Additional larval, juvenile, and adult specimens and live photographs of the Caribbean Kuna Goby, Coryphopterus kuna, expand the known geographic range for the species and allow a comprehensive description of all the life stages for this recently-discovered species, including age and growth estimates from daily otolith increments. The Kuna Goby is found widely throughout the tropical western Atlantic, including southern Florida, Quintana Roo on the Yucatan Peninsula of Mexico, Belize, Honduras, Panama, San Andres Island, Bonaire, and Guadeloupe. The additional specimens indicate that C. kuna has a pelvic frenum and that females have a black flag on the outer portion of the first two spinous dorsal-fin membranes, while males have a dark stripe along the mid-length of the spinous dorsal fin. The development of melanophores on pelagic larvae through the transition to settled juvenile is described. The Kuna Goby is a notably small goby: larvae settle around 7–9 mm SL, adults mature at 10–11 mm SL and then only attain about 17 mm SL. Kuna Gobies settle after a 60-day pelagic larval life, and mature rapidly. They are reproductive in as few as three weeks and live for about two months after settlement. This is the first reported fish in which the pelagic larval duration is generally longer than the post-settlement lifespan.