94 Chapter 4 Euphausiids
Remarks
Euphausia lucens resembles E. vallentini (particularly non-spined specimens), due to the rostrum which varies from acute to subacute (Zimmer 1915) and to the variability in the shape and
size of the lobe on the 1st antennular segment
(Hansen 1911; Zimmer 1915; John 1936; Boden
1955; Bary 1956). As discussed above, the distinction between the 2 species is based on the
size and shape of the dorsal keel of the 3rd an tennular segment, the denticles on the inner border
of the subterminal spines, and the distribution of
the setae on the setiferous lobe of the petasma.
T~ese 2 spe~ies can also be distinguished by the
d1fferences m the coxal plates and the sternite
which forms the thelycum ( Guglielmo and Cos~
tanzo 1978).
Distribution
Euphausia lucens is endemic to the Southern
Hemisphere with a typically circumpolar distribution, avoiding the cooler latitudes of the subAntarctic (John 1936). Off South America, E.
lucens is found in Atlantic and Pacific waters including the fjords of southern Chile. In Atla~tic
waters near South America, it was collected off
the Rio de la Plata estuary to the North of the
Antarctic Convergence (Antezana and Brinton
1981). In the Eastern South Pacific, it occupies
an area immediately north of E. vallentini.
. It is. co~centrated from 41 °-45°S and expands
1ts latltudmal range toward the Chilean coast
reaching 37°S to the north and 52°S to the soutl~
(Antezana 1978, 1981).
Within the fjords of Chile, it was frequently,
but not densely, found at the surface, north of
50os in waters as saline as 27 ppm (Antezana
197~). It has not been previously reported in the
Strmts ofMagellan (Guglielmo et al. 1991; Antezana et al. 1992). In the present study, it was sampled throughout the Pacific sector up to St. 9,
where it was found from 100-200 m; in the Atlantic, it was sampled only at the entrance to the
Straits (St. 26) from 0-30 m. Both males and females had a well-developed petasma and thelycum.
Remarks
Euphausia lucens resembles E. vallentini (particularly non-spined specimens), due to the rostrum which varies from acute to subacute (Zimmer 1915) and to the variability in the shape and
size of the lobe on the 1st antennular segment
(Hansen 1911; Zimmer 1915; John 1936; Boden
1955; Bary 1956). As discussed above, the distinction between the 2 species is based on the
size and shape of the dorsal keel of the 3rd an tennular segment, the denticles on the inner border
of the subterminal spines, and the distribution of
the setae on the setiferous lobe of the petasma.
T~ese 2 spe~ies can also be distinguished by the
d1fferences m the coxal plates and the sternite
which forms the thelycum ( Guglielmo and Cos~
tanzo 1978).
Distribution
Euphausia lucens is endemic to the Southern
Hemisphere with a typically circumpolar distribution, avoiding the cooler latitudes of the subAntarctic (John 1936). Off South America, E.
lucens is found in Atlantic and Pacific waters including the fjords of southern Chile. In Atla~tic
waters near South America, it was collected off
the Rio de la Plata estuary to the North of the
Antarctic Convergence (Antezana and Brinton
1981). In the Eastern South Pacific, it occupies
an area immediately north of E. vallentini.
. It is. co~centrated from 41 °-45°S and expands
1ts latltudmal range toward the Chilean coast
reaching 37°S to the north and 52°S to the soutl~
(Antezana 1978, 1981).
Within the fjords of Chile, it was frequently,
but not densely, found at the surface, north of
50os in waters as saline as 27 ppm (Antezana
197~). It has not been previously reported in the
Strmts ofMagellan (Guglielmo et al. 1991; Antezana et al. 1992). In the present study, it was sampled throughout the Pacific sector up to St. 9,
where it was found from 100-200 m; in the Atlantic, it was sampled only at the entrance to the
Straits (St. 26) from 0-30 m. Both males and females had a well-developed petasma and thelycum.