Lavaniegos: Vertical distribution of euphausiicl life stages 



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05005 05005 050 5 01 01 01001 OIOOI 



Abundance (ind/m 3 ) 

 Figure 6 



Vertical distribution of life stages of Nematoscelis calyptopis stages; 

 M = metanauplii, Cj-C, = calyptopis stages; Fj-F 3 = furcilia stages; 

 J = juveniles; ND = no data. 



Cj in the thermocline (E. gibboides and N. difficilis) 

 and those with C x in the mixed layer (N. simplex, E. 

 eximia, and E. recurva ). These positions may be near 

 the level of liberation of youngest larvae in species 

 protecting eggs in maternal ovisacs such as done by 

 N. simplex andN. d iffieilis (Brinton, 1966; Mauchline 

 and Fisher, 1969 ). One day or even hours would have 

 elapsed before moulting from metanauplius into Cj 

 stage. For Nyetiphanes couchii in the Celtic Sea, the 

 liberation of mature metanauplii occurred within the 

 euphotic zone, and moulting into calyptopis stage 1 

 (Cj) occurred in a matter of hours (Williams and 

 Fragopoulu, 1985). 



These authors observed in summer a stratified 

 distribution of N. couchii during hours of light, with 



larger euphausiids at greater depths than smaller 

 euphausiids. Similarly, in the northern Benguela 

 Current, during winter, the larval calyptopes of 

 Nyetiphanes capensis showed a shallower range of 

 vertical distribution than furcilia (Barange and Pil- 

 lar, 1992). In the present study the occurrence of older 

 furcilias (F 4 -F 6 ) of AT. simplex at 200 m off Point 

 Eugenia (Fig. 3) during daytime could indicate, as 

 with N. couchii and N. capensis, an active daily mi- 

 gration. The restriction of early stages (Cj-Fg) of AT. 

 simplex to the nearshore station ( 32 km ), exclusively 

 in the surface layers, whereas late furciliar and post- 

 larval stages extended to 64 km from the coast (from 

 the surface into the layer below) may be explained 

 by offshore flows, produced by coastal upwelling. As 



