Species, GC (%), AT (%), G (bases), C (bases), A (bases), T (bases), Maximum lifespan (yrs) Ichthyomyzon unicuspis, 34.8, 65.2, 346, 132, 444, 452, 8.0, Lampetra aepyptera, 36.6, 63.4, 361, 143, 440, 433, 8.0, Lampetra fluviatilis, 37.2, 62.8, 359, 153, 445, 420, 10.0, Lethenteron camtschaticum, 35.8, 64.2, 351, 142, 454, 430, 7.0, Lethenteron reissneri, 35.9, 64.1, 349, 145, 451, 432, 4.0, Petromyzon marinus, 36.1, 63.9, 354, 143, 452, 428, 9.0,