Publication Date:
2021-09-01
Description:
The duration of egg incubation was calculated using formular given by Laptikhovskii [38], connecting this duration with egg size and water temperature in cephalopods with large eggs inhabiting the Bering Sea, the Sea of Okhotsk, the northern seas of Russia, and the Polar Basin. The calculation showed that octopi of the generae Bathypolypus, Benthoctopus and Graneledone brood eggs from 1.5 to almost 3 years, and all this time the females sit on their eggs, protecting them. According to our calculations, the duration of egg development in the finned octopi Cirroteuthis muelleri and Opisthoteuthis spp., whose eggs are protected with strong chitinous shell, is 20-32 months. In the sepiolid cuttlefishes Rossia pacifica, R. palpebrosa, and R. moelleri, whose eggs are sheltered from enemies, the duration of egg development is 4-4.5 months; however, taking into account the experimental data, the latter is probably not less than half a year. The duration of egg incubation in the gonatid squids Gonatus fabricii, G. onyx, and Berryteuthis magister lasts 12-16 weeks and, in the Antarctic octopods Grimpoteuthis glacialis and Megaleledone senoi, 2.5-3.5 years. lf the period of embryonal development and, for brooding bottom octopodids, the period from egg release to female death (which normally concurs with the hatching of young) are both included in the life cycle, the life span of cephalopods appears to be much longer than previously thought. Because deep-sea squids and brooding octopus females cease feeding before egg release, the duration of incubation and of egg brooding does not affect the specific production of cephalopods and is of no importance to the biological economy of the ocean. However, one should consider that if squids and octopi consume a lot of food and grow rapidly, it is because this is necessary not only for them to mature rapidly, breed, and complete their life cycle, but also for them to accumulate sufficient nutrients to leave successful progeny. The question of whether female gonatid squids actually brood their laid eggs is discussed.
Type:
Article
,
PeerReviewed
Format:
text
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