Hydrobiologia 298: 105-112, 1995.
D. Belk, H. 1. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture II.
© 1995 Kluwer Academic Publishers.
105
Some notes on the ecology of a German Branchipus schaefferi population
(Crustacea: Anostraca)
Jtirgen Hossler, Gerhard Maier 1 & Uwe Tessenow
Abt. Biologie III, Okologie und Morphologie der Tiere, Albert-Einstein-Allee 11, D-89069 ULMIDo., Germany
(Iauthor Jor correspondence)
Key words: Branchipus schaefferi, habitat preference, seasonal cycle, starvation resistance, hatching of eggs,
predators
Abstract
Habitat preference, seasonal occurrence, starvation resistance, hatching of eggs of Branchipus schaefferi, and
effects of predation on B. schaefferi were studied. Branchipus was only present in turbid, unvegetated ponds
and absent in ponds which contain higher aquatic vegetation and the alga Spirogyra sp. The first individuals of
B. schaefferi appeared in April when mean water temperature was ~ 10 °C and the last adults in November at a
water temperature of 3.5 °C. Up to 6 reproducing generations were observed during this period. Abundance of
B. schaefferi was higher in temporary ponds than in permanent ponds. Sex ratio was close to unity for most of
the year. Body size of B. schaefferi males and females was significantly positively correlated with pond volume.
Without food B. schaefferi could survive for 1. 5 to 2 days at 20°C and 4 to 5 days at 10 °C. Hatching success of
eggs decreased when eggs were dried for 2' : 7 months. Freezing of eggs had no effect on hatching success. From
the predators tested, Chaoborus sp. larvae clearly selected small B. schaefferi; one consumed approximately 6
Branchipus d- I at a density of 6 to 12 prey I-I. The other predators, dragonfly larvae, and larvae and adults of
Triturus alpestris selected alternative prey types, for example Tubifex sp. and ostracods.
Introduction
Branchipus schaefferi is a typical summer form which
inhabits small ponds with loamy sediment; the species
is often associated with Triops cancriformis, Daphnia magna and Moina species (Flossner, 1972; Herbst,
1976; Alonso & Jaume, 1991). The eggs of B. schaeJJeri do not need drying for development. During summer, the development from nauplius to the adult instar
takes only about 2 weeks (e.g. Flossner, 1972).
In Germany B. schaefferi is one of the rarest crustacean species; only a few actual localities are known
(Rieder, 1979; Herbst, 1982; Hosler et al., 1989a,
1989b; Clausnitzer, 1993). Consequently, investigations on the ecology of German popUlations are
rare.
This study aims to close some gaps. Great importance is attached to habitat preference, seasonal occurrence, starvation resistance, hatching of eggs, and the
predators of Branchipus.
Study site
The 8 study ponds are situated in a military area in
the small Tobeltal Valley 8 km northwest of the city
of Ulm, South Germany. They were picked out from
about 100 ponds in the Tobeltal area. All ponds are
small (6 to 100 m 2 maximum surface area) and shallow (0.3 to 0.6 m maximum depth). Three of the ponds
are permanent, five are temporary with up to 8 drought
periods per year (Table 1). The thickness of the loamy
sediment is 2 to 18 cm.All ponds except pond 12 and 13
are turbid because the sediment is turned up by the driving activities of tanks and motor cycles. Most ponds
are completely free from higher aquatic vegetation;
only pond 12 is covered with the macrophytes ]uncus
injlexus, ]uncus buJonius, ]uncus articulatus, Glyceria
jluitans, and Alisma plantago aquatica. Ponds 12 and
13 contain blooms of Spirogyra sp. Ponds 27 and 35
are shaded by trees. Branchipus schaefferi is present
in 6 of the 8 ponds.
D. Belk, H. 1. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture II.
© 1995 Kluwer Academic Publishers.
105
Some notes on the ecology of a German Branchipus schaefferi population
(Crustacea: Anostraca)
Jtirgen Hossler, Gerhard Maier 1 & Uwe Tessenow
Abt. Biologie III, Okologie und Morphologie der Tiere, Albert-Einstein-Allee 11, D-89069 ULMIDo., Germany
(Iauthor Jor correspondence)
Key words: Branchipus schaefferi, habitat preference, seasonal cycle, starvation resistance, hatching of eggs,
predators
Abstract
Habitat preference, seasonal occurrence, starvation resistance, hatching of eggs of Branchipus schaefferi, and
effects of predation on B. schaefferi were studied. Branchipus was only present in turbid, unvegetated ponds
and absent in ponds which contain higher aquatic vegetation and the alga Spirogyra sp. The first individuals of
B. schaefferi appeared in April when mean water temperature was ~ 10 °C and the last adults in November at a
water temperature of 3.5 °C. Up to 6 reproducing generations were observed during this period. Abundance of
B. schaefferi was higher in temporary ponds than in permanent ponds. Sex ratio was close to unity for most of
the year. Body size of B. schaefferi males and females was significantly positively correlated with pond volume.
Without food B. schaefferi could survive for 1. 5 to 2 days at 20°C and 4 to 5 days at 10 °C. Hatching success of
eggs decreased when eggs were dried for 2' : 7 months. Freezing of eggs had no effect on hatching success. From
the predators tested, Chaoborus sp. larvae clearly selected small B. schaefferi; one consumed approximately 6
Branchipus d- I at a density of 6 to 12 prey I-I. The other predators, dragonfly larvae, and larvae and adults of
Triturus alpestris selected alternative prey types, for example Tubifex sp. and ostracods.
Introduction
Branchipus schaefferi is a typical summer form which
inhabits small ponds with loamy sediment; the species
is often associated with Triops cancriformis, Daphnia magna and Moina species (Flossner, 1972; Herbst,
1976; Alonso & Jaume, 1991). The eggs of B. schaeJJeri do not need drying for development. During summer, the development from nauplius to the adult instar
takes only about 2 weeks (e.g. Flossner, 1972).
In Germany B. schaefferi is one of the rarest crustacean species; only a few actual localities are known
(Rieder, 1979; Herbst, 1982; Hosler et al., 1989a,
1989b; Clausnitzer, 1993). Consequently, investigations on the ecology of German popUlations are
rare.
This study aims to close some gaps. Great importance is attached to habitat preference, seasonal occurrence, starvation resistance, hatching of eggs, and the
predators of Branchipus.
Study site
The 8 study ponds are situated in a military area in
the small Tobeltal Valley 8 km northwest of the city
of Ulm, South Germany. They were picked out from
about 100 ponds in the Tobeltal area. All ponds are
small (6 to 100 m 2 maximum surface area) and shallow (0.3 to 0.6 m maximum depth). Three of the ponds
are permanent, five are temporary with up to 8 drought
periods per year (Table 1). The thickness of the loamy
sediment is 2 to 18 cm.All ponds except pond 12 and 13
are turbid because the sediment is turned up by the driving activities of tanks and motor cycles. Most ponds
are completely free from higher aquatic vegetation;
only pond 12 is covered with the macrophytes ]uncus
injlexus, ]uncus buJonius, ]uncus articulatus, Glyceria
jluitans, and Alisma plantago aquatica. Ponds 12 and
13 contain blooms of Spirogyra sp. Ponds 27 and 35
are shaded by trees. Branchipus schaefferi is present
in 6 of the 8 ponds.