Biomphalaria kuhniana (Clessin, 1883), planorbid mollusc from South America

Abstract

The validity of Biomphalaria kuhniana (Clessin, 1883) is confirmed through morphological study of specimens from Surinam (type locality) and the area of Tucurui (Tocantins river, state of Pará, Brazil) in comparison with B. straminea (Dunker, 1848), and throught crossing experiments which revealed complete reproductive isolation between the two species. The full-grown shell of kuhniana is smaller (about 7.5 mm) than that of straminea (11 mm to 16.5 mm). Anatomically they differ in the degree of corrugation of the vaginal wall (little developed in kuhniana, conspicuous in straminea), number and shape of prostatic diverticula (kuhniana 4 to 9, shorter and less branched; straminea 9 to 18, longer and more branched),number of muscle layers at the middle of the penis (two in kuhniana, three in straminea), distal segment of the spermiduct usually straight or slightly wavy in kuhniana, more or less curly in straminea. Differences between B. kuhniana and B. intermedia (paraense & Deslandes, 1962) are less marked. The latter has a shell up to about 12 mm in diameter, 7 to 15 prostatic diverticula, two muscle layers at the middle of the penis, and a vaginal wall with a combination of a more or less developed corrugation (or sometimes a mere swelling) on the left of the spermathecal duct and a rudimentary pouch on the right of the duct. A Biomphalaria straminea complex is proposed to include that species as well as B. kuhniana and B. intermedia.

Morphological and polymerase chain reaction-restriction fragment lenght polymorphism characterization of Biomphalaria kuhniana and Biomphalaria amazonica from Colombia

“…Interestingly, this kind of morphological variability was not detected at the intrapopulational level in contrast with the finding reported in B. kuhniana from Tucuruí, Brazil (Paraense 1988).…”

“…The remaining material was fixed and dissected for morphology of the shell and reproductive organs as described by Deslandes (1951) and Paraense (1975Paraense ( , 1976Paraense ( , 1988.…”

“…Concerning the epidemiological importance of B. straminea for schistosomiasis, this species is commonly confused with B. kuhniana and B. intermedia. For this reason, these three species were clustered into a group named B. straminea complex (Paraense 1988). The difficulties involved in specific identification based on morphological characters have motivated the use of more modern techniques such as molecular biology.…”

“…The type locality of B. kuhniana (Clessin, 1883) is Paramaribo, Surinam but it is also found in Cayenne, French Guyana (Floch & Fauran 1954a,b, Floch & Lajudie 1945, Venezuela (Baker 1930), Tucuruí, Pará, Brazil (Paraense 1988), and Panama (Paraense -pers. commun.…”

The schistosome vectors in the Americas

“…Originally described from Suriname, I collected it in Paramaribo and in localities on the Tocantins river basin, northern Brazil (Paraense 1988), and also in Panama (Paraense 1999), where it was named P. isthmicus by Pilsbry (1920). Samples labeled "B. straminea" from Venezuela and Colombia have been received for identification in this laboratory.…”