Differences in radular morphology in relation to microhabitat of assassin snails Anentome helena from Northern Thailand (Mollusca: Gastropoda)

Main Article Content

Nattawadee Nantarat
Nithinan Chomchoei


Anentome helena is a widespread freshwater snail, especially in Thailand. It is a successful predator in the ecosystem and an intermediate host of trematodes. The radula is a specific character of gastropods for feeding and often uses to limited species. However, it’s neither all morphological features of radulae and radular teeth are functionally adaptive or optimized for a specific function, nor all morphology should be viewed in an evolutionary context. This study aims to compare the radular morphology of assassin snail A. helena from different microhabitats in Northern Thailand and performs DNA fingerprints analysis using the high annealing temperature-random amplified polymorphic DNA marker (HAT-RAPD) of A. helena and related species. A total of 140 adult individuals of A. helena were collected from 14 different localities throughout Northern Thailand. There were 4 different types of microhabitats of A. helena including sand, mud, cement and plant root. The results showed that there were two morphotypes in the A. helena complex. The radula was investigated by using a light microscope and scanning electron microscope (SEM). The radula of all A. helena was stenoglossan but different in number and size of cusps on a central tooth and lateral teeth. Moreover, the radular teeth of A. helena from sand differed from those other microhabitats with more blunt-cusps teeth. HAT-RAPD analysis with 8 primers could be identified species-specific banding patterns for each freshwater snail species. In addition, it was separated two morphotypes of A. helena into two groups and showed the result that it was not related to their microhabitats. This finding has demonstrated morphological adaptation of A. helena radula in number and size of cusps which seems to be related to preferred substrata. This study will help to understand the ecology that can affect to the radular morphology of A. helena. In addition, HAT-RAPD profiling was a useful tool to determine the genetic relationship between freshwater snail species and variation that might occur on their radular morphology.

Article Details

How to Cite
Nantarat, N.; Chomchoei, N. Differences in Radular Morphology in Relation to Microhabitat of Assassin Snails Anentome Helena from Northern Thailand (Mollusca: Gastropoda). Microsc. Microanal. Res. 2019, 32, 18-22.
The 36th International Conference of The Microscopy Society of Thailand


[1] E. E. Strong, L. A. Galindo, Y. I. Kantor, Quid est Clea helena? evidence for a previously unrecognized radiation of assassin snails (Gastropoda: Buccinoidea: Nassariidae), PeerJ, 2017, 5, 1–41.
[2] A. Bogan, E. H. Hanneman, “A carnivorous aquatic gastropod in the pet trade in North America : the next threat to freshwater gastropods?,” Ellipsaria, 2013, 15, 18–19.
[3] L. Galindo, N. Puillandre, J. Utge, The phylogeny and systematics of the Nassariidae revisited (Gastropoda, Buccinoidea), Mol. Phylogenet. Evol., 2016, 99, 337–353.
[4] R. A. M. Brandt, The non-marine aquatic Mollusca of Thailand, Archiv fur Molluskenkunde, 1974, 105, 1–423.
[5] T. H. Ng, F. Junn Kitt, S. K. Tan, M. K. K. Chan, D. C. J. Yeo, First non-native establishment of the carnivorous assassin snail, Anentome helena (von dem Busch in Philippi, 1847), BioInvasions Rec., 2016, 5, 143–148.
[6] K. Chantima, J. Y. Chai, C. Wongsawad, Echinostoma revolutum: freshwater snails as the second intermediate hosts in Chiang Mai, Thailand, Korean J. Parasitol., 2013, 51, 183–189.
[7] J. R. Powell, C. E. Taylor, Genetic variation in ecologically diverse environments: Environmental diversity and intraspecific habitat choice, rather than heterosis, may be the answer to the question 'Why so many genotypes?', Am. Sci., 1979, 67(5), 590–596.
[8] J. S. Jones, Genetic differences in individual behaviour associated with shell polymorphism in the snail Cepaea nemoralis, Nature, 1982, 298(5876), 749–750.
[9] J. Utzinger, M. Tanner, Microhabitat preferences of Biomphalaria pfeifferi and Lymnaea natalensis in a natural and a man-made habitat in Southeastern Tanzania, Mem. Inst. Oswaldo Cruz, 2000, 95(3), 287–294.
[10] J. B. Burch, Freshwater snails (Mollusca: Gastropoda) of North America, U.S. Environmental Protection Agency, Washington, D.C., 1982.
[11] Y. Kameda, A. Kawakita, M. Kato, Cryptic genetic divergence and associated morphological differentiation in the arboreal land snail Satsuma (Luchuhadra) largillierti (Camaenidae) endemic to the Ryukyu Archipelago, Japan, Mol. Phylogenet. Evol., 2007, 45(2), 519–533.
[12] L. Madec, A. Bellido, A. Guiller, Shell shape of the land snail Cornu aspersum in North Africa: unexpected evidence of a phylogeographical splitting, Heredity, 2003, 91, 224–231.
[13] M. Eisapour, S. J. Seyfabadi, B. Daghooghi, Comparative radular morphology in some intertidal gastropods along Hormozgan province, Iran, J. Aquac. Res. Dev., 2015, 6(4), 6–8.
[14] M. Yakhchali, L. J. Deilamy, Radular variations in freshwater snails of the Family Lymnaeidae (Mollusca: Gastropoda: Basommatophora) from Northwestern Iran, Am. Malacol. Bull., 2012, 30(2), 323–326.
[15] S. Arularasan, K. Kesavan, P. S. Lyla, Scanning electron microscope ( SEM ) studies of Radula of the Dog Conch Strombus canarium (Gastropoda : Prosobranchia : Strombidae), 2011, 1(1), 122–127.
[16] M. Gayathri, M. Ramasamy, N. Santhiya, Radular ultrastructure of freshwater apple snail Pila virens (Gastropoda: Ampullariidae ), 2016, 1(1), 71–75.
[17] J. Kulsantiwong, S. Prasopdee, S. Piratae, P. Khampoosa, A. Suwannatrai, W. Duangprompo, T. Boonmars, W. Ruangjirachuporn, J. Ruangsittichai, V. Viyanant, P.D.N. Hebert, S. Tesana, Species-specific primers designed from RAPD products for Bithynia funiculata, the first intermediate host of liver fluke, Opisthorchis viverrini, in North Thailand, J. Parasitol., 2013, 99(3), 433–437.
[18] P. Butboonchoo, C. Wongsawad, Occurrence and HAT-RAPD analysis of gastrointestinal helminths in domestic chickens (Gallus gallus domesticus) in Phayao province, Northern Thailand, Saudi J. Biol. Sci., 2017, 24(1), 30–35.
[19] P. S. Walsh, D. A. Metzger, R. Higuchi, Chelex 100 as a medium for simple extraction of DNA for PCR based typing from forensic material, Biotechniques, 2013, 54(3), 134–139.
[20] R. R. Sokal, C. Michener, A statistical method for evaluating systematic relationships, University of Kansas Science Bulletin, 1958.
[21] J. Felsenstein, Evolutionary Trees from DNA Sequences: A Maximum Likelihood Approach, The American Naturalist, 1981.
[22] A. Criscuolo, Molecular phylogenetics and evolution morePhyML: improving the phylogenetic tree space exploration with PhyML 3, Mol. Phylogenet. Evol., 2011, 61(3), 944–948.
[23] N. Nantarat, C. M. Wade, E. Jeratthitikul, C. Sutcharit, S. Panha, Molecular evidence for cryptic speciation in the Cyclophorus fulguratus (Pfeiffer, 1854) species complex (Caenogastropoda: Cyclophoridae) with description of new species, PLoS One, 2014, 9(10), 1–15.
[24] S. Chiba, Morphological divergence as a result of common adaptation to a shared environment in land snails of the genus Hirasea, J. Molluscan Stud., 2009, 75(3), 253–259.
[25] B. Hubendick, Factors conditioning the habitat of freshwater snails, Bull. World Heal. Organ., 1958, 18(5–6), 1072–1080.
[26] M.M.A. Desouky, S. Busais, Phylogenetic relationships of the land snail; Eobania vermiculata (Müller, 1774) from Egypt and Saudi Arabia. a combined morphological and molecular analysis, J. Basic Appl. Zool., 2012, 65(2), 144–151.
[27] J. Puizina, S. Puljas, Z. Fredotovic, I. Samanic, G. Pleslic, Phylogenetic relationships among populations of the vineyard snail Cernuella virgata (Da Costa , 1778), ISRN Zool., 2013, 2013, 9–12.