188
Systematic Account
3.33 Phaenna spinifera Claus 1863
Phaenna spiniJera Claus, 1863: p. 189, pI. 31
figs. 1-7 - Giesbrecht, 1892: p. 293, pI. 5 fig.
3, pI. 12 figs. 1-8,35-37, pI. 37 figs. 17-21Tanaka, 1960b: p. 85, fig. 81 (immature
female) - Grice, 1962: p. 203, pI. 15 fig. 1 -
Owre and Foyo, 1967: p. 57, figs. 91,292,293
(male) - Vidal, 1968: p. 30, pI. 14 figs. 5-9Bradford et aI., 1983: p. 67, figs 34,35 (male)
- Park, 1983: p. 318, figs. 1, 2.
For a more complete list of synonyms see
Vervoort (1965b).
Body length -
females: 2.88-3.02mm (4 specimens)
Female. Body robust and rounded. Rostrum
bifurcate. Cephalothorax 1.6 times longer
than wide, larger in correspondence to the
first pedigerous somite. Cephalothorax about
4 times as long as abdomen. Head and first
thoracic somite separated. Thoracic somites
4 and 5 incompletely separated; lateral side
of somites 3 and 4 with a rather long sensillum
on either side, also visible in dorsal view.
Posterior comers of thorax with an angular
distal projection in dorsal view and, in lateral
view, with a round distal margin covering
at least 1/3 the anterior genital somite.
Abdomen 3-segmented. Proportional lengths
of abdominal somites and furca 49: 18 : 13 : 20
= 100. Ventral surface of abdominal somites
ornated with stout setae, clearly visible in
lateral view; this ornamentation shown in
Giesbrecht (1892; pI. 37, fig. 19), is fragile
and can easily be lost in fixed specimens.
Caudal rami short, as long as wide. P5 absent.
Remarks
As noted by Vervoort (1965b), there seems
to be a great variability in the length of the
adult females of this species. Our specimens
(only 4 adult females) are longer than
generally reported in the literature (1.62.5 mm); but with regards to the morphological features, our specimens concord with
the descriptions given in the literature.
Distribution
P. spiniJera was originally described from the
Mediterranean Sea but is now known to be
widely distributed in the tropical, sub-tropical
and temperate regions of all oceans. Vervoort
(1965b) summarized its distribution from a
rich, but dispersed literature, and suggested
that this species is a fairly regular inhabitant
of intermediate waters of the warmer parts of
the Atlantic, Pacific and Indian Oceans,
capable of rapid diurnal vertical migrations.
In the Atlantic, this species penetrates as far
south as North Island, New Zealand (Farran
1929). Bjornberg (1973) and Bradford et ai.
(1983), respectively, found it in the eastern
and western South Pacific as far south as
42°S. Park (1983) collected two females close
to the southern coast of Western Australia.
P. spiniJera was reported from Chilean
waters by Fagetti (1962) and Vidal (1968). In
the present study, it was sampled only from
100-250 m at two stations in the Pacific area
of the Straits of Magellan.
Systematic Account
3.33 Phaenna spinifera Claus 1863
Phaenna spiniJera Claus, 1863: p. 189, pI. 31
figs. 1-7 - Giesbrecht, 1892: p. 293, pI. 5 fig.
3, pI. 12 figs. 1-8,35-37, pI. 37 figs. 17-21Tanaka, 1960b: p. 85, fig. 81 (immature
female) - Grice, 1962: p. 203, pI. 15 fig. 1 -
Owre and Foyo, 1967: p. 57, figs. 91,292,293
(male) - Vidal, 1968: p. 30, pI. 14 figs. 5-9Bradford et aI., 1983: p. 67, figs 34,35 (male)
- Park, 1983: p. 318, figs. 1, 2.
For a more complete list of synonyms see
Vervoort (1965b).
Body length -
females: 2.88-3.02mm (4 specimens)
Female. Body robust and rounded. Rostrum
bifurcate. Cephalothorax 1.6 times longer
than wide, larger in correspondence to the
first pedigerous somite. Cephalothorax about
4 times as long as abdomen. Head and first
thoracic somite separated. Thoracic somites
4 and 5 incompletely separated; lateral side
of somites 3 and 4 with a rather long sensillum
on either side, also visible in dorsal view.
Posterior comers of thorax with an angular
distal projection in dorsal view and, in lateral
view, with a round distal margin covering
at least 1/3 the anterior genital somite.
Abdomen 3-segmented. Proportional lengths
of abdominal somites and furca 49: 18 : 13 : 20
= 100. Ventral surface of abdominal somites
ornated with stout setae, clearly visible in
lateral view; this ornamentation shown in
Giesbrecht (1892; pI. 37, fig. 19), is fragile
and can easily be lost in fixed specimens.
Caudal rami short, as long as wide. P5 absent.
Remarks
As noted by Vervoort (1965b), there seems
to be a great variability in the length of the
adult females of this species. Our specimens
(only 4 adult females) are longer than
generally reported in the literature (1.62.5 mm); but with regards to the morphological features, our specimens concord with
the descriptions given in the literature.
Distribution
P. spiniJera was originally described from the
Mediterranean Sea but is now known to be
widely distributed in the tropical, sub-tropical
and temperate regions of all oceans. Vervoort
(1965b) summarized its distribution from a
rich, but dispersed literature, and suggested
that this species is a fairly regular inhabitant
of intermediate waters of the warmer parts of
the Atlantic, Pacific and Indian Oceans,
capable of rapid diurnal vertical migrations.
In the Atlantic, this species penetrates as far
south as North Island, New Zealand (Farran
1929). Bjornberg (1973) and Bradford et ai.
(1983), respectively, found it in the eastern
and western South Pacific as far south as
42°S. Park (1983) collected two females close
to the southern coast of Western Australia.
P. spiniJera was reported from Chilean
waters by Fagetti (1962) and Vidal (1968). In
the present study, it was sampled only from
100-250 m at two stations in the Pacific area
of the Straits of Magellan.