WILD LIFE IN NEW ZEALAND

Otago Witness, Issue 3475, 19 October 1920, Page 53

WILD LIFE IN NEW ZEALAND

By the Hon. G. M. Thomson, F.L.S. No. 103.—FLAT-FISHES (Continued.) Both in seine netting and in trawling in or near Otago Harbour numerous examples of the greenback flounder (Rhombosolea tapirina) are taken along with the more common sand flounder. The shape of the greenback is different from the other, being ovate instead of rhomboidal, and the pointed enout is produced over the mouth. It is from the latter character that the specific name is derived. The general colour is green, with dark blotches on the upper surface, and white beneath. It grows up to 14in or 15in in length. While quite common in our southern waters, I do not think this species is, at all well known in northern parts; I have not seen it in Wellington fish-shops. Yet it is a wide-spread form, and has been obtained at the Auckland Islands in the south, and from the Australian and Tas-. manian Seas. It is probably a denizen of cold water. Another flounder, especially common about the mouths and in the tidal waters of rivers, and the most familiar species in the Christchurch fish-shops, is the black flounder (Rhombosolea retirana). It seems to be the common form found in Lake Ellesmere. It would be interesting to find out whether this is the species which occurs in the Taieri River and m Lake Waihola. Its rounded head, with short, blunt snout, are distinguishing features. The colour is dark olive green, with darker patches mottled with brickred spots. These spots are very characteristic. The underside is yellowish, each scale being edged with brown. This is a very fine table fish, with a thick body which reaches a length of and a weight of 51b. Another fine flounder, frequently brought to the Dunedin market, especially from tidal . waters like Wycliffe Bay "and. Hooper's Inlet, is the yellow belly (Rhombosolea millari). The sp'ecies is wide-spread in New Zealand, though not taken'so abundantly as some others. It is easily recognised by the yellowish colour of the under surface, which is sometimes marked with small black spots. It grows to a considerable size, being frequently taken over * 18in in length. The lemon sole (Pelotretis flavilatus) is so named from the British fish of the same name which it resembles, but from which it differs by lying on the opposite side. It is common all round the New Zealand coast, and is taken at all depths down to 50 fathoms. Like many other species it makes periodic migrations, almost disappearing for a time and then re-appearing in considerable numbers. The causes of these movements are- not understood; they are probably conditioned by the vast and wide-spread migrations of the smaller organisms on which they feed. This fish has rather large eyes placed close together at the front of the head. The colour is "grey or brownish above, both body and fins with irregular though well-defined markings, sometimes absent; underside yellow." It commonly measures from 12in to 14in in length. This species spawns in August, and a nearly ripe specimen examined in July of this year was found to contain nearly a million eggs —952,880 was the estimated number. The egg 'is larger than that of the common sand flounder, which, however, produces more of them—a specimen examined at the same time as the former being estimated to contain 2,343,000 eggs. Assiime that all these eggs hatch, as would probably have been the case. > Then, I think, the astounding fact, is, not that 2,000,000 new little fishes come into the world, but that 1,999,999 of them dies before reaching maturity and reproducing their kind. The lemon sole feeds principally on brittle stars, but crabs (Halicarcinus planatusj, small bivalve molluses, worms and salpidae are also found in their 6tomachs.

Every one knows the common sole (Peltorhamphus novae-zealandiae) or think he does. It is the most familiar flat-fish which appears in the Dunedin fish-shops, and if it has no other claim on the reader's memory, perhaps the price he paid for the last specimen purchased may have made some impression. Most people also think thev know the taste of fillets of sole, but the fact that it appears on the menu of the last dinner at which it was announced is not proof that the diners were not eating some other kind of fried fish.

The appearance of the sole is quite characteristic, and enables it to be distinguished at once from other flat fishes; the rounded front' portion of the head, produced into an overarching hook which completely covers the mouth; ' the small eyes set well back from the front margin: the fine imbricating scales, produced both on the greenish grey upper surface and on the white under surface —-all tend to make this an easily recognised fish. It grows from 12in to as much as 18in long. The development of this species has been fairly well studied at the Portobello Hatchery, where millions of young fish have been hatched and liberated. The female fish begin to produce mature eggs when only a little over five inches long. These eggs are the smallest produced by any of the New Zealand flat-fishes. A specimen—l6in long—taken Otago Heads last July, was found to' contain 1,655,000 eggs. Hatching, occurs in July and August, and young soles from 3in to sin long are common in the Lower Harbour in April and May. The food of the common sole is similar to that of the lemon sole, and consists of brittle stars, small crabs, shrimps, whalefeed, amphipods, small shells and worms. I have already recorded the fact that there are thirteen species of flat-fishes found in New Zealand waters. In addition to these the attempt has been made to introduce one European species, the turbot (Rhombus maximus), and this is the only marine fish which

hae been brought to this country. Whether it has been naturalised in these southern seas or not is still unknown. Prom early historic times the turbot has been considered one of the finest of food-fishes, and in the days of Rome's most luxurious extravagance it was held in the highest esteem. Horace says— Great frurbots and the soup-dish lead To shame at last, and want of bread. Size seems to have been the standard of excellence aimed at, and Martial refers to a feat where . . . . the enormous fish Was wider than the broadest dish. There is an apocryphal story told of the Emperor Domitian summoning a meeting of the Senate in order that that august body might advise him as' to what sort and size of vessel might be used to cook an enormous turbot which had been sent to him. The Roman epicures kept their fish in salt-water tanks, for, though found occasionally in the Mediterranean, they have always been rare in that sea, and were probably brought great distances from the coasts of Gaul or Britain to the imperial city. The fish grows to a great size in its native northern seas. Thirty pounds, according to old Jonathan Couch, is a not uncommon weight, and he adds:—"l possess a note of an example of which the weight was 701 b; another is recorded to have been caught in Scotland of the weight of 90|lb; and these again were far exceeded by one which that eminent naturalist, Rondeletius, informs us he himself saw, which in length measured five cubits, or seven feet and a-half, with a breadth of four cubits, and in thickness a foot; -which dimensions will*fully answer, and perhaps exceed all that is said of the turbot of Domitian." /

The turbot is wider proportionately to its length than any other British flat-fish, and from its form it was called in Scotland the Bannock Fluke. Readers of Scott's Antiquary may recall the scene where Jonathan Oldbuck buys fish from Meg Mucklebackit, and incurs ,his sister's, wrath and scorn in consequence. The turbot lies on its right side, the reverse of most of the New Zealand flat-fishes. Its'colour varies from very light grey or brown to almost black, according. to the hue of the bottom on which it lies, but the whole body is mottled with darker spots the size of a sixpence, which alter in colour with that of the rest of the body. The introduction of this fish into New Zealand is too long a story to be told at the tail-end of an article.