Pasta tubes are a type of pasta that is shaped like a tube. The four crossword solutions for the term 'pasta tubes' are ZITI (4 letters), RIGATONI (8 letters), MACARONI (8 letters), and PENNE (5 letters). ZITI is a tubular-shaped pasta that is slightly curved, while RIGATONI is a large, ridged tube-shaped pasta. MACARONI is a smaller, elbow-shaped pasta, and PENNE is a short, diagonal-cut tube pasta. All of these pastas are popular in Italian cuisine.