Coexistence of similar species: evidence of a resource and microhabitat sharing in two intertidal hermit crab species
Por:
KRUESI, KARLA, Miguel Burciaga, Luis, ALCARAZ, GUILLERMINA
Publicada:
1 mar 2022
Categoría:
Aquatic science
Resumen:
Theory predicts that species can only coexist if they are sufficiently
different in their resource and/or microhabitat utilization; if their
needs are too similar, the stronger population will exclude the weaker,
unless the two species are equally strong competitors. This hypothesis
is difficult to assess in most species because populations are limited
by multiple resources simultaneously. In hermit crabs, however, fitness
is overwhelmingly limited by gastropod shells, which are their only
shelter from external pressures, from predation to harsh environmental
conditions. Several hermit crab species have similar shell requirements
and occupy the same habitat. Here, we examine the degree of overlap in
shell use and microhabitat occupation between two species, one of which
(Calcinus californiensis) is clearly dominant over the other
(Clibanarius albidigitus) in direct fights over shells. We hypothesized
that these species should show microhabitat separation or shell
partitioning. We sampled hermit crabs' presence and shell use in the
high- and mid-intertidal. The species overlapped in the two intertidal
sites, especially at the higher intertidal, and they occupied preferred
and suboptimal shells with similar frequency. The co-occurrence and
strong overlap in shell use of these two species could be explained by a
resource exploitation versus interference trade-off, relaxed selection
pressure on shell characteristics due to small body size,
spatial/temporal niche segregation, or dominance by Ca. californiensis
that has yet to result in habitat displacement of Cl. albidigitus.
Further research is needed to determine which of these hypotheses
explain the apparent coexistence of ecologically similar species.
Filiaciones:
KRUESI, KARLA:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Ecol & Recursos Nat, Mexico City 04510, DF, Mexico
Miguel Burciaga, Luis:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Ecol & Recursos Nat, Mexico City 04510, DF, Mexico
ALCARAZ, GUILLERMINA:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Ecol & Recursos Nat, Mexico City 04510, DF, Mexico
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