Diagnostic characters: Small to medium-sized fishes (rarely exceeding 16 cm); body oblong or
rounded, moderately to markedly compressed laterally. Eyes moderate to large, preceded by a
short, snubnosed snout. Maxilla concealed under the preorbital, except for the widened posterior end
which curves downward and is tucked into a groove beneath the eye (giving these fishes the
appearance of being “down in the mouth”). Mouth highly protrusible, when extended forming a tube
directed either upwards (Secutor spp.), forward (Gazza spp.), or forward or downward (Leiognathus spp.).
Teeth small, punctate, arranged in 1 or several rows (Gazza spp. additionally with a pair of curved canines
at front of upper jaw and several in lower jaw). A pair of lateral elevated bony ridges on top of head between
eyes, each preceded by a single spine or a pair of small spines, and, medially, another ridge terminating
posteriorly in a bony crest, often referred to as the “nuchal spine”. All fin spines and soft rays fragile; a
single dorsal fin with VIII (rarely VII or IX) spines, the first one very small, and 16 or 17 soft rays; anal
fin with III spines and 14 soft rays; caudal fin deeply emarginate to forked; pectoral fins short; pelvic fins
very short. Trunk covered with small cycloid scales, except for breast and, less frequently, an area
just behind head in some species; head without scales in all but a few species which have a patch
of small scales below eye. Colour: silvery, with characteristic markings on the upper half of sides which
are useful for identification