INVESTIGADORES
GRIFFIN Miguel
artículos
Título:
Borers and encrusters as indicators of the presence of hermit crabs in Antarctic Eocene gastropod shells
Autor/es:
CASADIO, S.; PARRAS, A.; GRIFFIN, M.; MARENSSI, S.
Revista:
ANTARCTIC SCIENCE
Editorial:
Antarctic Science, Ltd.
Referencias:
Año: 2007 vol. 19 p. 297 - 309
ISSN:
0954-1020
Resumen:
Abstract: The community of encrusting and boring organisms developed on shells of the gastropodThe community of encrusting and boring organisms developed on shells of the gastropod
Antarctodarwinella ellioti from the lower section of the La Meseta Formation (Eocene) exposed on
Seymour (Marambio) Island, Antarctic Peninsula, allows inference that the shells were inhabited by hermit
crabs. A Chi-square Independence Test revealed that the community - dominated by polychaetes and
bryozoans - shows preference for the aperture interior area of the shell. A subsequent Cochran Q Test
indicated that the differences in frequency of encrusting and boring organisms as counted on the different
interior sectors of the aperture were statistically significant. Thus, polychaetes, boring bryozoans, and
encrusting bryozoans, do not show the same frequency in each interior sector of the aperture; they are
more frequent on the columella (P , 0.0001, P, 0.01 and P , 0.001 respectively). Encrusting bryozoans
also appear to show a preference - albeit not as high as on the columella - for the outer lip. This
community of boring and encrusting organisms and their distribution on the shell confirms that the shells
were inhabited by hermit crabs. The community is similar to that described in Recent hermitted shells from
mid-latitude temperate water environments, suggesting that such communities were already established in
the Eocene.
also appear to show a preference - albeit not as high as on the columella - for the outer lip. This
community of boring and encrusting organisms and their distribution on the shell confirms that the shells
were inhabited by hermit crabs. The community is similar to that described in Recent hermitted shells from
mid-latitude temperate water environments, suggesting that such communities were already established in
the Eocene.
Seymour (Marambio) Island, Antarctic Peninsula, allows inference that the shells were inhabited by hermit
crabs. A Chi-square Independence Test revealed that the community - dominated by polychaetes and
bryozoans - shows preference for the aperture interior area of the shell. A subsequent Cochran Q Test
indicated that the differences in frequency of encrusting and boring organisms as counted on the different
interior sectors of the aperture were statistically significant. Thus, polychaetes, boring bryozoans, and
encrusting bryozoans, do not show the same frequency in each interior sector of the aperture; they are
more frequent on the columella (P , 0.0001, P, 0.01 and P , 0.001 respectively). Encrusting bryozoans
also appear to show a preference - albeit not as high as on the columella - for the outer lip. This
community of boring and encrusting organisms and their distribution on the shell confirms that the shells
were inhabited by hermit crabs. The community is similar to that described in Recent hermitted shells from
mid-latitude temperate water environments, suggesting that such communities were already established in
the Eocene.
also appear to show a preference - albeit not as high as on the columella - for the outer lip. This
community of boring and encrusting organisms and their distribution on the shell confirms that the shells
were inhabited by hermit crabs. The community is similar to that described in Recent hermitted shells from
mid-latitude temperate water environments, suggesting that such communities were already established in
the Eocene.
from the lower section of the La Meseta Formation (Eocene) exposed on
Seymour (Marambio) Island, Antarctic Peninsula, allows inference that the shells were inhabited by hermit
crabs. A Chi-square Independence Test revealed that the community - dominated by polychaetes and
bryozoans - shows preference for the aperture interior area of the shell. A subsequent Cochran Q Test
indicated that the differences in frequency of encrusting and boring organisms as counted on the different
interior sectors of the aperture were statistically significant. Thus, polychaetes, boring bryozoans, and
encrusting bryozoans, do not show the same frequency in each interior sector of the aperture; they are
more frequent on the columella (P , 0.0001, P, 0.01 and P , 0.001 respectively). Encrusting bryozoans
also appear to show a preference - albeit not as high as on the columella - for the outer lip. This
community of boring and encrusting organisms and their distribution on the shell confirms that the shells
were inhabited by hermit crabs. The community is similar to that described in Recent hermitted shells from
mid-latitude temperate water environments, suggesting that such communities were already established in
the Eocene.
also appear to show a preference - albeit not as high as on the columella - for the outer lip. This
community of boring and encrusting organisms and their distribution on the shell confirms that the shells
were inhabited by hermit crabs. The community is similar to that described in Recent hermitted shells from
mid-latitude temperate water environments, suggesting that such communities were already established in
the Eocene.
P , 0.0001, P, 0.01 and P , 0.001 respectively). Encrusting bryozoans
also appear to show a preference - albeit not as high as on the columella - for the outer lip. This
community of boring and encrusting organisms and their distribution on the shell confirms that the shells
were inhabited by hermit crabs. The community is similar to that described in Recent hermitted shells from
mid-latitude temperate water environments, suggesting that such communities were already established in
the Eocene.