1902 Some spring Movements of Sea-Fish 10 1 



This is, with the majority, from south-west to north- 

 east, the first mackerel being taken in very early spring off 

 the south-west coast of Ireland; then shoals gradually 

 appear farther and farther east along our own south coast, 

 beginning with Mounts Bay and progressing past Meva- 

 gissey and Plymouth to the easternmost Channel grounds 

 at Hastings and Dover. Most fish, that is to say, move 

 inshore to spawn ; but a few, like the sole, move farther 

 out to sea. What may be the precise objects in either 

 case it is not easy to say. It is clearly not true that 

 the sole moves out into the deeper water in order that the 

 increased pressure may help it to get rid of its eggs ; for 

 it would, if that were necessary, be unable to spawn in the 

 shallow tanks of the aquarium, which it has nevertheless 

 been often known to do. If there is a sea-fish to which this 

 necessity for a deep spawning-bed applies, it is not the sole, 

 but the conger eel, and on that necessity, I suspect, rests all 

 that there is of truth in the theory that the conger spawns 

 once and then dies. Death, it is true, overtook some female 

 congers in the Plymouth Aquarium, but they were in a 

 wretched state, and quite unable to discharge their eggs 

 under the conditions of their captivity. Therefore, some- 

 what hastily, I think, it was declared that the same fate 

 would overtake them in nature, and this in spite of the well- 

 known fact that their natural breeding-grounds and the 

 haunts of the developing Lcptocephali, as the larval stages 

 are called, lie in the deepest parts of the Mediterranean, and 

 doubtless also of other seas as well. 



It is, in fact, quite impossible in our present limited know- 

 ledge of fish life in the seas to lay down any rule that shall 

 cover every case. We may argue that the sole is sensible in 

 depositing its floating eggs in the offshore waters, since the 

 ferment of the breakers, particularly in rough weather, would 

 seriously prejudice their already slender chances of develop- 

 ment in the shallows ; but the same objections would apply 

 with equal force to all the fishes that successfully deposit 

 their eggs close to the land. We may equally endeavour to 

 draw some line of distinction between the majority of the 

 fishes which lay floating eggs and the minority (including the 

 herring) which lay eggs that sink ; but the facts are too 



