3.25 Clausocalanus brevipes
Frost and Fleminger 1968
Clausocalanus brevi pes Frost and Fleminger,
1968: p. 70, pIs. 56-59 - Ramirez, 1969: p. 52
figs. 47, 48 - Heron and Bowman, 1971:
p. 159, figs. 116-129.
Clausocalanus arcuicornis Ramirez, 1966:
p. 10, pI. 2 figs. 1-8.
Body length -
females: 1.47-1.80mm (13 specimens)
males: 1.27 -1.59 mm (8 specimens)
Female. Cephalothorax 2.5 times longer
than wide. Rostrum slender and curved
in lateral view. A1 reaching end of
genital somite. Proportional lengths of
cephalothorax and abdomen 74: 26; proportional lengths of abdominal somites and
furca 35 :23: 18: 10: 14 = 100. Seminal
receptacle conspicuous in ventral view. In
lateral view, dorsal lobe of seminal receptacle
large and bulb-like, constricted in region of
attachment to ventral lobe. Third joint of P5
more than 2 times as long as first joint;
terminal points of P5 spinulated along both
margins.
Male. Body more robust than female.
Rostrum knob-like in lateral view. Proportionallengths of cephalothorax and abdomen
69: 31. Proportional lengths of abdominal
Family Clausocalanidae"
somites and furca 7:41:21:18:3:10 = 100.
Left P5 much shorter than urosome.
Remarks
Females of C. brevi pes_ are easily distinguished from C. ingens for the characteristic shape of the seminal receptacle.
Males of C. brevi pes are the only ones in
this genus having a P5 with a left ramus
shorter than the abdomen. Our specimens
differ from those described by Frost and
Fleminger only by the somewhat larger size
(on average, both females and males are
0.2mm larger).
Distribution
According to Frost and Fleminger (1968) C.
brevi pes is characteristic of sub-Antarctic
waters. It was reported for the first time for
Chilean fjords by Marin and Antezana
(1985) but had previously been recorded
by Ramirez (1969, 1970, 1971) for the
Argentinian continental shelf, both in
surface and deep waters. In the present
study, it was frequently sampled throughout
the study area with the exception of the
Primera Angostura and more Atlantic
stations. It was mainly found in the 0-300 m
layer of the Pacific and Central areas of the
Straits of Magellan and in the entire water
column in the Atlantic area.
Frost and Fleminger 1968
Clausocalanus brevi pes Frost and Fleminger,
1968: p. 70, pIs. 56-59 - Ramirez, 1969: p. 52
figs. 47, 48 - Heron and Bowman, 1971:
p. 159, figs. 116-129.
Clausocalanus arcuicornis Ramirez, 1966:
p. 10, pI. 2 figs. 1-8.
Body length -
females: 1.47-1.80mm (13 specimens)
males: 1.27 -1.59 mm (8 specimens)
Female. Cephalothorax 2.5 times longer
than wide. Rostrum slender and curved
in lateral view. A1 reaching end of
genital somite. Proportional lengths of
cephalothorax and abdomen 74: 26; proportional lengths of abdominal somites and
furca 35 :23: 18: 10: 14 = 100. Seminal
receptacle conspicuous in ventral view. In
lateral view, dorsal lobe of seminal receptacle
large and bulb-like, constricted in region of
attachment to ventral lobe. Third joint of P5
more than 2 times as long as first joint;
terminal points of P5 spinulated along both
margins.
Male. Body more robust than female.
Rostrum knob-like in lateral view. Proportionallengths of cephalothorax and abdomen
69: 31. Proportional lengths of abdominal
Family Clausocalanidae"
somites and furca 7:41:21:18:3:10 = 100.
Left P5 much shorter than urosome.
Remarks
Females of C. brevi pes_ are easily distinguished from C. ingens for the characteristic shape of the seminal receptacle.
Males of C. brevi pes are the only ones in
this genus having a P5 with a left ramus
shorter than the abdomen. Our specimens
differ from those described by Frost and
Fleminger only by the somewhat larger size
(on average, both females and males are
0.2mm larger).
Distribution
According to Frost and Fleminger (1968) C.
brevi pes is characteristic of sub-Antarctic
waters. It was reported for the first time for
Chilean fjords by Marin and Antezana
(1985) but had previously been recorded
by Ramirez (1969, 1970, 1971) for the
Argentinian continental shelf, both in
surface and deep waters. In the present
study, it was frequently sampled throughout
the study area with the exception of the
Primera Angostura and more Atlantic
stations. It was mainly found in the 0-300 m
layer of the Pacific and Central areas of the
Straits of Magellan and in the entire water
column in the Atlantic area.