Fig. 182.—Three-spined Stickleback, Gasterosteus aculeatus L. Wood's Hole, Mass.
Fig. 183.—Four-spined Stickleback, Apeltes quadracus Mitchill. Wood's Hole, Mass.
Eucalia inconstans is the stickleback of the clear brook from New York to Indiana and Minnesota. The male is jet black in spring with the sheen of burnished copper and he is intensely active in his work of protecting the eggs of his own species and destroying the eggs and fry of others. Spinachia spinachia is a large sea stickleback of Europe with many dorsal spines.
No fossil Gasterosteidæ are recorded, and the family, while the least specialized in most regards, is certainly not the most primitive of the suborder.
The Aulorhynchidæ.—Closely related to the sticklebacks is the small family of Aulorhynchidæ, with four soft rays in the ventral fins. Aulorhynchus, like Spinachia, has many dorsal spines and an elongate snout approaching that of a trumpet-fish. Aulorhynchus flavidus lives on the coast of California and Aulichthys japonicus in Japan. The extinct family of Protosyngnathidæ is near Aulorhynchus, with the snout tubular, the ribs free, not anchylosed as in Aulorhynchus, and with the first vertebræ fused, forming one large one as in Aulostomus. Protosyngnathus sumatrensis occurs in Sumatra. Protaulopsis bolcensis of the Eocene of Italy has the ventral fins farther back, and is probably more primitive than the sticklebacks.
Cornet-fishes: Fistulariidæ.—Closely related to the sticklebacks so far as structure is concerned is a family of very different habit, the cornet-fishes, or cornetas (Fistulariidæ). In these fishes the body is very long and slender, like that of a garfish. The snout is produced into a very long tube, which bears the short jaws at the end. The teeth are very small. There are no scales, but bony plates are sunk in the skin. The ventrals are abdominal, each with a spine and four rays. The four anterior vertebræ are very much elongate. There are no spines in the dorsal and the back-bone extends through the forked caudal, ending in a long filament. The cornet-fishes are dull red or dull green in color. They reach a length of two or three feet, and the four or five known species are widely distributed through the warm seas, where they swim in shallow water near the surface. Fistularia tabaccaria, the tobacco-pipe fish, is common in the West Indies, Fistularia petimba, F. serrata, and others in the Pacific. A fossil cornet-fish of very small size, Fistularia longirostris, is known from the Eocene of Monte Bolca, near Verona. Fistularia kœnigi is recorded from the Oligocene of Glarus.
The Trumpet-fishes: Aulostomidæ.—The Aulostomidæ, or trumpet-fishes are in structure entirely similar to the Fistulariidæ, but the body is band-shaped, compressed, and scaly, the long snout bearing the feeble jaws at the end. There are numerous dorsal spines and no filament on the tail. Aulostomus chinensis (maculatus) is common in the West Indies, Aulostomus valentini abounds in Polynesia and Asia, where it is a food-fish of moderate importance. A species of Aulostomus (bolcensis) is found in the Italian Eocene. Allied to it is the extinct family Urosphenidæ, scaleless, but otherwise similar. Urosphen dubia occurs in the Eocene at Monte Bolca. Urosphen is perhaps the most primitive genus of the whole suborder of Hemibranchii.
