3.19 Eucalanus longiceps
Matthews 1925
Eucalanus longiceps Matthews, 1925: p. 127,
pI. 9 figs. 1-10 - Ramirez, 1969: p. 43,-figs.
35,36.
Eucalanus acus Farran, 1929: p. 218, fig. 3.
Body length -
females: 4.21-5.lOmm (3 specimens)
Female. Cephalothorax
elongate
and
slender, slightly enlarged at base of first
somite. Head tapered into acute conical
point. Postero-Iateral corners of last thoracic
somite rounded. Proportional lengths of
cephalothorax and abdomen 89 : 11; proportional lengths of abdominal somites and
furca 54: 13: 20: 13 = 100. Abdomen 3segmented. Genital somite laterally swollen
in dorsal view, with pronounced circular
genital pores in proximity of the lateral
margins. Caudal rami very short, more or
less as long as wide.
Remarks
E. longiceps was originarily described by
Matthews (1925) and then erroneously
redescribed by Farran (1929) as E. acus n.sp.
This mistake was noted and corrected for by
Eucalanus longiceps
121
Sewell (1947). E. longiceps is very easily
distinguished from all other eucalanid species
due to its very characteristic elongated conical
head. In our samples, we found very few
adult females and a number of juvenile
stages but no males.
Distribution
The species has frequently been reported in
cold waters of the Southern hemisphere.
Farran (1929) found E. acus (synonymus)
from the surface to 80 m south of New
Zealand. Hardy and Gunther (1935) reported
it from intermediate cold Antarctic waters
around South Georgia. Sena et ai. (1963)
reported this species as characteristic of subAntarctic waters. Also Ramirez (1969, 1970)
recorded it in sub-Antarctic waters from the
surface to 500-600m in the SW Atlantic
Ocean. Atkinson and Peck (1988) reported
E. longiceps as a strong migrant species
concentrated at depths greater than 500 m in
the oceanic area around South Georgia.
Marin and Antezana (1985) reported it for
the first time in Chilean fjords. In the
present study, the species was mainly
sampled in the Pacific area and at a single
station off Cape Froward. It was distributed
from 100-500 m with a maximum abundance
from 250-300m.
Matthews 1925
Eucalanus longiceps Matthews, 1925: p. 127,
pI. 9 figs. 1-10 - Ramirez, 1969: p. 43,-figs.
35,36.
Eucalanus acus Farran, 1929: p. 218, fig. 3.
Body length -
females: 4.21-5.lOmm (3 specimens)
Female. Cephalothorax
elongate
and
slender, slightly enlarged at base of first
somite. Head tapered into acute conical
point. Postero-Iateral corners of last thoracic
somite rounded. Proportional lengths of
cephalothorax and abdomen 89 : 11; proportional lengths of abdominal somites and
furca 54: 13: 20: 13 = 100. Abdomen 3segmented. Genital somite laterally swollen
in dorsal view, with pronounced circular
genital pores in proximity of the lateral
margins. Caudal rami very short, more or
less as long as wide.
Remarks
E. longiceps was originarily described by
Matthews (1925) and then erroneously
redescribed by Farran (1929) as E. acus n.sp.
This mistake was noted and corrected for by
Eucalanus longiceps
121
Sewell (1947). E. longiceps is very easily
distinguished from all other eucalanid species
due to its very characteristic elongated conical
head. In our samples, we found very few
adult females and a number of juvenile
stages but no males.
Distribution
The species has frequently been reported in
cold waters of the Southern hemisphere.
Farran (1929) found E. acus (synonymus)
from the surface to 80 m south of New
Zealand. Hardy and Gunther (1935) reported
it from intermediate cold Antarctic waters
around South Georgia. Sena et ai. (1963)
reported this species as characteristic of subAntarctic waters. Also Ramirez (1969, 1970)
recorded it in sub-Antarctic waters from the
surface to 500-600m in the SW Atlantic
Ocean. Atkinson and Peck (1988) reported
E. longiceps as a strong migrant species
concentrated at depths greater than 500 m in
the oceanic area around South Georgia.
Marin and Antezana (1985) reported it for
the first time in Chilean fjords. In the
present study, the species was mainly
sampled in the Pacific area and at a single
station off Cape Froward. It was distributed
from 100-500 m with a maximum abundance
from 250-300m.