118 Chapter 4 Euphausiids
According to Costanzo and Guglielmo (1976b),
in these 2 species of the maximum-group, the
thelycum is likewise formed by the coxal plates
only. The large pocket is more widely opened in
S. maximum, where the edges of the coxal plates
are connecting near the bottom of the pocket,
whereas in S. abbreviatum they are connecting
earlier. In both species, several bristles are implanted along the frontal margin of the coxal
plates.
Distribution
S. maximum is a mesopelagic cosmopolitan species except that it does not occur in polar regions. It is widely found in the Atlantic and Indian Oceans (Hansen 1910, 1912; Zimmer 1914; Illig 1930; Tattersall1939; Ponomareva 1963) and
Mediterranean Sea (Ruud 1936; Casanova-Soulier 1968). In the Pacific, S. maximum occupies a
wide range between 60°N (Gulf of Alaska) to
63°S in the western South Pacific. Around South
America, it has been found off Argentina (Antezana and Brinton 1981). Off Chile, solitary subadult and adult specimens have been randomly
sampled throughout the Humboldt and Cape
Horn Currents, as far as 60°S (Antezana 1978)
and along the southern fjords (Antezana 1976).
Although considered a mesopelagic species,
larval stages, juveniles and occasionally adults of
S. maximum have been found in the upper 200 m
(Brinton 1962b; Antezana 1976, 1978). In the
present study, only o ne female was sampled from
200-300 mat St. 15.
According to Costanzo and Guglielmo (1976b),
in these 2 species of the maximum-group, the
thelycum is likewise formed by the coxal plates
only. The large pocket is more widely opened in
S. maximum, where the edges of the coxal plates
are connecting near the bottom of the pocket,
whereas in S. abbreviatum they are connecting
earlier. In both species, several bristles are implanted along the frontal margin of the coxal
plates.
Distribution
S. maximum is a mesopelagic cosmopolitan species except that it does not occur in polar regions. It is widely found in the Atlantic and Indian Oceans (Hansen 1910, 1912; Zimmer 1914; Illig 1930; Tattersall1939; Ponomareva 1963) and
Mediterranean Sea (Ruud 1936; Casanova-Soulier 1968). In the Pacific, S. maximum occupies a
wide range between 60°N (Gulf of Alaska) to
63°S in the western South Pacific. Around South
America, it has been found off Argentina (Antezana and Brinton 1981). Off Chile, solitary subadult and adult specimens have been randomly
sampled throughout the Humboldt and Cape
Horn Currents, as far as 60°S (Antezana 1978)
and along the southern fjords (Antezana 1976).
Although considered a mesopelagic species,
larval stages, juveniles and occasionally adults of
S. maximum have been found in the upper 200 m
(Brinton 1962b; Antezana 1976, 1978). In the
present study, only o ne female was sampled from
200-300 mat St. 15.