Nesiarchus.—Body covered with small scales. Several strong fangs in the jaws; no teeth on the palate. First dorsal not extending to the second. No detached finlets. Ventrals small, but perfectly developed, thoracic. Caudal fin present. A dagger-shaped spine behind the vent.
A rather large fish (N. nasutus), very rarely found in the sea off Madeira. The two or three specimens found hitherto measure from three to four feet in length. Probably living at the same depth as the preceding genus.
Aphanopus.—Scales none. Two very long dorsal fins; caudal well developed; ventrals none. A strong dagger-shaped spine behind the vent. Strong teeth in the jaws; none on the palate.
One species only is known, named A. carbo from its coal-black colour; it is evidently a deep-sea fish, very rarely obtained in the sea off Madeira. Upwards of four feet long.
Euoxymetopon.—Body naked, very long and thin. Profile of the head regularly decurved from the nape to the snout, the occiput and forehead being elevated and trenchant. Jaws with fangs; palatine teeth present. One dorsal only, continued from the head to the caudal fin, which is distinct. A dagger-shaped spine behind the vent. Pectoral fins inserted almost horizontally, with the lowest rays longest, and with the posterior border emarginate. Ventral fins rudimentary, scale-like.
This is another deep-sea form of this family, but, at present, no observations have been made as regards the exact depth at which it occurs. A specimen has been known since the year 1812; it was found on the coast of Scotland, and described as Trichiurus lepturus. The same species has been re-discovered in the West Indies, where, however, it is also extremely scarce.
Lepidopus.—Body band-like; one single dorsal extends along the whole length of the back; caudal well developed. Ventrals reduced to a pair of scales. Scales none. Several fangs in the jaws; teeth on the palatine bones.
Fig. 192.—Lepidopus caudatus.
The Scabbard-fish (L. caudatus) is rather common in the Mediterranean and warmer parts of the Atlantic, extending northwards to the south coast of England, where it is an occasional visitor, and southwards to the Cape of Good Hope. More recently it has been observed on the coasts of Tasmania and New Zealand. We may, therefore, justly consider it to be a deep-sea fish, which probably descends to the same depth as the preceding allied forms. It grows to a length of five or six feet, but its body is so much compressed that it does not weigh more than as many pounds. It is well known in New Zealand, where it is called “Frost-fish,” and esteemed as the most delicious fish of the colony. A still more attenuated species (L. tenuis) occurs in the sea off Japan, at a depth of some 340 fathoms.