Lewis & Short

piscīnārĭus, a, um, adj. [piscina],

  1. I. of or belonging to fish-ponds: macellum, Varr. R. R. 3, 17 ex conject. Ponted.; v. Schneid. ad loc.
  2. II. Subst.: piscīnārĭus, ii, m., one fond of fish-ponds, Cic. Att. 1, 19, 6; 1, 20, 3; Macr. S. 1, 11.