3.1 Augaptilus glacialis Sars 1900
Augaptilus glacialis Sars·, 1900: p. 88, pIs. 26,
27; 1924-1925: p. 254, pI. 76 figs. 1-16 -
Brodskii, 1950: p. 368, fig. 258 - Vervoort,
1951: p. 144, figs. 80, 81 - 1957: p. 138, fig.
131 - Tanaka 1964b: p. 77, fig. 212 - Tanaka
and Omori, 1971: p. 259, fig. 5a.
Augaptilus zetesios Wolfenden, 1902: p. 369,
pI. 3.
Body length -
females: 4.51-5.19mm (15 specimens)
males: 4.04-4.39mm (10 specimens)
Female. Cephalothorax oblong and ovate,
2.51 times longer than wide. Last thoracic
somite narrowly rounded at distal corners.
Al exceeds end of furca by distal 4-5 segments. Proportional lengths of cephalothorax
and abdomen 69: 31. Abdomen 3-segmented.
Proportional lengths of abdominal somites
and furca 39:11:17:33 = 100. Genital
somite slightly asymmetrical. Caudal rami
5 times longer than wide and strongly
divergent. Anal somite and furca naked on
dorsal side, coarsely covered with fine hairs
on ventral surface. Mandibular blade with
two sets of large teeth of equal length, one
single smaller tooth and another single large
tooth with serrated fringe. Inner marginal
spine of P5 Re2 reaching base of 3rd inner
marginal seta of Re3.
Male. Cephalothorax 2.6 times longer than
wide. Proportional lengths of cephalothorax
and abdomen 71 :29. Left Al geniculated.
Abdomen 5-segmented. Proportional lengths
of abdominal somites and furca 16: 13 : 13 :
11 : 14: 33 = 100. Ventral side of caudal rami
Order CALANOIDA
Family Augaptilidae
bearing long hairs. P5 slightly asymmetrical;
distal joint of right exopod bearing two
spines of unequal length, the larger spine
slightly longer than Re3. Inner distal margin
of B2 of both legs bearing small bump with
cluster of short blunt denticles. This latter
feature is reported only for right B2 by
Brodskii (1950).
Remarks
It seems to be remarkably difficult to separate
A. glacialis from A. longicaudatus (Claus
1863) as discussed by Vervoort (1965b). The
lengths reported for A. g. females from different areas are always larger than 4 mm,
while for A. I. they are generally smaller
(Tanaka and Omori 1971). Otherwise, a
comparison of the data available for A. I.
suggests that this species is greatly variable in
length; Farran (1908) reported an extremely
wide length range for females from the Irish
Atlantic slope (3.6-6.1 mm). InA. I. females,
the caudal rami and anal somite are covered
by spiniform hairs; in A. g. the furca may be
completely naked, but usually there are fine
hairs along the internal borders. Our specimens are in the size range usually reported
for A. g.; the caudal rami and anal somite of
females are coarsely covered with fine hairs
on the ventral side (no spiniform hairs as in
A. I.) and the genital somite is only slightly
asymmetrical without the remarkable swelling on the left side (in dorsal view) characterizing A. I. females (as shown also by
Tanaka and Omori (1971, p. 260). In the
specimens from the Straits of Magellan, as
also in the specimens analyzed by Vervoort
(1965b), the female does not have the blunt,
coarsely serrulated internal marginal spine of
Augaptilus glacialis Sars·, 1900: p. 88, pIs. 26,
27; 1924-1925: p. 254, pI. 76 figs. 1-16 -
Brodskii, 1950: p. 368, fig. 258 - Vervoort,
1951: p. 144, figs. 80, 81 - 1957: p. 138, fig.
131 - Tanaka 1964b: p. 77, fig. 212 - Tanaka
and Omori, 1971: p. 259, fig. 5a.
Augaptilus zetesios Wolfenden, 1902: p. 369,
pI. 3.
Body length -
females: 4.51-5.19mm (15 specimens)
males: 4.04-4.39mm (10 specimens)
Female. Cephalothorax oblong and ovate,
2.51 times longer than wide. Last thoracic
somite narrowly rounded at distal corners.
Al exceeds end of furca by distal 4-5 segments. Proportional lengths of cephalothorax
and abdomen 69: 31. Abdomen 3-segmented.
Proportional lengths of abdominal somites
and furca 39:11:17:33 = 100. Genital
somite slightly asymmetrical. Caudal rami
5 times longer than wide and strongly
divergent. Anal somite and furca naked on
dorsal side, coarsely covered with fine hairs
on ventral surface. Mandibular blade with
two sets of large teeth of equal length, one
single smaller tooth and another single large
tooth with serrated fringe. Inner marginal
spine of P5 Re2 reaching base of 3rd inner
marginal seta of Re3.
Male. Cephalothorax 2.6 times longer than
wide. Proportional lengths of cephalothorax
and abdomen 71 :29. Left Al geniculated.
Abdomen 5-segmented. Proportional lengths
of abdominal somites and furca 16: 13 : 13 :
11 : 14: 33 = 100. Ventral side of caudal rami
Order CALANOIDA
Family Augaptilidae
bearing long hairs. P5 slightly asymmetrical;
distal joint of right exopod bearing two
spines of unequal length, the larger spine
slightly longer than Re3. Inner distal margin
of B2 of both legs bearing small bump with
cluster of short blunt denticles. This latter
feature is reported only for right B2 by
Brodskii (1950).
Remarks
It seems to be remarkably difficult to separate
A. glacialis from A. longicaudatus (Claus
1863) as discussed by Vervoort (1965b). The
lengths reported for A. g. females from different areas are always larger than 4 mm,
while for A. I. they are generally smaller
(Tanaka and Omori 1971). Otherwise, a
comparison of the data available for A. I.
suggests that this species is greatly variable in
length; Farran (1908) reported an extremely
wide length range for females from the Irish
Atlantic slope (3.6-6.1 mm). InA. I. females,
the caudal rami and anal somite are covered
by spiniform hairs; in A. g. the furca may be
completely naked, but usually there are fine
hairs along the internal borders. Our specimens are in the size range usually reported
for A. g.; the caudal rami and anal somite of
females are coarsely covered with fine hairs
on the ventral side (no spiniform hairs as in
A. I.) and the genital somite is only slightly
asymmetrical without the remarkable swelling on the left side (in dorsal view) characterizing A. I. females (as shown also by
Tanaka and Omori (1971, p. 260). In the
specimens from the Straits of Magellan, as
also in the specimens analyzed by Vervoort
(1965b), the female does not have the blunt,
coarsely serrulated internal marginal spine of