INVESTIGADORES
BALSEIRO Esteban Gabriel
artículos
Título:
When mating increases predation risk: the relationship between the flatworm Mesostoma ehrenbergii and the copepod Boeckella gracilis.
Autor/es:
TROCHINE, C.; MODENUTTI, BE; ESTEBAN GABRIEL BALSEIRO,
Revista:
ARCHIV FUR HYDROBIOLOGIE
Editorial:
E. Schweizerbart'sche Verlagsbuchhandlung
Referencias:
Año: 2005 vol. 163 p. 555 - 569
ISSN:
0003-9136
Resumen:
The zooplanktivorous flatworm Mesostoma ehrenbergii and the calanoid
copepod Boeckella gracilis were observed to coexist in Patagonian fishless ponds. In
laboratory experiments, we studied the vulnerability of B. gracilis to M. ehrenbergii
Mesostoma ehrenbergii and the calanoid
copepod Boeckella gracilis were observed to coexist in Patagonian fishless ponds. In
laboratory experiments, we studied the vulnerability of B. gracilis to M. ehrenbergii
Boeckella gracilis were observed to coexist in Patagonian fishless ponds. In
laboratory experiments, we studied the vulnerability of B. gracilis to M. ehrenbergiiB. gracilis to M. ehrenbergii
predation, testing the attack rates on copulating pairs and single adults in different
abundances. We also determined B. gracilis dimorphism, sex ratio and copulating pair
ratio on two occasions in a temporary pond, with and without M. ehrenbergii. Our
results indicated that B. gracilis exhibited a male-skewed sex ratio irrespective of the
presence of the predator. A marked dimorphism characterized this copepod species
(females are about 40 % larger than males) and a large proportion of adults were
observed participating in copulating pairs that lasted for days. M. ehrenbergii ate similar
quantities of single males and females of B. gracilis but significantly more copulating
pairs. The use of mucus threads allowed Mesostoma to ingest both members of
the pairs instead of only one in most attacks. Larger prey may create more turbulence
in the water while swimming, so the hydrodynamic signals produced by pairs should
be greater than those produced by single individuals, making them more vulnerable.
Besides, the attack rates obtained in the different prey abundances showed that encounter
rate is the factor that determines M. ehrenbergii predation. We suggest that B.
gracilis prolonged mating duration (days) is dangerous because it increases predation
risk.
B. gracilis dimorphism, sex ratio and copulating pair
ratio on two occasions in a temporary pond, with and without M. ehrenbergii. Our
results indicated that B. gracilis exhibited a male-skewed sex ratio irrespective of the
presence of the predator. A marked dimorphism characterized this copepod species
(females are about 40 % larger than males) and a large proportion of adults were
observed participating in copulating pairs that lasted for days. M. ehrenbergii ate similar
quantities of single males and females of B. gracilis but significantly more copulating
pairs. The use of mucus threads allowed Mesostoma to ingest both members of
the pairs instead of only one in most attacks. Larger prey may create more turbulence
in the water while swimming, so the hydrodynamic signals produced by pairs should
be greater than those produced by single individuals, making them more vulnerable.
Besides, the attack rates obtained in the different prey abundances showed that encounter
rate is the factor that determines M. ehrenbergii predation. We suggest that B.
gracilis prolonged mating duration (days) is dangerous because it increases predation
risk.
M. ehrenbergii. Our
results indicated that B. gracilis exhibited a male-skewed sex ratio irrespective of the
presence of the predator. A marked dimorphism characterized this copepod species
(females are about 40 % larger than males) and a large proportion of adults were
observed participating in copulating pairs that lasted for days. M. ehrenbergii ate similar
quantities of single males and females of B. gracilis but significantly more copulating
pairs. The use of mucus threads allowed Mesostoma to ingest both members of
the pairs instead of only one in most attacks. Larger prey may create more turbulence
in the water while swimming, so the hydrodynamic signals produced by pairs should
be greater than those produced by single individuals, making them more vulnerable.
Besides, the attack rates obtained in the different prey abundances showed that encounter
rate is the factor that determines M. ehrenbergii predation. We suggest that B.
gracilis prolonged mating duration (days) is dangerous because it increases predation
risk.
B. gracilis exhibited a male-skewed sex ratio irrespective of the
presence of the predator. A marked dimorphism characterized this copepod species
(females are about 40 % larger than males) and a large proportion of adults were
observed participating in copulating pairs that lasted for days. M. ehrenbergii ate similar
quantities of single males and females of B. gracilis but significantly more copulating
pairs. The use of mucus threads allowed Mesostoma to ingest both members of
the pairs instead of only one in most attacks. Larger prey may create more turbulence
in the water while swimming, so the hydrodynamic signals produced by pairs should
be greater than those produced by single individuals, making them more vulnerable.
Besides, the attack rates obtained in the different prey abundances showed that encounter
rate is the factor that determines M. ehrenbergii predation. We suggest that B.
gracilis prolonged mating duration (days) is dangerous because it increases predation
risk.
M. ehrenbergii ate similar
quantities of single males and females of B. gracilis but significantly more copulating
pairs. The use of mucus threads allowed Mesostoma to ingest both members of
the pairs instead of only one in most attacks. Larger prey may create more turbulence
in the water while swimming, so the hydrodynamic signals produced by pairs should
be greater than those produced by single individuals, making them more vulnerable.
Besides, the attack rates obtained in the different prey abundances showed that encounter
rate is the factor that determines M. ehrenbergii predation. We suggest that B.
gracilis prolonged mating duration (days) is dangerous because it increases predation
risk.
B. gracilis but significantly more copulating
pairs. The use of mucus threads allowed Mesostoma to ingest both members of
the pairs instead of only one in most attacks. Larger prey may create more turbulence
in the water while swimming, so the hydrodynamic signals produced by pairs should
be greater than those produced by single individuals, making them more vulnerable.
Besides, the attack rates obtained in the different prey abundances showed that encounter
rate is the factor that determines M. ehrenbergii predation. We suggest that B.
gracilis prolonged mating duration (days) is dangerous because it increases predation
risk.
Mesostoma to ingest both members of
the pairs instead of only one in most attacks. Larger prey may create more turbulence
in the water while swimming, so the hydrodynamic signals produced by pairs should
be greater than those produced by single individuals, making them more vulnerable.
Besides, the attack rates obtained in the different prey abundances showed that encounter
rate is the factor that determines M. ehrenbergii predation. We suggest that B.
gracilis prolonged mating duration (days) is dangerous because it increases predation
risk.
M. ehrenbergii predation. We suggest that B.
gracilis prolonged mating duration (days) is dangerous because it increases predation
risk.
prolonged mating duration (days) is dangerous because it increases predation
risk.