3.10 Centro pages brachiatua
Dana 1849
Pontella brachiata Dana, 1849: p. 27.
Caianopia brachiata Dana, 1853: pp. 1133,
1853, pI. 79 figs. 7a-b, 8a-b, 9a-g.
Centro pages brachiatus Brady, 1883: p. 82,
pI. 26 figs. 1-7 - Giesbrecht, 1892: p. 304, pI.
17 figs. 26, 37, pI. 18 fig. 7, pI. 38 figs. 2, 17 -
Unteriiberbacher, 1964: p. 28, pIs. 29, 30 -
Ramirez, 1966: p. 15, pI. 3 figs. 13-21 -
Vidal, 1968: p. 35, pI. 12 figs. 1-6 - Ramirez,
1969: p. 75, pI. 14 figs. 105, 106, 110, 112,
113, 115 - Arcos, 1974: p. 221, figs. 9, 11, 14,
15; 1975: p. 20, pI. 7 figs. 58-64.
Body length -
females: 1.67-2.21 mm (7 specimens)
males: 1.76 - 1.86mm (5 specimens)
Female. Body robust. Last thoracic somite
with sinuous posterior margins; posterolateral
comers produced into elongated, asymmetrical processes extending to mid-genital
somite. Al as long as caudal rami and with
spines on segments 1, 2 and 5. Proportional
lengths of cephalothorax and abdomen 69 : 31;
proportional lengths of abdominal somites
and furca 30: 32: 13: 25 = 100. Genital
somite strongly asymmetrical with two spines
on either side visible on different focal
planes. Second abdominal somite bears
cluster of hairs on dorsal side and short spine
on ventral side. P5 biramous; Re2 with broad
spiniform process on inner side. Terminal
spine of last exopodal joint shorter than this
joint and closely serrated along external
margin.
Male. Posterior margins of last thoracic
somite less sinuous than in females and with
Family Centropagiidae
less pronounced asymmetrical pointed
comers. Right A1 geniculated with spines on
segments 1, 2, 5, 13, 15, 16 and segments
17 -19 with finely serrated margins. Proportionallengths of cephalothorax and abdomen
70: 30; proportional lengths of abdominal
somites and furca 15: 18: 18: 16: 33 = 100. P5
biramous, asymmetrical. Right leg ending in
strong chela; Re2 with long, thin, naked
spine. Ril and Ri3 of both right and left legs
ornated with clusters of hairs.
Remarks
Our specimens differ from those drawn by
Brady (1883) in the male left P5. Ri3 bears 6
setae compared to 7 reported by Brady. Re2
bears 3 short, strong spines, also reported by
Ramirez (1969) and Arcos (1975), compared
to Brady's figures that show 4 apical spines.
Distribution
C. brachiatus is a cold-living species which
occurs more frequently in the Southern
rather than Northern hemisphere. The
presence of this species in Southern Oceans
has been reported by numerous authors
including Bjornberg (1963) for the coast of
Brazil and Ramirez (1969, 1970, 1971, 1977)
off Argentina. It has been reported as one of
the dominant species along the Chilean coast
(Vidal 1968; Marin and Antezana 1985;
Peterson et ai. 1988). In other cases, it seems
to be sporadic in occurrence, as in the Bahia
de Conception (Arcos 1975). Mazzocchi and
lanora (1991) found it at only seven stations
situated qn the Pacific side of the Straits of
Magellan. In the present study, C. brachiatus
was sporadically present in surface waters
throughout the Straits.
Dana 1849
Pontella brachiata Dana, 1849: p. 27.
Caianopia brachiata Dana, 1853: pp. 1133,
1853, pI. 79 figs. 7a-b, 8a-b, 9a-g.
Centro pages brachiatus Brady, 1883: p. 82,
pI. 26 figs. 1-7 - Giesbrecht, 1892: p. 304, pI.
17 figs. 26, 37, pI. 18 fig. 7, pI. 38 figs. 2, 17 -
Unteriiberbacher, 1964: p. 28, pIs. 29, 30 -
Ramirez, 1966: p. 15, pI. 3 figs. 13-21 -
Vidal, 1968: p. 35, pI. 12 figs. 1-6 - Ramirez,
1969: p. 75, pI. 14 figs. 105, 106, 110, 112,
113, 115 - Arcos, 1974: p. 221, figs. 9, 11, 14,
15; 1975: p. 20, pI. 7 figs. 58-64.
Body length -
females: 1.67-2.21 mm (7 specimens)
males: 1.76 - 1.86mm (5 specimens)
Female. Body robust. Last thoracic somite
with sinuous posterior margins; posterolateral
comers produced into elongated, asymmetrical processes extending to mid-genital
somite. Al as long as caudal rami and with
spines on segments 1, 2 and 5. Proportional
lengths of cephalothorax and abdomen 69 : 31;
proportional lengths of abdominal somites
and furca 30: 32: 13: 25 = 100. Genital
somite strongly asymmetrical with two spines
on either side visible on different focal
planes. Second abdominal somite bears
cluster of hairs on dorsal side and short spine
on ventral side. P5 biramous; Re2 with broad
spiniform process on inner side. Terminal
spine of last exopodal joint shorter than this
joint and closely serrated along external
margin.
Male. Posterior margins of last thoracic
somite less sinuous than in females and with
Family Centropagiidae
less pronounced asymmetrical pointed
comers. Right A1 geniculated with spines on
segments 1, 2, 5, 13, 15, 16 and segments
17 -19 with finely serrated margins. Proportionallengths of cephalothorax and abdomen
70: 30; proportional lengths of abdominal
somites and furca 15: 18: 18: 16: 33 = 100. P5
biramous, asymmetrical. Right leg ending in
strong chela; Re2 with long, thin, naked
spine. Ril and Ri3 of both right and left legs
ornated with clusters of hairs.
Remarks
Our specimens differ from those drawn by
Brady (1883) in the male left P5. Ri3 bears 6
setae compared to 7 reported by Brady. Re2
bears 3 short, strong spines, also reported by
Ramirez (1969) and Arcos (1975), compared
to Brady's figures that show 4 apical spines.
Distribution
C. brachiatus is a cold-living species which
occurs more frequently in the Southern
rather than Northern hemisphere. The
presence of this species in Southern Oceans
has been reported by numerous authors
including Bjornberg (1963) for the coast of
Brazil and Ramirez (1969, 1970, 1971, 1977)
off Argentina. It has been reported as one of
the dominant species along the Chilean coast
(Vidal 1968; Marin and Antezana 1985;
Peterson et ai. 1988). In other cases, it seems
to be sporadic in occurrence, as in the Bahia
de Conception (Arcos 1975). Mazzocchi and
lanora (1991) found it at only seven stations
situated qn the Pacific side of the Straits of
Magellan. In the present study, C. brachiatus
was sporadically present in surface waters
throughout the Straits.