Le merlan (Cadus merlangus L.) de la côte française de l'Atlantique.

Among the North and Western European countries, France is the one that fishes whiting the most: in 1937, our fishermen caught 36% of the total tonnage. In the same year, France is followed by Scotland with 18%. According to the Department of Merchant Navy, in 1937, 26,813 tons of whiting (worth 70 millions Francs) were unloaded in French harbours. These figures represent a thirteenth of the total tonnage of sea fish unloaded in France. From this point of view, whiting comes after cod, herring and sardine, but before hake and mackerel. Tonnagewise, whiting is the fourth French fish. In 1937, North Sea and Channel French harbours received 21,918 tons of whiting, the third largest tonnage after cod and herring for this coast. The Atlantic coast harbours received 2,683 tons and the Mediterranean ones 378 tons only. The first two harbours are Boulogne-sur-Mer (17,279 tons) and Dieppe (3,210 tons). The biology of this fish has been extensively studied in Iceland, North Sea and Channel, but very few works have been conducted on the Atlantic whiting. This study first aims at analysing the reproduction and growth of the whiting on the Breton Atlantic coast. We will study: 1° its reproduction: spawning period, egg-laying areas, temperature conditions, size and age of the first sexual maturity; 2° its quantitative growth: growth speed based on measurings and otolith reading; extreme size and et longevity; 3° its qualitative growth: relative growth of the different body parts throughout the fishes growth; 4° relative growth of both genders and of secondary sexual characters. Our material comes from the northern latitudes: 1.8° at 46° 50'; most of them have been fished off the Glénans, Groix and Belle-Ile from 1938 to May 19... The study on sexual maturity and growth has been conducted on 1,900 fish (and 616 whitings measured in February 1938). Body proportions were established according to 358 fishes divided into 20 size groups. For each section, our observations are compared with the results obtained in the neighbourhood seas, and especially in the Channel and the North Sea. (unverified OCR)