Describing intermediate host snails in Kapatagan, Lanao del Norte, Philippines: a phenetic analysis

Paper Details

Research Paper 01/09/2018
Views (351) Download (14)

Describing intermediate host snails in Kapatagan, Lanao del Norte, Philippines: a phenetic analysis

Johara F. Aquino, Sharon Rose M. Tabugo
Int. J. Biosci.13( 3), 58-67, September 2018.
Certificate: IJB 2018 [Generate Certificate]


Many species of freshwater snails served as intermediate hosts of highly infective fluke (trematode) larvae of the genus Schistosoma which cause Schistosomiasis however, the nature of populations remained ambiguous. This study shed light on the nature of populations of intermediate hosts snails from two barangays: Curvada and Tiacungan, Kapatagan, Lanao del Norte, Philippines. This study determined and described species composition of populations and correlates positive and negative infected snails with size and shape morphology. Phenetic analysis was used to describe and delineate morphology of snails based on important shell characters. A total of 42 characters were used to construct the character matrix. The important characters in species delineation were mainly on the suture, last or body whorl width, color, basal lip, shell size, body whorl banding patterns, spire coloration and the presence of spines. The generated phenogram revealed the existence of two possible clusters based on overall phenotypic similarity. Results revealed the presence of five (5) morphotypes belonging to three genera: Oncomelania, Tricula and Thiara, which was contrary to local knowledge that a single genus was the sole intermediate host snail. Noteworthy, an important character that helped in species delineation was body whorl banding patterns. Shell size was evidently reduced in infected populations. Parasite infected snails has narrow body whorl, arch-shaped apex and pronounced narrow apertural opening.


Bethel WM, Holmes JC. 1973. Altered evasive behavior and responses to light in amphipods harboring acanthocephalan cystacanths. The journal of parasitology 59, 945-956.

Burch JB. 1984. Freshwater Snails of the Philippines. Walkerana  Trans. POETS Soc. 2, 81-112.

Caldeira RL, Jannotti-Passos LK, Lira PM, Carvalho OS. 2004. Diagnostic of Biomphalaria snails and Schistosoma mansoni: DNA obtained from traces of shell organic materials. Memorias do Instituto Oswaldo Cruz 99, 499-502.

Davis GM, Wu WP, Xu XJ. 2006. Ecogenetics of shell sculpture in Oncomelania (Gastropoda) in canals of Hubei, China, and relevance for schistosome transmission. Malacologia 48, 253-264.

Duncombe J, Clements A, Hu W, Weinstein P, Ritchie S, Espino FE. 2012. Geographical information systems for dengue surveillance. The American journal of tropical medicine and hygiene 86, 753-755.

Gutierrez PM, Torres MAJ, Demayo CG. 2011. Thin-Plate Spline (TPS) and Correlation Based on Distances (CORIANDIS) Analyses as Tools for the analysis of Morphological Differences in Dragonfly Wings. In 2011 2nd International Conference on Environmental Science and Technology (ICEST 2011) 2, 375-379.

Kim SB, Oh HS, Kim WT, Tadauchi O. 2009. Phenetic Analysis of the Anisoptera (Insecta: Odonata) in Jeju Island, Korea, based on Morphological Characters. Journal of the Faculty of Agriculture, Kyushu University 54, 123-132.

Köhler F. 2003. Brotia in space and time: phylogeny and evolution of Southeast Asian freshwater gastropods of the family Pachychilidae (Caenogastropoda, Cerithioidea). na.

Lefevre T, Thomas F. 2008. Behind the scene, something else is pulling the strings: emphasizing parasitic manipulation in vector-borne diseases. Infection, Genetics and Evolution 8, 504-519.

Mayr E, Ashlock P. 1991. Principles of Systematic Zoology (2nd edition). McGraw-Hill Inc, Singapore.

Moneva CSO, Torres MAJ, Wada T, Joshi R, Demayo CG. 2012. Relative warp and correlation analysis based on distances of the morphological shell shape patterns of Pomacea canaliculata Lamarck from Japan and the Philippines. Advances in Environmental Sciences 4, 12-21.

Oetinger DF, Nickol BB. 1981. Effects of acanthocephalans on pigmentation of freshwater isopods. The Journal of Parasitology 67, 672-684.

Olveda DU, Li Y, Olveda RM, Lam AK, Chau TN, Harn DA, Williams GM, Gray DJ, Ross AG. 2013. Bilharzia: pathology, diagnosis, management and control. Tropical medicine & surgery 1, 1-19.

Rumpus AE, Kennedy CR. 1974. The effect of the acanthocephalan Pomphorhynchus laevis upon the respiration of its intermediate host, Gammarus pulex. Parasitology 68, 271-284.

Skorping A. 1985. Parasite–induced reduction in host survival and fecundity: the effect of the nematode Elaphostrongylus rangiferi on the snail intermediate host. Parasitology 91, 555-562.

Tabugo SRM, Torres MAJ, Demayo CG. 2013. Describing species of Neurothemis Dragonflies found in Iligan City, Philippines. Natura 17, 3-14.

Thieltges DW, Jensen KT, Poulin R. 2008. The role of biotic factors in the transmission of free-living endohelminth stages. Parasitology 135, 407-426.

Vasallo Jr EGR, Gorospe JM, Torres MAJ, Amparado Jr RF, Demayo CG. 2015. Relative Warp Analysis of Parasite–Induced Plasticity in the Shell Shape of Bithynia sp.(Bithyniidae). Journal of Medical and Bioengineering 4, 159.

Webster JP, Shrivastava J, Johnson PJ, Blair L. 2007. Is host-schistosome coevolution going anywhere? BMC evolutionary biology 7, 91

Zhao QP, Jiang MS, Littlewood DTJ, Nie P. 2010. Distinct genetic diversity of Oncomelania hupensis, intermediate host of Schistosoma japonicum in mainland China as revealed by ITS sequences. PLoS neglected tropical diseases 4, e611.