ATLANT. DEEP-SEA EXPED. 1910. VOL. III]. 



MURAENOID LARVAE. 



41 



Leptocephalus Congri vulgaris, (small larvae) Schmidt (30) 

 Congri balearici, — — 



— ingolfianus, — 



— Hjorti, (small larvae) Blegvad (1) 

 polymerus, Autor 



The numerous remaining species have either been caught 

 below the surface, or information on this point is lacking. 



The table shows further that most of the species (20 

 in all) were taken between 50 and 150 metres below the 

 surface. And that no larvae were taken beyond 1300 

 metres in spite of the fact that at 1500 metres a large 

 shrimp net 3 metres in diameter, which according to 

 all experience is best adopted for catching such large 

 organisms as are being discussed here, was used. We 

 therefore seem justified in concluding that most of the 

 species of muraenoid larvae are to be found below the 

 surface, between 50 and 1300 metres, with a strongly 

 marked maximum at depths from 50 to 150 metres. 



It appears, however, from the "Michael Sars" material 

 as well as from the Danish investigations (Schmidt 30) that 

 one species, L. Congri balearici, is a well-marked surface 

 form, and one of the species occurring most frequently. 



Distribution in relation to the physical 

 conditions. 



In order to elucidate if possible, the peculiar horizontal 

 and vertical distribution of the larvae, I have drawn up 

 the two following tables showing the temperature and 

 salinity of the water in relation to the number of larvae 

 caught; these tables seem to disclose such variations in 

 the number of species as may guide us in forming an 

 idea of the conditions which determine their distribution. 



The first table shows the number of individuals and 

 species taken in water of different temperatures. 



Number of 



larvae taken in water of different temperatures. 









Species 



o 

 O 



V 



O 



7 



o 

 O 



o 



T 



o 



O 

 CO 



T 



o 



CN 



O 



7 



o 

 CO 



o 



7 



o 



3= 



7 



o 



o 



7 



o 



to 



O 

 OO 



7 



o 



O 



7 



o 



OO 



o 



O 



CN 



1 



o 



o 



O 



CN 



A 



Leptocephalus 



— Anguillae vulgaris 



11 



3 



1 



1 

 1 



1 

 1 



4 

 2 



1 



1 



3 



1 



3 



1 



1 



1 



1 



2 



1 



3 



3 



1 



1 

 1 



14 



1 



19 



1 

 1 



1 

 1 



1 

 1 



1 



1 



6 



2 

 1 



4 



1 



1 



2 



1 

 4 



1 



83 

 1 



2 



— Synaphobranchi pinnati . . . 



— Histiobranchi infernalis ... 



— Cyematis atri 



— Congri vulgaris 



— — mystacis 



— — balearici 



— spinocadux 



— Michael-Sarsi 



— splendens 



— enchodon 



— euryurus 



— proboscideus 



— dolichorhynchus 



— stylurus 



— Saurenchelydis cancrivorae . 



— urosema 



— megacara . • 



— — „ 2 



— — . 3 



— mysticus 



— Gastrostomus Bairdii 



Number of individuals 



19 



8 



4 



4 



3 



2 



10 



38 



13 



5 



9 



86 





7 



4 



2 



2 



3 



1 



6 



7 



7 



2 



5 



3 



Temperatures below 15°: 



40 larvae belonging to 10 species. 



Temperatures above 15°: 



161 larvae belonging to 21 species. 



