116
MALCOLM R. CLARKE
larger than the others (Fig. 7, F). Okutani (1965) drew attention to the
great length of the proboscis in 8. oualaniensis when describing differences between rhynchoteuthis of Todarodes pacijicus and rhynchoteuthie
of other ommastrephids from Japanese waters. During growth to the
adult, the arms become relatively longer, the head relatively shorter
and the body relatively narrower compared with the mantle length.
I n the form with a dorsal light organ, females become mature (i.e.
have enlarged nidamental glands and ovaries) a t a dorsal mantle
length of about 18.0 cm and males become mature (i.e. have spermatophores and a hectocotylus) at a dorsal mantle length of less than 13.6
cm; in the form without a dorsal light organ the females become mature
at less than 10.7 cm (Clarke, in preparation). The largest female of
the form with a dorsal light organ, known to the author (ignoring
published records because it is uncertain which form is involved),
is 30.5 cm (in mantle length) and the largest male 14-0 cm. I n the other
form the largest female is 25.0 cm and the male 14.0 cm.
The hectocotylus is slightly swollen, devoid of suckers a t the tip
and has several small holes running from the base of the suckers to the
sides of the arms. The spermatophores are stuck on to the buccal
membranes of the female and seminal receptacles are also present
(Sasaki, 1929a). The oval eggs in the oviduct measure 0.7-1.0 mm
(Sasaki, 1929a).
It has been recorded from stomachs of a Booby and White-capped
Noddy (Voss, 1954b) and from Sula piscator (Hoyle, 1886, 1904b).
At Christmas Island both forms are clearly very important in the diet
of sea birds (Ashmole, in preparation). It is commonly sold for food
at Okinawa (Sasaki, 1929a).
C. Dosidicus
This genus is generally considered to include only one species.
1. Dosidicus gigas (d’orbigny, 1835)
Ommastrephes gigas d’orbigny, see 1835-1848
Ommastrephes giganteus d’orbigny, see 1835-1 848
Dosidicus Eschrichtii Steenstrup, 1857
Dosidicus Steenstrupii Pfeffer, 1884
There are many records of this species along the western coast of
South America (d’orbigny, 1835-48, 1845; Steenstrup, 1880; Martens,
1894; Steinhaus, 1903; Dall, 1910; Berry, 1912b; Pfeffer, 1912; Robson,
1929a; Schneider, 1930; Odhner, 1931; Wilhelm, 1931; Duncan, 1941;
de Sylva, 1962; Garcia-Tello, 1964; etc.). It has also been recorded
from the Galapagos Islands (Boone, 1933), off California (Carpenter,
MALCOLM R. CLARKE
larger than the others (Fig. 7, F). Okutani (1965) drew attention to the
great length of the proboscis in 8. oualaniensis when describing differences between rhynchoteuthis of Todarodes pacijicus and rhynchoteuthie
of other ommastrephids from Japanese waters. During growth to the
adult, the arms become relatively longer, the head relatively shorter
and the body relatively narrower compared with the mantle length.
I n the form with a dorsal light organ, females become mature (i.e.
have enlarged nidamental glands and ovaries) a t a dorsal mantle
length of about 18.0 cm and males become mature (i.e. have spermatophores and a hectocotylus) at a dorsal mantle length of less than 13.6
cm; in the form without a dorsal light organ the females become mature
at less than 10.7 cm (Clarke, in preparation). The largest female of
the form with a dorsal light organ, known to the author (ignoring
published records because it is uncertain which form is involved),
is 30.5 cm (in mantle length) and the largest male 14-0 cm. I n the other
form the largest female is 25.0 cm and the male 14.0 cm.
The hectocotylus is slightly swollen, devoid of suckers a t the tip
and has several small holes running from the base of the suckers to the
sides of the arms. The spermatophores are stuck on to the buccal
membranes of the female and seminal receptacles are also present
(Sasaki, 1929a). The oval eggs in the oviduct measure 0.7-1.0 mm
(Sasaki, 1929a).
It has been recorded from stomachs of a Booby and White-capped
Noddy (Voss, 1954b) and from Sula piscator (Hoyle, 1886, 1904b).
At Christmas Island both forms are clearly very important in the diet
of sea birds (Ashmole, in preparation). It is commonly sold for food
at Okinawa (Sasaki, 1929a).
C. Dosidicus
This genus is generally considered to include only one species.
1. Dosidicus gigas (d’orbigny, 1835)
Ommastrephes gigas d’orbigny, see 1835-1848
Ommastrephes giganteus d’orbigny, see 1835-1 848
Dosidicus Eschrichtii Steenstrup, 1857
Dosidicus Steenstrupii Pfeffer, 1884
There are many records of this species along the western coast of
South America (d’orbigny, 1835-48, 1845; Steenstrup, 1880; Martens,
1894; Steinhaus, 1903; Dall, 1910; Berry, 1912b; Pfeffer, 1912; Robson,
1929a; Schneider, 1930; Odhner, 1931; Wilhelm, 1931; Duncan, 1941;
de Sylva, 1962; Garcia-Tello, 1964; etc.). It has also been recorded
from the Galapagos Islands (Boone, 1933), off California (Carpenter,