Hydrobiologia 298: 159-165, 1995.
D. Belk, H. J. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture II.
© 1995 Kluwer Academic Publishers.
159
Larviculture of the fairy shrimp, Streptocephalus proboscideus (Crustacea:
Anostraca): effect of food concentration and physical and chemical
properties of the culture medium
A. lawahar Ali & Henri 1. Dumont
Laboratory of Animal Ecology, University of Ghent, K. L. Ledeganckstraat 35, B-9000 Ghent, Belgium
Key words: Anostraca, algal food, temperature, conductivity, water quality, growth, maturation, survival
Abstract
Food concentration (0.5 x 10 3 - 5 X 10 5 Scenedesmus cells ml- i ) significantly influenced the somatic growth,
maturation and survivorship of S. proboscideus larvae. A density of 5 x 10 4 cells ml- I was optimal for early larval
stages. Of four temperatures tested (20--35 QC), 30 QC resulted in the best growth and survival. Maturation time
was inversely related to temperature, and was size- rather than age-dependent. Larvae were tolerant of a wide
conductivity range, but optimal growth and survival were observed at 260 JLS cm- I . Nitrite-Nitrogen (N02-N)
caused a larval mortality of 50% after 24 h at 0.58 mg I-I.
Introduction
Freshwater anostracans (fairy shrimps) are of growing
interest for various types of applications. Their inherent ability for mass-producing strongly resistant cysts
with long-term viability, makes these organisms attractive for various purposes. Their use in aquaculture (De
Walsche et al., 1991; Prasath etal., 1994) and in aquatic toxicology (Centeno et ai., 1993), for example, is
well documented.
The majority offreshwater anostracans live in temporary ponds characterized by unstable abiotic conditions. Temporary pools have been recognized as stressful habitats (Belk & Cole, 1975; Vernberg & Vernberg,
1983). Intense mortality in the early part of the life
cycle, rapid development and early reproduction are
important features of the organisms that live in these
habitats (Williams, 1985).
Larval nutrition appears to be a major bottleneck
for the mass culture of several aquaculturally important
crustaceans, including anostracans (Sorgeloos, 1991).
Since freshwater anostracans begin to feed on exogenous food from the third instar larvae onwards, heavy
mortalities are not uncommon (Anderson, 1966). In
addition to food, temperature can also be expected to
playa major role in larval survival.
Much information is available on the effect of food
density, physical and chemical properties of the culture medium on adult stages (Sluzhevskaya, 1981; De
Walsche et ai., 1991; Brendonck, 1993a & b), but
not on larvae of freshwater anostracans (Lake, 1969;
Anderson & Hsu, 1990).
The present study examines the effect of algal food
concentration, temperature, conductivity and water
quality (N02-N) on growth and survival of Streptocephalus proboscideus.
Material and methods
Cysts of S. proboscideus were obtained from continuous laboratory bulk cultures (De Walsche et ai., 1991).
Nauplii (I and II instar) were hatched from the cysts
of the same batch, cultured in a recirculation system.
Healthy, free-swimming nauplii were separated using
a fibre light source.
All experiments were conducted in a static culture system. Nauplii (20 or 30) were introduced in
cy lindro-conical glass tubes (1.5 1 capacity) containing
1 1 of prefiltered synthetic freshwater medium (EPA)
(U.S. Environmental Protection Agency, 1985), except
for the conductivity experiments, in which conductivities were varied from 35 to 2010 JLS em-I. The glass
D. Belk, H. J. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture II.
© 1995 Kluwer Academic Publishers.
159
Larviculture of the fairy shrimp, Streptocephalus proboscideus (Crustacea:
Anostraca): effect of food concentration and physical and chemical
properties of the culture medium
A. lawahar Ali & Henri 1. Dumont
Laboratory of Animal Ecology, University of Ghent, K. L. Ledeganckstraat 35, B-9000 Ghent, Belgium
Key words: Anostraca, algal food, temperature, conductivity, water quality, growth, maturation, survival
Abstract
Food concentration (0.5 x 10 3 - 5 X 10 5 Scenedesmus cells ml- i ) significantly influenced the somatic growth,
maturation and survivorship of S. proboscideus larvae. A density of 5 x 10 4 cells ml- I was optimal for early larval
stages. Of four temperatures tested (20--35 QC), 30 QC resulted in the best growth and survival. Maturation time
was inversely related to temperature, and was size- rather than age-dependent. Larvae were tolerant of a wide
conductivity range, but optimal growth and survival were observed at 260 JLS cm- I . Nitrite-Nitrogen (N02-N)
caused a larval mortality of 50% after 24 h at 0.58 mg I-I.
Introduction
Freshwater anostracans (fairy shrimps) are of growing
interest for various types of applications. Their inherent ability for mass-producing strongly resistant cysts
with long-term viability, makes these organisms attractive for various purposes. Their use in aquaculture (De
Walsche et al., 1991; Prasath etal., 1994) and in aquatic toxicology (Centeno et ai., 1993), for example, is
well documented.
The majority offreshwater anostracans live in temporary ponds characterized by unstable abiotic conditions. Temporary pools have been recognized as stressful habitats (Belk & Cole, 1975; Vernberg & Vernberg,
1983). Intense mortality in the early part of the life
cycle, rapid development and early reproduction are
important features of the organisms that live in these
habitats (Williams, 1985).
Larval nutrition appears to be a major bottleneck
for the mass culture of several aquaculturally important
crustaceans, including anostracans (Sorgeloos, 1991).
Since freshwater anostracans begin to feed on exogenous food from the third instar larvae onwards, heavy
mortalities are not uncommon (Anderson, 1966). In
addition to food, temperature can also be expected to
playa major role in larval survival.
Much information is available on the effect of food
density, physical and chemical properties of the culture medium on adult stages (Sluzhevskaya, 1981; De
Walsche et ai., 1991; Brendonck, 1993a & b), but
not on larvae of freshwater anostracans (Lake, 1969;
Anderson & Hsu, 1990).
The present study examines the effect of algal food
concentration, temperature, conductivity and water
quality (N02-N) on growth and survival of Streptocephalus proboscideus.
Material and methods
Cysts of S. proboscideus were obtained from continuous laboratory bulk cultures (De Walsche et ai., 1991).
Nauplii (I and II instar) were hatched from the cysts
of the same batch, cultured in a recirculation system.
Healthy, free-swimming nauplii were separated using
a fibre light source.
All experiments were conducted in a static culture system. Nauplii (20 or 30) were introduced in
cy lindro-conical glass tubes (1.5 1 capacity) containing
1 1 of prefiltered synthetic freshwater medium (EPA)
(U.S. Environmental Protection Agency, 1985), except
for the conductivity experiments, in which conductivities were varied from 35 to 2010 JLS em-I. The glass