by their noticeably longer anal spine, anal fin configuration, and body shape. The four large species are immediately recognizable by their more streamlined appearance given by their longer, narrower body shape. Many individual species bear a close resemblance to one another, although they may be from the same or different oceans; identification is better left up to experts. The two Atlantic large species (C. undecimalis and C. poeyi) are virtually identical in appearance. They can usually only be distinguished by the number of gill rakers each possesses. The robalo or common snook (C. undecimalis) commonly has 11 to 13 nonrudimentary gill rakers and the Mexican snook (C. poeyi) is most often found to possess 15 to 18 nonrudimentary gill rakers. The Pacific robalo nato or white snook (C. viridis) is also a dead ringer for the common snook. The distinguishing feature is also the nonrudimentary gill raker count with 13 to 15 for the white snook. They act, breed, grow, and fight virtually the same. Curiously, laboratory-reared specimens of the common snook showed meristic variations in vertebrae, fin ray, and gill raker numbers not observed in specimens from the wild. These variations are suspected to be due to diet and growth rates. Large robalo caught in Lake Gatun invariably cause a wealth of confusion. The IGFA requires verification of the species by a designated authority for world-record claims. The two Pacific species of large robalo are somewhat easier to distinguish. The robalo redondo or black snook (C. nigrescens) can be differentiated by three visually apparent characteristics when compared to the C. viridis The body of C. nigrescens, while similarly elongated, is rounder and heavier in general appearance, being thicker through the middle than C. viridis. The head of C. nigrescens is bigger and the undershot jaw, characteristic of all róbalo, is far less pronounced than in C. viridis. Most importantly, the fourth dorsal spine of C. nigrescens is taller than the third. In both species, the first two dorsal spines are hardly noticeable. In large specimens, these first two spines are only a quarter of an inch long, while the third spine is over two inches in length. Therefore, if the first long dorsal spine is longer than all the others, it is a C. viridis, but if the first long dorsal spine is shorter than the second long dorsal spine it is a C. nigrescens. Species Armed snook, C.