132 
BULLETIN OF THE BUREAU OF FISHERIES 
Order HAPLOMI 
' ' ' ' . ■ ■ • • 
Family XXX. — ESOCIDAi. The pikes, pickerel, and muskallunges 
Body very elongate, not elevated, and not much compressed; head long; snout long and broad, 
depressed; mouth very large; mandible projecting; margins of upper jaws formed by maxillaries, 
provided with a supplemental bone; teeth present on jaws, vomer, palatines, and tongue; gill 
slits wide; gill membranes not united and free from the isthmus; gill rakers small, tuberclelike or 
toothed; branchiostegals numerous; lateral line weak, obsolete in young; scales small, wanting on 
upper surface of head and snou't, cheeks and opercles partly or completely scaled; dorsal placed 
far back, similar to and opposite the anal; caudal fin forked; no adipose fin; air bladder simple. 
This family consists of a single genus. 
43. Genus ESOX Linnaeus. Pikes; Pickerels; Muskallunges 
The characters of the genus are included in the family description. 
KEY TO THE SPECIES 
a. Dorsal rays 13 or 14 (counting branched rays only); anal 12 or 13; branchiostegals 14 to 16; 
scales 122 to 126; adults with numerous lines, forming reticulations on the sides 
reliculatus, p. 132 
aa. Dorsal rays 11 or 12; anal 11 or 12; branchiostegals 11 to 13; scales about 105; sides usually 
with black vertical bars; no reticulations americanus, p. 134 
55. Esox reticulatus LeSueur. Eastern pickerel; “ Chain pickerel”; “Pike.” 
Esox reticulatus LoSueur, Journ., Ac. Nat. Sci., Phila., I, 1818, p. 414; Connecticut River, Adams, Mass.; Philadelphia. 
Uhler and Lugger, 1876, ed. I, p. 145; ed. II, p. 124; Bean, 1883, p. 366; Evermann and Hildebrand, 1910, p. 159; Fowler, 1912, p. 54. 
Lucius reticulatus Jordan and Evermann, 1896-1900, p. 627; Smith and Bean, 1899, p. 184. 
Head 2.7 to 3.3; depth 5.3 to 6.6; D. 13 or 14 (counting divided rays only; 18 or 19 including 
rudiments); A. 12 or 13 (counting divided rays only; 16 or 17 including rudiments); scales 122 to 
126. Body rather slender, somewhat compressed, deepest near the middle; head large, depressed 
above, the profile a little concave over snout; snout long and broad, equal to or a little longer than 
postorbital part of head, 2.1 to 2.8 in head; eye 5 to 10; interorbital 5.5 to 12; mouth large, nearly 
horizontal; the lower jaw projecting; maxillary scarcely reaching eye in very young, to or slightly 
past anterior margin of pupil in large specimens, 2 to 2.8 in head; teeth present on jaws, vomer, 
palatines, and tongue; the lateral teeth on lower jaw and those on vomer enlarged; branchiostegals 
14 to 16; scales small, covering entire cheek and opercle; dorsal fin mostly opposite the anal, its 
origin about an eye’s diameter in advance of origin of anal; caudal fin forked, the lower lobe the 
larger; anal fin similar to the dorsal; ventral fins rather small, inserted a little nearer the origin of the 
anal than base of pectorals; pectoral fins similar to the ventrals, 2.5 to 6.6 in head. 
Color greenish above; pale underneath; scales above with golden luster; sides in adult reticu- 
lated with dark lines and streaks. These reticulations are most evident in the largest specimens and 
entirely wanting in the very young. A dark vertical bar under the eye and the young also with a 
dark longitudinal bar extending from the tip of the snout, through the eye, to margin of opercle. 
Fins plain, the dorsal and caudal darker than the others. 
Many specimens of this pickerel, ranging from 28 to 490 millimeters ( 1 J4 to 19)4 inches) in length, 
were preserved, and these fish form the basis for the foregoing description. The chief diagnostic 
differences between this species and the banded pickerel are shown in the key to the species. The 
principal change that takes place with age is in color. The reticulations that are characteristic of the 
species, according to specimens at hand, are not well defined until the fish reaches a length of about 
12 inches. The very young (1 to 2 inches long) are grayish in color in spirits, and the upper parts 
everywhere bear dusky punctulations. A black bar extends from the tip of the snout, through 
the eye, to the margin of the opercle. When the fish exceeds a length of 2J4 inches dark areas 
appear on the sides, which for some time become more prominent with age. As the fish increases 
in length, narrow, pale, vertical bars appear along the upper parts of the sides. These pale bars 
