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Schistosomiasis malayensis-like infection among the Penan and other interior tribes (Orang Ulu) in upper Rejang River Basin Sarawak Malaysia

Sagin DD, Ismail G, Fui JN, Jok JJ

Southeast Asian J. Trop. Med. Public Health, 2001 Mar;32(1):27-32.
PMID: 11485090

A serosurvey of various indigenous interior tribes (Orang Ulu) in upper Rejang River Basin Sarawak Malaysia, the site of a multibillion Ringgit hydroelectric power project, found 6.8% of the individual surveyed were seropositive for schistosomiasis, as determined by ELISA method using the soluble egg antigen of Schistosoma malayensis Baling strain. In all age group, the seroprevalence rate is higher (9.5%) in males than in females (4.5%) except for the 31-40 age group. Seroprevalence of schistosomiasis was found to increase with age with the above 60 age group having the highest rate followed by the 31-40 age group. Seroprevalence rate among the tribes ranges from 4.1% among the Penan to 11.6% among the Kajang. There was no seroevidence of schistosomiasis among the Ukits. A snail survey found four snail species including Brotia species, the intermediate host of the lung fluke Paragonimus westermani, however no schistosome snail host was identified. Although schistosomiasis malayensis-like infection may be endemic in the area, its public health significance remains undetermined.

Matched MeSH terms: Snails/parasitology
Life cycle of Catatropis indica Srivastava, 1935 (Trematoda: Notocotylidae)

Rohde K, Onn LF

Z Parasitenkd, 1967;29(2):137-48.
PMID: 5601175
Matched MeSH terms: Snails
[The distribution of Opistorchis and Paragonimus in Malaya and possible sources of infection of man with these parasites]

Rohde K

Z Tropenmed Parasitol, 1967 Jul;18(2):152-61.
PMID: 5628712
Matched MeSH terms: Snails
Fulltext Cryptic diversity: Two morphologically similar species of invasive apple snail in Peninsular Malaysia

Rama Rao S, Liew TS, Yow YY, Ratnayeke S

PLoS One, 2018;13(5):e0196582.
PMID: 29734361 DOI: 10.1371/journal.pone.0196582

Invasive snails in the genus Pomacea have spread across Southeast Asia including Peninsular Malaysia. Their effects on natural and agricultural wetlands are appreciable, but species-specific effects are less clear because of morphological similarity among the species. Our objective was to establish diagnostic characteristics of Pomacea species in Malaysia using genetic and morphological criteria. The mitochondrial COI gene of 52 adult snails from eight localities in Peninsular Malaysia was amplified, sequenced, and analysed to verify species and phylogenetic relationships. Shells were compared using geometric morphometric and covariance analyses. Two monophyletic taxa, P. canaliculata and P. maculata, occurred in our samples. The mean ratio of shell height: aperture height (P = 0.042) and shell height: shell width (P = 0.007) was smaller in P. maculata. P. maculata co-occurred with P. canaliculata in five localities, but samples from three localities contained only P. canaliculata. This study is the first to confirm the presence of two of the most invasive species of Pomacea in Peninsular Malaysia using a molecular technique. P. canaliculata appears to be the more widespread species. Despite statistical differences, both quantitative and qualitative morphological characteristics demonstrated much interspecific overlap and intraspecific variability; thus, shell morphology alone cannot reliably verify species identity. Molecular techniques for distinguishing between these two highly invasive Pomacea species are needed to understand their specific ecological niches and to develop effective protocols for their management.

Matched MeSH terms: Snails/cytology*; Snails/genetics*
Allozyme variation in the camaenid tree snails Amphidromus atricallosus (Gould, 1843) and A. inversus (Müller, 1774)

Prasankok P, Ota H, Toda M, Panha S

Zoolog Sci, 2007 Feb;24(2):189-97.
PMID: 17409732

We examined allozyme variation in two camaenid tree snails, Amphidromus atricallosus and A. inversus, across two principal regions of Thailand and from Singapore, plus for A. inversus, one site in peninsular Malaysia. Using horizontal starch gel electrophoresis, 13 allozyme loci (11 polymorphic) were screened for A. atricallosus and 18 (5 polymorphic) for A. inversus. Heterozygosity was higher in A. atricallosus (Hexp=0.018-0.201, mean=0.085) than in A. inversus (Hexp=0-0.023, mean= 0.002). Genetic heterogeneity among samples was higher in A. inversus (Fst=0.965) than in A. atricallosus (Fst=0.781). Within A. atricallosus, populations were more differentiated in southern Thailand (Fst=0.551) than in eastern Thailand (Fst=0.144). The high Fst and low Hexp in populations of A. inversus suggest that this species is likely to have experienced a series of strong bottlenecks, perhaps occurring chiefly on offshore continental-shelf islands. The low Fst values of A. atricallosus in eastern Thailand suggest frequent gene flows among populations in this region. The southern and eastern samples of A. atricallosus exhibited fixed allele differences at four loci and great genetic distance (Nei's D=0.485-0.946), suggesting that these two samples may actually represent, or else be evolving into, separate species.

Matched MeSH terms: Snails/classification; Snails/enzymology; Snails/genetics*
Gross mismatch between thermal tolerances and environmental temperatures in a tropical freshwater snail: climate warming and evolutionary implications

Polgar G, Khang TF, Chua T, Marshall DJ

J Therm Biol, 2015 Jan;47:99-108.
PMID: 25526660 DOI: 10.1016/j.jtherbio.2014.11.009

The relationship between acute thermal tolerance and habitat temperature in ectotherm animals informs about their thermal adaptation and is used to assess thermal safety margins and sensitivity to climate warming. We studied this relationship in an equatorial freshwater snail (Clea nigricans), belonging to a predominantly marine gastropod lineage (Neogastropoda, Buccinidae). We found that tolerance of heating and cooling exceeded average daily maximum and minimum temperatures, by roughly 20°C in each case. Because habitat temperature is generally assumed to be the main selective factor acting on the fundamental thermal niche, the discordance between thermal tolerance and environmental temperature implies trait conservation following 'in situ' environmental change, or following novel colonisation of a thermally less-variable habitat. Whereas heat tolerance could relate to an historical association with the thermally variable and extreme marine intertidal fringe zone, cold tolerance could associate with either an ancestral life at higher latitudes, or represent adaptation to cooler, higher-altitudinal, tropical lotic systems. The broad upper thermal safety margin (difference between heat tolerance and maximum environmental temperature) observed in this snail is grossly incompatible with the very narrow safety margins typically found in most terrestrial tropical ectotherms (insects and lizards), and hence with the emerging prediction that tropical ectotherms, are especially vulnerable to environmental warming. A more comprehensive understanding of climatic vulnerability of animal ectotherms thus requires greater consideration of taxonomic diversity, ecological transition and evolutionary history.

Matched MeSH terms: Snails/physiology*
Fulltext Land snail fauna in Gunung Kuang Limestone Hill, Perak, Malaysia and its conservation implications (Mollusca, Gastropoda)

Phung CC, Yong YZ, Said MAM, Liew TS

Zookeys, 2018.
PMID: 29988791 DOI: 10.3897/zookeys.769.25571

This paper presents the first land snail species checklist for Gunung Kuang (Kuang Hill), a limestone hill located next to Gunung Kanthan that is recognised as one of the most important limestone hills for its diverse land snail fauna in Kinta Valley. Samplings were carried out at five plots in Gunung Kuang. This survey documented 47 land snail species, in which six species were identified as unique to Gunung Kuang. Approximately half of the land snails from Gunung Kanthan were found in Gunung Kuang. In addition, one of six unique species from Gunung Kanthan was also found in Gunung Kuang. These rich land snail species in Gunung Kuang are similar to other hills in Kinta Valley, but it is relatively lesser than the adjacent Gunung Kanthan. In view of Gunung Kuang's unique land snail species, and its location closest to disturbed Gunung Kanthan, Gunung Kuang should be considered in the conservation management plan for Gunung Kanthan.

Matched MeSH terms: Helix (Snails); Snails
Fulltext A checklist of land snails from the west coast islands of Sabah, Borneo (Mollusca, Gastropoda)

Phung CC, Yu FTY, Liew TS

Zookeys, 2017.
PMID: 28769672 DOI: 10.3897/zookeys.673.12422

Sabah, situated in one of the world's biodiversity hotspots, has the largest number of islands in Malaysia with more than 500 of various sizes and degrees of isolation. However, information on the islands' biodiversity is limited. This study provides an up-to-date checklist of land snail species found on 24 west coast islands in Sabah. A total of 67 species (nearly 20% of the total number of land snail species in the state) representing 37 genera and 19 families is enumerated based on systematic field surveys of 133 sampling plots, BORNEENSIS database records and species checklists published between 2000 and 2016. The number of species on the islands ranges from four to 29. Labuan Island has the highest number of species (29), followed by Tiga Island (25), Mantanani Besar Island (24) and Gaya Island (23). However, the populations of some land snail species may have declined as several previously recorded species on the islands were not found in a recent systematic field sampling. This checklist is provided as a baseline inventory for future island land snail studies and to better inform biodiversity conservation plans of marine parks and other islands on the Sabah west coast.

Matched MeSH terms: Snails
Fulltext Sexual dimorphism in shell size of the land snail Leptopoma perlucidum (Caenogastropoda: Cyclophoridae)

Phung CC, Choo MH, Liew TS

PeerJ, 2022;10:e13501.
PMID: 35651743 DOI: 10.7717/peerj.13501

Sexual dimorphism in the shell size and shape of land snails has been less explored compared to that of other marine and freshwater snail taxa. This study examined the differences in shell size and shape across both sexes of Leptopoma perlucidum land snails. We collected 84 land snails of both sexes from two isolated populations on two islands off Borneo. A total of five shell size variables were measured: (1) shell height, (2) shell width, (3) shell spire height, (4) aperture height, and (5) aperture width. We performed frequentist and Bayesian t-tests to determine if there was a significant difference between the two sexes of L. perlucidum on each of the five shell measurements. Additionally, the shell shape was quantified based on nine landmark points using the geometric morphometric approach. We used generalised Procrustes and principal component analyses to test the effects of sex and location on shell shape. The results showed that female shells were larger than male shells across all five measurements (all with p-values < 0.05), but particularly in regards to shell height and shell width. Future taxonomic studies looking to resolve the Leptopoma species' status should consider the variability of shell size caused by sexual dimorphism.

Matched MeSH terms: Snails*
The inophyllums, novel inhibitors of HIV-1 reverse transcriptase isolated from the Malaysian tree, Calophyllum inophyllum Linn

Patil AD, Freyer AJ, Eggleston DS, Haltiwanger RC, Bean MF, Taylor PB, et al.

J Med Chem, 1993 Dec 24;36(26):4131-8.
PMID: 7506311

As part of a search for novel inhibitors of HIV-1 reverse transcriptase, the acetone extract of the giant African snail, Achatina fulica, was shown to be active. Fractionation of the extract yielded inophyllums A, B, C, and E and calophyllolide (1a, 2a, 3a, 3b, and 6), previously isolated from Calophyllum inophyllum Linn., a known source of nutrition for A. fulica. From a methanol/methylene chloride extract of C. inophyllum, the same natural products in considerably greater yield were isolated in addition to a novel enantiomer of soulattrolide (4), inophyllum P (2b), and two other novel compounds, inophyllums G-1 (7) and G-2 (8). The absolute stereochemistry of inophyllum A (1a) was determined to be 10(R), 11(S), 12(S) from a single-crystal X-ray analysis of its 4-bromobenzoate derivative, and the relative stereochemistries of the other inophyllums isolated from C. inophyllum were established by a comparison of their 1H NMR NOE values and coupling constants to those of inophyllum A (1a). Inophyllums B and P (2a and 2b) inhibited HIV reverse transcriptase with IC50 values of 38 and 130 nM, respectively, and both were active against HIV-1 in cell culture (IC50 of 1.4 and 1.6 microM). Closely related inophyllums A, C, D, and E, including calophyllic acids, were significantly less active or totally inactive, indicating certain structural requirements in the chromanol ring. Altogether, 11 compounds of the inophyllum class were isolated from C. inophyllum and are described together with the SAR of these novel anti-HIV compounds.

Matched MeSH terms: Snails/chemistry
A survey of snail hosts and larval trematodes collected by peninsular Malaysia and Singapore from 1972 to 1977

Palmieri JR, Sullivan JT, Ow-Yang CK

Southeast Asian J. Trop. Med. Public Health, 1977 Jun;8(2):275-7.
PMID: 918717
Matched MeSH terms: Snails/parasitology*
Strigeoid trematodes of Malaysia with descriptions of a new genus and three new species

Palmieri JR, Krishnasamy M, Sullivan JT

J Helminthol, 1979 Mar;53(1):51-63.
PMID: 458132

Six species of strigeoid trematodes are reported from Malaysia. One new genus and 3 new species are described: Apatemon (Apatemon( jamesi sp. n (Strigeidae); cercaria Cotylurus sullivani sp. n. (Strigeidae); Neodiplostomum (Neodiplostomum) sp. (Diplostomatidae); Fibricola ramachandrani (Diplostomatidae); Pseudoscolopacitrema otteri gen. n. et sp. n. (Diplostomatidae); and cercaria Cyathocotyle malayi sp. n. (Cyathocotylidae). The life cycles of A. jamesi and C. malayi have also been investigated.

Matched MeSH terms: Snails/parasitology
Fulltext Inferring microevolution from museum collections and resampling: lessons learned from Cepaea

Ożgo M, Liew TS, Webster NB, Schilthuizen M

PeerJ, 2017;5:e3938.
PMID: 29093997 DOI: 10.7717/peerj.3938

Natural history collections are an important and largely untapped source of long-term data on evolutionary changes in wild populations. Here, we utilize three large geo-referenced sets of samples of the common European land-snail Cepaea nemoralis stored in the collection of Naturalis Biodiversity Center in Leiden, the Netherlands. Resampling of these populations allowed us to gain insight into changes occurring over 95, 69, and 50 years. Cepaea nemoralis is polymorphic for the colour and banding of the shell; the mode of inheritance of these patterns is known, and the polymorphism is under both thermal and predatory selection. At two sites the general direction of changes was towards lighter shells (yellow and less heavily banded), which is consistent with predictions based on on-going climatic change. At one site no directional changes were detected. At all sites there were significant shifts in morph frequencies between years, and our study contributes to the recognition that short-term changes in the states of populations often exceed long-term trends. Our interpretation was limited by the few time points available in the studied collections. We therefore stress the need for natural history collections to routinely collect large samples of common species, to allow much more reliable hind-casting of evolutionary responses to environmental change.

Matched MeSH terms: Snails
The reproductive systems of Indoplanorbis exustus (Deshayes) (Planorbidae: Pulmonata) and Lymnae rubiginosa (Michelin) (Lymnaeidae: Pulmonata) a description in healthy and trematode habouring snails

Ong PL, Kuan E

Southeast Asian J. Trop. Med. Public Health, 1973 Mar;4(1):46-54.
PMID: 4718128
Matched MeSH terms: Snails/anatomy & histology*
Fulltext RELATIONSHIP OF CONDITION INDEX AND REPRODUCTIVE STATUS OF BLACK SNAIL, FAUNUS ATER IN MERCHANG LAGOON

Nurul Husna Hassan, Roslizawati Ab Lah

UMT Journal of Undergraduate Research, 2020;2(1):1-8.
MyJurnal

Black snail, Faunus ater is an abundant species in Malaysia yet not many research have focused on its physiological and biological activities. This research aimed to assess the condition index (CI) and reproductive status based on the gonadosomatic index (GSI) for short-term duration. Samples were collected monthly from Merchang Lagoon, from November 2018 to January 2019. Four different types of condition indices equation were applied in this study and the results revealed that there were significant differences between four equations for measuring the CI (P=0.000). However, the result for the GSI shows no significant difference between three month of sampling (P>0.05). CI based on fresh weight measurement (Fww/Tww x 100) and dry weight measurement (Fdw/Fww x 100) reached its peak when GSI decreased. The rest of the trend for CI fluctuated and CI was not affected by GSI. Overall, this study concluded that, there were trends observed in CI and GSI for the black snails. However, it is suggested that longer term observation in future research is needed have a better understanding on the black snails.

Matched MeSH terms: Snails
Orthorhombic modification of triphenyltin 3-ureidopropionate

Ng SW

Acta Crystallogr C, 2000 Mar 15;56(Pt 3):E86-7.
PMID: 15263207

The Sn atom in catena-poly[triphenyltin(IV)-micro-(3-ureidopropionato-O(1):O(3))], [Sn(C(6)H(5))(3)(C(4)H(7)N(2)O(3))](n), is five-coordinate and has a trans-C(3)SnO(2) trigonal-bipyrmidal geometry arising from bridging through the O atom of the ureido fragment of an adjacent carboxylate group. Infinite chains propagate helically along the c axis and adjacent chains are linked by N-H.O [N.O 2.851 (4) A] hydrogen bonds into layers.
Fulltext Data of feed formulation for Indonesian short-fin eel, Anguilla bicolor McClelland, 1844 elver

Muchlisin ZA, Sofyan M, Dewiyanti I, Nur FM, Batubara AS, Fadli N, et al.

Data Brief, 2020 Jun;30:105581.
PMID: 32346582 DOI: 10.1016/j.dib.2020.105581

This article describes the data of raw material compositions for formulating the diet for Indonesian short-fin eel, Anguilla bicolor Anguilla bicolor McClelland, 1844 elver. The data on growth performance, survival and feed utilization of eel elver from the formulated diet test results are also presented here. Four formulated diets and one commercial feed were tested for the eel elver. The formulated diet was formulated from animal and plant based protein sources such as; fish meal, cornmeal, soybean meal, fine bran, ebi-shrimp meal, golden snail meal, bloodmeal, and tapioca flour. Vitamins and minerals were added into the diet. In addition, probiotics and papain enzyme and its combination were also included into the experimental diets to boost the growth performance, survival and feed utilization of the fish. The tested treatments were; (A) commercial diet without probiotic and papain enzyme, (B) experimental diet without probiotic and papain enzyme, (C) experimental diet with probiotic 10 ml kg-1 feed, (D) experimental diet with papain enzyme 10 g kg-1 feed, (E) experimental diet with probiotic 10 ml kg-1 + papain 10 g kg-1 feed, (F) experimental diet with probiotic 5 ml kg-1 + papain 5 g kg-1 feed. Each experimental fish group was fed on an experimental diet twice a day at 08.00 AM and 06.00 PM at feeding level of 10% body weight for 60 days. The results showed that the weight gain ranged between 4.60 g to 5.92 g, daily growth rate between 0.063 g day-1 and 0.098 g per day-1, the specific growth rate varies from 0.72% day-1 to 1.35% day-1, survival rate 50.00% to 73.33%, feed conversion ratio from 2.35 to 4.17, and feed efficiency between 41.82% to 58.98%. The best treatment was found in fish fed on the experimental diet with papain enzyme 10 g kg-1 of feed.

Matched MeSH terms: Snails
Impacts of Thermal Treatments on Major and Minor Allergens of Sea Snail, Cerithidea obtusa (Obtuse Horn Shell)

Misnan R, Salahudin Abd Aziz N, Mohamad Yadzir ZH, Bakhtiar F, Abdullah N, Murad S

Iran J Allergy Asthma Immunol, 2016 Aug;15(4):309-316.
PMID: 27921412

Snail is one of the worst causes of food allergy. Thus, the aim of this study was to identify the major and minor allergens of the local marine snail (Cerithidea obtusa) and subsequently to investigate the impacts of heat treatment on the IgE-binding activity of snail allergens. Proteins from raw and heat-treated snails (boiled, roasted and fried) were extracted and then resolved by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Immunoblotting of all extracts were then performed using sera from patients with snail allergy. The results showed that the raw extract contains numerous protein bands between 12 to>250 kDa. Some thermostable proteins, predominantly the 33 and 42 kDa bands, remained detected in all cooked extracts with decreasing intensities from boiled to roasted to fried extracts, while the majority of thermolabile bands denatured after heating. Boiled snail had more protein bands compared to roasted and fried snails. Immunoblotting of raw extract demostrated 19 IgE-binding bands ranging from 15 to 240 kDa. The thermostable bands of 33 and 42 kDa and a thermolabile of 30 kDa band were identified as the major allergens of this snail. The cooked extracts yielded less allergenic bands. The boiled extract yielded approximately 14 IgE-binding bands with some smeared bands at high molecular weight regions. The roasted extract had lesser IgE-binding bands and the majority appeared as smears, while the IgE-reactivity in the fried extract was less visible and appeared as weak smears. This study indicated that both raw and cooked snails played a crucial role in snail allergenicity, as this species of snail contains both thermostable and thermolabile major allergens. The degree of snail allergenicity was revealed in the order: raw> boiled > roasted> fried. Thus, the results would facilitate in the development of effective diagnosis and management strategies of snail allergy in this country.

Matched MeSH terms: Snails*
Identification of major and cross-reactive allergens of local freshwater snail (Pila polita) and the impact of thermal and non-thermal food processing on allergen stability

Misnan R, Kamarazaman NA, Sockalingam K, Yadzir ZHM, Bakhtiar F, Abdullah N, et al.

J Sci Food Agric, 2023 Sep;103(12):5819-5830.
PMID: 37092326 DOI: 10.1002/jsfa.12659

BACKGROUND: Snail allergy is rare but can be fatal. Pila polita, a freshwater snail, was considered as a popular exotic food, particularly in tropical countries, and consumed in processed forms. Thus, the purpose of this study was to identify the major and cross-reactive allergens of P. polita and to determine the impact of food processing on the allergen stability.
RESULTS: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis fractionated raw snail extract to approximately 24 protein bands, between 9 and 245 kDa. The prominent band at 33 kDa was detected in all raw and processed snail extracts. Immunoblotting tests of the raw extract demonstrated 19 immunoglobulin E (IgE)-binding proteins, and four of them, at 30, 35, 42 and 49 kDa, were revealed as the major IgE-binding proteins of P. polita. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry identified the 49 and 42 kDa major allergens as actin, whereas the 30 and 35 kDa major allergens were identified as tropomyosin. Immunoblotting revealed that the raw snail had more allergenic proteins than the processed snail. The degree of allergenicity in decreasing order was raw > brine pickled> boiled > roasted > fried > vinegar pickled. The presence of cross-reactivity between P. polita and the shellfish tested was exhibited with either no, complete, or partial inhibitions.
CONCLUSION: Actin and tropomyosin were identified as the major and cross-reactive allergens of P. polita among local patients with snail allergy. Those major allergens are highly stable to high temperatures, acidic pH, and high salt, which might played a crucial role in snail allergy in Malaysia. © 2023 Society of Chemical Industry.

Matched MeSH terms: Snails
Features of intertidal bioerosion and bioconstruction on limestone coasts of Langkawi Islands, Malaysia

Miklós Kázmér, Mohd Shafeea Leman & Kamal Roslan Mohamed, Che Aziz Ali, Danko Taboroši

Sains Malaysiana, 2015;44:921-929.

The purpose of this paper was to provide a practical guide assisting field workers in identification and interpretation of frequently occurring bioerosional textures created in limestone by intertidal organisms along the coasts of Langkawi Islands, Malaysia. The discussion follows the textural succession from the supratidal down to the lower intertidal zone. Traces left by lichens, boring sponges, molluscs (littorinid snails, the chiton Acanthopleura, the bivalve Lithophaga) and the echinoid Echinometra are illustrated. Products of bioconstructing organisms, specifically oysters and barnacle are also described. Ecological tolerance of each group is given.

Matched MeSH terms: Snails

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