REVIEW O F TRE SYSTEMATICS AND ECOLOGY O F OCEANIC SQUIDS
101
ings occur where warm and cold waters meet and at first it seemed
Architeuthis inhabited cold water (Ritchie, 1922); subsequent records
are more indicative of a warm water origin and Bruun (1945) suggested
strandings possibly occur when animals chase food into colder water
and become paralysed with cold before being washed ashore. Most
North Atlantic strandings have been in autumn or winter (Fig. 3, C)
when the water is cooling down at the northern limit of distribution.
In August the surface water off both Newfoundland and northern
Europe lies between mean temperatures of 1Oo-15"C; by November these
have dropped to 5"-10"C and by February to 0"-10°C. If Architeuthis
were detrimentally affected by a drop in temperature indicated by a
fall in surface temperatures to about 5O-1OoC the way these isotherms
spread out in the eastern Atlantic could explain the more extensive
area of strandings on this side compared with the more limited area of
strandings in the western Atlantic (Robson, 1933). If, indeed, annual
fluctuations of temperature are the cause of Architeuthis becoming
stranded it probably lives at depths less than 400 m at which annual
fluctuations become negligible. Robson's hypothesis (1 933) that they
live between 200-400 m or deeper where the surface temperatures are
high is credible, though based on little evidence for it must be remembered that the main reason we tend to think they live fairly deep is
that only moribund individuals have been seen a t the surface. Also,
the distribution of finds around oceanic islands and coasts may be
misleading as it could arise from our complete inability to catch these
active animals in the open ocean.
Reasons for stranding in a few specific instances have been suggested. Storms are sometimes coincident with strandings of Architeuthis
(Verrill, 1882c; Allan, 1948) and other species. In Norway the distribution of strandings indicates that the squids probably reach the west
coast with the Atlantic Current (Kjennerud, 1958; Nordghrd, 1928).
Specimens stranded on the Mississippi delta and at Malmo (Sweden)
may have been incapacitated by the low salinities of these regions.
Dell (1952) suggested that the New Zealand strandings occur on coasts
near to deep water and that, when chasing food, squids may become
detrimentally affected if they enter shallower water.
The greatest number found at any one time was the mortality of
over thirty on the Grand Banks in 1875 (Verrill, 188lb). These animals
cannot be very rare in the sea because they are an important and
regular part of the diet of Sperm whales around Madeira (Clarke,
1962a), the Kuril Islands (Akimushkin, 1955a) and South Africa
(Clarke, in preparation).
Mature males have the two ventral arms hectocotylized (Knudsen,
101
ings occur where warm and cold waters meet and at first it seemed
Architeuthis inhabited cold water (Ritchie, 1922); subsequent records
are more indicative of a warm water origin and Bruun (1945) suggested
strandings possibly occur when animals chase food into colder water
and become paralysed with cold before being washed ashore. Most
North Atlantic strandings have been in autumn or winter (Fig. 3, C)
when the water is cooling down at the northern limit of distribution.
In August the surface water off both Newfoundland and northern
Europe lies between mean temperatures of 1Oo-15"C; by November these
have dropped to 5"-10"C and by February to 0"-10°C. If Architeuthis
were detrimentally affected by a drop in temperature indicated by a
fall in surface temperatures to about 5O-1OoC the way these isotherms
spread out in the eastern Atlantic could explain the more extensive
area of strandings on this side compared with the more limited area of
strandings in the western Atlantic (Robson, 1933). If, indeed, annual
fluctuations of temperature are the cause of Architeuthis becoming
stranded it probably lives at depths less than 400 m at which annual
fluctuations become negligible. Robson's hypothesis (1 933) that they
live between 200-400 m or deeper where the surface temperatures are
high is credible, though based on little evidence for it must be remembered that the main reason we tend to think they live fairly deep is
that only moribund individuals have been seen a t the surface. Also,
the distribution of finds around oceanic islands and coasts may be
misleading as it could arise from our complete inability to catch these
active animals in the open ocean.
Reasons for stranding in a few specific instances have been suggested. Storms are sometimes coincident with strandings of Architeuthis
(Verrill, 1882c; Allan, 1948) and other species. In Norway the distribution of strandings indicates that the squids probably reach the west
coast with the Atlantic Current (Kjennerud, 1958; Nordghrd, 1928).
Specimens stranded on the Mississippi delta and at Malmo (Sweden)
may have been incapacitated by the low salinities of these regions.
Dell (1952) suggested that the New Zealand strandings occur on coasts
near to deep water and that, when chasing food, squids may become
detrimentally affected if they enter shallower water.
The greatest number found at any one time was the mortality of
over thirty on the Grand Banks in 1875 (Verrill, 188lb). These animals
cannot be very rare in the sea because they are an important and
regular part of the diet of Sperm whales around Madeira (Clarke,
1962a), the Kuril Islands (Akimushkin, 1955a) and South Africa
(Clarke, in preparation).
Mature males have the two ventral arms hectocotylized (Knudsen,