.4±0.5 to 7.8±0.9 min and handling time ranged between 18.8±1.01 to 25±1.0 min, depending on the snail size and the predator vulnerability. The adult water bug could kill and consume small-, medium-and large-sized snails. Number of snails consumed/ day differed according to their size and density. Preference experiments showed that the adult predator prefers small size snails than medium or large ones. This study suggested that the predator , S. urinator may be potentially suitable as a bio-control agent against Fasciola intermediate host, L. natalensis.
... In 2006 over 3000 hectares of corn were damaged by it in Qi County, Kaifeng City, Henan Province alone (Wang, 2008;Liu and Wu, 2011). Fu and Meyer-Rochow (2012) emphasized that larval aquatic fireflies have the potential of serving as biological control agents in the fight against disease transmitting freshwater snails. Therefore, it is now relevant to investigate if terrestrial snail-consuming firefly larvae might not also be usable in controlling pest land snails. ...
... Although using firefly larvae for the biological control of land snails is not a new idea, e.g., L. noctiluca L. was earlier imported to New Zealand from the U.K. for the biological control of Helix aspersa Mull. (Clausen, 1940), this measure has not received widespread recognition and acceptance. Releasing larval fireflies into greenhouses and gardens to control snails remains an alternative to more conventional control methods; besides it has the potential of attracting people to watch fireflies and their bioluminescent displays and could thus become a sightseeing attraction. ...
... Another concern is food safety. Snails often function as intermediate hosts to a variety of parasites harmful to humans and animals [31]. To cite an example, Angiostrongylus cantonensis is a parasitic nematode for which P. canaliculata could be a suitable host [32]. ...
... Macedo et al. [5] compared the elevational ranges of seven families of beetles in Brazil, and fireflies were found to be the most specialised among groups of beetles, i.e., highly specialised in lower or upper elevational zones. Aside from the temperature, these restricted distributions across elevations could be explained by the fireflies requiring obligate prey at the larval stage and specific microhabitat requirements at different stages of their lifecycles [23,38,64,65]. ...
Studies of the effects of elevation and associated habitat changes on biodiversity have a rich history in conservation biology and have seen a resurgence of interest in recent decades. Mountainous regions are particularly important because they harbour endemic species and are relatively spared from anthropogenic effects. The rather drastic temperature decrease as elevation increases in tropical regions has generated more research on the effects of elevation, especially since global warming could negatively impact the biodiversity of tropical forest mountainous species. Fireflies, especially the solitary species, represent a challenge to work with because though they are biologically diverse, they typically occur at low densities and have rarely been studied across elevations. Many are habitat specialists and have limited dispersal abilities. Firefly diversity changes on five mountains located on the main mountain range of Peninsular Malaysia, which is highly representative of five major elevational forest types, were assessed. Fireflies were restricted to a certain eleva-tional range of mountains, and the turnover of species was significant among forest types across elevations. The forest type and canopy closure were the main characteristics affecting species diversity , although other habitat characteristics may be significant. The ability to reveal any possible associations was limited, as strong statistical associations were not possible due to their low abundance and difficulty in detecting their presence. The firefly species occurrence across elevations is restricted, and habitat loss could pose a risk to lower-elevation species, while global warming could be a threat to high-elevation species.
... On the other hand, A. helena significantly preferred the operculate snail F. bengalensis and non-operculate snail R. luteola and did not show any significant prey preference towards invasive P. acuta. As the native predators avoid the native operculate prey snails both in the Indian context (Aditya & Raut, 2005) and as observed in other regions of the world (Reyes et al., 1970;Fu & Meyer-Rochow, 2012), the probable invasion of the exotic predator, A. helena, may impart negative impacts on the abundance of the operculate snail, F. bengalensis due to significantly higher preference. Unlike the native predators, A. helena did not significantly prefer the invasive snail P. acuta which may facilitate further establishment of P. acuta in the newer habitats by preferring another competing native snail, R. luteola, following the chance dispersal of the exotic predator. ...
The ornamental pet trade is a biologically diverse multi-billion-dollar industry that transports various exotic pets worldwide. Among aquarium pets, Anentome helena is a carnivorous snail sold widely for its high aesthetic value and aquarium pest snail control ability. The present study documents the differences in prey consumption, selectivity, and predation-derived potential impacts of the exotic predator, A. helena, and native predators, the leech Glossiphonia weberi and the waterbug Diplonychus rusticus, on selected native and invasive snails of West Bengal, India, through laboratory-based prey-choice experiments. Maximum prey consumption was observed in case of D. rusticus, but A. helena consumed a significantly (p < 0.05) higher number of operculate snails. Both native predators preferred non-operculate snails, Racesina luteola and Physella acuta, whereas A. helena preferred R. luteola and an operculate snail, Filopaludina bengalensis, as prey. Proximately, P. acuta faced more apparent competition from other prey snails following the predation of native predators. However, F. bengalensis might face higher apparent competition following the predation of A. helena. Considering the differential predation pattern and higher vulnerability of operculate snails from A. helena predation, awareness should be raised among aquarium enthusiasts to reduce the risk of chance dispersal of such exotic predators.
... Fireflies are not pests, they do not damage padi crops or parasitise little shrimps, in fact fireflies control pests (Fu & Meyer-Rochow, 2012) like snails in a padi field. The firefly larvae help keep in check the invertebrates population in the mangrove ecosystem. ...
... Another concern is food safety. Snails often function as intermediate hosts to a variety of parasites harmful to humans and animals [31]. To cite an example, Angiostrongylus cantonensis is a parasitic nematode for which P. canaliculata could be a suitable host [32]. ...
In the present paper, we describe the farming system of Pomacea canaliculata, an edible freshwater snail, as it is practiced by a farmer as mini-livestock in the vicinity of Andong in Korea. We visited the snail farm several times in the summer and winter of the year and conducted interviews with the farm manager using a semi-structured questionnaire. The farm is housed in polythene tunnels and uses a tank pen of trench type made up of propylene and measuring 1 m × 2 m × 0.5 m (length × width × height) in size. A regulated inflow of fresh water and outflow of used water was installed, with water level not exceeding 5 to 7 cm. As feed of snails, commercial fish feed is generally provided. The life cycle of the P. canaliculata might differ in captivity under the controlled environmental conditions than that of an individual in the wild environment. The farming system of snails, particularly P. canaliculata, does not involve high labor-intensive, high capital investment and also does not require high through-put cutting edge technology. In addition to providing nutrient-dense snail meat, establishing a snailery could therefore augment the economic condition of farmers in the poorer regions of the world and encourage sustainability and biodiversity conservation.
... Our findings also indicate that the forest floor is an important space for the growing larva. Larval stage is when they are hunting for food such as snails or slugs on the ground and mould into several instar stages (Fu & Meyer-Rochow, 2012Liew & Schilthuizen, 2014;Madruga Rios & Hernández Quinta, 2010). Fireflies spend a good amount of time in larval form before becoming adults. ...
A survey on solitary fireflies was carried out at Kangkawat Research Station in October 2018. A total of 33 fireflies were collected; three adult males, 13 adult females and 17 larvae. Three fireflies species were identified from male specimens, namely Pygoluciola wittmeri, Luciola sp. and most larvae consists of Pyrocoelia sp. This is a new record, mapping the existence of the species in Imbak, hence expanding the geographical knowledge of Pygoluciola, Luciola and Pyrocoelia. There are five morphospecies of unidentified females and three morphospecies of larvae. Three videos of larvae showed an emission of a long glow while the adult female in captivity exhibited single-peaked pulsing light. Male flashes were observed to emit long glows with intermittent rest. Most adult fireflies were caught flying between trees while larvae were found among twigs, leaf litter and leaves.
... The species is very sensitive to water quality and pollution and is considered endangered, with populations known to be in decline [1]. The larvae of A. leii live in standing and clean water and feed on freshwater snails, a feature potentially useful in the biological control of various parasites that use freshwater snails as intermediate hosts [2]. Light organ sexual dimorphism is distinct, with two ventral segments (six and seven) in males but only one ventral segment (six) in females. ...
Aquatica leii Fu and Ballantyne is a species of rare aquatic firefly and endemic in China. It is considered good material to study the molecular mechanism of sexual flash communication systems. To improve conservation and behavioral research strategies, large-scale genetic studies involving gene-expression analysis are required and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is the most commonly used method. However, there have been very few reports on appropriate reference genes in any species of firefly. Here, we evaluated eight widely utilized reference genes including 18S, Actin, Reep5, Odc1, Tub, Gapdh, Ef1a and S27Ae for their expression stabilities in A. leii under three different conditions, i.e., life stage, tissue and dsRNA injection. Based on the gene stability ranking calculated by RefFinder, which integrates four algorithms (geNorm, delta Ct method, NormFinder, and BestKeeper), we recommend S27Ae and Reep5 as the most appropriate reference genes for molecular studies in different life stages; Ef1a and Odc1 for different tissues; Tub and Odc1 for RNAi studies. The most appropriate reference genes in all treatments are S27Ae and Tub. The results of this study will help improve accuracy and reliability to normalize RT-qPCR data in A. leii for further molecular analysis.
... The mandibular channel of lampyrids is closed, internal and forms already during the embryonic stage (Cicero, 1994). All mentioned adephagan and polyphagan groups perform extra-oral digestion of the prey tissues by injecting histolytic substances through the mandibular channel, and subsequently sucking the predigested liquids (Haddon, 1915;De Marzo, 1979;Fu & Meyer-Rochow, 2012), i.e. the same way as in the Hydrophilidae. The structural similarities of these feeding systems are convergences gained as adaptations to an aquatic (submerged) lifestyle. ...
Larvae of water scavenger beetles (Coleoptera: Hydrophiloidea) are adapted to a wide variety of aquatic habitats, but little is known about functional and evolutionary aspects of these adaptations. We review the functional morphology and evolution of feeding strategies of larvae of the families Hydrophilidae and Epimetopidae based on a detailed scanning electron microscope (SEM) analysis, analysis of video records of feeding behaviour and observations of living larvae. There are two main types of feeding mechanisms: chewing and piercing-sucking. The character mapping using the latest phylogenetic hypothesis for Hydrophiloidea infers the chewing system as the ancestral condition. The piercing-sucking mechanism evolved at least four times independently: once in Epimetopidae (Epimetopus) and three times in Hydrophilidae (Berosini: Berosus + Hemiosus; Laccobiini: Laccobius group; Hydrobiusini: Hybogralius). The piercing-sucking apparatus allows underwater extra-oral digestion and decreases the dependence of larvae on an aerial environment. A detailed study of the tracheal morphology of the piercing-sucking lineages reveals four independent origins of the apneustic respiratory system, all of them nested within lineages with piercing-sucking mouthparts. We conclude that piercing-sucking mouthparts represent a key innovation, which allows for the subsequent adaptation of the tracheal system, influences the diversification dynamics of the lineages and allows the shift to new adaptive zones.
... Aquatica leii belongs to the order Coleoptera, family Lampyridae, subfamily Luciolinae, genus Aquatica (Fu and Meyer-Rochow, 2012;Jiao et al., 2013) and is mainly distributed in the middle and lower reaches of the Yangtze River in mainland China. A. leii is the most widely studied aquatic firefly species. ...
Aquatic fireflies are important indicators of the quality of freshwater environments and key models for research on insect adaptation to freshwater environments. For these investigations, gene expression analyses using quantitative real-time PCR are heavily dependent on reliable reference genes. In this study, based on a transcriptome assembly and annotation for the aquatic firefly Aquatica leii at the adult and larval stages, 10 candidate reference genes (α-tubulin, β-tubulin, β-actin, EF1A, SDHA, UBQ, GST, GAPDH, RPS31, and RPL13A) were identified for analyses of expression stability. Quantitative real-time PCR analyses for each candidate reference genes in A. leii was conducted for four developmental stages, four adult tissue types, two adult sexes, and two ecological stressors [adults exposed to five temperatures and larvae exposed to four concentrations of benzo(a)pyrene]. Results were evaluated by three independent algorithms (geNorm, NormFinder, and BestKeeper) and one comparative algorithm (RefFinder). The expression stability of candidate reference genes in A. leii differed under various conditions. Reference genes with the most stable expressions levels in different tissues, temperatures, sexes, developmental stages, and concentrations of benzo(a)pyrene were α-tubulin, GST, β-actin, β-tubulin, and α-tubulin, respectively. Furthermore, the optimal normalization factors (NFs) for the quantification of the expression levels of target genes by quantitative real-time PCR analyses of A. leii were identified for each experimental group. In particular, NF = 2 for different tissues (α-tubulin + β-tubulin), different sexes (β-actin + EF1A), and larvae exposed to different concentrations of benzo(a)pyrene (α-tubulin + EF1A); NF = 3 for developmental stages (GST + GAPDH + SDHA) and adults exposed to different temperatures (β-tubulin + EFA + GST). In addition, we surveyed the expression profiles of two target genes (CYP3A and CSP8) in larvae exposed to different concentrations of benzo(a)pyrene and in different adult tissues. The results further validated the reliability of the reference genes. The optimal reference genes for various experimental conditions identified in these analyses provide a useful tool for ecological studies of aquatic fireflies.
... Dalu et al. 10 also found that Diptera were very tolerant to pollution and normally dominated in polluted areas. Some of the taxa that were positively correlated with the pollution level in the water column were air-breathing organisms, e.g. the large freshwater snails Radix balthica and Lymnaea palustris from the family Lymnaeidae, which is aquatic pulmonate gastropod 22 , as well as the backswimmer Notonecta glauca and the beetle Helophorus sp. The fact that these taxa are air-breathing may explain their positive correlation with the pollution in the water column. ...
Constructed stormwater ponds mitigate runoff volumes and pollution, and provide other ecosystem services, such as supporting biodiversity, but these services attracted relatively less attention. The impacts of the pollution levels in the water column and sediments, the physical characteristics of ponds, and the presence of amphibians on the macroinvertebrate community composition and biodiversity were explored in twelve stormwater ponds in Norway. Also, the similarities between macroinvertebrate, zooplankton and plant communities were explored. Most of the taxa displayed in the ordination diagram were positively correlated with the pond size and the number of neighbouring ponds, and negatively correlated with the pollution levels in the water column and sediments. However, no statistically significant impacts on the number of taxa and Shannon index were observed. There were low similarities between the macroinvertebrate and zooplankton community compositions as well as between the plant and macroinvertebrate community compositions in the stormwater ponds. We observed a significant positive correlation between the number of plant and of zooplankton taxa, and a weak non-significant positive correlation between the number of plant and of macroinvertebrate taxa. Overall, the explanatory variables had a significant impact on the community composition, but not on the number of taxa nor Shannon index.
... Hofkin et al. [12] have tried Crayfish (Procrambrus Clarkii) to overcome the schistosome-transmitting snails in the laboratory and temporary man-made ponds in Kenya with encouraging results. In addition to that, the German scientists Xinhua and Meyer-Rochow [17] have also investigated the morphological and behavioral adaptation of the aquatic larvae of Aquatica lei (Colepotera; Lampridae) to prey upon fresh water snails that serve as intermediate host for liver fluke. They have carried out the series of laboratory based predation experiment and found the larvae of Aquatica lei (Colepotera; Lampridae) revealed well developed pygypodia and specialized mouth parts to attack and overpower the water snails while they have wide dietary spectrum and can also feed on dead snails with similar feeding pattern of nymphs of dragonflies as reported in the present experiment. ...
The predatory potential of dragonfly nymphs was studied on water snails (Indoplanorbis exustus and Lymnaea luteola) and their larval stages under laboratory conditions. The water snails (snail's cocoons, young snails and adult snails etc.) and dragonfly nymphs were collected from stagnant water resources of protected areas and brought to laboratory, maintained with aquatic weeds and mulberry leaves in the artificial cement tank. The collected water bodies were used in the requisite quantity in glass containers of 6 litre water capacity each with snails, aquatic weeds and dragonfly nymphs for trial groups while the container of control group was kept without dragonfly nymphs. Observation recorded from 0, 3, 6, 12, 24, 48, 72 and 96 hrs of nymphs entry while feeding activity of nymphs was judged by counting the remaining numbers of snails and their larval stages in the different containers. The pond water quality analysis was envisaged, average dissolve oxygen (DO-0.4-0.7 ppm), hydrogen ion concentration (pH-6.7-8.7) and total dissolve solids (TDS-71-84 ppm) during the entire period of experiment. Remarkable reduction (82-97 %) in the cocoons and young snail population were noticed whereas 18-40% mortality have also encountered in the snails of control group. The predacious nature and potentials of the dragonfly nymphs may be promoted as one of the appropriate biological control agent to overcome the snail borne parasitic diseases.
... have been a few studies on the potential for using predatory flies (74) [Berkenhout]) will feed on snails and may play a role in reducing snail densities in natural areas (76,77). Furthermore, it appears that over time, apple snails have accumulated natural enemies in Japan as local wildlife adapted to feed on and consume the snails. ...
Apple snails (Ampulariidae) occur throughout tropical and subtropical rice-growing regions. Native apple snails rarely damage rice; however, in hot and humid tropical regions, some native species will damage wet-direct-seeded rice (i.e., Pomacea spp. in Suriname and Brazil). Similarly, exotic apple snails in wet, temperate regions can damage direct-seeded rice (i.e., Pomacea canaliculata in Japan). However, if left unmanaged, exotic apple snails in warm tropical regions (i.e., P. canaliculata and P. maculata in South East Asia) can cause significant economic losses even to transplanted rice (which is more robust that direct-seeded rice). The negative impact of apple snails on rice yield can be reduced by reducing seedling vulnerability or controlling snail population densities. Reducing vulnerability is a more sustainable solution to apple snails but requires new methods such as seedling broadcasting and machine transplanting to decrease labor costs. To avoid further spread of apple snails, the implementation of effective quarantine directives is recommended for tropical countries that are vulnerable to exotic apple snails.
... In general, the aquatic snail hosts of Schistosoma occur in shallow water near the shores of lakes, ponds, marshes, streams, and irrigation channels. They live on water plants and mud that is rich in decaying organic matter (Rondelaud et al. 2011;Fu and Meyer-Rochow 2012). Schistosomiasis is one of the most widespread of all human parasitic diseases, ranking second only to malaria in terms of its socioeconomic and public health importance in tropical and subtropical areas. ...
The water bug, Sphaerodema urinator (Hemiptera : Belostomatidae), shares the same habitat of the freshwater snails in ponds, lakes, and streams. Studies conducted in lakes show that fish and crayfish predators play an important role in determining the abundance of freshwater snails. In contrast, shallow ponds and marches often lack fish and crayfish but have abundant insect predators. This study has been carried out to evaluate the predatory potential of S. urinator adult on two freshwater snails that serves as intermediate hosts of Schistosoma. Laboratory evaluation of predation by S. urinator on these intermediate hosts revealed that the adult bug could kill and consume the two intermediate hosts: Bulinus truncatus and Biomphalaria alexandrina. The number of snails consumed differed according to the snail type, size, and density. The times taken for searching and handling times were depending on the snail size, type, and vulnerability of the predator. The predation rate varied also with respect to snail type and density. Prey size is a major factor influencing predator preferences. This study indicated that the predator, S. urinator, may be a suitable bio-control agent in connection with Schistosoma intermediate hosts in the aquatic area.
... Liver flukes can cause huge losses to livestock industries and affect the health of humans where fascioliasis is an important human disease [4][5][6] . In their general distribution, freshwater pulmonate snails are benthic animals living in the shallower water of lakes, ponds, marshes, rivers, streams and ditches [7,8]. Snail control strategies are considered a priority for the reduction of transmission. ...
Objective: To evaluate the predatory capacity of the Odonata, Hemianax ephippiger nymph as a biocontrol agent for the freshwater snail Lymnaea natalensis, intermediate host of Fasciola gigantica.
Methods: Observations on the searching, attacking and devouring of the snails with a series of laboratory-based predation experiments, whose aims were to determine daily predation rate, differential predation on small-, medium- and large-sized snails were carried out.
Results: Laboratory evaluation revealed that, the Odonata nymph could kill and consume all three sizes of snails. Searching and handling time of the predator differed depending on snail size and predator vulnerability. The predation rate varied also with respect to snail size and density.
Conclusions: Our observations suggested that the predator Hemianax ephippiger may be a suitable bio-control agent of Lymnaea natalensis snail population.
The current study investigates the predatory relationship between the firefly larvae (Aspisoma ignitum) and the giant African snail (Achatina fulica). The principal objective of this study was to examine the specific predator responsiveness of the firefly larvae against the giant African snails under experimental conditions. This was evaluated using two (2) treatments T1 and T2. T1 investigated giant African snail neonates of size 0.5 cm with a larva to snail ratio of 1:5. In T2, larvae to snail ratio of 3:1 was investigated using 2 cm giant African snail neonates. Control treatments were included in the experimental design with the absence of the larvae. Each treatment was replicated five (5) times. There were 100 % mortality effects for T1 and T2. Commonalities existed in both the spatial and the temporal characteristics to possibly consider the firefly larvae as an idealistic and highly compatible predator for the giant African snail neonates. Ecological engineering strategies to encourage the presence of the firefly will aid in suppressing the giant African snail population. The study concludes that the firefly larvae can be a possible predator for the control of the giant African snail once the firefly populations are encouraged in both crop and non-crop spaces.
Background
Fireflies (Coleoptera: Lampyridae) are commonly recognized by adult traits, such as a soft exoskeleton, lanterns and associated glow and flash patterns, but their larval stage is far less appreciated. However, fireflies spend most of their lives as larvae, and adults of most species rely solely on resources previously obtained. Therefore, studying the immature stages is imperative towards a comprehensive understanding of fireflies. This paper reviews and indicates key gaps in the biology of firefly larvae based on available literature.
Methodology
We reviewed the literature on firefly larvae to identify key issues and important taxonomic, geographic, and subject biases and gaps.
Results
We found 376 papers that included information on firefly larvae. Only 139 species in 47 genera across eight of eleven lampyrid subfamilies have been studied during larval stages. These numbers reveal a staggering gap, since 94% of species and over half of the genera of fireflies were never studied in a crucial stage of their life cycle. Most studies on firefly larvae focus on two subfamilies (Luciolinae and Lampyrinae) in four zoogeographic regions (Sino-Japanese, Oriental, Nearctic, and Palearctic), whereas the other subfamilies and regions remain largely unstudied. These studies mainly dealt with morphology and behavior, other subjects remaining greatly understudied by comparison, including habitats, life cycle, physiology and interactions.
Conclusions
Together, these literature biases and gaps highlight how little is known about firefly larvae, and warmly invite basic and applied research, in the field and in the lab, to overcome these limitations and improve our understanding of firefly biology to better preserve them.
Freshwater gastropods comprise a diverse and highly imperiled taxonomic group that is threatened by anthropogenic factors including the introduction of nonnative species. We surveyed 10 wetland ponds in Turnbull National Wildlife Refuge to assess the possible expansion of the nonnative European ear snail (Radix auricularia) and to determine the genus richness and relative abundance of native gastropods. D-frame dip nets were used to sample gastropods at 4 locations in each pond. Six genera of gastropods were found, including R. auricularia in 6 ponds where it was not previously known. Radix auricularia is now the dominant genus in Middle Pine and Lower Pine Lakes, with relative abundances of 84.13% and 92.31%, respectively. Due to the high abundance and spread of R. auricularia in Turnbull National Wildlife Refuge, resource managers need to investigate the snail's impacts and implement strategies to reduce possible negative effects of this nonnative snail on native gastropods and other wildlife.
The first record of the little native limnic/ freshwater mussel/ naiad Rhipidodonta rhombea (Wagner, 1827) in the Santa Catarina State/ SC territory is available ...
The occurrence of the asiatic golden mussel Limnoperna fortunei (Dunker, 1857), only freshwater/ limnic representative known of the family Mytilidae (an invasive introduced species), was confirmed for first time in Santa Catarina’s State/ SC and the system of the Upper Uruguay River Basin, central southern Brazil, in 2012 (see pp. 33-35) ...
This book, which contains 15 chapters, draws together the available information on the diversity of organisms that constitute the natural enemies of terrestrial gastropods. In a series of review chapters, it provides an authoritative synthesis of current knowledge and research for predators, parasites and pathogens. This book is for both students and professionals concerned with the conservation of gastropod communities in natural habitats and management of pestiferous species.
The aquatic larvae of the firefly Luciola leii Fu and Ballantyne occur on the substrate of rice fields and ditches in Hubei Province of central China. The behaviour and ecology of L. leii are described. We recorded L. leii larvae attacking four species of aquatic snails: Lymnaea stagnalis (L.) (Basommatophora: Lymnaeidae), Gyraulus convexiusculus (Hutton) (Basommatophora: Planorbidae), Radix auricularia (L.) (Lymnaeidae), and Bellamya purificata Heude (Mesogastropoda: Viviparidae). At dusk, flying males produced two types of advertising flashes. One type consisted of a train of 8 rapid, green flashes followed by 2–3 slow, prolonged flashes produced by patrolling males as a long-distance signal. The duration of flashes in the patrolling pattern was 530 ms and the interflash interval was 80 ms. The other type was a short-range signal consisting of a green glow, which was emitted by flying males that had located a female. Once a female had been located, the male landed and switched to a courting pattern. The male courtship pattern consisted of single flashes of about 400 ms duration, delivered every 1.8 s. Females produced single answering flashes of 910 ms duration, with a latency of approximately 630 ms after the male flash. Luciola leii was univoltine. Females oviposited 1 to 7 times (mean = 4.78). Females laid, on average, 187.19 eggs. The eggs hatched at 21.52 days. Eggs became luminescent 4 or 5 days before hatching. The larval stage had six instars. Mature larvae climbed onto land to construct pupal cells at the end of April of the next year. The pupal stage lasted, on average, 4.88 days. The imago lasted 10.13 days. No predators of larvae were observed. The spider Tetragnatha praedonia Koch (Araneae: Tetragnathidae) was frequently observed to capture adult male fireflies in its web.
Aquatica, a new genus of aquatic fireflies from mainland China, is described and keyed from males of A. leii (Fu et
Ballantyne 2006), A. ficta (Olivier 1909), A. hydrophila (Jeng et al. 2003) and A. lateralis (Motsch. 1860), all transferred
from Luciola, and A. wuhana sp. n. from Hubei Province, which is described from adult males and females and larvae.
Adult females and larvae are associated for all species. Five species of aquatic fireflies are now recorded from China.
Male adults of the firefly Pyrocoelia pectoralis discharge fluids from along elytral and pronotal margins and around the antennal sockets, but females when tactually stimulated only discharge fluids from pronotal margins and antennal sockets. Both genders, when disturbed, may also occasionally discharge fluid from the anus. With regard to its content of haemocytes and proteins, the discharged fluid conforms to haemolymph. A series of circular, but irregularly spaced depressions in the insect's cuticle along the pronotal and elytral margins seems to be related to the ‘reflex-bleeding’ response. Each depression features a centrally-placed columnar structure, which is connected to its surroundings by a thin membrane that easily ruptures and, once broken, initiates reflex-bleeding. The whitish and viscous blood oozing out is very effective in repelling ants. Reflex-bleeding in the adults of Pyrocoelia pectoralis seems associated with thanatosis and luminescence and, thus, supports other defense reactions that the beetle has at its disposal.
The world’s gastropod fauna from continental waters comprises ∼4,000 valid described species and a minimum of 33–38 independent
lineages of Recent Neritimorpha, Caenogastropoda and Heterobranchia (including the Pulmonata). The caenogastropod component
dominates in terms of species richness and diversity of morphology, physiology, life and reproductive modes and has produced
several highly speciose endemic radiations. Ancient oligotrophic lakes (e.g., Baikal, Ohrid, Tanganyika) are key hotspots
of gastropod diversity; also noteworthy are a number of lower river basins (e.g., Congo, Mekong, Mobile Bay). But unlike many
other invertebrates, small streams, springs and groundwater systems have produced the most speciose associations of freshwater
gastropods. Despite their ecological importance in many aquatic ecosystems, understanding of even their systematics is discouragingly
incomplete. The world’s freshwater gastropod fauna faces unprecedented threats from habitat loss and degradation and introduced
fishes and other pests. Unsustainable use of ground water, landscape modification and stock damage are destroying many streams
and springs in rural/pastoral areas, and pose the most significant threats to the large diversity of narrow range endemics
in springs and ground water. Despite comprising only ∼5% of the world’s gastropod fauna, freshwater gastropods account for
∼20% of recorded mollusc extinctions. However, the status of the great majority of taxa is unknown, a situation that is exacerbated
by a lack of experts and critical baseline data relating to distribution, abundance, basic life history, physiology, morphology
and diet. Thus, the already considerable magnitude of extinction and high levels of threat indicated by the IUCN Red List
of Threatened Species is certainly a significant underestimate.
When attacked or otherwise disturbed, larvae of the aquatic firefly Luciola leii display fork-shaped glands laterally from the meso- and metathorax as well as each abdominal segment. Glandular eversion
is accompanied by a strong pine oil-like odour, thanatosis and glowing from paired larval light organs. Observations by SEM
and TEM revealed that there are numerous, almost spherical protuberances, measuring 9 µm in diameter on the surface of each
gland. Each protuberance is connected to a well developed secretory cell via a 0.1 µm thick and 0.2 µm long stalk and bears
three to six 7 µm long spines on its apex. The convoluted glandular walls measure 0.2 µm. The cytoplasm of the secretory cells
is characterized by the presence of numerous mitochondria and an extensive system of cisternae and tubular endoplasmic reticulum.
Preliminary GC-MS analysis of the glandular secretion revealed two volatile terpenoids: terpinolene and γ-terpinene. Choice
and no-choice bioassays involving fish and ants as well as other predators demonstrate that the secretions serve as an effective
deterrent against a range of ecologically relevant enemies. The larval postural adjustments, light emission, everted glands,
and glandular release of distasteful or repellent compounds, appear to function as a multi-modal, aposematic larval defence.
The tandem evolution of glandular secretions and conspicuousness in larval fireflies could partially explain their successful
radiation into both aquatic and terrestrial habitats.
The creation of large freshwater reservoirs is one of the most dramatic anthropogenic impacts on the natural environment.
With worldwide rising demand for water, the construction of more reservoirs is inevitable. Although the effects of reservoir
construction on many medically important parasites are well known and appreciated, changes to aquatic wildlife host–parasite
interactions have been largely undervalued even though a large body of literature exists. The present review examines changes
in the wildlife parasite fauna during the impoundment of reservoirs, focusing on the parasites of invertebrates, fish, and
birds, the effects both upstream and downstream of the reservoir, parasitic zoonoses, the associated pollution generated,
and assesses the impact of the recently completed Three Gorges Dam in China on the Yangtze River’s parasite fauna.
Analysis of the data available from traditional faunistic approaches to mollusc-trematode systems covering large spatial and/or temporal scales in Europe convinced us that a parasite community approach in well-defined aquatic ecosystems is essential for the substantial advancement of our understanding of the parasite response to anthropogenic pressures in urbanised areas which are typical on a European scale. Here we describe communities of larval trematodes in two lymnaeid species, Radix auricularia and Lymnaea stagnalis in four man-made interconnected reservoirs of the Ruhr River (Germany) focusing on among- and within-reservoir variations in parasite prevalence and component community composition and structure.
The mature reservoir system on the Ruhr River provides an excellent environment for the development of species-rich and abundant trematode communities in Radix auricularia (12 species) and Lymnaea stagnalis (6 species). The lake-adapted R. auricularia dominated numerically over L. stagnalis and played a major role in the trematode transmission in the reservoir system. Both host-parasite systems were dominated by bird parasites (13 out of 15 species) characteristic for eutrophic water bodies. In addition to snail size, two environmental variables, the oxygen content and pH of the water, were identified as important determinants of the probability of infection. Between-reservoir comparisons indicated an advanced eutrophication at Baldeneysee and Hengsteysee and the small-scale within-reservoir variations of component communities provided evidence that larval trematodes may have reflected spatial bird aggregations (infection 'hot spots'). Two life history groupings of dominant species, the 'cyprinid' and 'anatid' parasites, that depict two aspects of progressive eutrophication in this mature reservoir system, were identified.
We conclude that trematode communities in the lake-adapted R. auricularia are better suited for monitoring the effect of environmental change on host-parasite associations in the reservoir system on the Ruhr River and other similar systems due to the important role of this host in trematode transmission in lakes. Whereas variations in trematode community diversity and abundance may indicate the degree of eutrophication on a larger scale (among reservoirs), the infection rates of the two life history groups of dominant species, the 'cyprinid' and 'anatid' assemblages, may be particularly useful in depicting environmental variability, eutrophication effects and infection 'hot spots' on smaller spatial scales.
The objectives of this investigation were to assess the effect of temperature on the development of Schistosoma japonicum harboured in Oncomelania hupensis and to determine the lowest temperature threshold at which the hibernation of O. hupensis occurs. In the first experiment, adult infection-free O. hupensis, collected from Jiangsu province in eastern China, were infected with S. japonicum miracidia and raised at different temperatures under laboratory conditions. The development of miracidia until the release of cercariae was monitored employing the cercarial shedding method. In the second experiment, batches of O. hupensis were kept at temperatures below 13 degrees C with the temperature gradually reduced. Snail activity was assessed by a pin puncture method. We found a positive relationship between the development of S. japonicum within O. hupensis and temperature. In snails kept at 15.3 degrees C, S. japonicum arrested their development, while the fastest development occurred at 30 degrees C. The temperature at which half of the snails were in hibernation (ET(50)) was 6.4 degrees C. Our results underscore the pivotal role temperature plays on the biological activity of O. hupensis and the development of S. japonicum within the intermediate host. These findings are likely to have implications for the transmission of schistosomiasis in a warmer future China.
This study investigated the potential of ducks for the control of the golden apple snail in irrigated rice. The varieties of duck recommended for the biological control of snail in decreasing preference were William Siam > Taiwan > Mallard > Peking > Muscovy. Cherry Valley, a variety with a bigger body size was not suitable for snail control because of its poor adaptation to rice field conditions. A density of 5–10 ducks ha−1 in continuous grazing for a period of 1–2 months significantly reduced the pest density from 5 snailsm−2 to less than 1 snail m−2. This density of ducks was recommended for biological control of snails in rice. Timely release of ducks was crucial as they damaged young rice seedlings. In transplanted rice, it was appropriate to release the ducks when the seedlings were 4 weeks old. For direct seeded rice, a longer waiting period of 6 weeks was necessary. Numerically, ducks preyed on more snails in transplanted than in direct seeded rice, but the difference was not statistically significant. The increase in plant density under direct seeding probably reduced the browsing efficiency of the ducks. This difference would be expected to diminish under prolonged grazing. It is suggested that ducks were an effective biological control agent against the golden apple snail.
The Golden Apple snail, Pomacea caualiculala, introduced in Asia in 1980 for farming purposes, has turned into a major pest of rice and other aquatic crops. The snail can only damage the crop when there is standing water in the field. Yet, this aquatic environment is equally suitable for raising fish - potential snail predators. To determine the impact of predation by common carp Cyprinus carpio and Nile tilapia Oreochromis niloticus on these snails, experiments were conducted under controlled laboratory conditions. In functional response experiments using juvenile snails <3-mm shell height (SH) as prey, C. carpio showed a distinctly stronger feeding response than 0. niloticus. When grouped into weight classes of 5, 20 and 40 g, 40-g carp consumed significantly more snails (P<0.05) than 40-g tilapia at all prey densities but the lowest. Also, at this size, C. carpio preyed upon snails reaching up to 12-nun SH whereas, for 0. niloticus, predation declined sharply when snail SH exceeded 4 mm. Results show that the common carp is a more effective snail biocontrol agent than Nile tilapia and could substantially contribute to snail biocontrol in rice.
The morphology of the pygypodia, the eversable terminal appendages of the abdomens of photurid firefly larvae, was studied with particular reference to the integumental and muscle systems. The eversable nature and observed versatility of these appendages apparently result from the antagonistic action of pygypodia-associated muscles and those muscles which control (pseudo)coelomic fluid pressure in the abdomen, as well as from several fine structural features of the integument. Continuous sheets of parallel microfibrils in the endocuticle form a tough elastic inner sheath within each pygypodium. The integument bears rows of spurs, whose interconnection by the microfibril sheets may aid in their positioning as well as in their orderly and consistent packing during inversion and eversion of the pygypodia. The loose organization, irregularity of shape, and sparsity of sites of attachment of the epidermal cells, relative to the basement membrane, may all contribute to the flexible, yet strong, inner structure of the integument.
An artificial rearing apparatus for the aquatic firefly Luciola leii Fu and Ballantyne is described, consisting of two small rearing boxes placed inside a larger outer box, a choice of diet, and a suitable substrate for oviposition. Larvae feeding on crushed prey snails (Gyraulus convexiusculus Huton and Lymnaea stagnalis (L.)) showed moderate growth, while those feeding exclusively on muscle of the snail Bellamya purificata Heude grew the best, with a pupation rate of 71%, adult emergence rate of 88.7%, larval duration of 203 days, and pupal duration of 5.1 days. Larvae feeding on fish meat (Carassius auratus L.) and pork meat did not rear well, having lower pupation rates (11% and 5.5%, respectively) and lower emergence rates (54.5% and 54.5%, respectively). Analysis of the three species of aquatic snails, isolated fish meat, and isolated pork meat revealed that the concentrations of amino acids in a protein sample of B. purificata were higher than those in samples of the other two snails, G. convexiusculus and L. stagnalis, but less than those in samples of the fish and pork meat. It is concluded that the rearing apparatus and the diet, which affects water quality, are important factors in the successful rearing of the aquatic firefly L. leii.
A new species of aquatic firefly, Luciola leii sp. nov., from Hubei Province in mainland China is described from males, females, and larvae. It is the fifth species of aquatic firefly recorded from China, and it differs significantly from Luciola substriata Gorham. Cuticular plates in the female reproductive system (bursa) are described and their possible functions are discussed.
1. We investigated the individual and combined effects of two predators (the climbing perch, Anabas testudineus, and the wetland crab, Esanthelphusa nimoafi) indigenous to wetlands in Laos, on the behaviour and survival of the invasive South American golden apple snail (Pomacea canaliculata). The snail is considered a pest, consuming large amounts of rice and other aquatic vegetation in the region.
2. Snail avoidance reactions to released predator chemical cues were investigated in aquaria while the effects of predators on a mixed snail population were studied in field enclosures that contained native aquatic plants (Salvinia cucullata, Ludwigia adscendens and Ipomoea aquatica).
3. In the aquaria experiment, neonate (2–3 mm) and medium-sized snails (8–10 mm) responded to fish chemical cues by going to the surface, whereas adult snails (35–40 mm) went to the bottom. In contrast, no size class of snails reacted to chemical cues released by crabs.
4. In the field experiment, fish reduced the abundance of neonate snails, and crabs reduced the abundance of all size classes. The effect of the combined predators could not be predicted from the mortality rate observed in single predator treatments. The survival of neonate and medium-sized snails was greater and of adults less than expected. The presence of predators did not affect egg production. Snails consumed significant amounts of plants despite the presence of predators.
5. Our findings suggest that some indigenous Asian predators have lethal and sublethal effects on P. canaliculata that depend on snail size and predator type. When in the presence of several predators the response of snails to one predator may either increase or decrease the vulnerability of snails to the others.
The golden apple snail (Pomacea canaliculata), a native of freshwater wetlands of South America, has invaded many Asian countries and grazed heavily in agricultural and
wild areas. Common carp (Cyprinus carpio) has been proposed as a biological control agent against this snail, but little is known about its impact on non-target aquatic
plants and animals. In a 8-week enclosure experiment, we quantified the impact of common carp on three species of aquatic
macrophytes and nine species of snails, including the apple snail, in a shallow pond. The results showed that the apple snail
or carp alone significantly reduced the plant biomass, although the apple snail had a stronger overall herbivorous effect
than the carp. The carp completely removed juvenile apple snails, but had only a weak predatory effect on larger apple snails
and no effect on the adults’ oviposition frequency. Furthermore, the carp significantly reduced the populations of most species
of other snails that occurred naturally in the pond. Our results thus indicate that common carp can be an effective biological
control agent against the invasive apple snail, but caution should be taken about its potential to reduce wetland floral and
faunal diversity.
The apple snail Pomacea canaliculata is an invasive species and a serious pest of rice in many Asian countries. We studied predatory activities of various animals
living in Japanese freshwater habitats, by keeping each individual of a potential predator species with 36 snails of various
sizes for three days in the aquarium. Forty-six species were tested, and 26 in eight classes fed on small snails. A species
of leech, crabs, the common carp, turtles, the mallard duck and the Norway rat attacked even adult snails of 20–30 mm in shell
height. These findings will be helpful in identifying effective predators for biological control of the pest snail. In addition,
most of the animals attacking snails are reported to be common in rivers or ponds, but few live in modernized paddy fields
having little connections with natural water systems. This may be a reason why this snail maintains large populations in paddy
fields but not in other freshwater habitats.
We conducted a field survey for flatworms to select species as potential biological control agents against Aedes aegypti and Culex pipiens (Diptera, Culicidae) breeding in artificial containers. Laboratory experiments were performed to determine the daily predation rate, differential predation on each mosquito larval instar, selective predation on either A. aegypti or C. pipiens, and predator tolerance to water from artificial containers. Girardia anceps (Tricladida, Paludicola, Dugesiidae), Mesostoma ehrenbergii and Bothromesostoma cf. evelinae (Rhabdocoela, Typhloplanoida, Typhloplanidae) were found in temporary puddles and permanent pools. In the laboratory, they killed between 52% and 100% of immature mosquitoes coexisting in the same habitat. No preference of flatworms for mosquito preys was detected. Predation rate was related to predator size and instar of preys. Girardia anceps and B. evelinae survived after a dry period and when re-flooding occurred, they laid eggs. Tolerance to water from artificial containers was highest in G. anceps and this species could be a suitable predator to reduce mosquito populations from artificial containers using an inoculative approach.
The concept of rice–fish farming was employed to evaluate five species of fish for biological control of golden apple snail in rice. Aquaria trials were initially used to observe the predation potential of the individual fish species, followed by replicated field trials. In the aquaria studies all the fish species preyed upon the hatchlings of the golden apple snail, but at the field level only common carp and African catfish consumed snails significantly more than the other species. Common carp, which attained a recovery rate of 90% was the only fish species suitable for biological control of snail in rice. African catfish was not adaptable to the rice field conditions; the fish suffered a low recovery rate of 17% even when the plots were covered with nets to protect the fish from natural predators. The density of common carp recommended for biological control of snail in rice was 2041 fish/ha. However, it was essential to set up a pond refuge to improve survival rate and to enhance fish production. The study revealed that under direct seeding planting method, the increase in plant density restricted the foraging activities of the fish. Consequently, the number of snail sampled in direct seeded plots was significantly greater than in transplanted plots. Throughout the studies, the fish neither caused a significant increase in rice yields nor a reduction in stem borer, case worm and stink bug infestations. Common carp was however, an effective predator of the golden apple snail in rice.
Dongting Lake, covering a very large surface water area of 2691km(2), is located in Hunan Province in the southern part of the People's Republic of China. It is the second-largest freshwater lake in China and plays an important role in regulating the amount of water in the Yangtze River, China's longest river. The annual water level of the lake changes by as much as 15m, rising in summer and falling in winter. Asian schistosomiasis has been endemic in the Dongting Lake region for centuries and it has had a devastating effect on the public health of the local people. After a difficult struggle for more than four decades, a concerted programme, supported by the World Bank Loan and instigated in 1992, has resulted in remarkable progress in the control of the disease in many endemic areas of the region. However, the great challenge remains to consolidate and maintain the achievements made to date. The Schistosoma japonicum intermediate host (Oncomelania hupensis hupensis) snail habitats are huge, estimated at 1768km(2) in 1996; these are increasing at a rate of 34.7km(2) annually due to high silt deposition from the Yangtze River itself and from the connecting rivers in Hunan province, and construction of embankments in the Dongting Lake region. It is anticipated that the construction of the Three Gorges Super Dam, the largest engineering project ever undertaken, will substantially extend the range of the snail habitats and increase the number of new schistosomiasis cases. In many areas, human re-infections with S. japonicum after drug (praziquantel) treatment remain unacceptably high (up to 20% of those treated are re-infected annually) due to occupational (mainly fishing) water contact. This paper reviews the history and the current status of schistosomiasis control in the lake region, it explores the epidemiological factors which influence the prevalence of the infection and the disease it causes, and it provides insight into future approaches to control which might finally eradicate the infection.
Opisthorchis viverrini is a human liver fluke endemic in Thailand, Lao PDR and Cambodia. Three subspecies of Bithynia siamensis and 18 species of cyprinoid fish are susceptible first and second intermediate hosts, respectively. The differentiation between the adult worm of O. viverrini and that of the closely related species, Opisthorchis felineus and Clonorchis sinensis, is mainly based on the shape and position of the testes and the arrangement of the vitellaria. Eggs of these flukes are morphologically similar and problematic in identification. However, the differentiation between opisthorchid and lecithodendrid eggs is possible. Morphology and biology of each stage are comparatively reviewed. Biological aspects of snail and fish hosts are also included.
Except for imported cases, we have had no new Schistosoma japonicum infection in Japan since 1977. But there are still two habitats of the intermediate snail host: Oncomelania nosophora in the previous endemic areas of Kofu Basin and Obitsu. O. nosophora from Kofu Basin and Obitsu are susceptible to Chinese and Philippine strains of S. japonicum. The number of immigrants from current endemic areas in China or the Philippines is increasing. In order to prevent re-emerging of S. japonicum infections in Japan, we should continue monitoring on those existing snail hosts and investigate an adequate quarantine system. In Japan, elimination of schistosomiasis has been mainly accomplished by control of the snail host. As measures of snail control, cement-lining of ditches and chemical mollusciciding were most effective in Japan. But the cost of this joint program is too expensive compared with health budget in almost developing countries. In endemic areas of Japan, land reformation from paddy field to fruit farm was also effective. The intermediate snail host in the Philippines, Oncomelania quadrasi is much more aquatic than O. nosophora. For control of O. quadrasi, small drainage of the water and land reclamation from swampy field to rice-field were effective. Based on biological characteristics of Oncomelania spp., we can modify the past successful snail control program in Japan to be adapted ecologically and economically to each endemic area of developing countries.
Poyang Lake, the largest fresh water lake in China, is the major transmission site of Schistosoma japonicum in China. This paper reviews the history of prevalence, efforts and achievements of controlling schistosomiasis and current status of endemicity. The epidemiological characteristics including descriptions of the endemic areas, snail host, definitive hosts, infection source, transmission and impacts of water conservancy, as well as objectives and strategy of control in Poyang Lake are discussed.
The rearing of aquatic firefly Luciola ficta. The magazine of
- S Q Chen
- R Z Chen
Chen, S.Q., Chen, R.Z., 1997. The rearing of aquatic firefly Luciola ficta. The magazine
of Yilan Science University 14, 25-32 (in Chinese).
Rearing aquatic glowworms in a water tank as an eco-system
- N Ohba
Ohba, N., 1991. Rearing aquatic glowworms in a water tank as an eco-system.
Insectarium 28, 12-15.