Fig. 195.—Semiophoris velitans.
Inhabitants of tropical and temperate seas. Carnivorous. They appear first in cretaceous formations, where they are represented by Platax and some Caranx-like genera (Vomer and Aipichthys from the chalk of Comen in Istria). They are more numerous in various Tertiary formations, especially in the strata of Monte Bolca, where some still existing genera occur, as Zanclus, Platax, Caranx (Carangopsis), Argyriosus (Vomer), Lichia, Trachynotus. Of the extinct genera the following belong to this family:—Pseudovomer (Licata), Amphistium, Archæus, Ductor, Plionemus (?), and Semiophorus. Equula has been recently discovered in the Miocene marls of Licata in Sicily.
Caranx (including Trachurus).—Body more or less compressed, sometimes sub-cylindrical. Cleft of the mouth of moderate width. The first dorsal fin continuous, with about eight feeble spines, sometimes rudimentary; the soft dorsal and anal are succeeded by finlets in a few species. Two anal spines, somewhat remote from the fin. Scales very small. Lateral line with an anterior curved, and a posterior straight, portion, either entirely or posteriorly only covered by large plate-like scales, several of which are generally keeled, the keel ending in a spine. Dentition feeble. Air-bladder forked posteriorly.
Fig. 196.—Plates of the lateral line of Caranx hippos.
The “Horse-mackerels” are found in abundance in almost all temperate and, especially, tropical seas. Many species wander to other parts of the coast, or to some distance from land, and have thus gradually extended their range over two or more oceanic areas; some are found in all tropical seas. The species described are very numerous, about ninety having been properly characterised and distinguished. Some attain to a length of three feet and more, and all are eatable. They feed on other fish and various marine animals.
Of the most noteworthy species the following may be mentioned:—C. trachurus, the common British Horse-mackerel, distinguished by having the lateral line in its whole length armed with large vertical plates; it is almost cosmopolitan within the temperate and tropical zones of the northern and southern hemispheres. C. crumenophthalmus, C. carangus, and C. hippos, three of the most common sea-fishes, equally abundant in the Atlantic and Indo-Pacific oceans; C. ferdau, from the Indo-Pacific, upwards of three feet in length. C. armatus, ciliaris, gallus, etc., which have an exceedingly short and compressed body, with rudimentary spinous dorsal fin, and with some of the rays of the dorsal and anal prolonged into filaments.
Fig. 197.—Caranx ferdau.