384
THE BIOLOGY OF EUPHAUSIIDS
Vitamin A
other invertebrate sources
economy is suggested by Lasker (1966). Euphausiids moult, on average,
once every 5 days and the dry weight of the cast material is about
one tenth that of the dry weight of the moulting euphausiid. I n
laboratory experiments) Lasker found that moulting was confined to the
Vitamin A
euphausiids
Sea
night period, that is to the time when the euphausiids have migrated
from the deeper layers and are living nearer the surface. The casts are
degraded by chitinoclastic bacteria of which there are two nutritional
types (Seki and Taga, 1965) : (1) those that require chitin plus other
THE BIOLOGY OF EUPHAUSIIDS
Vitamin A
other invertebrate sources
economy is suggested by Lasker (1966). Euphausiids moult, on average,
once every 5 days and the dry weight of the cast material is about
one tenth that of the dry weight of the moulting euphausiid. I n
laboratory experiments) Lasker found that moulting was confined to the
Vitamin A
euphausiids
Sea
night period, that is to the time when the euphausiids have migrated
from the deeper layers and are living nearer the surface. The casts are
degraded by chitinoclastic bacteria of which there are two nutritional
types (Seki and Taga, 1965) : (1) those that require chitin plus other