3.44 Oncaea curvata Giesbrecht 1902
Oncaea curvata Giesbrecht, 1902: p. 42, pI.
13 figs. 12-17 - Tanaka, 1960a: p. 68, pI. 30
figs. 1-11, pI. 31 figs. 1-3 - Heron, 1977: p.
70, fig. 21d-q.
Body length -
females: 0.57-0.69mm (10 specimens)
male:
0.53 mm (1 specimen)
Female. Prosome 2.1 times longer than
wide. Proportional lengths of prosome and
urosome 63 : 37; proportional lengths of
urosomites and furca 5: 45 : 10 : 9 : 15: 16
=. 100. Genital somite about 112 as long as
wIde, swollen laterally about mid-length in
dorsal view. Caudal rami about three times
longer than wide. Inner surface of second
s~gment ?f maxilliped with two spines, pro~mal sp~ne wi~h long and short spinules,
dIstal spIlle wIth two rows of denticles'
.
'
antenor surface with long hairs. Endopods of
P2, P3 with terminal conical projection; P4
la~king projection. In P4 endopod, distal
spIlle about as long as last joint. P5 small;
Oncaea curvata
237
segment not delimited from Th5 somite, with
two terminal setae.
Male. General body shape as female, with
prosome and urosome having the same proportional lengths. Prosome 2.2 times longer
than wide. Proportional lengths ofurosomites
and furca 7: 51 : 5 : 4: 4 : 13 : 16 = 100. Genital
somite ovate, about 1.6 times longer than
wide.
Distribution
O. curvata is characteristic of the Antarctic
(Farran 1929; Vervoort 1957; Tanaka 1960a;
Heron 1977; Bradford 1971b). Jt has been
reported for Chilean (Fagetti 1962) and
Argentinian waters (Ramirez 1969; Ramirez
and Dinofrio 1976), and was previously
recorded in high numbers in the Straits of
Magellan by Mazzocchi and lanora (1991). In
the present study, the species was very rare.
A few specimens were sampled from 300400 m at a single Pacific station and from
l00-250m at two stations in the Central area
of the Straits of Magellan.