Colura zoophaga
Encyclopedia
Colura zoophaga is a species of epiphytic
liverwort
that is endemic to the African highlands, specifically parts of Kenya
. It belongs to the genus Colura
, which has been hypothesized to be have carnivorous
attributes as early as 1893. It is a recently described species that was the subject of the first scientific study aimed at investigating the allegations of carnivory in liverworts.
that measures no more than several millimetres in size and grows on the trunk and branches of Cliffortia nitida. It possesses elongated water sacs formed by the fusion of the upper leaf margin rolling inward down to the rest of the leaf. A funnel-shaped channel at the lower leaf margin leads to a small opening into the water sac and is covered by a movable lid that only open inward. Leaves are 1 mm long or smaller. It is because of this bladder-like configuration that these traps have been compared to those of Utricularia.
s such as Brocchinia reducta
, an epiphytic bromeliad. The carnivorous habit typically evolves in genera and species that are located in nutrient-poor habitats, but are very moist. In that way, this species of liverwort at least fits the profile for a carnivorous plant.
The traps have been described as early as 1893 by Karl von Goebel
. Other botanists, such as Kerner von Marilaun, also noted the trap structure and described how prey were captured in other members of the genus. Colura zoophaga was chosen as a subject for study in an investigation into the claims of liverwort carnivory. Wilhelm Barthlott
and his colleagues noticed that ciliate
s were grazing the surface of the leaves for bacteria
. In the lab they introduced Blepharisma americana and observed them also grazing for bacteria in the funnel-shaped channel, pressing on the one-way door. The ciliate's behavior resulted in them getting trapped in the water sac, eventually dying and bursting, releasing their contents.
It has not been determined, however, if and how Colura zoophaga attracts its prey or if it produces protease
s or other digestive enzymes to break down the prey. Barthlott et al. suggested that it may be reasonable to assume it does not produce such enzymes and that, like some other species of carnivorous plants (e.g. some Heliamphora
species), it may rely on commensals such as bacteria to break down the prey. There has been no experimental evidence of this, nor has there been evidence of absorption of the prey by the traps. These are typically the criteria by which other carnivorous plants have been identified.
Epiphyte
An epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...
liverwort
Marchantiophyta
The Marchantiophyta are a division of bryophyte plants commonly referred to as hepatics or liverworts. Like other bryophytes, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information....
that is endemic to the African highlands, specifically parts of Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
. It belongs to the genus Colura
Colura
Colura is a genus of epiphytic liverworts and consists of approximately 60 species that are distributed mostly in the tropics. Species in this genus are no larger than a couple millimetres in size and may possess small water sac organs formed from fused leaf margins that trap small ciliates. It is...
, which has been hypothesized to be have carnivorous
Carnivorous plant
Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans, typically insects and other arthropods. Carnivorous plants appear adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic...
attributes as early as 1893. It is a recently described species that was the subject of the first scientific study aimed at investigating the allegations of carnivory in liverworts.
Description
Colura zoophaga is a small epiphytic liverwortMarchantiophyta
The Marchantiophyta are a division of bryophyte plants commonly referred to as hepatics or liverworts. Like other bryophytes, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information....
that measures no more than several millimetres in size and grows on the trunk and branches of Cliffortia nitida. It possesses elongated water sacs formed by the fusion of the upper leaf margin rolling inward down to the rest of the leaf. A funnel-shaped channel at the lower leaf margin leads to a small opening into the water sac and is covered by a movable lid that only open inward. Leaves are 1 mm long or smaller. It is because of this bladder-like configuration that these traps have been compared to those of Utricularia.
Carnivory
The habitat of Colura zoophaga, epiphytic and deriving all nutrients from rainwater, has been compared to that of known carnivorous plantCarnivorous plant
Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans, typically insects and other arthropods. Carnivorous plants appear adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic...
s such as Brocchinia reducta
Brocchinia reducta
Brocchinia reducta is one of few carnivorous bromeliads. It is native to southern Venezuela, Brazil and Guyana, and is found in nutrient-poor soil....
, an epiphytic bromeliad. The carnivorous habit typically evolves in genera and species that are located in nutrient-poor habitats, but are very moist. In that way, this species of liverwort at least fits the profile for a carnivorous plant.
The traps have been described as early as 1893 by Karl von Goebel
Karl von Goebel
Karl Immanuel Eberhard Ritter von Goebel ForMemRS was a German botanist. His main fields of study were comparative functional anatomy, morphology, and the developmental physiology of plants under the influence of both phylogenetic and extrinsic factors.Starting in 1873, Goebel studied theology...
. Other botanists, such as Kerner von Marilaun, also noted the trap structure and described how prey were captured in other members of the genus. Colura zoophaga was chosen as a subject for study in an investigation into the claims of liverwort carnivory. Wilhelm Barthlott
Wilhelm Barthlott
Wilhelm Barthlott is German botanist and the head of the Nees-Institute for Biodiversity of Plants and director of the Botanical Gardens of the University of Bonn.- External links :*...
and his colleagues noticed that ciliate
Ciliate
The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagella but typically shorter and present in much larger numbers with a different undulating pattern than flagella...
s were grazing the surface of the leaves for bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
. In the lab they introduced Blepharisma americana and observed them also grazing for bacteria in the funnel-shaped channel, pressing on the one-way door. The ciliate's behavior resulted in them getting trapped in the water sac, eventually dying and bursting, releasing their contents.
It has not been determined, however, if and how Colura zoophaga attracts its prey or if it produces protease
Protease
A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein....
s or other digestive enzymes to break down the prey. Barthlott et al. suggested that it may be reasonable to assume it does not produce such enzymes and that, like some other species of carnivorous plants (e.g. some Heliamphora
Heliamphora
The genus Heliamphora contains 23 species of pitcher plants endemic to South America. The species are collectively known as sun pitchers, based on the mistaken notion that the heli of Heliamphora is from the Greek helios, meaning "sun"...
species), it may rely on commensals such as bacteria to break down the prey. There has been no experimental evidence of this, nor has there been evidence of absorption of the prey by the traps. These are typically the criteria by which other carnivorous plants have been identified.
External links
- The Carnivorous Plant FAQ page on Colura zoophaga.