Observation on the morphology of Australorbis glabratus

Abstract

The present morphological study of A. glabratus was based on the observation of shell, radula, renal region and genitalia of 50 specimens having a shell diameter of 18 mm. In this summary we record the data pertaining to the chracteristics that can be used in systematics. The numerals refere to the mean and their standard deviation; no special reference being made, they correspond to length measurements. Shell: 18 mm in diameter, 5.59 ± 0.24 mm in greatest width, 5 to 6 whorls. Right side umbilicated, left one weakly depressed. Last whorl about thrice as tall as the penultimate one at the aperture, the measurements being taken on the right side. Aperture perpendicular or a little oblique. Body, extended: 47.06 ± 3.31 mm. Renal tube: Narrow and elongated, 23.84 ± 1.90 mm, showing a pigmented ridge along its ventral surface. Ovotestis: 12.78 ± 1.50 mm. Mainly trifurcate diverticula attaching in fan-like manner to the collecting canal (this arrangement is seen to best advantage in the cephalic middle of the ovotestis). The collecting canal greatly swells at the cephalic end, narrowing suddenly as it leaves the ovotestis. Ovisperm duct: 13.70 ± 1.68 mm, including the non-unwound seminal vesicle. The latter, situated about 1 mm from the beginning af the ovisperm duct, was 1.14 ± 0.29 mm in greatest diameter, and is beset by numerous short diverticula. Sperm duct: 14.16 ± 1.27 mm, pursuing a sinous course along the oviduct. Prostate: Prostate duct 5.53 ± 0.74 mm, collecting a row of long diverticula, the latter 21.6 ± 3.5 in number. Last diverticulum generally simple or bifurcate, penultimate generally arborescent, bifurcate or simple, antepenultimate nearly always arborescent, the remaining ones arborescent. The arborescent diverticula frequently give off secondary branches. Vas deferens: 17.50 ± 2.05 mm. The ratio vas deferens/vergic sac was 4.7 ± 0.6. Verge: 3.70 ± 0.54 mm long, 0.12 ± 0.03 mm wide. Free end tapering to a point where the sperm canal opens. No penial stylet. Vergic sac: 3.77 ± 0.50 mm long, 0.19 ± 0.01 mm wide. The length ratio vergic sac/preputium was 1 ± 0.02. Preputium: Deeply pigmented, 3.79 ± 0.40 mm long, 0.89 ± 0.12 mm wide in the middle. Muscular diaphragm between it and the vergic sac. Two muscular pilasters along its lateral walls. Oviduct: 10.24 ± 1.29 mm, suddenly swollen at the cephalic end so that it forms a folded pouch capping the beginning of the uterus. Uterus: 10.58 ± 1.18 mm. Vagina: 2.06 ± 0.15 mm long, 0.32 ± 0.05 mm wide, showing a swelling at its caudal portion, just above the opening of the spermathecal duct. Spermatheca: 1.57 ± 0.41 mm long, 0.92 ± 0.23 mm wide. Spermathecal duct 1.15 ± 0.23 mm. Radula: 125 to 163 rows of teeth (mean 141.4 ± 9.8). Radula formula 27-1-27 to 34-1-34 (mean 30.9 ± 1.7).<br>Foi feito um estudo da morfologia do A. glabratus, baseado na observação da concha, da rádula, da região renal e da genitália de 50 espécimes cujas conchas mediam 18 mm em diâmetro. Apresentamos a seguir os dados referentes aos caracteres utilizáveis na sistemática. Os números...

A geoprocessing approach for studying and controlling schistosomiasis in the state of Minas Gerais, Brazil

“…Mollusks were collected in breeding places from different municipalities in MG at different times, using scoops and tweezers and then packed to be transported to the laboratory (Souza & Lima 1990). Specific identification was performed according to the morphology of the shells, reproductive system and renal ridge of the mollusks (Deslandes 1951, Paraense & Deslandes 1955a, b, 1959, Paraense 1975, 1981 and more recently by low stringency polymerase chain reaction and restriction fragment length polymorphism (Vidigal et al 2000).…”

Geographical distribution of Biomphalaria snails in the State of Minas Gerais, Brazil

“…Snails were collected in breeding places from different municipalities in Minas Gerais at different periods, using scoops and tweezers, and then packed to be transported to the laboratory (Souza & Lima 1990). Specific identification was performed according to the morphology of the shells, reproductive system and renal ridge of the snails (Deslandes 1951, Paraense & Deslandes 1955a,b, 1959, Paraense 1975, 1981, or recently through low stringency polymerase chain reaction and restriction fragment lenght polymorphism (Vidigal et al 2000). Different researchers, whose works are quoted in the references, collected and identified the snails.…”

Growth changes induced by gamma radiation on Biomphalaria straminea (Dunker, 1848)

“…Biomphalaria are hermaphrodite snails (Paraense & Deslandes 1955, Leal 1976 and their species glabrata, straminea and tenagophila (Paraense & Deslandes 1955) exist in Brazil. These snails are intermediate hosts for S. mansoni with B. straminea being prevalent in many regions of Brazil (Paraense & Deslandes1955, Leal 1976.…”