46
THE BIOLOGY O F EUPHAUSIIDS
northern distribution while T. subaequalis is the dominant species in
the southern latitudes. Indian : except for the positive identification of
T. subaequalis from the Straits of Mozambique, all other records have
been ascribed to T. aequalis and await confirmation ; Baker (personal
communication) found T . subaequalis from the equator to 37"s along
90"E. T. aequalis is associated with temperatures between 11" and
16°C at 200 m and T. subaequalis with temperatures higher than 16°C
at 200 m. Adults of both species present below 140 m during the day ;
perform diurnal vertical migrations. Length 13 to 20 mm. (Hansen,
1905b, 1915 ; Tattersall, 1912a, 1924, 1927, 1936c, 1939 ; Colosi, 1922b ;
Lebour, 1926d, 1950; Denis, 1929; Illig, 1930; Leavitt, 1935, 1938;
Ruud, 1936; Moore, 1949, 1950, 1952; Boden, 1954, 1961a; Lewis,
1954; Boden and Brinton, 1957; Dion and Nouvel, 1960; Bacescu and
Mayer, 1961; Brinton, 1962a; Grice and Hart, 1962; Kinzer, 1963;
Ponomareva, 1963, 1964; Soulier, 196313; Nemoto, 1965; Roger, 1967b;
Casanova-Soulier, 196813).
Thysanopoda obtusifrons G. 0. Sars, 1883
T . obtusqrons G. 0. Sars, 188310: 21-22; 1885: 102-104, pl. xii, figs. 1-14;
Hansen, 1910: 81; 1912: 215-217, pl. iv, fig. 5, a-f; Bodon et al., 1955: 303-307,
fig. 10. T. vulgaris Hansen, 1905a: 15. T. distinguenda Hanscn, 1905a: 17-18,
fig. 13 ( f i d e Illig, 1908b: 114-115).
Widespread in tropical and subtropical regions (Fig. 13). Atlantic :
in west and east between about 40"N and 40"s ; not in Mediterranean.
Pacific : between 34"N and 5"N and between 9"s and 35"s ; present in
small numbers throughout these areas. Indian : taken off South Africa
and northwards between l0"N and 30"s. Adults and juveniles below
280 m during the day ; performs a diurnal vertical migration. Grows to
about 20 mm. (Ortmann, 1893; Alcock and Anderson, 1894; Hansen,
1905a,b; Tattersall, 1924, 1936c, 1939; Illig, 1930; Ruud, 1936;
Leavitt, 1938 ; Boden, 1954 ; Brinton, 1962a; Ponomareva, 1963;
Grindley and Penrith, 1965; Nemoto, 1965; Roger, 1966).
Thysanopoda pectinata Ortmann, 1893
T. pectinata Ortmann, 1893 : 10, taf. 1, fig. 4 ; Hansen, 1905b : 25-26 ; 1912 :
218-222, pl. 5, fig. 1, a-m; Illig, 1930: 510-512, figs. 192-193; Boden et al.,
1955 : 307-309, fig. 11. Parathysanopoda foliifera Illig, 1909 : 225 ; Hansen, 1911 :
This is a mesopelagic species (Fig. 13). Atlantic : has been recorded
in Bay of Biscay a t about 45"N and extends southwards to South Africa
(40"s). Pacific : found south of 34"N and extends in the south to about
35"s. Indian: present between l0"N and 30"s. This species occurs
14-15.
THE BIOLOGY O F EUPHAUSIIDS
northern distribution while T. subaequalis is the dominant species in
the southern latitudes. Indian : except for the positive identification of
T. subaequalis from the Straits of Mozambique, all other records have
been ascribed to T. aequalis and await confirmation ; Baker (personal
communication) found T . subaequalis from the equator to 37"s along
90"E. T. aequalis is associated with temperatures between 11" and
16°C at 200 m and T. subaequalis with temperatures higher than 16°C
at 200 m. Adults of both species present below 140 m during the day ;
perform diurnal vertical migrations. Length 13 to 20 mm. (Hansen,
1905b, 1915 ; Tattersall, 1912a, 1924, 1927, 1936c, 1939 ; Colosi, 1922b ;
Lebour, 1926d, 1950; Denis, 1929; Illig, 1930; Leavitt, 1935, 1938;
Ruud, 1936; Moore, 1949, 1950, 1952; Boden, 1954, 1961a; Lewis,
1954; Boden and Brinton, 1957; Dion and Nouvel, 1960; Bacescu and
Mayer, 1961; Brinton, 1962a; Grice and Hart, 1962; Kinzer, 1963;
Ponomareva, 1963, 1964; Soulier, 196313; Nemoto, 1965; Roger, 1967b;
Casanova-Soulier, 196813).
Thysanopoda obtusifrons G. 0. Sars, 1883
T . obtusqrons G. 0. Sars, 188310: 21-22; 1885: 102-104, pl. xii, figs. 1-14;
Hansen, 1910: 81; 1912: 215-217, pl. iv, fig. 5, a-f; Bodon et al., 1955: 303-307,
fig. 10. T. vulgaris Hansen, 1905a: 15. T. distinguenda Hanscn, 1905a: 17-18,
fig. 13 ( f i d e Illig, 1908b: 114-115).
Widespread in tropical and subtropical regions (Fig. 13). Atlantic :
in west and east between about 40"N and 40"s ; not in Mediterranean.
Pacific : between 34"N and 5"N and between 9"s and 35"s ; present in
small numbers throughout these areas. Indian : taken off South Africa
and northwards between l0"N and 30"s. Adults and juveniles below
280 m during the day ; performs a diurnal vertical migration. Grows to
about 20 mm. (Ortmann, 1893; Alcock and Anderson, 1894; Hansen,
1905a,b; Tattersall, 1924, 1936c, 1939; Illig, 1930; Ruud, 1936;
Leavitt, 1938 ; Boden, 1954 ; Brinton, 1962a; Ponomareva, 1963;
Grindley and Penrith, 1965; Nemoto, 1965; Roger, 1966).
Thysanopoda pectinata Ortmann, 1893
T. pectinata Ortmann, 1893 : 10, taf. 1, fig. 4 ; Hansen, 1905b : 25-26 ; 1912 :
218-222, pl. 5, fig. 1, a-m; Illig, 1930: 510-512, figs. 192-193; Boden et al.,
1955 : 307-309, fig. 11. Parathysanopoda foliifera Illig, 1909 : 225 ; Hansen, 1911 :
This is a mesopelagic species (Fig. 13). Atlantic : has been recorded
in Bay of Biscay a t about 45"N and extends southwards to South Africa
(40"s). Pacific : found south of 34"N and extends in the south to about
35"s. Indian: present between l0"N and 30"s. This species occurs
14-15.