Urine Formation in A Pulmonate Land Snail, Achatina Fulica

Abstract

1. Inulin is filtered into the urine of Achatina fulica. The process is not subject to poisoning but water reabsorption may raise the U/B ratio to 2.8. The U/B ratios of substances actively reabsorbed or secreted reaches 1 when transport is poisoned thus verifying filtration as a first step in urine formation. 2. Exogenous urea is excreted by filtration. 3. Glucose is filtered and actively reabsorbed. Reabsorption can be poisoned with phlorizin. 4. Chloride is actively reabsorbed. 5. Phenol red and PAH are actively secreted. The secretory process may be poisoned with dinitrophenol. 6. The clearance of phenol red may be taken as an estimate of blood flow through the kidney, which may reach 5.6 ml./min./kg. in Achatina fulica. 7. The PAH clearance is depressed by simultaneous excretion of phenol red and the quantitative measurements of transport give evidence that the same secretory mechanism is used for both phenol red and PAH.

Case report: Four cases of kidney disease in Giant African Land Snails (Lissachatina fulica)

“…Kidney anatomy and urine formation in L. fulica were already described by Van Benthem Jutting in 1951 ( 7 ), Ghose in 1964 ( 8 ) and Martin et al in 1965 ( 9 ). Van Benthem Jutting ( 7 ) showed the general anatomy on the basis of dissected L.fulica and described the kidney as one elongated organ, lying transversally in the left mantle cavity.…”

Comparative diagnostic imaging in giant African land snails (Achatinidae)

“…The single (usually left, as the right one has disappeared during evolution) nephridium or kidney of Lissachatina fulica is positioned transversely-oriented parallel to the heart ( 2 ) and is described as a single-lobed, thin structure with a compressed lumen much flattened in one dimension ( 10 , 37 , 38 ). The average size in a full-grown snail is approximately 5×1.2 cm.…”

“…Sonographically, the internal structure of the kidney should be visible, but in living animals, it cannot be accessed due to its peripheral position in the shell and the surrounding lung. The reno-pericardial canal, which should connect the pericardium with the lumen of the kidney, could not be visualized either ( 38 ). For proper visualization of such a canal, an intramuscular iodine contrast study may have been useful but was not performed as already mentioned.…”