3.3 Heterorhabdus spinifrons
Claus 1863
Heterochaeta spiniJrons Claus, 1863: p. 183,
pI. 32 - Giesbrecht, 1892: p. 372, pI. 20 figs.
1,3, 11, 16, 19,31, pI. 39 figs. 42, 43, 51, 52,
54.
Heterorhabdus spinifrons Esterly, 1905: p.
183, fig. 37a,b; 1906: p. 77, pI. 14 fig. 93 -
Sars, 1925: p. 227, pI. 62 figs. 9-12-Brodskii,
1950: p. 351, fig. 246 - Grice, 1962: p. 222,
pI. 24 figs. 10, 11 - Tanaka, 1964a: p. 13, fig.
179a-e - Mazza, 1965: p. 401, figs. 2c,f,g,
3-5, 6a - Arcos, 1975: p. 22, pI. 8 figs.
68-70.
Body length -
females: 3.49-3.82mm (12 specimens)
males: 3.43-3.59mm (9 specimens)
Female. Large species, easily recognized for
its prolonged forehead ending with a sharp
spine. Rostrum bearing two long, fine
filaments. Postero-Iateral comers of last
thoracic somite rounded. Al exceeds caudal
rami by about 2 segments. Proportional
lengths of cephalothorax and abdomen 68:
32; proportional lengths of abdominal somites
and furca 42: 15: 12: 12: 19 = 100. In dorsal
view, posterior margins of abdominal somites
bordered by small spinules. At light microscope, ventral surface of genital somite fringed
with row of small denticles on either side of
genital aperture. At SEM, these "denticles"
appear as tubules. Caudal rami asymmetrical; left ramus longer, bearing very long
strong inner marginal seta. Inner spine of P5
Re2 as long as Re3. Terminal spine of Re3
about 1/3 length of the joint.
Family Heterorhabdidae
Male. General shape of body as female,
slightly smaller. Cephalothorax 2.3 times
longer than wide. Proportional lengths of
cephalothorax and abdomen 75: 32; proportionallengths of abdominal somites and furca
23: 19: 16: 11 : 8: 23 = 100. Posterior margins
of abdominal somites omated with spinules
on dorsal side, as in female. Caudal rami
asymmetrical, with short hairs on dorsal side.
P5 asymmetrical. Both left and right B2 with
prolonged inner borders forming ear-shaped
expansion omated with numerous fine hairs.
Re2 of right leg dilated; inner border bearing
bilobed expansion omated with tufts of long
hairs. Re3 about twice as long as second
exopodal joint with pointed end bearing
long, fine, apical spine. Re2 of left leg with
large triangular expansion; Re3 ending in
one long spine and bearing two short, strong
spines.
Remarks
There are two other Heterorhabdus species
closely resembling H. spinifrons: H. subspinifrons described by Tanaka (1964a) for
specimens from deep waters of Sagami Bay,
Japan, and H. spiniJer described by Park
(1970) for specimens from the Caribbean Sea
and Gulf of Mexico. Our specimens differ
from the descriptions given for the above
species in several anatomical details. Also,
they are bigger in size compared to H.
spiniJer (1.6-1.7mm) and do not bear small
processes on either side above the genital
aperture characterizing H. sUb-spinifrons
females.
Claus 1863
Heterochaeta spiniJrons Claus, 1863: p. 183,
pI. 32 - Giesbrecht, 1892: p. 372, pI. 20 figs.
1,3, 11, 16, 19,31, pI. 39 figs. 42, 43, 51, 52,
54.
Heterorhabdus spinifrons Esterly, 1905: p.
183, fig. 37a,b; 1906: p. 77, pI. 14 fig. 93 -
Sars, 1925: p. 227, pI. 62 figs. 9-12-Brodskii,
1950: p. 351, fig. 246 - Grice, 1962: p. 222,
pI. 24 figs. 10, 11 - Tanaka, 1964a: p. 13, fig.
179a-e - Mazza, 1965: p. 401, figs. 2c,f,g,
3-5, 6a - Arcos, 1975: p. 22, pI. 8 figs.
68-70.
Body length -
females: 3.49-3.82mm (12 specimens)
males: 3.43-3.59mm (9 specimens)
Female. Large species, easily recognized for
its prolonged forehead ending with a sharp
spine. Rostrum bearing two long, fine
filaments. Postero-Iateral comers of last
thoracic somite rounded. Al exceeds caudal
rami by about 2 segments. Proportional
lengths of cephalothorax and abdomen 68:
32; proportional lengths of abdominal somites
and furca 42: 15: 12: 12: 19 = 100. In dorsal
view, posterior margins of abdominal somites
bordered by small spinules. At light microscope, ventral surface of genital somite fringed
with row of small denticles on either side of
genital aperture. At SEM, these "denticles"
appear as tubules. Caudal rami asymmetrical; left ramus longer, bearing very long
strong inner marginal seta. Inner spine of P5
Re2 as long as Re3. Terminal spine of Re3
about 1/3 length of the joint.
Family Heterorhabdidae
Male. General shape of body as female,
slightly smaller. Cephalothorax 2.3 times
longer than wide. Proportional lengths of
cephalothorax and abdomen 75: 32; proportionallengths of abdominal somites and furca
23: 19: 16: 11 : 8: 23 = 100. Posterior margins
of abdominal somites omated with spinules
on dorsal side, as in female. Caudal rami
asymmetrical, with short hairs on dorsal side.
P5 asymmetrical. Both left and right B2 with
prolonged inner borders forming ear-shaped
expansion omated with numerous fine hairs.
Re2 of right leg dilated; inner border bearing
bilobed expansion omated with tufts of long
hairs. Re3 about twice as long as second
exopodal joint with pointed end bearing
long, fine, apical spine. Re2 of left leg with
large triangular expansion; Re3 ending in
one long spine and bearing two short, strong
spines.
Remarks
There are two other Heterorhabdus species
closely resembling H. spinifrons: H. subspinifrons described by Tanaka (1964a) for
specimens from deep waters of Sagami Bay,
Japan, and H. spiniJer described by Park
(1970) for specimens from the Caribbean Sea
and Gulf of Mexico. Our specimens differ
from the descriptions given for the above
species in several anatomical details. Also,
they are bigger in size compared to H.
spiniJer (1.6-1.7mm) and do not bear small
processes on either side above the genital
aperture characterizing H. sUb-spinifrons
females.