Author: Dagosta & de Pinna, 2021
Comments: The Rio Taquarizinho is ca. 15 m wide at the collection locality; the water is clear, slightly milky and with moderate current. Specimens were collected by seining on sand banks in the middle of the river, especially in sectors shaded by riparian vegetation. There was no aquatic vegetation and depth of collection ranged from 30-150 cm. This species is sympatric with <i>Paravandellia oxyptera</i>, both are relatively abundant at the type locality. These two species are psammophilic, but with different microhabitat preferences where <i>P. saci</i> favors fine sand, while <i>P. oxytera</i> prefers sectors with coarser granulation. Segregation is not complete however, and occasionally they were captured together in the same net. Some female specimens have large eggs, approximately eye-sized or slightly larger, visible by transparency. Eggs distributed along ventral margin of hypaxial musculature from shortly posterior to end of pectoral fin to nearly end of abdominal cavity, with approximately 20 eggs visible in lateral layer of each side (certainly more in inner portions of gonad) (Ref. 124573).