368
THE BIOLOGY OF EUPHAUSIIDS
the little auks (Plotus alle = Plautus alle (L.)), and the Spitzbergen
puffins (Fratercula arctica naumunni (L.)) consumed them to some
extent. I n the southern Atlantic, off South Africa, Rand (1960) has
shown that the Cape penguin, Spheniscus demersus (L.), feeds to a
notable extent on Nyctiphanes capensis and off Australia Sheard (1953)
states that the vast breeding aggregations of the Tasmanian mutton
bird, Pufinus tenuirostris Temminck, in the Bass Strait during the
period October to April appear to be feeding on Nyctiphanes australis
and Thysanoessa gregaria. There are few data on the feeding of birds
in the North Pacific but Banner (1954) records T . raschii and T . inermis
in the stomachs of Sabines gulls from Point Barrow, Alaska, and Komaki
(1967a) states that the sea gull, Lams crassirostris Vieillot and a small
blackish bird, Cerorhinca monocerata (Pallas), feed on Euphausia
paeijca in Japanese coastal waters.
The Antarctic euphausiids, especially Euphausia superba which
swarms frequently at the surface, are probably the basic diet of all
Antarctic sea birds, organisms such as cephalopod molluscs being of
secondary importance (Marr, 1962 ; Ozawa, 1965). I n reviewing this
subject, Marr lists the birds that, although not feeding exclusively on
euphausiids, habitually include them in their otherwise catholic diets ;
these are the wandering albatross, Diomedea exulans L., the blackbrowed albatross, D . melanophris Temminck, the light-mantled sooty
albatross, Phoebetria palpebrata (Forster), the silver-grey petrel,
Priocella glacialoides (Smith), the Antarctic petrel, Thalassoica
antarctica (Gmelin), the snow petrel, Pagodroma nivea (Forster), the
Wilson’s petrel, Oceanites oceanicus (Kuhl), the Antarctic whale bird,
Pachyptela desolata (Gmelin), the Antarctic tern, Sterna vittata Gmelin,
the Arctic tern, S. macrura Naumann, the wreathed tern, X. vittata
georgiae Reichenow, the Cape pigeon, Daption capensis L., and the blue
petrel, Halobaena caerulea Gmelin. The Adelie and Gentoo penguins
are voracious consumers of euphausiids and Marr discusses the probable
extent of their predation, suggesting that the rookery at Cape Adare
alone harvests some 370 million euphausiids (approximately 250 tons)
per day. The giant petrel or stinker, Macronectes giganteus Gmelin, and
the brown skua of South Georgia, Catharacta skaa lonnbergi (Mathews),
consume euphausiids at third hand, obtaining them from penguin
chicks. The sooty shearwater, Pufinus griscus Gmelin, is known to feed
on surface swarms of euphausiids when these are available. Thus, there
is probabIy a significant harvest of euphausiids appropriated by the
immense populations of Antarctic birds.
All these predators contribute to the mortalit,y rates of young and
adult euphausiids by eating them but another source of mortality
THE BIOLOGY OF EUPHAUSIIDS
the little auks (Plotus alle = Plautus alle (L.)), and the Spitzbergen
puffins (Fratercula arctica naumunni (L.)) consumed them to some
extent. I n the southern Atlantic, off South Africa, Rand (1960) has
shown that the Cape penguin, Spheniscus demersus (L.), feeds to a
notable extent on Nyctiphanes capensis and off Australia Sheard (1953)
states that the vast breeding aggregations of the Tasmanian mutton
bird, Pufinus tenuirostris Temminck, in the Bass Strait during the
period October to April appear to be feeding on Nyctiphanes australis
and Thysanoessa gregaria. There are few data on the feeding of birds
in the North Pacific but Banner (1954) records T . raschii and T . inermis
in the stomachs of Sabines gulls from Point Barrow, Alaska, and Komaki
(1967a) states that the sea gull, Lams crassirostris Vieillot and a small
blackish bird, Cerorhinca monocerata (Pallas), feed on Euphausia
paeijca in Japanese coastal waters.
The Antarctic euphausiids, especially Euphausia superba which
swarms frequently at the surface, are probably the basic diet of all
Antarctic sea birds, organisms such as cephalopod molluscs being of
secondary importance (Marr, 1962 ; Ozawa, 1965). I n reviewing this
subject, Marr lists the birds that, although not feeding exclusively on
euphausiids, habitually include them in their otherwise catholic diets ;
these are the wandering albatross, Diomedea exulans L., the blackbrowed albatross, D . melanophris Temminck, the light-mantled sooty
albatross, Phoebetria palpebrata (Forster), the silver-grey petrel,
Priocella glacialoides (Smith), the Antarctic petrel, Thalassoica
antarctica (Gmelin), the snow petrel, Pagodroma nivea (Forster), the
Wilson’s petrel, Oceanites oceanicus (Kuhl), the Antarctic whale bird,
Pachyptela desolata (Gmelin), the Antarctic tern, Sterna vittata Gmelin,
the Arctic tern, S. macrura Naumann, the wreathed tern, X. vittata
georgiae Reichenow, the Cape pigeon, Daption capensis L., and the blue
petrel, Halobaena caerulea Gmelin. The Adelie and Gentoo penguins
are voracious consumers of euphausiids and Marr discusses the probable
extent of their predation, suggesting that the rookery at Cape Adare
alone harvests some 370 million euphausiids (approximately 250 tons)
per day. The giant petrel or stinker, Macronectes giganteus Gmelin, and
the brown skua of South Georgia, Catharacta skaa lonnbergi (Mathews),
consume euphausiids at third hand, obtaining them from penguin
chicks. The sooty shearwater, Pufinus griscus Gmelin, is known to feed
on surface swarms of euphausiids when these are available. Thus, there
is probabIy a significant harvest of euphausiids appropriated by the
immense populations of Antarctic birds.
All these predators contribute to the mortalit,y rates of young and
adult euphausiids by eating them but another source of mortality