THE N.Z MUD FISH

Evening Post, Volume CX, Issue 83, 4 October 1930, Page 7

THE N.Z MUD FISH

BARE- AND PECULIAR

QUEER PUGNACITY

A EOXTON MND

There is just now in the office of the Chief Inspector of Fisheries (Mr. A. E. Hefford) one of "the queerest fish imaginable, the New Zealand mud fish (Neoehanna^apoda), the best-known Maori name of which is Hauhau. To cay that it is rare may not be entirely correct, as most of the specimens secured since 1867, quite a number have been found accidentally, and a systematic search of swamp spots all over New Zealand has not been made, but it is certain, from what has been discovered about- it from time to time, that exiended draining and development of land will eventually cause it to disappear. This one is living at present in a glass dish of. water containing river weed 3 full of insect food, as, like most ifishes, it is carnivorous. The specimen is five and a half inches Jong, and about half an inch in diameter, almost round of body, and has no central'fins "amidships," but has a longish dorsal fin of seventeen rays near the tail. Its anal fin, also of seventeen rays, lies underneath the dorsal. The fish is of a beautiful shade of deep amber and semi-transparent. The back is regularly spotted in velvety-looking dark markings, giving a very close resemblance to the back of an adder. The 3iead is peculiar in having two anterior nostrils projected into two small tubes. When it was taken the eyes appeared to be very small, but since it lias been exposed to a lighter environment, although still smaller than those of many fishes of the same size, they have somewhat protruded, and appear therefore larger. Its pectoral fins are well developed. The fish has one peculiarity new to those who have made a study of fishes, its pugnacity. When its nose is tickled it promptly bites, and the smali teeth can be distinctly felt. The bite isnot the gradual investigation of what might prove to be food, but a sudden snap, evidently in defence. Not even the pike, a. most bellicose fish, can be induced to do this when kept in captivity.. ,The head looks tough, and the muth would be described by a physiognomist as determined, such as is commonly ascribed to American captains of industry and argumentative Scottish jfjivines of the old school. The present specimen was found in sjwampy land near the Manawatu Kiver by Mr. Evans, of Foxton, who in drainage operations had unearthed several previous specimens, and the attention of Captain Hayes, who was engaged on •whitebait investigations nearby, was drawn to it. It was found embedded in the mud amongst the roots of some decaying raupo, the whole soil being full «jf channels thus left. This is the first time that this species of fish has been jreported from the Manawatu. It is a truly remarkable little fish, and its characteristics enable it to be practically . amphibious, as it can breathe through its nostrils. This one got out of its dish one night, and was discovered on the table none the'worse in the morning. It has every appearance of being a swamp fish with facilities to enable it to escape the consequences of droughts, which has had to adapt itself perforce permanently in certain cases, where swamps have been idrained, to the underground life. "Its Jtabitat is a pool or small creek in swampy grounds," vrrites Mr. B. O.j "Reid in "Rambles on the Golden J Coast of the South Island," in ISS6, *' where it remains swimming freely nearly all the year round. The fry liateh in September and October, and young fish half an inch in length can be obtained in January.'' Mr. W. J. Phillipps,. F.L.S., in a paper on it in 1926, says that "it hibernates in the ■winter, .which would account for the fact that all these fish found in. the mud have been reported very fat, having stored lip against the long starve. ; The mud fish was apparently fairly plentiful on the Weat Coast near Hokitika in the gold digging days, and was fr.eely eaten by the miners, but Mr. Phillipps, who has studied it, says that inquiries made in Hokitika in 1920 led Juni to the conclusion that it had almost disappeared ithere. In 1923 Mr. PhilJipps wrote that two specimens were obtained with difficulty from a swamp near Hokitika. Then it was supposed t>iat it existed only at Hokitika and in the Rangitikei, but in. a paper in 1926 lie mentions that specimens had been secured at Opunake, Peilding, and at Jhe Masterton hatchery. It was first recognised by Sir George Grey in 1867. Mr. Sehaw, a -warden of the district, forwarding one to Dr. Gunther, wrote; "It has often been excavated from considerable depths in clayey soil. As the water dries up it is forced to wriggle into the mud at the bottom or sides of the swampy pools it inhabits. In some cases it has been known to follow down the moisture in holes left'by decaying roots into quite a considerable .depth underground. ■When tho surface of the ground has been perfectly dry, and the whole cleared and improved, the discovery of a healthy fish fivo or sis feet below in solid ground has been looked upon as truly miraculous." The first specimen was found four feet from the surface in clay embedding the roots of trees in ■what had" been a forest swamp. The spot •was 37ft above the level of the river. The township of Kanieri was then springing up on the site of fthe old swamp, and the surface clay deposit liad boen so riddled by holes made by miners into the gravel below that no (surface water stood there. It is interesting to note that this fish belongs to the same family (Galaxiidae) as the- common kokopo, or New Zealand rock trout, and the inanga ( the parent of the New Zealand whitebait), but has been placed in a separate genus (Neoehanna) on account of the absence of tl»e paired ventral fins, which characteristic occurs, on the contrary, in all species of the genus Galaxias. Writing of this many ago, Dr. Gunther pays: "The chief Jjunetion of the ventral fins is to balance the fish while swimming, and in fishes moving during g, great part of their life »ver swampy ground or through more or ievc consistent mud, the function of the ventral fin ceases, and Nature can dispense ■with these organs altogether."