Carnivorous aquatic plants of the genus Utricularia (Lentibulariaceae) are well known to capture small aquatic invertebrates, using structures called bladders. But information is coming to the fore suggesting that Utricularia could be re-classified as an omnivore as phytoplankton species can make up a major proportion of bladder contents. It is not fully understood if phytoplankton cells are preyed upon or if they are taken in merely as a consequence when invertebrate prey triggers the bladder. Past studies have indicated that both scenarios could be possible. Some studies now also suggest that a mutual-symbiotic relationship exists between Utricularia and the community in the within the bladders. The present study is to determine a potential role for phytoplankton in nutrient supply to Utricularia. The identification and quantification phytoplankton species was carried out on the contents of bladders sampled from the carnivorous bladderwort Utricularia australis. Samples of three full Utricularia filaments were taken from 18 central Italian sites and the contents of 10 or 15 randomly chosen bladders were observed. These data were compared to the external phytoplankton community and water chemico-physical and nutrient variables. Every bladder was shown to contain some phytoplankton cells, with findings showing species spread across 6 divisions (Chlorophyta, Bacillariophyta, Pyrrophyta, Euglenophyta, Cryptophyta, Cyanophyta). Significant relationships of phytoplankton species assemblages within the bladders and those in the ambient water were found. Also in the majority of bladders there were a high proportion of live compared to dead cells. Many bladders had phytoplankton-only communities. It was not possible to say for certain if phytoplankton was preyed upon or not, or if there was a mutualistic-symbiotic relationship, but the presence of many living cells could suggests the latter option is possible. The findings here imply that the bladder phytoplankton community is a consequence of the ambient community given the relationships between them. The presence of phytoplankton-only contents in many bladders implies possible automatic- rather than prey-triggered bladder functioning.

Ellwood, N.T.W., Congestri, R., Ceschin, S. (2017). The potential nutritional role of phytoplankton in traps of carnivorous bladderworts (Utricularia, Lentibulariaceae).. In Riunione Scientifico annuale del Gruppo di Algologia (pp.23-23).

The potential nutritional role of phytoplankton in traps of carnivorous bladderworts (Utricularia, Lentibulariaceae).

Neil Thomas William Ellwood
;
Simona Ceschin
2017-01-01

Abstract

Carnivorous aquatic plants of the genus Utricularia (Lentibulariaceae) are well known to capture small aquatic invertebrates, using structures called bladders. But information is coming to the fore suggesting that Utricularia could be re-classified as an omnivore as phytoplankton species can make up a major proportion of bladder contents. It is not fully understood if phytoplankton cells are preyed upon or if they are taken in merely as a consequence when invertebrate prey triggers the bladder. Past studies have indicated that both scenarios could be possible. Some studies now also suggest that a mutual-symbiotic relationship exists between Utricularia and the community in the within the bladders. The present study is to determine a potential role for phytoplankton in nutrient supply to Utricularia. The identification and quantification phytoplankton species was carried out on the contents of bladders sampled from the carnivorous bladderwort Utricularia australis. Samples of three full Utricularia filaments were taken from 18 central Italian sites and the contents of 10 or 15 randomly chosen bladders were observed. These data were compared to the external phytoplankton community and water chemico-physical and nutrient variables. Every bladder was shown to contain some phytoplankton cells, with findings showing species spread across 6 divisions (Chlorophyta, Bacillariophyta, Pyrrophyta, Euglenophyta, Cryptophyta, Cyanophyta). Significant relationships of phytoplankton species assemblages within the bladders and those in the ambient water were found. Also in the majority of bladders there were a high proportion of live compared to dead cells. Many bladders had phytoplankton-only communities. It was not possible to say for certain if phytoplankton was preyed upon or not, or if there was a mutualistic-symbiotic relationship, but the presence of many living cells could suggests the latter option is possible. The findings here imply that the bladder phytoplankton community is a consequence of the ambient community given the relationships between them. The presence of phytoplankton-only contents in many bladders implies possible automatic- rather than prey-triggered bladder functioning.
2017
Ellwood, N.T.W., Congestri, R., Ceschin, S. (2017). The potential nutritional role of phytoplankton in traps of carnivorous bladderworts (Utricularia, Lentibulariaceae).. In Riunione Scientifico annuale del Gruppo di Algologia (pp.23-23).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/364680
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