This species is medically important pest,[3] because of transferring the disease intestinal schistosomiasis. (Intestinal schistosomiasis is the most widespread of all types of schistosomiasis).
Biomphalaria tenagophila guaibensisParaense, 1984[5] – Biomphalaria tenagophila guaibensis can be distinguished from the nominal subspecies according to the details on the reproductive system only.[5]
There are also three "old-style" proposals of subspecies, based on shell characteristics:[5]
Planorbis tenagophilus chemnitziana Beck, 1837 – this name is based on the catalog for the shell in Museum of Copenhagen, but without description.[5]
Planorbis tenagophilus orbignyana Beck, 1837 – the same situation as in P. t. chemnitziana[5]
This species has recently expanded its native range.[3][10]
The non-indigenous distribution of Biomphalaria tenagophila includes a hypothermal spring near Răbăgani, Romania (46°45´1.3´´N, 22°12´44.8´´E).[10]
Shell description
The shell is sinistrally coiled (has left-handed coiling). The flat shells are yellow-brown, discoidal, deeply and symmetrically biconcave, and consist of 5 or 6 slowly increasing whorls. The last whorl is rounded; the intermediate whorls are slightly angled on the left side. The aperture is circular or slightly ovate and angled toward the left side of the shell (i.e., toward the upper surface on the bottom right shell). Fine, parallel, rib-like transverse lines can be seen on the outer surface of the whorls.[10]
The width of the shell is usually from 11 to 13 mm,[10] but in the largest individuals, the shell can reach 21 mm in width, 6.5 mm in height and have 6.5 whorls.[5]
A shell of Biomphalaria tenagophila.
A cross section of apertural view of the shell of Biomphalaria tenagophila. The shell is sinistral in coiling, thus the sunken spire is on top and the umbilicus at the bottom in this image
Reproductive system of Biomphalaria tenagophila. Scale bar is 1 mm. ag – albumin gland bc – bursa copulatrix hp – distal part of the hepatopancreas ng – nidamental gland od – oviduct ot – ovotestis pp – preputium pr – prostate ps – penis sheath sd – spermiduct sv – seminal vesicles vd – vas deferens vp – vaginal pouch.
Anatomy
The anatomy of this species was firstly published under the synonym Australorbis nigricans in 1955.[11]
The radula has from 125 to 168 rows of denticles (tiny teeth). The number of lateral teeth varying from 28 to 36. The mode radula formula is 31-0-31.[11]
The specific characteristics of the reproductive system of Biomphalaria tenagophila are: more than 200 diverticulae of the ovotestis; 7–11 main lobes of the prostate; and presence of vaginal pouch.[10]
Ecology
Habitat of Biomphalaria tenagophila is tropical standing water or freshwater.[10]
Biomphalaria tenagophila is an intermediate host for Schistosoma mansoni and a vector of schistosomiasis.[12]Schistosoma mansoni came to Neotropics from Africa in context of the slave trade.[8]Schistosoma mansoni was not able to infect Biomphalaria tenagophila in 1916 and it has adapted to this host since 1916.[8]
This article incorporates public domain text from the reference.[10]
^ abd’Orbigny A. (1835) Synopsis terrestrium et fluviatilium molluscoum, in suo per Americam meridionalem itinere collectorum. Magasin de zoologie5(62): 1–44. Page 26.
^Spix J. B. & Wagner J. A. (1827) Testacea Fluviatilia Brasiliensis. vi. + 36 pp., 29 tab., typ. C, Wolf, Monachii.
^ abcPointier, J. P.; David, P.; Jarne, P. (2005). "Biological invasions: The case of planorbid snails". Journal of Helminthology. 79 (3): 249–256. doi:10.1079/JOH2005292. PMID16153319.
^Pilsbry, H. A. (1951). "Notes on some Brazilian Planorbidae". Nautilus. 65 (1): 3–6.
^Paraense W. L. (2001) "The Schistosome Vectors in the Americas". Memórias do Instituto Oswaldo Cruz96(Supplement): 7–16. textArchived July 6, 2011, at the Wayback Machine, PDFArchived July 6, 2011, at the Wayback Machine
^Pereira, C. A. J.; Martins-Souza, R. L.; Coelho, P. M. Z.; Lima, W. S.; Negrão-Corrêa, D. (2006). "Effect of Angiostrongylus vasorum infection on Biomphalaria tenagophila susceptibility to Schistosoma mansoni". Acta Tropica. 98 (3): 224–233. doi:10.1016/j.actatropica.2006.05.002. PMID16750811.
