REVIEW OF THE SYSTEMATICS AND ECOLOGY OF OCEANIC SQUIDS
157
largest recorded specimen has a mantle length of 30.0 cm (Okutani and
Nemoto, 1964).
Nesis (1965) in a detailed study of the food of the juveniles found
that 49% of stomachs were empty. Copepods were present in 56% of
stomachs containing food and represented 40% of the food organisms;
euphausids were present in 35% of stomachs and represented 55% of
the organisms; amphipods, pteropods and chaetognaths together were
present in 9% of stomachs and represented 5% of the organisms.
Up to three species were present in a single stomach. The food species
identified were Calanus jinmarchicus, C. hyperboreus, Pareuchaeta
norvegica, Metridia sp., Thysanoessa longicaudata (up to 10 in a stomach),
Hyperia galba, Pseudalibrotus sp., Limacina retroversa and Sagitta
maxima. The smallest squid feed on euphausid and Calanus young
while the larger squid juveniles eat adult copepods, amphipods and
Sagitta. While the young feed on animals much smaller than themselves,
once the hooks have developed (at a mantle length of 2-5 cm) fish
form an important part of the diet and the adults can feed on animals
larger than themselves.
There is no doubt that G. fabricii is a very important food organism
being the squid of the '' Bottle nose grounds '' in the Norwegian Sea
(Murray and Hjort, 1912) and the main food of the Bottlenose whale
in the Atlantic (Hjort and Ruud, 1929); it has also been recovered
from this whale off California (Rice, 1963) and is a very important part
of the diet of Sperm whales of the Pacific (Pike, 1950; Akimushkin,
1955; Beteshava and Akimushkin, 1955; Schubert, 1955) and off Iceland
(Collett, 1912). Schools of Hyperoodon ampullatus and Monodon
monoceros pursue the adult squid into the Norwegian Sea from the
Atlantic (Grimpe, 1933). It has been taken from Cystophora cristata
(Lonnberg, 1898a) and Dall (1899) found it second only in importance
to pollack in food of the northern fur seal (see also Lucas, 1899; Fiscus
et al., 1965). It has been recovered from unidentified fish (Verrill, 1881a),
is abundant in stomachs of coalfish (Sars, 1878), cod (Verrill, 1880b;
Grieg, 1933a), tuna (Joubin and Roule, 1918), Sebastes marinus (Grieg,
1933a; Nesis, 1965), Somniosus microcephalus (Soot-Ryen, 1925),
Gadus aeglejinus, G. virens, and G. morhua (Grieg, 1933a). It has also
been recovered from the stomach of a gull (Sasaki, 1929a) and Fulmarus
glacialis (Grieg, 1933a). Greenland eskimos use it for bait in the cod
and the shellfish (paltus) industry and for human food (Nesis, 1965).
2. Gonatus antarcticus Lonnberg, 1898
Often regarded as merely the Southern form of G. fabricii, this has been
recorded from Punta Arenas, near the Straits of Magellan (Lonnberg,
157
largest recorded specimen has a mantle length of 30.0 cm (Okutani and
Nemoto, 1964).
Nesis (1965) in a detailed study of the food of the juveniles found
that 49% of stomachs were empty. Copepods were present in 56% of
stomachs containing food and represented 40% of the food organisms;
euphausids were present in 35% of stomachs and represented 55% of
the organisms; amphipods, pteropods and chaetognaths together were
present in 9% of stomachs and represented 5% of the organisms.
Up to three species were present in a single stomach. The food species
identified were Calanus jinmarchicus, C. hyperboreus, Pareuchaeta
norvegica, Metridia sp., Thysanoessa longicaudata (up to 10 in a stomach),
Hyperia galba, Pseudalibrotus sp., Limacina retroversa and Sagitta
maxima. The smallest squid feed on euphausid and Calanus young
while the larger squid juveniles eat adult copepods, amphipods and
Sagitta. While the young feed on animals much smaller than themselves,
once the hooks have developed (at a mantle length of 2-5 cm) fish
form an important part of the diet and the adults can feed on animals
larger than themselves.
There is no doubt that G. fabricii is a very important food organism
being the squid of the '' Bottle nose grounds '' in the Norwegian Sea
(Murray and Hjort, 1912) and the main food of the Bottlenose whale
in the Atlantic (Hjort and Ruud, 1929); it has also been recovered
from this whale off California (Rice, 1963) and is a very important part
of the diet of Sperm whales of the Pacific (Pike, 1950; Akimushkin,
1955; Beteshava and Akimushkin, 1955; Schubert, 1955) and off Iceland
(Collett, 1912). Schools of Hyperoodon ampullatus and Monodon
monoceros pursue the adult squid into the Norwegian Sea from the
Atlantic (Grimpe, 1933). It has been taken from Cystophora cristata
(Lonnberg, 1898a) and Dall (1899) found it second only in importance
to pollack in food of the northern fur seal (see also Lucas, 1899; Fiscus
et al., 1965). It has been recovered from unidentified fish (Verrill, 1881a),
is abundant in stomachs of coalfish (Sars, 1878), cod (Verrill, 1880b;
Grieg, 1933a), tuna (Joubin and Roule, 1918), Sebastes marinus (Grieg,
1933a; Nesis, 1965), Somniosus microcephalus (Soot-Ryen, 1925),
Gadus aeglejinus, G. virens, and G. morhua (Grieg, 1933a). It has also
been recovered from the stomach of a gull (Sasaki, 1929a) and Fulmarus
glacialis (Grieg, 1933a). Greenland eskimos use it for bait in the cod
and the shellfish (paltus) industry and for human food (Nesis, 1965).
2. Gonatus antarcticus Lonnberg, 1898
Often regarded as merely the Southern form of G. fabricii, this has been
recorded from Punta Arenas, near the Straits of Magellan (Lonnberg,