— 145 — 



intense black. The pectorals also were of a deep black. In connection with these changes 

 in the outer appearance was also the fact, that the sexual organs were often more 

 developed in the eels brought up by the whirlpools than in those found in shallow 

 water. Thus Gkassi and Calandruccio found males, in the testes of which there were 

 here and there groups of ripe spermatozoa which resembled those in the conger 

 {Conger vulgaris). Ripe females do not seem to have been found, at least are not 

 mentioned; it is only said quite generally that the sexual organs are often more developed 

 than is usual in the silver eels. 



Similar eels to those mentioned were also obtained by Gkassi and Calandruccio in 

 another way, namely from the stomachs of the sword-fish (pesce-spada) which is frequently 

 taken in the Messina Straits and the favourite food of which seems to be the eel. The 

 Italian authors sum up their observations as follows : in the period from November to July 

 the currents bring up eels from deep water, which are much more forward in develop- 

 ment than those which migrate to the sea but are nevertheless not fully ripe. 



In spite of their incompleteness the observations of Grassi and Calandruccio are 

 very interesting, as they seem to show that the eel must get into great depths before it 

 spawns. Here as with the Leptocephali it is the whirlpool of the Messina Straits to which 

 the Italian authors owe their observations, and which has saved them the apparatus and 

 boats elsewhere indispensable. 



In this connection it should be mentioned that a freshwater eel has been found in the 

 open sea since Grassi and Calandruccio's observations, this time however not in the 

 Mediterranean but in the Atlantic Ocean. Concerning this, the French ichthyologist L. 

 Vaillant who has done good work in the investigation of the eel in other directions also, 

 gives an interesting report. This eel which was present in the collection of Prince Albert 

 of Monaco had a length of 90 cm. (weight 1500 — 2000 gm.) and was as thick as an arm. 

 It was taken from the stomach of a cachalot by Captain Chaves the director of the Ob- 

 servatory at Punta Delgada on the Azores. Vaillant remarks on this inter alia as 

 follows': "Cette capture, dans de telles circonstances, non seulement confirme le fait in- 

 contesté, que l'Anguille descend à la mer, mais encore montre que dans certains cas elle 

 s'y avance assez loin pour devenir la proie d'animaux qui ne vivent qu'au large, comme 

 les grands Cétacés." . . . "Peut-être font-elles partie de cette faune pélagique, qui ne parait 

 jamais à la surface et de même ne touche jamais le fond, faune dont les découvertes 

 déjà faites par S. A. S. le prince Albert de Monaco , dans des circonstances analogues 

 permettent aujourd'hui d'entrevoir l'existence." 



This discovery undoubtedly shows that the common eel travels out to the open sea. 

 That it should lead there a pelagic (i. e. bathypelagic) existence during the spawning 

 period is certainly not excluded. In any case there is no doubt that the eel occasion- 

 ally lives pelagically. This is shown by other observations in addition to Vaillant's. 

 Thus, as mentioned above, Grassi and Calandruccio's often found eels in stomachs of 

 the sword-fish (pesce-spada) which is a pelagic species. Sometimes also eels are taken on 

 hooks held up in the water without being sunk to the bottom, as is mentioned for 

 example by Yarrell. Finally I may quote from the "Dansk Fiskeritidende" (Nr. 4, 1906) 



I L. Vaillant, Sur la présence de l'Anguille commune en haute mer (Comptes Rendus, tome 126, 1898, 

 p. 1429 — 30). Vaillant states nothing concerning the exact locality or date of the discovery of this eel, 

 nor concerning the sexual organs. 



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