INVESTIGADORES
IRIBARNE Oscar Osvaldo
artículos
Título:
Evidences of habitat structure-generated bottleneck in the recruitment process of the SW Atlantic crab Cyrtograpsus angulatus
Autor/es:
MENDEZ CASARIEGO, A.; E. SCHWINDT; O. IRIBARNE
Revista:
MARINE BIOLOGY
Editorial:
Springer Verlag
Referencias:
Lugar: Berlin; Año: 2004 vol. 145 p. 215 - 243
ISSN:
0025-3162
Resumen:
Abstract Shelters generated by the introduced reefbuilding
polychaete Ficopomatus enigmaticus (Serpulidae)
significantly enhance settlement of the crabShelters generated by the introduced reefbuilding
polychaete Ficopomatus enigmaticus (Serpulidae)
significantly enhance settlement of the crabFicopomatus enigmaticus (Serpulidae)
significantly enhance settlement of the crab
Cyrtograpsus angulatus (Grapsidae) in a SW Atlantic
coastal lagoon (Mar Chiquita, 3732¢S; 5726¢W;
Argentina). However, their ultimate role in recruitment
does not appear to be very important, suggesting a
habitat-generated bottleneck that occurs between settlement
and recruitment. Laboratory and field experiments
show that newly settled crabs actively select
refuges similar in size. Inside the reefs, decreases in crab
density of each newly settled cohort mirror the ratio of
decreases in the number of reef refuges of similar sizes,
suggesting that habitat fractal structure determines the
mortality rate after settlement. Field experiments using
artificial shelters show that as crabs increase in size, they
move outside reefs. Field tethering of juvenile- and
adult-sized crabs without access to refuges showed that
juvenile crabs suffer a much higher risk of mortality than
adults. Our results show that the availability of small
refuges provided by polychaete reefs enhances crab
settlement, but, then, due to a decrease in the number of
refuges as size increases, produces a demographic bottleneck
during recruitment. Thus, independent of settlement
intensity, enhanced survivorship in the smallest
size classes due to refuge is not transmitted to larger size
classes. This is likely one reason why stock-recruitment
relationships may not hold in species that use shelters
during both recently settled and juvenile life stages.
These results provide a good example of why habitat
enhancement programs need to incorporate a comprehensive
evaluation of the species ontogenic ecology to
avoid class size-specific bottlenecks.(Grapsidae) in a SW Atlantic
coastal lagoon (Mar Chiquita, 3732¢S; 5726¢W;
Argentina). However, their ultimate role in recruitment
does not appear to be very important, suggesting a
habitat-generated bottleneck that occurs between settlement
and recruitment. Laboratory and field experiments
show that newly settled crabs actively select
refuges similar in size. Inside the reefs, decreases in crab
density of each newly settled cohort mirror the ratio of
decreases in the number of reef refuges of similar sizes,
suggesting that habitat fractal structure determines the
mortality rate after settlement. Field experiments using
artificial shelters show that as crabs increase in size, they
move outside reefs. Field tethering of juvenile- and
adult-sized crabs without access to refuges showed that
juvenile crabs suffer a much higher risk of mortality than
adults. Our results show that the availability of small
refuges provided by polychaete reefs enhances crab
settlement, but, then, due to a decrease in the number of
refuges as size increases, produces a demographic bottleneck
during recruitment. Thus, independent of settlement
intensity, enhanced survivorship in the smallest
size classes due to refuge is not transmitted to larger size
classes. This is likely one reason why stock-recruitment
relationships may not hold in species that use shelters
during both recently settled and juvenile life stages.
These results provide a good example of why habitat
enhancement programs need to incorporate a comprehensive
evaluation of the species ontogenic ecology to
avoid class size-specific bottlenecks.¢S; 5726¢W;
Argentina). However, their ultimate role in recruitment
does not appear to be very important, suggesting a
habitat-generated bottleneck that occurs between settlement
and recruitment. Laboratory and field experiments
show that newly settled crabs actively select
refuges similar in size. Inside the reefs, decreases in crab
density of each newly settled cohort mirror the ratio of
decreases in the number of reef refuges of similar sizes,
suggesting that habitat fractal structure determines the
mortality rate after settlement. Field experiments using
artificial shelters show that as crabs increase in size, they
move outside reefs. Field tethering of juvenile- and
adult-sized crabs without access to refuges showed that
juvenile crabs suffer a much higher risk of mortality than
adults. Our results show that the availability of small
refuges provided by polychaete reefs enhances crab
settlement, but, then, due to a decrease in the number of
refuges as size increases, produces a demographic bottleneck
during recruitment. Thus, independent of settlement
intensity, enhanced survivorship in the smallest
size classes due to refuge is not transmitted to larger size
classes. This is likely one reason why stock-recruitment
relationships may not hold in species that use shelters
during both recently settled and juvenile life stages.
These results provide a good example of why habitat
enhancement programs need to incorporate a comprehensive
evaluation of the species ontogenic ecology to
avoid class size-specific bottlenecks.