Fig. 282.—The Pike. (Esox lucius.)
Fossil Pike, belonging to the existing genus, have been found in the freshwater-chalk of Oeningen, and in the diluvial marl of Silesia. Remains of the common Pike occur in abundance in quaternary deposits.
Eleventh Family—Galaxiidæ.
Body naked, barbels none. Margin of the upper jaw chiefly formed by the intermaxillaries, which are short, and continued by a thick lip, behind which are the maxillaries. Belly rounded; adipose fin none; dorsal opposite to anal. Pyloric appendages in small number. Air-bladder large, simple; pseudobranchiæ none. The ova fall into the cavity of the abdomen before exclusion.
Small freshwater fishes of the southern hemisphere, belonging to two genera, Galaxias and Neochanna. Of the former genus five species are found in New Zealand, where this type is most developed, three in New South Wales, two in Tasmania, and four in the southern extremity of South America. Their native name in New Zealand is “Kokopu,” and they were dignified with the name of “Trout” by the settlers before the introduction of true Salmonidæ. They rarely exceed a length of eight inches. Neochanna is a degraded form of Galaxias, from which it differs by the absence of ventral fins. This fish has hitherto been found only in burrows, which it excavates in clay or consolidated mud, at a distance from water.
Fig. 283.—Galaxias truttaceus, from Tasmania.
Twelfth Family—Mormyridæ.
Body and tail scaly; head scaleless; barbels none. The margin of the upper jaw is formed in the middle by the intermaxillaries, which coalesce into a single bone, and laterally by the maxillaries. Sub- and inter-operculum present, the latter very small. On each side of the single parietal bone a cavity leading into the interior of the skull, and covered with a thin bony lamella. All the fins are well developed, in Mormyrus; or caudal, anal, and ventral fins are absent, in Gymnarchus. No adipose fin. Pseudobranchiæ none; gill-openings reduced to a short slit. Air-bladder simple. Two coeca pylorica behind the stomach.
This family is characteristic of the freshwater fauna of tropical Africa. Of Mormyrus (including Hyperopisus and Mormyrops), fifty-one species are known, of which eleven occur in the Nile. Some attain a length of three or four feet, others remain small. Their flesh is said to have an excellent flavour. The species figured (and probably other allied species) was an object of veneration to the ancient Egyptians, and, therefore, frequently occurs in their emblematic inscriptions. They abstained from eating it because it was one of three different kinds of fishes accused of having devoured a member of the body of Osiris, which, therefore, Isis was unable to recover when she collected the rest of the scattered members of her husband.