The long, semi-cylindrical Pipe-fishes, partly on account of their peculiar form and colour, and partly on account of their swaying motions, so closely resemble the fronds of seaweed amongst which they dwell as to pass unnoticed by their enemies. Unlike the Tube-mouths, just described, the care of the eggs and young devolves upon the males. The young are borne in a pouch, but, ventral fins being wanting, this is formed by a fold of skin developed from each side of the trunk and tail, the free margins being united in the middle line. Here the eggs remain till they are hatched. But the pouch is by no means done with after this event, for the young continue to occupy it for some time, returning when danger threatens—a habit which recalls the custom of the young of the kangaroo. Mr. Yarrell relates a curious fact which he gleaned from some fishermen—to wit, that if they take a pipe-fish, open the pouch, and drop the young into the sea, they will not disperse, but hover around the spot, as if waiting for their parent. Then, if the newly opened fish be held in the water, the young immediately return and enter the pouch. In another species of pipe-fish the eggs, instead of being carried in a pouch, are held by a sticky secretion to a groove in the under surface of the parent. This groove would seem to indicate the beginning from which the complete pouch has been developed. The pipe-fishes swim in a very peculiar manner, holding the body now in a vertical, and now in a horizontal position, accompanied by contortions of every conceivable kind, poking their long snouts into bunches of seaweed in search of food as they go.
Photo by A. S. Rudland & Sons.
BLACK-SPOTTED GLOBE-FISH.
Globe-fishes possess the power of inflating the body with air, when they float at the surface, and thus escape enemies.
Photo by N. Lazarnick] [New York.
TRIGGER-FISH.
A well-known member of the File-fishes.
The Sea-horses have a still more eccentrically modified form, inasmuch as the body is thrown into a series of curves, the head being bent upon the trunk in a manner suggestive of the head and neck of the horse; hence the name of the group. The tail, which lacks the membranous portion, or fin, can be spirally coiled, and is used as an organ of prehension, and on this account is unique amongst fishes. Gripping the stems of seaweeds with this tail, and swaying the body to and fro among the vegetation, the fish is rendered comparatively inconspicuous, the lines of the body being broken up by numerous more or less filamentous processes, which in one species, the Fucus-like Sea-horse, become excessively developed, forming long, frond-like blades. These, streaming in the water, both by their shape and coloration render the resemblance to the vegetable growths in which the animal hides so perfect that detection is almost impossible. Thus they furnish one of the most remarkable examples of adaptation to the environment amongst living animals. The males of most sea-horses, like the pipe-fishes, carry the eggs and young in a pouch on the abdomen, but in the species just mentioned the eggs are embedded in the soft skin on the under surface of the tail.