Observation on the morphology of Australorbis glabratus

• Autor(a) principal: Paraense,W. Lobato
• Data de Publicação: 1955
• Outros Autores: Deslandes,Newton
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Memórias do Instituto Oswaldo Cruz
• Texto Completo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02761955000100009

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).