Ten species from Indian and Chinese seas.
Chatoëssus.—Body compressed; abdomen serrated. Scales of moderate size. Snout obtuse, or obtusely conical, more or less projecting beyond the cleft of the mouth, which is narrow, more or less transverse. Maxillary joined to the ethmoid, its upper portion being behind the intermaxillary. Teeth none. Anal fin rather long; dorsal opposite to the ventrals, or to the space between ventrals and anal. Gill-membranes entirely separate; branchial arches forming two angles, one pointing forward and the other backwards; the fourth branchial arch with an accessory organ; branchiostegals of moderate length, five or six in number.
Ten species from the coasts, brackish and fresh waters of Central America (one species ranges to New York), Australia, the East Indies, and Japan.
Clupea.—Body compressed, with the abdomen serrated, the serrature extending forwards to the thorax. Scales of moderate or large, rarely of small size. Upper jaw not projecting beyond the lower. Cleft of the mouth of moderate width. Teeth, if present, rudimentary and deciduous. Anal fin of moderate extent, with less than thirty rays; dorsal fin opposite to the ventrals. Caudal forked.
This genus comprises more than sixty different species, the geographical distribution of which coincides with that of the family. The majority are of greater or less utility to man, but a few tropical species (C. thrissa, C. venenosa, and others) acquire, probably from their food, highly poisonous properties, so as to endanger the life of persons eating them. The most noteworthy species are—
1. C. harengus (the “Herring”).—It is readily recognised by having an ovate patch of very small teeth on the vomer. D. 17–20. A. 16–18. L. lat. 53–59. Vert. 56. Gill-cover smooth, without radiating ridges. It inhabits, in incredible numbers, the German Ocean, the northern parts of the Atlantic, and the seas north of Asia. The Herring of the Atlantic coasts of North America is identical with that of Europe. A second species has been supposed to exist on the British coast (C. leachii), but it comprises only individuals of a smaller size, the produce of an early or late spawn. Also the so-called “White-bait” is not a distinct species, but consists chiefly of the fry or the young of herrings, and is obtained “in perfection” at localities where these small fishes find an abundance of food, as in the estuary of the Thames.
[Separate accounts on the Herring may be found in Cuvier and Valenciennes, “Hist. nat. des Poissons,” vol. xx.; J. M. Mitchell, “The Herring, its Natural History and National Importance,” Edinb. 1864, 8vo; P. Neucrantz, “De Harengo,” Lübeck, 1654; J. S. Dodd, “Essay towards a Natural History of the Herring,” Lond. 1768, 8vo; Bock, “Versuch einer vollstændigen Natur-und Handels-Geschichte des Hærings,” Königsberg, 1769, 8vo.]
2. C. mirabilis.—The Herring of the North Pacific.
3. C. sprattus.—The “Sprat.” Without vomerine teeth. D. 15–18. A. 17–20. L. lat. 47–48. Vert. 47–49. Gill-cover, smooth, without radiating ridges. Abundant on the Atlantic coasts of Europe.
4. C. thrissa.—One of the most common West Indian fishes, distinguished by the last dorsal ray being prolonged into a filament. Hyrtl has discovered a small accessory branchial organ in this species.