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Description
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General description Brief description of the body form and size, recognisable attributes
Why do scientists study these organisms and why are they important to the public at large (e.g. important to CCAMLR policy-makers) Why are they included in MEASO? Microprotozooplankton ciliates are a monophyletic group of protozoans, or unicellular eukaryotes, characterised by the presence of hair-like organelles called cilia or cirri (compound ciliary organelles) used for locomotion and feeding. Ciliates also possess two types of nuclei, including at least one somatic macronucleus and one germline micronucleus. The DNA in the micronucleus is transferred during conjugation (sexual reproduction). Species are characterised by body shape, colour, and size with the majority of species occupying microplankton sizes 20-200 μm. Ciliates consume prey ranging from bacteria, microalgae (eg. diatoms), other protists, metazoans, dissolved organic matter and other organic particles. Several ciliates, predominantly oligotrichs, are mixotrophic and can account for 40-60% of the total alorica ciliate biomass in Southern Ocean regions (Christaki et al. 2008). Ciliates are prey to copepods, pteropods, and other higher trophic organisms. Ciliates are divided into two groups: aloricate (including oligotrichs) and loricate (including choreotrichs), referring to the absence and presence of an outer shell known as a lorica. In the Southern Ocean, loricate and aloricate ciliate densities often dominate microzooplankton biomass (Strzepek at al. 2005), and can account for 54-64% of total zooplankton composition (Sushin et al. 1986). Based on reports published between 1900 and 2011, 192 species are recorded to exist south of 40°S, however most reports come from data sets originating from summer with very little reference to mesh sizes of nets used and/or water volumes sampled (Dolan and Pierce, 2014). Highest abundances of tintinnids occur at the ice edge during austral summer (Alder and Boltovskoy 1991). When associated with Phaeocystis blooms, ciliate densities have been recorded up to 150,000 ind. m-3 (Davidson and Marchant, 1992). Microzooplankton, comprised of both ciliates and heterotrophic flagellates, make up one of three biogenic Fe pools in the Southern Ocean as recognised by field experiments measuring the ability of microzooplankton to regenerate Fe from prey (Hutchins et al. 1993; Bowie et al. 2001). Other biogenic Fe pools include primary producers and mesozooplankton (Bowie et al. 2001). Microzooplankton serve the functional role of predators tightly coupled with prey, comprised of both heterotrophs and autotrophs, in the microbrial foodweb (Landry et al. 1993). Chase and Price (1997) showed that microzooplankton have significant Fe demands, and laboratory studies have shown the importance of their contribution to what has been referred to as the "Ferrous Wheel" for their participation in the high demand and recycling of Fe within the microbial foodweb (Kirchman 1996; Barbeau et al. 1996; Hutchins and Bruland 1994). Choreotrich ciliates, including tintinnids, are surface water planktonic protists found predominantly in coastal and pelagic ecosystems, and cosmopolitan, as part of temperate, tropical and polar fauna (Pierce and Turner, 1993). Globally there are over 700 species that are identified by the morphological characteristics of their lorica, or shell, into which the ciliate cell can withdraw, which can be tubular or vase-like in shape (Kofoid and Campbell 1929, 1930). The composition of tintinnid loricae predominantly comprise of proteins, however the relative amounts of all contents (eg. proteins, carbohydrates, lipids, etc) is unknown. The influence of dead loricae on benthic communities and nutrient cycles upon reaching the deep sea is also unknown (Agatha and Simon 2012). Oligotrich ciliates have prominent oral cilia. Like choreotrich ciliates, oligotrichs form a large proportion of the protozoan biomass, and are important grazers of nanoplankton populations (Paranjape 1987; 1990) and bacteria (Sherr et al. 1989). Microprotozooplankton can contribute significantly (<7 to <75 %) to total micro- and nanoplankton carbon (Garrison 1991).
Typical photograph/s
Fig. 1 Examples of tintinnid species typical of the Southern Ocean: (a) Salpingella laackmanni, (b) Salpingella decurtata, (c) Salpingella faurei, (d) Laackmanniella naviculaefera, (e) Laackmanniella forma prolongata, (f) Amphorellopsis quinquelata, (g) Amphorides laackmanni, (h) Acanthostomella obtusa, (i) Codonellopsis pusilla, (j) Epiplocylcoides reticulata, (k) Codonellopsis gaussi, (l) Codonellopsis gaussi, (m) Codonellopsis gaussi forma globosa, (n) Codonellopsis gaussi forma cylindricoconica, (o) Condonellopsis gaussi forma coxiella, (p) Cymatocylis affinis/convallaria, (q) Cymatocylis affinis/convallaria forma calcyformis, (r) Cymatocylis affinis/convallaria forma subrotundata, (s) Cymatocylis affinis/convallaria forma drygalski, (t) Cymatocylis affinis/ convallaria forma cylindrica. Species found only the Southern Ocean are Laackmanniella naviculaefera (d–e), Amphorellopsis quinquelata (f), Codonellpsis gaussi (k–o) and Cymatocylis affinis/convallaria (p–t). Note the different morphologies shown by the Southern Ocean endemics. |
Summary role in ecosystem
Summary statement of role in ecosystems, global significance and known/expected significance in Southern Ocean
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In the microbial foodweb there is a tight coupling between prey, comprised of autotrophs and heterotrophs, and microzooplankton predators (Landry et al. 1993). This tight coupling is likely the reason for the constant supply of algal stocks within iron-limited oceanic zones (Strom et al. 2000), such as the HNLC (high nutrient low chlorophyll) waters of the Southern Ocean.
As a functional group, tintinnid ciliates are a member of the microzooplankton (20-200 μm), and can often dominate grazing of small phytoplankton (2-20 μm) among most pelagic ecosystems (Dolan et al. 2012; Karayanni et al. 2005). Tintinnids have also been reported to feed on cyanobacteria (Karayanni et al. 2005). Tintinnids are prey for Southern Ocean pelagic organisms including copepods, krill, mysid shrimp, salps, chaetognaths, larval Antarctic silverfish, and benthic organisms such as octocorals and deep sea isopods (reviewed by Dolan et al. 2012; Brökeland et al. 2010; Buck et al. 1992; Hopkins 1987; Kellermann 1987; Kruse et al. 2009; Lonsdale et al. 2000; Mauchline 1980; Orejas et al. 2003).
Autecology
Summarise the autecology of the group and whether this differs between sectors, and/or over years
Auteology is the ecology of an individual species, and includes its life history, movement, food, energetics, and rate processes. Here we summarise the autecology of the group and whether this differs between sectors, and/or over years.
Include at the beginning a general description of the important features of the group's autecology. As far as possible, include this general detail in figures (rather than text) illustrating the life cycle, phenology (timing of events) and other general attributes. (please put figures in placeholders in the template)
The following sections provide specific estimates/conclusions about how to represent these attributes in models of this group, which may be qualitative network models or dynamic models.
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Conjugation is a distinctive feature of the life cycle of ciliates which gamonts (conjugating partners/cells) partially and temporarily fuse, known as gamontogamy, and a bridge forms between their cytoplasms. Micronuclei undergo meiosis, macronuclei disappears, and haploid micronuclei are then exchanged over the bridge. In most ciliates, gamonts separate after conjugation and new macronuclei emerge from micronuclei in each gamont. Fission follows both conjugation and autogamy.
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- Temporary and partial fusion occurs between two compatible gamonts
- Micronuclei undergo meiosis, forming four haploid micronuclei per gamont
- One haploid micronucleus undergoes mitosis; the three remaining micronuclei disintegrate
- The fused gamonts exchange a micronucleus via cytoplasmic bridge
- Gamonts separate
- Syngamy in each gamont occurs where micronuclei fuse to form a new diploid micronucleus (synkaryon)
- Mitosis occurs another three times, producing eight micronuclei
- Four of the newly formed micronuclei become macronuclei, leaving the original macronucleus to disintegrate
- Four identical daughter cells are formed through two rounds of binary fission
Life history
Include in the table only available estimates of life history parameters and their error, wherever possible. Delete parameters that are not relevant. Add parameters that are relevant but not included in the tables. The reference/s estimating the parameters should be cited, along with any statements as to the maturity of the estimates if known (e.g. under development, personal communications, future work is examining.....). For some species, life history information and parameters are co-opted from areas outside of the subject area, e.g. from outside the Southern Ocean. This proxy information is reasonable to include. Please include also the rationale for co-opting these data, and citations. If the parameters are different between locations/sectors then include those differences in the table.
Parameters | Values | Notes | References |
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Maximum age | |||
Average adult size | Size fractions range 20 to >60 μm | Klaas (1997) classify size classes as large (>60 μm), medium (40-60 μm) and small (20-40 μm) | Klaas, 1997 |
Age at maturity | |||
Size at maturity | |||
Spawning/breeding area | |||
Spawning/breeding season | |||
Larval/gestation period | |||
Location of recruits | |||
Size of recruits | |||
| Overall natural mortality rate | |||
Non-predation natural mortality rates |
Migration, movement
Depending on species group - this could be large movements of populations in and out of the region (e.g. whales) or it could detail diurnal vertical migration of fish/plankton species.
Population scale - need to include time of year when migration/movement might be more prevalent. Small scale migration - time of day, depths etc
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Diet (foraging and consumption)
Summary dietary information - e.g. "This species feeds predominantly on krill, with a small percentage of it's diet made up of mesopelagic fish species. Winter diets are predominantly fish based and located north of 60degS." Summaries from the Southern Ocean Dietary Database would be useful to include here. If there are variations in diet between sectors or locations then include those differences as well. Also include assessment of change in diet, when available, seasonally and over years. Isotopic or genetic analyses would be useful to include.
In comparison to protists such as oligotrich ciliates and heterotrophic dinoflagellates, Southern Ocean ciliated tintinnids are generally a minor component of the microzooplankton, but can at times be considered major grazers on small phytoplankton (2-20 μm) but only when surface waters are not dominated by larger primary producers, such as diatoms and/or Phaeocystis (Caron et al. 2000; Froneman, 2004; reviewed by Dolan et al. 2012).
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Among microprotozooplankton tested south of 50°S, estimates of grazing pressure based on a specific growth rate of 0.1 day-1 indicate heavier grazing pressure by protozoa >40 μm (larger sized); however grazing pressure based on average clearance rate of 1 μL ind.-1h-1 indicate heavier grazing pressure from smaller (20-40 μm) size classes (Klaas, 1997).
Energetics
Include basic estimates for energetic calculations here. If measures of these parameters are available for considering changes over time then this may help identification of system-level change.
The summary table here can have references to more detailed tables compiled from many references etc.
Parameters | |
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| Ingestion rate | Estimated grazing of primary production by microprotozooplankton (Klaas, 1997):
Clearance rate estimates for dinoflagellates and ciliates vary from 0.1 to >20 μL ind.-1h-1 (Capriulo et al. 1991) Under controlled conditions, values range 0.1 to 26 μl ind.-1h-1 for oligotrichous ciliates (Jonsson 1986) Clearance rates on phytoplankton by Antarctic protozoa, measured by radioactive isotopes: 0.0-0.2 μL ind.-1h-1 (Lessard and Rivkin, 1986) Average clearance rate of microprotozooplankton = 1 μL ind.-1h-1 (Garrison and Buck, 1989) |
| Metabolism | |
Fecundity | |
Length-weight relationships | |
Growth rate | Uniform 0.1 day-1 (Klaas 1997) |
Size at age | |
| Population Productivity (average life time) |
Habitat
In the introduction to this section, provide a general description of the locations where the group is expected to be found, including depth, proximity to the continent/islands/shelf areas. Also introduce the physical and biological dependencies of the group. e.g. distribution is constrained by the temperature range, or the group is only found in sedimentary environments and so on.
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Ciliate protists are found in a range of Southern Ocean and Antarctic habitats, including marine and freshwater (Petz et al. 2007) pelagic environments and brine channels within sea-ice.
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Variable | Taxon size/stage impacted | Functional response (icon) | Parameters and uncertainties | Risk areas/regions impacted | Notes |
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Population
Summarise the population status, trends and prognoses for the species/group and whether this differs between sectors, and/or over years. Consideration of threshold population sizes, the location of local populations with respect to the range (habitat conditions) etc. will be beneficial.
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Range and Structure
Distribution and abundance of the population. Consideration of the abundances relative to an assessed range of the species would be beneficial.
Include here
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Dynamics
Assessments of variability, trends over time and prognoses. Analyses of possible links to drivers (habitat, food web) to be included here.
- Abundance information - general overview, comment on increases or decreases in population size and where/why?
- Placeholder for trends in abundance in different sectors
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Synecology
Synecology refers to the ecology of interactions between species, including food webs (consumers), competition, disease and so on.
Include here, 2-3 sentence summary of the type of interactions with other species. Also describe differences in the relationships between sectors/locations.
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Consumers (predators)
2-3 sentence summary of the type of consumers at different times of the year, including evidence of whether these have changed over time..
Competitors
Assessment of overlap with potential competitors of the species/group.
Consumers (predators)
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Competitors
Placeholder for content, please contact us if you have data or information you would like to contribute to Soki. Other interactions e.g. disease
Tintinnids have been observed agglutinating (ie. adhering) mineral particles and/or dead biogenic matter (eg. diatom frustules) to their loricae, however reasons for this behaviour remain unknown. Many believe that the type of particles agglomerated to loricae is randomly selected and thought to reflect the predominant concentrations of such particles found within the adjacent environment (Winter et al. 1986; Henjes and Assmy 2008). Tintinnids possessing loricae without particles attached are considered "hyaline" whereas those with particles attached are "agglomerated" (Agatha et al. 2013). Armbrecht et al. (2017) reported the first observations of East Antarctic tintinnids Laackmanniella naviculaefera and Codonellopsis gaussi agglutinating live diatoms Fragilariopsis curta, F. cylindrus, F. pseudonana and F. rhombica to their loricae. Species such as Laackmanniella are believed to suck out and ingest the protoplasts of diatoms before agglomerating the empty frustules to their loricae (Gowing and Garrison, 1992).
Human Impacts
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When known, include this section and present information on direct human impacts on this group. For example, from fisheries, polution and the like. Placeholder for content, please contact us if you have data or information you would like to contribute to Soki.
Assessments of Status
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IUCN Red List
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| Year of classification: | 'None of these species has been assessed for the Red List' |
| Red List Category & Criteria: | |
| Assessment Justification: | include description and link to the web site |
Other
Include assessments from other bodies if available. Placeholder for content, please contact us if you have data or information you would like to contribute to Soki.
References
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A list of references referred to on this page.
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