and ports; it may reach a length of two feet or even a little beyond two and a half feet. It is 

 eaten locally. 



Fishermen in small dinghies also go after wrasses, fishes of the family Labridae with brilliant 

 colours and numerous species, which live in coastal regions. In the .Mediterranean they bring 

 back girelles and scorpion-fishes. All these lighter craft delight the summer visitors, and 

 it is most often on board them that they make their first sea-trip in a " nice fishing party ". 

 The old boatman looks at them with a smile, for he reckons that the sea-sickness of his passengers 

 will give him a good share in their hampers of tasty food. With this end in view he slyly holds 

 his dinghv athwart the waves. 



Rivers and lakes of the northern continents. 



In the peaceful plains of western Europe, idly flowing streams twist and turn between curtains 

 of poplars that shiver with the slightest breeze. A fairly perceptible current flows over the 

 middle of the river bed to play against the arches of old village bridges with the musical 

 sound of a small cascade. But along the banks, lined with rushes and reeds, under the cover of 

 small willow-trees, the waters are almost still. The sun gleams on these waters and the move- 

 ments of aquatic insects send out ever widening ripples that rebound from the river banks. 

 The shadows of water-lilies stand out on the brown muddy bottom. 



These streams are the home of cyprinid fishes, a group with extremely numerous species. 

 We may mention : carp (Ciiprinus carpio). barbel (Barbus fliiviatilis), gudgeon (Gobio vulgaris), 

 tench (Tinea tinea), minnows (Phoxinus phoxinus), rudd (Scardinius eriflhrophlhalmus), 

 roach ( Leucisciis rnlilus), dace (L. leucisciis), chub (L.cephalus), orfe (Idas melanola), bleak 

 (Alburnns alburnus), and bream ( Abramis hrama). These fishes, which are usually slow- 

 moving, are seized with a feverish activity at spawning time. They become agitated, leap 

 out of the water, then gather in shoals and move to the quietest creeks to lay their eggs. 

 The shoals of roach and rudd are so dense tliat the rubbing of one fish against another produces 

 a kind of rasping noise that. can be heard a long way off. When sexually stimulated, cyprinids 

 lose all sense of danger, and their predators, taking advantage of this, exact a heavy toll. The 

 males are more numerous than the females : three or four of them court one female and share 

 in the fertilisation of the eggs. On the back and sides of the males, particularly in carp, are 

 rough tubercles which must play some part in defence during the fights that go on at the breeding 

 season. With these tubercles the males also butt the sides of the females when the eggs are 

 being laid, for pairing has its brutal side. In tench the differences between the sexes are expressed 

 in modifications of the pelvic fin rays. The breeding season is in summer and spawning occurs 

 in watersof rather high temperature. The number of eggs varies according to the size or length 

 of the female: a four and a half pound carp carries 400,000 eggs, one of seventeen and a half 

 pounds contains more than a million. The gudgeon, with large eggs, lays a rather small number, 

 while those of the tench, being much smaller in size, are expelled in hundreds of thousands. The 

 species of cyprinids are still not very stable and cross-breeding between them is quite common. 



Among the cyprinids, particular mention must be made of the habits of the bitterling (Rho- 

 deus armariis). These small (2 to 3 inch) fishes are usually a grey-green with brightly coloured 

 underparts, but at the breeding period, purple and pink shades are added to form the breeding 

 dress of the male. The male also has outgrowths of skin on the snout. The female has a long 

 spawning tube or ovipositor and with this organ she can insert the eggs in a safe place. Bitterling 

 have discovered such a secure shelter inside the shells of certain freshwater mussels called Unio 

 and Anodonla. The fishes do not have to look after the aeration of the spawn, for this is done 

 by the respiratory currents of the molluscs, which also help to ensure the fertilisation of the 

 eggs. It has been stated that the males are not initially stimulated on seeing the females, but 

 that this is generally brought about by their approach to shells containing the progeny of their 

 own kind. There is certainly a real biological association between the bivalves and bitterling; 

 and the spawning of these animals occurs at the same season. The molluscs ensure the fertilis- 

 ation and aeration of the eggs and young fishes. On the other hand, the larvae of Unio and 



