ZOOLOGICAL
46
ESOCHLSE (Pikes). Plate 25, Map i.
This group includes six or seven species of carnivorous and voracious fresh-water fishes, which are exclusively confined to the temperate and subarctic portions of the Northern Hemisphere. Esox, the typical genus, contains four or five species, including Esox lucius, the only representative of the family in Britain, occurring also in Northern Asia and North America. The second genus, Umbra, contains two species, one occurring in Austro-Hungary, and the other in Canada and the United States.
HAPLOCHITONIDZE (Southern Salmon). Plate 25, Map i.
Only four species of this family are known, one belonging to the typical genus Haplochiton and three to Prototroctes. The first-named occurs in the extreme south of South America and in the Falkland Islands, while the other three are natives of New Zealand, South Australia and Queensland respectively. They are all Trout-like in appearance, and are exclusively confined to fresh water.
GALAXIIDiE (Pikelets). Plate 25, Map i.
About 30 species are referred to this family, and they are chiefly confined to fresh waters in the Southern Hemisphere, although one species occurs also in the sea. The peculiar distribution of these fishes, as shown on the map, added to the fact that one or two species at least are partially marine, furnishes a strong argument in favour of the theory that there formerly existed a huge Antarctic continent, connecting the remote areas inhabited by the Galaxiidse, now so remote from one another.
MURiENIDiE (Muraenoid Eels, &c.). Plate 25, Map i.
This family is a large one, containing about 150 species of universal distribution. They are most abundant in warm seas, especially in the neighbourhood of coral reefs. The Murry (Mursena helena) is much esteemed as food in the countries surrounding the Mediterranean, and was a great favourite with the ancient Romans. It has occurred, though very rarely, off the coast of England. Several remarkable deep-sea forms belong to this family, and these are often placed in separate families. Saccopharynx and its allies are among the most extraordinary-looking fishes known, possessing a pharynx and stomach so dilatable that the fish is able to swallow another one much larger than itself. These and other interesting forms occur down to a depth of 2000 fathoms.
ANGUILLIDiE (Typical Eels). Plate 25, Map ii.
The Typical Eels, of which about 150 species are known, occur in all temperate and tropical seas, while a few species also inhabit fresh water. Many are deep-sea forms and occur down to 2500 fathoms. Two species occur in British waters, namely, the Common Eel (Anguilla vulgaris) and the Conger (Conger vulgaris), both of which are abundant and widely-distributed within the British area. The Common Eel has also a wide range in the Northern Hemisphere and descends to the sea to spawn; while the Conger is almost cosmopolitan in its distribution. Many species of Anguillidse are important articles of food.
S YMBR AN CHID JE (Single-Slit Eels). Plate 25, Map ii.
Half a dozen species only are referred to this family, three of which occur in India, the Malay Archipelago, China and Japan; two in Australia and Tasmania, and one in Central and South America. The Australian forms are marine, but all the rest inhabit fresh or brackish waters.
LORICARIIDZE (Mailed Cat-Fishes). Plate 25, Map ii.
This is an interesting family, containing some 200 species, which are confined to the Neotropical Region, and are exclusively inhabitants of fresh waters. Fourteen genera have been recognised, which are grouped into two sub-families. In one, the Arginse, the body is naked; while in the other, the typical one, Loricariinee, the body is protected by bony plates.
SILURID2E (Cat-Fishes). Plate 25, Map ii.
This is one of the most important families of fishes, containing over a thousand species. These are, with a few exceptions, confined to fresh waters, and occur in nearly all the temperate and tropical portions of the world. In North America they do not occur west of the Rocky Mountains. At least 120 genera are differentiated by our modern authorities, and these are arranged in no fewer than eight sub-families. Although occurring in Central Europe, they are entirely absent from the western portion of the continent, including Britain. Madagascar possesses representatives, but New Zealand has none.
CYPRINIDiE (Carps, &c.). Plate 25, Map iii.
The Carp family is an extensive one, containing about 1300 species. They are exclusively fresh-water fishes, and occur in all parts of the world, except South America, Madagascar and the Australian region. In Europe, Asia and North America they outnumber all other fresh-water fishes, but in Africa they are comparatively feebly represented, only about 100 species occurring in that continent. Sixteen species occur in Britain, including the Barbel (Barbus vulgaris); Gudgeon (Gobio Jluviatilis) ■ Roach, Chub, Dace, Rudd and Minnow (Leuciscus spp.); Tench (Tinea vulgaris); Bream (Abramis brama); and Loach (Nemachilus barbatulus).
GYMNOTIDtE (Electric Eels). Plate 25, Map iii.
The Gymnotid* are a group of about 30 species of fishes, entirely confined to the fresh waters of Central and South America. Although somewhat like Eels in external appearance, these fishes are not related to them structurally, but are nearly allied to the Characinidse, which are dealt with
FISTULARIIDiE (Flute-Mouths). Plate 24, Map iv.
The members of this family, seven or eight of which are known, are sometimes described as “gigantic marine Sticklebacks.” They are found in most tropical and subtropical seas, generally near the shore. Fisfularia tabaccaria grows to a length of six feet. The genus Aulostoma is sometimes referred to a separate family, as are also Aulorhynchus and Auliscus.
GASTROSTEIDjE (Sticklebacks). Plate 24, Map iv.
These well-known little fishes are found in both fresh and salt water, and are entirely restricted to the Northern Hemisphere. They are remarkable for their nest-building habits, the male undertaking this duty and also that of guarding the eggs until hatched. Five species are found in British waters, the Three-spined and Ten-spined Sticklebacks (Gastrosteus aculeatus and pungitius) being among the most familiar of our native fishes. Almost identical forms inhabit Europe and North America, rendering an exact estimate of the number of species a difficult matter; probably, however, about a dozen may be regarded as distinct.
LAMPRIDIDiE (The Opah or King-Fish). Plate 24, Map v.
The sole representative of this family is a handsome and bulky fish, known as the Opah or King-Fish (Lampris luna). It occurs in the North Atlantic, the Mediterranean, and certain parts of the Pacific, and is not very uncommon off the British coasts. It attains a length of about four feet, and is said to be excellent eating.
FIERASFERIDiE (Pearl-Fishes). Plate 24, Map v.
About 10 species of this family are known; all are small eel-shaped fishes belonging to a single genus, Eierasfer. They are remarkable for the fact that they spend the whole of their lives as commensals within the bodies of Holothurians (Sea Cucumbers), starfishes, or bivalved molluscs. They are found near the coasts of nearly all tropical and subtropical seas, and one species (F. dentatus) has occurred off the coasts of Ireland.
NOTACANTHIDiE (Thornbacks). Plate 24, Map v.
The Notacanthidse are elongated deep-sea fishes found in the Mediterranean Sea and the Atlantic and Pacific Oceans, occurring at depths of 400 to 1875 fathoms. Nine species have been described, belonging to the two genera Notacanthus and Polyacanthonotus.
PERCOPSIDiE (Trout-Perches). Plate 24, Map v.
Only two species, each belonging to a distinct genus, are referred to this purely North-American family. The first of these (Percopsis guttata) abounds in the great lakes and their tributaries, occurring also in various rivers of Canada and the United States. The other species (Columbia transmontana) is much rarer, occurring only in lagoons in the lower basin of the Columbia River in the Western States. Both these fishes are remarkable for the possession of the so-called adipose fin, so characteristic of the Salmon and its allies.
AMBLYOPSIDiE (Blind-Fishes). Plate 24, Map vi.
This family includes three genera and six species, which occur only in ditches, streams, and subterranean waters within a restricted area in the Eastern United States. The best-known representative is the famous Blind-Fish (Amblyopsis spelled), inhabiting the Kentucky and other caves east of the Mississippi. This species, and two others found in similar situations, have only rudimentary eyes, and appear to depend largely for their safety on the sense of touch, which is highly developed.
CYPRINODONTID7E (Killifishes). Plate 24, Map vi.
The Cyprinodontidse inhabit fresh or brackish waters in the warmer portions of both hemispheres, but of the 200 known species about 170 are natives of America. One of the most interesting genera of the family is Anableps, ■which contains three species inhabiting Tropical America, and known as Double-eyes or Four-eyed Fishes. In these curious fishes the eyes are divided into two portions, an upper and a lower, so that the creature when swimming near the surface can see into the air and into deep water at the same time.
KNERIIDAl (Kneria). Plate 24, Map vi.
This small family contains only two species, placed in a single genus {Kneria), and is confined to fresh waters in Angola and East Africa respectively. They are small fishes, from two to four inches in length, with a somewhat Loach-like general appearance.
SCOPELIDAJ (Lantern-Fishes, &c.). Plate 24, Map vi.
The Scopelidse are a large and universally distributed family, containing over 100 species, many of which are deep-sea forms of much interest. In correlation with their life at great depths, they are often provided with phosphorescent spots on the head and body, while in one genus (Ipnops) the eye is modified from a light-perceiving to a light-producing organ. Bathypterois is an interesting genus, discovered by the “ Challenger ” expedition, and remarkable for the extraordinarily elongated pectoral rays which act as organs of touch; one species, B. dubius, has recently been found in deep water off the S.-W. coast of Ireland. The four known species occurred at a depth varying from 520 to 2650 fathoms. Scopelus engraulis, one of the best-known representatives of the family, is sometimes called the “Phosphorescent Sardine.”