Hexagrammos octogrammus, the common greenfish of Alaska, and the greenling Hexagrammos stelleri, are also well-known species. Close to the latter species is the Abura ainame, or fat cod, Hexagrammos otakii, common throughout Japan. The red rock-trout, Hexagrammos superciliosus, is beautifully variegated with red, the color being extremely variable. Other species are found in Japan and Kamchatka. Agrammus agrammus of Japan differs in the possession of but one lateral line. Ophiodon elongatus, the blue cod, cultus cod, or Buffalo cod of California, is a large fish of moderate value as food, much resembling a codfish, but with larger mouth and longer teeth. The flesh and bones are deeply tinged with bluish green. Cultus is the Chinook name for worthless. Zaniolepis latipinnis is a singular-looking fish, very rough, dry, and bony, occasionally taken on the California coast. Oxylebius pictus is a small, handsome, and very active little fish, whitish with black bands, common among rocks and algæ on the California coast. It is, however, rarely brought into the markets, as it shows great skill in escaping the nets.
No fossil Hexagrammidæ are known.
The Flatheads or Kochi: Platycephalidæ.—The family of Platycephalidæ consists of spindle-shaped fishes, with flattened, rough heads and the body covered with small, rough scales. About fifty species occur in the East Indian region, where the larger ones are much valued as food. The most abundant species and usually the largest in size is Platycephalus insidiator, the kochi of the Japanese. The genus Insidiator contains smaller species with larger scales. In all these the head is very much depressed, a feature which separates them from all the Scorpænidæ. Hoplichthys langsdorfi, the nezupo or rat-tail of Japan, is the type of a separate family, Hoplichthyidæ, characterized by a bony armature of rough plates. Bembras japonicas, another little Japanese fish, with the ventrals advanced in position and the skin with rough plates, is the type of the family of Bembradidæ.
The Sculpins: Cottidæ.—The great family of Cottidæ or sculpins is one especially characteristic of the northern seas, where a great variety of species is found. These differ in general from the Scorpænidæ, from which they are perhaps derived, in the greater number of vertebræ and in the relative feebleness or degeneration of the spinous dorsal, the ventrals, and the scales. In all these regards great variation exists. In the most primitive genus, Jordania, the body is well scaled, the spinous dorsal well developed, and the ventral rays I, 5. In Hemitripterus a large number of dorsal spines remains, but the structure in other regards is highly modified. In the most degraded types, Cottunculus, Psychrolutes, Gilbertidia, which are also among the most specialized, there is little trace of spinous dorsal, the scales are wholly lost, and the ventral fin is incomplete. Most of the species of Cottidæ live on the bottom in shallow seas. Some are found in deep water and a few swarm in the rivers. All are arctic or subarctic, none being found to the south of Italy, Virginia, California, and Japan. None are valued as food, being coarse and tough. Scarcely any are found fossil.
Of the multitude of genera of Cottidæ we notice a few of the most prominent. Jordania zonope, a pretty little fish of Puget Sound, is the most primitive in its characters, being closely allied to the Hexagrammidæ.
Fig. 381.—Jordania zonope Starks. Puget Sound.
Scorpænichthys marmoratus, the great sculpin, or cabezon, of California reaches a length of 2½ feet. It has the ventral rays I, 5, although almost in all the other sculpins the rays are reduced to I, 3 or I, 4. The flesh has the livid blue color seen in the cultus cod Ophiodon elongatus.
Fig. 382.—Astrolytes notospilotus (Girard). Puget Sound.