Fig. 243.—The Lesser Weaver
The Greater Weaver (Trachinus draco) lives at the bottom of deep water, and is often dredged up in the trawl. Some fishermen call it the Sting Bull, and always take the precaution of cutting off the poisonous spines before disposing of the fish. It lives on the bottom with its mouth and eyes directed upward, always in readiness to seize its unwary prey, and the sharp spines of the dorsal fins are kept erect for the purpose of promptly attacking approaching foes. Its mouth and palate are armed with sharp teeth which render the escape of its prey almost impossible. The smaller species (T. vipera) seldom exceeds six inches in length. It lives in shallow water on sandy coasts, with dorsal spines erect; and the wounds it produces on the unprotected feet of bathers are often exceedingly painful on account of the injected poison, which also causes the part to swell and turn to a dark purple colour.
The remaining important families, although they contain well-known British food-fishes, do not include littoral species, and for this reason we shall pass them over with but brief notice.
The Mackerel (Scomber vernalis) belongs to the family Scomberidæ, and is so well known that no description need be given for the purposes of identification. We have already referred to it as a beautiful illustration of protective colouring, its upper surface resembling the ripples of a deep green sea and the lower the brightness of the sky. Mackerel swim in shoals in the open sea, pursuing and devouring the fry of herrings and other fish; and in order that they may be enabled to cover enormous distances their muscles are richly supplied with blood. This not only gives a pinkish colour to the flesh, but results in a greater amount of oxidation and the maintenance thereby of a body temperature several degrees higher than that of the surrounding water. We would also call attention to the five or six small fins behind the dorsal and anal fins as characteristic of the Scomberidæ.
Our next family (the Cyttidæ) contains the John Dory (Zeus-faber), concerning which some superstitions are still prevalent in parts. It is brightly coloured, but not graceful in form, and is often caught in large numbers off the coasts of Devon and Cornwall. Some fishermen call it the Cock, on account of the crest on the back; while others know it as St. Peter’s Fish, and will point out the impression of the Apostle’s finger on each side—a black spot surrounded by a light ring.
The Horse Mackerel (Caranx trachurus) is found principally in the same parts, where it devours the fry of other fishes. It is not a very close relative of the common mackerel, but belongs to a distinct family (Carangidæ), of which it is the only British representative. It is a carnivorous fish, easily distinguished from Scomber by its conical teeth, as well as by the bony plates of the lateral line, the posterior of which are keeled or spined.
While the last-mentioned families contain only fishes of truly pelagic habits, the next (Sparidæ), formed by the Sea Breams, generally keep near the coast, and often enter fresh waters. In these the body is much compressed laterally, and is covered with large scales; the first half of the dorsal fin is also spinous. The Common Sea Bream (Sparus auratus), characterised by its red colour with brilliant golden reflections, and by a dark spot on the shoulder, may often be angled from rocks and piers. The young, in which the dark spots have not yet appeared, are known as Chads, and are often regarded as a distinct species. The Black Bream (Cantharus lineatus) is an omnivorous feeder, and will take both animal and vegetable baits.
The Red Mullets (family Mullidæ) may be distinguished from the grey mullets previously described by the two long erectile barbules on the lower jaw. The scales are large and thin, with serrated edges, and the front portion of the dorsal fin has weak spines. The common British species (Mullus barbatus) frequents our south and east coasts, being specially abundant round Devon and Cornwall, where they often occur in vast shoals, and the young are often to be caught in estuaries and harbours.
Our last example is the Common Bass or Sea Perch (Morone abrax), of the family Serranidæ. It is also known locally as the White Salmon and the Salmon Dace. This fish may be taken with rod and line on rocky coasts and at the mouths of rivers. The sand-eel, or an artificial imitation of it, is commonly used as bait, but the Cornish fishermen more frequently employ a piece of herring or pilchard for the purpose. The first dorsal fin of this fish has very strong spines which may inflict severe wounds when the live creature is carelessly handled.