86
R. K. DEJ&
3. Cephalopodu
The benthic cephalopods from Antarctic seas have been treated by
Joubin (1903, 19050, 1906, 1914), Hoyle (1907, 1912), Massy (1916),
Berry (1917), Thiele (1921), Odhner (1923b), Robson (1930), and
in scattered references through the two volumes of his monograph
of the recent Cephalopoda (Robson, 1929, 1932), Dell (1959), Taki
(1961), and Nesis and Propp (1968).
The composition and distribution of benthic Antarctic cephalopods
are still relatively poorly recorded. The writer (Dell, 1959) listed the
benthic forms as :
Pareledone churcoti (Joubin), P. turqueti (Joubin), P. adelianu
(Berry), P. polymorphu (Robson), P. hurrissoni (Berry), P. untarctica
(Thiele), (? ) Graneledone setehos Robson, Bentheledone albidu (Berry),
B. rotunda (Hoyle), Thuumeledone gunteri Robson, Grimpoteuthis
mawsoni (Berry) and Cirroteuthis glacialis Robson.
Since then Taki (1961) has described two new eledonids, Megaleledone senoi (the genus also being described as new) and Pareledone
umitakae. Both species were collected at 6'7'51.5'5 33'13.5'E in 630680 m.
Amongst the Octopoda the dominant Antarctic forms are the
eledonids which can be distinguished a t sight from the genus Octopus
by the fact that the suckers on the arms are arranged in a single row
(uniserial) rather than in the double row (biserial) of Octopus. Species
of Octopus with biserially arranged suckers occur a t Kerguelen, a t
Campbell Island and in Tierra del Fuego. South of these areas the
Octopoda are represented by the uniserial eledonids and two species of
the Cirroteuthidae (Grimpoteuthis mawsoni and Cirroteuthis glacialis).
The range of eledonid genera, Pareledone, Graneledone, Bentheledone,
Thumeledone and Megaleledone may well represent another example of
adaptive radiation in the Antarctic. Robson (1932, pp. 51,256) discussed
the relationship of these eledonid forms and concluded that they were
probably diphyletic. He therefore classified Eledone and Pareledone in
the subfamily Octopodinae and Graneledone, Thuumeledone, and
Bentheledone in the subfamily Bathypolypodinae. This arrangement
can only be considered to be provisional. Some of the " genera " are
very poorly known.
As regards distribution in the Antarctic, too few records are available for useful discussion. Pareledone churcoti is certainly, and P.
turqueti is probably, circum-Antarctic. These two species reach as far
north as South Georgia.
Nesis and Propp (1968) have recorded a specimen of Megaleledone
senoi Taki from the Davis Sea weighing 6 200 g with the body 28.5 cm
R. K. DEJ&
3. Cephalopodu
The benthic cephalopods from Antarctic seas have been treated by
Joubin (1903, 19050, 1906, 1914), Hoyle (1907, 1912), Massy (1916),
Berry (1917), Thiele (1921), Odhner (1923b), Robson (1930), and
in scattered references through the two volumes of his monograph
of the recent Cephalopoda (Robson, 1929, 1932), Dell (1959), Taki
(1961), and Nesis and Propp (1968).
The composition and distribution of benthic Antarctic cephalopods
are still relatively poorly recorded. The writer (Dell, 1959) listed the
benthic forms as :
Pareledone churcoti (Joubin), P. turqueti (Joubin), P. adelianu
(Berry), P. polymorphu (Robson), P. hurrissoni (Berry), P. untarctica
(Thiele), (? ) Graneledone setehos Robson, Bentheledone albidu (Berry),
B. rotunda (Hoyle), Thuumeledone gunteri Robson, Grimpoteuthis
mawsoni (Berry) and Cirroteuthis glacialis Robson.
Since then Taki (1961) has described two new eledonids, Megaleledone senoi (the genus also being described as new) and Pareledone
umitakae. Both species were collected at 6'7'51.5'5 33'13.5'E in 630680 m.
Amongst the Octopoda the dominant Antarctic forms are the
eledonids which can be distinguished a t sight from the genus Octopus
by the fact that the suckers on the arms are arranged in a single row
(uniserial) rather than in the double row (biserial) of Octopus. Species
of Octopus with biserially arranged suckers occur a t Kerguelen, a t
Campbell Island and in Tierra del Fuego. South of these areas the
Octopoda are represented by the uniserial eledonids and two species of
the Cirroteuthidae (Grimpoteuthis mawsoni and Cirroteuthis glacialis).
The range of eledonid genera, Pareledone, Graneledone, Bentheledone,
Thumeledone and Megaleledone may well represent another example of
adaptive radiation in the Antarctic. Robson (1932, pp. 51,256) discussed
the relationship of these eledonid forms and concluded that they were
probably diphyletic. He therefore classified Eledone and Pareledone in
the subfamily Octopodinae and Graneledone, Thuumeledone, and
Bentheledone in the subfamily Bathypolypodinae. This arrangement
can only be considered to be provisional. Some of the " genera " are
very poorly known.
As regards distribution in the Antarctic, too few records are available for useful discussion. Pareledone churcoti is certainly, and P.
turqueti is probably, circum-Antarctic. These two species reach as far
north as South Georgia.
Nesis and Propp (1968) have recorded a specimen of Megaleledone
senoi Taki from the Davis Sea weighing 6 200 g with the body 28.5 cm