Little can be said of the biology of the blackfin tunny, which is also called the obese tunny 

 because of its thick-set body. It is very like the bluefin, from which it is particularly distin- 

 guished by its large eyes. It is more or less confined to the equatorial zone and lives in waters 

 of high temperature (more than 20oC.) and salinity (to 36 "/oq)- When these tunny disperse 

 on their migrations they proceed to the Moroccan coast as far as Cape Juby and to Madeira and 

 the Azores. In the South Atlantic the " big eye tuna " swims off the American Continent from 

 Mexico to Chile. To the west the " mebashi " is caught from the Hawaiian Islands to Japan 

 and it is also found around Australia. Its red meat is canned but is of limited economic impor- 

 tance. 



While the ancient writers have much to say about the bluefin tunny, they remain silent 

 on the albacore or germon, which they do not appear to have known. Even in the 16th century 

 the great ichthyologist Rondelet does not mention it. At last, in 1788, an Encyclopaedist, the 

 Abbe Bonnaterre gives a description of it and the Fishery Inspector Duhamel of Monceau 

 reports that Basque seamen who used to go to the New World to catch cod, took albacore on 

 trailing lines in the open Atlantic on the outward and homeward voyages. However, albacore 

 fishing, although unknown in Mediterranean civilisations, goes far back into the past and the word 

 " germon " as used in the Vendee may be of Ligurian origin. When the Moors occupied Portugal 

 and Spain, they also knew of these fine fishes that swam in schools and reminded them of a 

 herd of cattle. They called them " al beqr ", whence comes the name " albacora " used in 

 the Iberian Peninsula. 



For several centuries the west-coast ports have been equipped with sailing craft that leave 

 in June to catch tunny in the Bay of Biscay until October. These fine, well- made boats have 

 brown sails extending into long fishing yards or tangons to which the trailing fishing lines are 

 fastened. The fishermen knew from experience that in June they must look for the albacore 

 near the Spanish coasts; in July and August in the Bay; and later towards the west as far as 

 the Great Sole Bank, or even to the soutli of Ireland at the end of the season. Improvements 

 have come about during recent years. The fishermen of Luz have adopted first steam and 

 then motor vessels. A French engineer, Krebs, has provided the sailing craft with ice-cooled 

 holds. More and more under the influence of American techniques in the Pacific, the boats 

 are acquiring the gear of the Galifornian "tuna clippers", with refrigerators and wells contain- 

 ing live sardine bait for the fishery. 



When they are under way, albacore travel near the surface, often leaping out of the water. 

 Their silvery flanks gleam in the sun and their enormous pectoral fins enable them to move at 

 high speed. While investigating the movements of a shoal of these superb fishes in 1921 I was 

 able to learn something of their hitherto unknown biology. They have guided me in setting 

 up the theory of oceanic transgressions. Because of their completely stenothermal habits 

 I have, in fact, been able to determine that off the French coasts they only live in waters with 

 temperatures greater than 14°C. at 25 fathoms depth and a salinity of at least 35.5 "/oo- Since 

 they always follow these temperature conditions they are valuable biological indicators of the 

 encroaching water layers (transgressions) which they never leave. But the albacore of our 

 waters are immature fishes and the life of the reproductive individuals and their spawning- 

 grounds remained unknown. Thirty years later I was finally able to find some precise data 

 which have enabled me to build up a general picture of the biology of the Atlantic albacore. 



It is towards the west, in the prolific Sargasso Sea, that their spawning-place must be 

 sought. As early as 1925, two French scientists, Gruvel and Conseil, reported that they had 

 found sexually mature albacore near Martinique. Later, in these same regions, the Danish 

 oceanographer, Johannes Schmidt collected larvae that the Cterman Professor Ehrenbaum 

 regarded as Thiinniis alaliinga. Little notice was taken of these discoveries and ingenuity 

 was strained in seeking a spawning centre for albacore in the Madeira area, although in the 

 eastern Atlantic larvae or young have never been found. 



In November 1950 I caught small albacore of about 12 to 14 inches long on lines trolled 

 in the Caribbean Sea ofl" the Venezuelan coast, among the \\'indward Islands near Blanquilla. 

 These immature fishes must have been not more than 1 i to 2 years old and could not have been 



108 A cyprinid fish from Ceylon (Puntius nigrofasciatus). 



A cichlid from South Africa (Tilapia nalalensis). 

 Photographs by J. M. Baufle. 



