Naturalist.

Alexandra Herald and Central Otago Gazette, Issue 391, 5 November 1903, Page 7

Naturalist.

. WHERE; THEY HATCH FISH. fsßs! DON'T suppose you ever looked 1I» u P on hard boild eggs and borseggg; flesh as a suitable diet for growing fish! Well, neither did I, but an ingenious gentleman in the North of England, at Barrasford. in Northumberland, who is engaged in the delightful occupation of providing England with well-nourished trout, ' grown in our own garden' as it were k has definitely convinced me that, incredible as it may seem, such is indeed the case. It is a consolation to find, however, that the hard-boiled eggs are finely grated, and the horseflesh ground. You see, although it is not yet possible to artificially hatch and rear the fish of the oceans, the problem with regard to fresh water fish has been solved long ago, A primitive sort of hatchery was, in fact, carried on in the middle of the eighteenth century. • : - ' : ;« Imagine if you can a large lake, converted by a succession of perforated screens into no less than forty-two ponds. An effective screen is placed at the entrance to the lake, which, as the water runs in from a neighbouring stream, excludes dead leaves and other dangers. The first process is, of course, the incubation. After being artificially fertilised the ova are placed on grass grilles in the hatching boxos, and the different stages in development during the fifty days «r so of incubation can be observed by those interested. The visitor, indeed, may have the luck of witnessing the infant trout wriggling curiously out of its egg membrane. The little completed embryo enters the world with a good snpply of food in its yolk-sac, and until this is absorbed feediag is not necessary. Then comes the question of diet, which, as I said above, consists of such delicacies as finely grated hard-boiled eggs, and shrimp paste. The 'menu' of the tiny infant is afterwards enriched by the gradual addition of ground fish, meal, finely pounded liver, and ground horseflesh. Snould the trout have the good fortune to be retained in after life in connection with the hatchery these three last edibles will form its staple diet. On being turned into the outside ponds, however, it can And natural food in the way loi water snails, insect larvse, worms, and such like dainties.

At the age of one year the average trout has grown to three inches, but a robust specimen may reach quits double that siz9. Large quantities of them are now sent away to lakes and rivers, first of all being put in boxes and deprived of food for a day, to prepare them for their journey. I t& vjf •■• 11 ? There are many things to be done on a fish hatchery, and the duties include su?h items as the removal of dead or unfertilised eggs, and the membranes which have been deserted by the hatched infants; the careful feeding with the requisite food at the various stages, etc. Another important point, in which the professional fish hatcher fchows great skill, is the escouragemeat of the growth of

animal.food and plants calculated to attract insects and other animals for the consumption of the youthful fish. By the way, it ie not only the common brown trcut that is thus hatched, but also the American variety, both 'fontinahV and asd interestiEg croaseß between them Theaa various species differ to some extent in the amount of shelter they require from the eub's rays. For example, the rainbow will not flourish in Buch shallow wat6r as the brown trout. It as estimated that there are at least half a million trout at the EatresfOrd establishment. In the.Hatchery itself, the recently-born trout of about one inch long are massod in thousands, under ths covers of the ha'.cbery b:x s, while the outside ponds are literally alive with tho yearlings and the older fish. As in every business, however, there are drawbacks, and the bogie of the fish hatcher's existence is 'fungus,' that dread Baemy of the goldfish. Up to the present, fortunately, tho B?rrasiord troafc has been left alone by tbis uawelcome visitor, mainly owing to the scientific and sanitsry methods in vogue there. • The water, before entering the large laie through the perforated screen, is conducted along an open trough into a settling tanV, thua insuring freeness and purity from any sediment. Another precaution taken ia that of occasionally treating the trout to an artificial flood; they are thus kept iu as natural a condition as possible There are two separate water supplies, which can be used Beperately or together, according to temperature, and to acclimatise the young fish before turning into the natural ponds,

FISH AND LEPEOSY, Dc. Jonathan Hutchinson has returned from bis tour in India and Ceylon, in which countries he has bees studying the ffl iology of leprosy. Dr. Hutchinson has always held that leprosy is connected in some way with the eating of fish, and it was to test the truth of thia hypothesis that he made this tour, and, shortly before, one to South Africi. _Dj\ Hutchinson, as the remit of his icquirios, believes that only in a very small minority of cases of leprosy cin a fbb diet be excluded. Its great prevalence is almost always in or near a fishing district. Dr, Hutchin--1 son's general conclusion is "that, as regards leprosy in India, there are no facts which controvert or render untesable the fi3h hypothesis, and that there are some which afford it a support which he coßsiders to ba unassailable, At the Matanga Asylum a quite extraojdmary Kumber of the patients are 'Salsette Ciuistians,' or converted natives of tbo little island of Salsette, just north of the :city of Bombay. It has a population of 50,000, very largely engaged in fishing and fish-curieg. The Balsette Christians are all Eoman Catholics, and are the descendants of converts made bj the Jesuits in the time of the Portuguese occupation. Not only do they obseiva the fish faßt-days of their Church, but almost all of them are actually engaged in the fish trade. During eight years no other Christian commuaity in the Presidency, supplied a sißgle leper to the Matuago Asylum. Taey all came from this small, but very specially constituted, population.