44
THE BIOLOGY O F EUPHAUSIIDS
Thysanopoda tricuspidata Milne-Edwards, 1837
T . tricuspide Milne-Edwards, 1830 : 454, pl. xix. T. tricuspida Milne-Edwards,
1837 : 45, pl. xxvi, figs. 1-6. T. tricuspidata Milne-Edwards, 1837 : 466, pl. xxvi,
figs. 1-6 ; G. 0. Sers, 1885: 98-102, 165-169, pls. xvii, xxxi, figs. 1-22 ; Hansen,
1910: 82-84, pl. xii, fig. 3, a-b; 1912: 208, pl. iv, fig. 2a; Boden et al., 1955:
301-303, fig. 8. Cyrtopia rostrata Dana, 1852 : 130.
Has a widespread distribution in equatorial regions (Fig. 11).
Atlantic : extends from about 40"N to 40"s but commonest between
20"N and 15"s ; Sars records it in mid-Atlantic near 40"N and near 40"s.
Pacific: tropical regions between 36"N and 21"s in the west but is not
present in most of the eastern equatorial basin ; commonest between
about 10"N and 10"s. Indian: present off eastern South Africa and in
the northern area between 10°N and 10"s. Present below 500 m during
the day ; performs diurnal vertical migration. Attains length of 30 mm.
(Sars, 1885; Ortmann, 1893; Tattersall, 1912a, 1913, 1924,1927,1936~,
1939; Hansen, 1916; Illig, 1930; Leavitt, 1935, 1938; Lebour, 1950;
Boden, 1954, 1961a; Lewis, 1954; Evans, 1961 ; Legar6, 1961 ; Wickstead, 1961 ; Brinton, 1962a; Ponomareva, 1963, 1964; GrindIey and
Penrith, 1965; Nemoto, 1965; Roger, 1966, 1967b).
Thysanopoda aequalis Hansen, 1905
T . aequalis Hansen, 1905b: 18-20; 1910: 8 4 4 5 , pl. xii, fig. 4, a+, pl. xiii,
fig. l a ; 1912: 214-215, pl. iv, fig. 48; Boden et al., 1955: 303-305, fig. 9.
T. obtusifrons Lo Bianco, 1901 : 440 ; Thiele, 1905 : 452 ; Ortmann, 1905 : 964.
T . microphthalma Lo Bianco 1903: 192. T. aequalis var. latifrons Colosi, 1916:
67-68, figs. 6-7.
Thysanopodu subaequalis Boden, 1954
T . subaequalis Boden, 1954: 190-192, fig. 5 ; Boden and Brinton, 1957:
T . aequalis and T . subaequalis were distinguished by Boden and
Brinton (1957), T . subaequalis first being described by Boden (1954)
from the Straits of Mozambique. Juveniles of the two species cannot
be separated. Authorities earlier than 1957 may have confused the two
species, simply identifying them as T . aequalis. Consequently, the
separate distributions of these species in the Atlantic and Indian Oceans
are not known (Fig. 12). Specimens obtained from the western Atlantic
were identified as T . aequalis and likewise those from the eastern
Atlantic ; Bacescu and Mayer and Soulier show that T . subaequalis is
present throughout the Mediterranean.
Pacific : their combined
distribution extends from 40°N to between 35' and 40"s but both
species are absent from the eastern equatorial basin. T . aequalis
occupies the northwest and T . subaequalis the northeast areas of the
337-341, figs. 1-2.
THE BIOLOGY O F EUPHAUSIIDS
Thysanopoda tricuspidata Milne-Edwards, 1837
T . tricuspide Milne-Edwards, 1830 : 454, pl. xix. T. tricuspida Milne-Edwards,
1837 : 45, pl. xxvi, figs. 1-6. T. tricuspidata Milne-Edwards, 1837 : 466, pl. xxvi,
figs. 1-6 ; G. 0. Sers, 1885: 98-102, 165-169, pls. xvii, xxxi, figs. 1-22 ; Hansen,
1910: 82-84, pl. xii, fig. 3, a-b; 1912: 208, pl. iv, fig. 2a; Boden et al., 1955:
301-303, fig. 8. Cyrtopia rostrata Dana, 1852 : 130.
Has a widespread distribution in equatorial regions (Fig. 11).
Atlantic : extends from about 40"N to 40"s but commonest between
20"N and 15"s ; Sars records it in mid-Atlantic near 40"N and near 40"s.
Pacific: tropical regions between 36"N and 21"s in the west but is not
present in most of the eastern equatorial basin ; commonest between
about 10"N and 10"s. Indian: present off eastern South Africa and in
the northern area between 10°N and 10"s. Present below 500 m during
the day ; performs diurnal vertical migration. Attains length of 30 mm.
(Sars, 1885; Ortmann, 1893; Tattersall, 1912a, 1913, 1924,1927,1936~,
1939; Hansen, 1916; Illig, 1930; Leavitt, 1935, 1938; Lebour, 1950;
Boden, 1954, 1961a; Lewis, 1954; Evans, 1961 ; Legar6, 1961 ; Wickstead, 1961 ; Brinton, 1962a; Ponomareva, 1963, 1964; GrindIey and
Penrith, 1965; Nemoto, 1965; Roger, 1966, 1967b).
Thysanopoda aequalis Hansen, 1905
T . aequalis Hansen, 1905b: 18-20; 1910: 8 4 4 5 , pl. xii, fig. 4, a+, pl. xiii,
fig. l a ; 1912: 214-215, pl. iv, fig. 48; Boden et al., 1955: 303-305, fig. 9.
T. obtusifrons Lo Bianco, 1901 : 440 ; Thiele, 1905 : 452 ; Ortmann, 1905 : 964.
T . microphthalma Lo Bianco 1903: 192. T. aequalis var. latifrons Colosi, 1916:
67-68, figs. 6-7.
Thysanopodu subaequalis Boden, 1954
T . subaequalis Boden, 1954: 190-192, fig. 5 ; Boden and Brinton, 1957:
T . aequalis and T . subaequalis were distinguished by Boden and
Brinton (1957), T . subaequalis first being described by Boden (1954)
from the Straits of Mozambique. Juveniles of the two species cannot
be separated. Authorities earlier than 1957 may have confused the two
species, simply identifying them as T . aequalis. Consequently, the
separate distributions of these species in the Atlantic and Indian Oceans
are not known (Fig. 12). Specimens obtained from the western Atlantic
were identified as T . aequalis and likewise those from the eastern
Atlantic ; Bacescu and Mayer and Soulier show that T . subaequalis is
present throughout the Mediterranean.
Pacific : their combined
distribution extends from 40°N to between 35' and 40"s but both
species are absent from the eastern equatorial basin. T . aequalis
occupies the northwest and T . subaequalis the northeast areas of the
337-341, figs. 1-2.