42 



EINAR LEA. 



[REP. OF THE "MICHAEL SARS" NORTH 



In discussing the results brought out by this table 

 we may first consider those larvae recorded from com- 

 paratively cold water (under 10°). As far as Leptocephalus 

 Angaillae vulgaris, L. Synaphobranchi pinnati and L. 

 Congri vulgaris are concerned, it may be that they were 

 taken in water having a temperature below 10°, into which 

 they have immigrated, but it is quite another matter in 

 respect of the single larva of L. Congri mystacis; in this 

 case we may presume that it was caught nearer the sur- 

 face, while the net with 2000 metres of wire out was 

 being lowered or raised, for all the other larvae of this 

 species were taken in water having a temperature higher 

 than 16°. The phase of development too coincides with 

 the "preleptocephalid" stage of many of the larvae taken 

 in the upper strata of water. The same remarks apply to 

 L. similis, one larva of which was taken near the surface, 

 whereas another larva in a similar phase of development 

 and in the same locality came up in a net with 2000 

 metres of wire out. It is doubtful whether the three 

 remaining species really live at a temperature lower than 



10° or not. In the case of L. mysticus and L. Gastro- 

 stomi Bairdii the advanced phase of development indi- 

 cates that they may have been taken in deep water 

 having a low temperature, and they may have to be 

 referred to the same class as the 11 larvae of Anguillae 

 vulgaris and the 3 larvae of Synaphobranchus pinnatus, 

 which were also in an advanced stage of development. 

 At the foot of the table the number of individuals 

 and species taken at the various temperatures is indicated, 

 and it will be noticed that at 15° there is a sudden change 

 both in the number of species and of individuals: only 

 39 individuals belonging to 10 species were taken at 

 temperatures below 15°, whereas 161 individuals belonging 

 to 21 species were caught in water having a higher 

 temperature. From this table we may therefore conclude 

 that in the North Atlantic the majority of muraenoid larvae 

 occur in water with a temperature exceeding 15°. We may 

 now consider the number of species and individuals taken 

 in water of varying salinity, as set forth in the following 

 table:— 



Number of larvae taken 



in water of different salinities (in 



%>o). 









Species 



350- 

 35-1 



35-2- 

 35-3 



35-4- 

 35-5 



35-6- 

 35-7 



35-8- 

 35-9 



36-0- 

 36-1 



36-2- 

 36-3 



36-4- 

 36-5 



36-6- 

 36-7 



36-8- 

 36-9 



Leptocephalus Anguillae vulgaris 



Synaphobranchi pinnati 



— Histiobranchi infernalis 



Cyematis atri 



Congri vulgaris 



— — mystacis 



— balearici 



— polymerus 



1 

 1 



11 

 2 



1 



6 

 2 



1 



1 



3 



1 

 1 



1 



4 

 2 



1 



7 

 1 

 1 

 3 

 1 



1 

 1 



12 

 2 



17 



1 

 1 



1 



1 



1 

 3 



1 



1 



2 

 6 



2 



1 



1 



1 

 2 



1 



1 



83 

 1 



1 



4 



— Michael-Sarsi 



splendens 



— enchodon 



— euryurus 



— proboscideus 



— dolichorhynchus 



— stylurus 



— Saurenchelydis cancrivorae 



— canaricus 



— megacara 



— small nr. 1 



— - . 2 



— — „ 3 



— Gastrostomi Bardii 





Number of individuals 



2 



14 



10 



6 



7 



15 



35 



18 



5 



89 



Number of species 



2 



3 



4 



4 



3 



7 



7 



9 



4 



4 



Salinities below 36 %o: 

 39 larvae belonging to 

 10 species. 



Salinities above 36%>o: 



162 larvae belonging to 

 22 species. 



