3.18 Eucalanus elongatus hyalinus
Giesbrecht 1892
Eucalanus elongatus hyalinus Giesbrecht,
1892: p. 131, pI. 11 figs. 2, 7, 12, 20, 25, 32,
36, pI. 35 figs. 1, 2, 13, 23, 24 - Johnson,
1938: p. 170, figs. 3, 17, 19,21, 24-Brodskii,
1950: p. 103, fig. 29.
Eucalanus spinifer Scott, 1894: p. 29, pI. 1
figs. 15-23.
Eucalanus atlanticus Wolfenden, 1904: p.
111, pI. 9 figs. 3, 4.
Eucalanus elongatus Ramirez, 1969: p. 45,
pI. 7 figs. 43, 44.
Body length -
females: 6.90-7.35 mm (4 specimens)
Female. Body very transparent and limp.
Rostrum robust, elongated, and ending in
fine filaments. Cephalothorax about 3 times
longer than wide. Head triangular; last
thoracic somite with pointed and slightly
elongated posterior comers. Proportional
lengths of cephalothorax and abdomen 86 : 12.
Last thoracic somite ornated with small
spinules on dorsal posterior margin.
Abdomen 4-segmented; anal somite and
furca fused. Proportional lengths of
abdominal somites and furca 48: 15 : 9 : 28 =
100. Genital somite longer than wide. Left
caudal ramus larger than right; left second
inner seta much stronger and longer than
right. Anal somite with tufts of hairs and
sparse spinules on ventral side and spinules
along ridge of anal plate. PI with 3-jointed
exopod, distal joint with long terminal spine
and one outer, shorter spine; endopod 2jointed; proximal joint with tuft of hairs on
inner edge. P5 absent.
Family Eucalanidae
Remarks
Although Eucalanus is a morphologically distinct genus and its species are widespread,
there is still much confusion regarding the
validity and rank of its nominal species and
subspecies (Fleminger 1973-). Difficulties in
the identification of this species are largely
due to the absence of distinctive, sexually
modified appendages. Our specimens (4
adult females and a few copepodites) agree
with the descriptions for E. elongatus
hyalin us by Giesbrecht (1892). This species
was discussed by Vervoort (1946, 1963) and
reported by Brodskii (1950), although this
latter author considered only the two species
E. elongatus and E. hyalin us in a successive
paper, distinguishing them on the basis of the
shape of the posterior comers of the last
thoracic somite (Brodskii et aI. 1983).
Fleminger (1973) widely discussed the genus
Eucalanus and commented on the elongatus
complex. He considered as useful characters
the seminal receptacles and integumental
organs (sensilla and glandular pore). We did
not use this latter character since we had only
a limited number of specimens and these
were heavily damaged.
Distribution
E. elongatus hyalin us has been recorded in
the North Atlantic, Indian Ocean and
Mediterranean Sea. It seems to have a fairly
wide distribution in the northern Pacific
(Johnson 1938). However, according to
Brodskii (1950), it is difficult to determine
the range of this species in the Pacific owing
to its confusion with E. bungii. This species is
considered mainly, though not exclusively,
Atlantic, being distributed over nearly the
Giesbrecht 1892
Eucalanus elongatus hyalinus Giesbrecht,
1892: p. 131, pI. 11 figs. 2, 7, 12, 20, 25, 32,
36, pI. 35 figs. 1, 2, 13, 23, 24 - Johnson,
1938: p. 170, figs. 3, 17, 19,21, 24-Brodskii,
1950: p. 103, fig. 29.
Eucalanus spinifer Scott, 1894: p. 29, pI. 1
figs. 15-23.
Eucalanus atlanticus Wolfenden, 1904: p.
111, pI. 9 figs. 3, 4.
Eucalanus elongatus Ramirez, 1969: p. 45,
pI. 7 figs. 43, 44.
Body length -
females: 6.90-7.35 mm (4 specimens)
Female. Body very transparent and limp.
Rostrum robust, elongated, and ending in
fine filaments. Cephalothorax about 3 times
longer than wide. Head triangular; last
thoracic somite with pointed and slightly
elongated posterior comers. Proportional
lengths of cephalothorax and abdomen 86 : 12.
Last thoracic somite ornated with small
spinules on dorsal posterior margin.
Abdomen 4-segmented; anal somite and
furca fused. Proportional lengths of
abdominal somites and furca 48: 15 : 9 : 28 =
100. Genital somite longer than wide. Left
caudal ramus larger than right; left second
inner seta much stronger and longer than
right. Anal somite with tufts of hairs and
sparse spinules on ventral side and spinules
along ridge of anal plate. PI with 3-jointed
exopod, distal joint with long terminal spine
and one outer, shorter spine; endopod 2jointed; proximal joint with tuft of hairs on
inner edge. P5 absent.
Family Eucalanidae
Remarks
Although Eucalanus is a morphologically distinct genus and its species are widespread,
there is still much confusion regarding the
validity and rank of its nominal species and
subspecies (Fleminger 1973-). Difficulties in
the identification of this species are largely
due to the absence of distinctive, sexually
modified appendages. Our specimens (4
adult females and a few copepodites) agree
with the descriptions for E. elongatus
hyalin us by Giesbrecht (1892). This species
was discussed by Vervoort (1946, 1963) and
reported by Brodskii (1950), although this
latter author considered only the two species
E. elongatus and E. hyalin us in a successive
paper, distinguishing them on the basis of the
shape of the posterior comers of the last
thoracic somite (Brodskii et aI. 1983).
Fleminger (1973) widely discussed the genus
Eucalanus and commented on the elongatus
complex. He considered as useful characters
the seminal receptacles and integumental
organs (sensilla and glandular pore). We did
not use this latter character since we had only
a limited number of specimens and these
were heavily damaged.
Distribution
E. elongatus hyalin us has been recorded in
the North Atlantic, Indian Ocean and
Mediterranean Sea. It seems to have a fairly
wide distribution in the northern Pacific
(Johnson 1938). However, according to
Brodskii (1950), it is difficult to determine
the range of this species in the Pacific owing
to its confusion with E. bungii. This species is
considered mainly, though not exclusively,
Atlantic, being distributed over nearly the