Hiodon tergisus LeSueur, 1818
Species overview
Together with. H. alosoides in shape of body the most herring like species of all Osteoglossomorpha, with all fins well developed, caudal fin forked. Silvery with bluish back,
countershaded. Eye large, with silvery shine of its back in artificial light reflected by the tapetum lucidum, hence the common name "mooneye".
Size observed: may grow up to 45 cm, usually about 30 cm. Esteemed for sport, though not for its meat.
Taxonomic description
In outer appearence vers similar to Hiodon alosoides, i. e.herring like with evenly convex back and convex ouline of belly. Distinctive character are the round, blunt scales on the gular region and the belly in front of the pelvic fins.
-Head short, slightly deeper than long.
-Mouth terminal, its edge extending below posterior rim of pupil.
-Snout shorter than diameter of eye.
-Eye large, with small distance from both maxilla and front line of head; iris silvery, eye shine white in artificial light.
-Opercular cleft long, its posterior border almost perpendicular to axis of body.
-Origin of pectotal fin below level of edge of mouth, at lower curvature of opercle.
-Pelvic fins abdominal at about middle od body.
-Origin of dorsal fin slightly anterior to origin, its end ca. above first third of anal fin.
-Caudal fin large, deeply forked, its lobes pointed.
-Scales moderately large.
-Coloration, brillant silvery with bluish back, countershaded.
Type locality
Not known.
Distribution
Rivers emptying into the Hudson Bay and tributaries of Saint Lawrence River, southern parts of the Great Lakes and south to Arkansas and Alabama. In general more distributed to the North and East than H. alosoides. Prefers clean water in lakes and rivers.