Hydrobiologia 298: 133-139, 1995.
D. Belk, H. J. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture II.
© 1995 Kluwer Academic Publishers.
133
Food-dependent color patterns in Thamnocephalus platyurus Packard
(Branchiopoda: Anostraca); a laboratory study
Alejandro M. Maeda-Martinez, Hortencia Obreg6n & Henri J. Dumont
Laboratory of Animal Ecology, University of Ghent, K. L. Ledeganckstraat 35, B-9000 Ghent, Belgium
Key words: ;3-carotene, baker's yeast, growth, survival
Abstract
Coloration of phyllopods varies from place to place and from one life stage to another. It ranges from translucent
or whitish through gray, blue, green, orange, and reddish. Here, we present experimental evidence for a fooddependent color pattern in Thamnocephalus platyurus Packard. The presence or absence of the synthetic pigment
trans-;3-carotene in a baker's yeast diet was the controlling factor. All the 24 old larvae used in the experiment
were whitish in color. From day 6 until the end of the experiment (day 11), 100% of the shrimps under a diet with
synthetic trans-;3-carotene (treatment 1) exhibited a characteristic color pattern which consisted of an orange color
in the cercopods, and in all thoracopods; the rest of the body exhibited no particular color. In comparison, 100%
of the shrimps under a diet without synthetic trans-;3-carotene (treatment 2) were whitish throughout the body. In
females from treatment 1, the ovaries and oocytes were green-bluish, while in females from treatment 2 the ovaries
and oocytes were whitish. No significant differences in survival and growth were found, except that at day 9, there
was a significant difference in growth, the females with the synthetic trans-;3-carotene group growing faster.
Introduction
Coloration of phyllopods is highly variable, differing
from place to place and from one life stage to another (Dexter, 1959; pers. obs.). Pennak (1989) pointed
out that their color ranges from translucent or withish
through gray, blue, green, orange, to reddish, probably governed to a large extent by the type of food
ingested.
Packard (1883) quoted Dr Watson, who noted that
Streptocephalus texanus Packard collected in Kansas
in June and July had red tails and some had blue bodies,
while specimens collected in October and November
were pure white, but specimens of Thamnocephalus
platyurus Packard were mostly pinkish, with the edge
of the tail red, and the genitals light blue. Dexter (1943)
reported much variation in the color of Eubranchipus vernalis (Verrill) from different ponds, although
specimens from single ponds were usually uniform in
color. Specimens were orange-pink, or light orange,
but in two ponds they were colorless, and in eight,
females were bluish-gray while males were light green.
In later visits to three of the ponds which had orangepink populations, the females were bluish-gray while
the males were light-green (Dexter, 1943). Dexter &
Ferguson (1943) found that metanauplii of E. serratus Forbes were of a brilliant salmon color, and as
they grew the color became light gray, brilliant green,
brown, or reddish-brown. These reports illustrate that
as fairy shrimps grow, their color changes. Later, Dexter (1946) reported a population of E. vernalis which
had an unusual light blue color. He pointed out that
the pigment was found throughout the body but was
particularly noticeable in the head and at the tips of the
appendages, and suggested that a chemical property of
the water was possibly responsible for the color of the
shrimps.
Ermakow (1928, in Gilchrist & Green, 1960)
described the coloration of Artemia by noting that
females were salmon pink with green heads and thoracopods, while males had green bodies and reddish
thoracopods. Bond (1933) mentioned that it was supposed, at that time, that the color of Artemia depended
on the strength of the brine, or on food. He concluded
that Artemia specimens fed on colorless bacteria were
transparent to white, those fed on green organisms such
D. Belk, H. J. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture II.
© 1995 Kluwer Academic Publishers.
133
Food-dependent color patterns in Thamnocephalus platyurus Packard
(Branchiopoda: Anostraca); a laboratory study
Alejandro M. Maeda-Martinez, Hortencia Obreg6n & Henri J. Dumont
Laboratory of Animal Ecology, University of Ghent, K. L. Ledeganckstraat 35, B-9000 Ghent, Belgium
Key words: ;3-carotene, baker's yeast, growth, survival
Abstract
Coloration of phyllopods varies from place to place and from one life stage to another. It ranges from translucent
or whitish through gray, blue, green, orange, and reddish. Here, we present experimental evidence for a fooddependent color pattern in Thamnocephalus platyurus Packard. The presence or absence of the synthetic pigment
trans-;3-carotene in a baker's yeast diet was the controlling factor. All the 24 old larvae used in the experiment
were whitish in color. From day 6 until the end of the experiment (day 11), 100% of the shrimps under a diet with
synthetic trans-;3-carotene (treatment 1) exhibited a characteristic color pattern which consisted of an orange color
in the cercopods, and in all thoracopods; the rest of the body exhibited no particular color. In comparison, 100%
of the shrimps under a diet without synthetic trans-;3-carotene (treatment 2) were whitish throughout the body. In
females from treatment 1, the ovaries and oocytes were green-bluish, while in females from treatment 2 the ovaries
and oocytes were whitish. No significant differences in survival and growth were found, except that at day 9, there
was a significant difference in growth, the females with the synthetic trans-;3-carotene group growing faster.
Introduction
Coloration of phyllopods is highly variable, differing
from place to place and from one life stage to another (Dexter, 1959; pers. obs.). Pennak (1989) pointed
out that their color ranges from translucent or withish
through gray, blue, green, orange, to reddish, probably governed to a large extent by the type of food
ingested.
Packard (1883) quoted Dr Watson, who noted that
Streptocephalus texanus Packard collected in Kansas
in June and July had red tails and some had blue bodies,
while specimens collected in October and November
were pure white, but specimens of Thamnocephalus
platyurus Packard were mostly pinkish, with the edge
of the tail red, and the genitals light blue. Dexter (1943)
reported much variation in the color of Eubranchipus vernalis (Verrill) from different ponds, although
specimens from single ponds were usually uniform in
color. Specimens were orange-pink, or light orange,
but in two ponds they were colorless, and in eight,
females were bluish-gray while males were light green.
In later visits to three of the ponds which had orangepink populations, the females were bluish-gray while
the males were light-green (Dexter, 1943). Dexter &
Ferguson (1943) found that metanauplii of E. serratus Forbes were of a brilliant salmon color, and as
they grew the color became light gray, brilliant green,
brown, or reddish-brown. These reports illustrate that
as fairy shrimps grow, their color changes. Later, Dexter (1946) reported a population of E. vernalis which
had an unusual light blue color. He pointed out that
the pigment was found throughout the body but was
particularly noticeable in the head and at the tips of the
appendages, and suggested that a chemical property of
the water was possibly responsible for the color of the
shrimps.
Ermakow (1928, in Gilchrist & Green, 1960)
described the coloration of Artemia by noting that
females were salmon pink with green heads and thoracopods, while males had green bodies and reddish
thoracopods. Bond (1933) mentioned that it was supposed, at that time, that the color of Artemia depended
on the strength of the brine, or on food. He concluded
that Artemia specimens fed on colorless bacteria were
transparent to white, those fed on green organisms such