Tintinnid Species Research Articles

The role of picoplankton (cyanobacteria and plastidic picoflagellates) in the diet of tintinnids

Food vacuole contents in naturally occurring populations of tintinnids in surface waters at the mouth of the Bay of Villefranche were examined from November 1988 to December 1989. Three types of prey were considered: cyanobactena ( Synechococcus spp.), plastidic pico- and nanoflagel lates. The relative frequency (%) of these were observed in the diet of 18 tintinnid species. Results confirm that nanoflagellates constitute the dominant fraction in the diet of most of the tintinnids examined. They are preferentially ingested by some species, such as Amphorides quadrilineata and Favella sp. Nevertheless, picoplankton is ingested throughout the year by all the tintinnids, and can reach up to 100% of the ration mainly during winter and summer. Cyanobacteria are the prey most ingested by Rhabdonella spiralis and the only prey observed in food vacuoles of Salpingella acuminaia . As indicated by the Strauss linearity index values, picoflagellates are actively grazed by some species (e.g. Dictyocysta elegans, Eutintinnus spp.). The implications of the ingestion of picoplankton by tintinnids in the food webs are discussed.

Microzooplankton and tintinnid species-specific assemblage structures: patterns of distribution and year-to-year variations in the Weddell Sea (Antarctica)

Silicoflagellates, large heterotrophic dinoflagellates, radiolarians, tintinnids and micro- crustaceans were counted in 72 screened (15 urn) samples retrieved at 0-150 m from the Weddell Sea in January 1989. Tintinnid species were identified and biomass estimates were carried out for all groups on the basis of measurements of cell dimensions. Dinoflagellates dominated the micro- heterotrophic community at all stations and depths (65% of overall microzooplanktonic carbon in the 0-150 m interval), followed by the tintinnids (18%), microcrustaceans (16%) and radiolarians (1%). All groups, with the exception of silicoflagell ates, peaked noticeably in the vicinity of the southern end of the transect (76-77°S). Relationships between concentrations of chlorophyll a and microzooplanktonic biomass were present, yet not altogether consistent, but both phyto- and microzooplankton seemed to generally respond to regional enhancements associated with the ice edge. Comparison with similar Weddell and Weddell-Scotia data retrieved in February-March 1987 and November 1988-December 1989, respectively, are highly coherent in terms of microplankton ic abundances, their geographic and vertical distribution patterns, and the specific make-up and distribution of tintinnid assemblages. Analyses of the oral diameters of tintinnid morphotypes suggest that the latitudinal and vertical distribution of their five dominant taxa (which account for >90% of all individuals) is structured so as to maximize resource partitioning.

Vertical distribution of tintinnids and associated microplankton in the upper layer of the Barents Sea

Abstract In 61 samples collected in August 1988 in the upper 50 m of the Barents Sea the vertical distribution of chlorophyll a, dinoflagellates, tintinnids, micro crustaceans and fecal pellets did not show clear associations with the physical vertical structure of the waters involved. Tintinnid concentrations ranged between < 1 and 314 indll, with an average of 46 indll for the 0–50 m layer. Mean organic carbon estimated per individual ranged from 1200 pg for the smallest tintinnid species, to 14 000 for the largest one, yielding an average of 0.33 µg C/l (max: 2.1 µg C/l). At this time of the year tintinnids may consume 0.16–5.0 % (mean: 1.4 %) of total primary production. Tintinnid size was positively correlated with chlorophyll a concentrations, suggesting that food availability enhances lorica growth. In total, nine tintinnid species were recorded; however, only three of these (Acanthostomella norvegica, Ptychocylis obtusa, and Parafavella denticulata) accounted for almost 90 % of all the individuals.

Role of zooplankton in the nitrogen cycle off the west coast of the South Island, New Zealand, winter 1987

Abstract Zooplankton abundance, feeding, and ammonia regeneration rates were measured along three transects off the west coast of the South Island, New Zealand, in winter (July) 1987. Crustacean nauplii and copepodites dominated the 55–200 μm fraction of the microzooplankton. Tintinnid population dynamics were related to the degree of freshwater influence. Tintinnid species with silica‐encrusted bowls were common close inshore and species with no encrustations were common offshore. The most abundant macrozooplankton were the small copepods Acartia ensifera, Paracalanus indicus, Oithona similis, Centropages aucklandicus, and Clausocalanus jobei. A. ensifera dominated at the inshore stations, whereas the outer stations had a mixture of neritic/outer shelf and oceanic species. Zooplankton biomass was highest at the outer station off Hokitika. Offshore displacement of coastal water and alongshore wind‐driven flow were important determinants of zooplankton dynamics. Ingestion rates of particulate nitrogen by zooplankton > 55 μm were equivalent to 0.3–20% of the daily uptake of nitrogen by phytoplankton and were highest close inshore. Regeneration of ammonia‐nitrogen by zooplankton > 55 μm averaged 12% of ammonia remineralisation. Small oligotrichs and heterotrophic nanoflagellates are suggested as the major agents for remineralisation; nanoflagellates may be an important additional link in the food chain between picoplankton and zooplankton > 55 μm.

Distribution and abundance of tintinnids in the Quoddy Region of the Bay of Fundy

The seasonal cycle of tintinnid species compositions, numerical abundance, and average lorica oral diameter was examined along a nearshore–offshore transect in the Quoddy Region of the Bay of Fundy. Among 27 species identified, Stenosemella nivalis was most abundant. Highest abundances of tintinnids were observed near the surface; hyaline forms dominated near the surface while agglutinated forms were predominant in subsurface waters. Maximum abundances of 1.8 × 108 and 9.0 × 106 cells/m2 were observed at near- and off-shore stations, respectively, in summer. Hyaline tintinnids were more numerous in midsummer and at the offshore site, possibly because of the necessity of a sedimentary phase in the life cycle of agglutinated forms. The seasonal decrease in the lorica oral diameter of tintinnids was paralleled by a decrease in average cell volume of phytoplankton. Annual tintinnid productivity was estimated as 250 kJ/m2 in Passamaquoddy Bay (nearshore) and total productivity from May to October was 34 kj/m2 in the lower Bay of Fundy (offshore). We conclude that tintinnid ciliates are an important trophic intermediate in the planktonic food web because of their high productivity and their ability to feed on the small, highly productive phytoplankton.

Relationships between lorica volume, carbon, nitrogen, and ATP content of tintinnids In Narragansett Bay

Lorica volume, carbon, nitrogen, and ATP content were measured in nine species of tintinnid ciliates spanning a size range of two orders of magnitude. Tintinnid carbon was linearly related to both lorica volume and ATP content. The mean C:ATP ratio was 65. Tintinnid ATP as a percentage of total ATP in the < 153 /un fraction averaged 7% over an annual cycle in Narragansett Bay. It is concluded that ATP is a useful indicator of living phytoplankton carbon in pre-screened, smallvolume samples during periods of moderate to high phytoplankton biomass, but that protozoan microzooplankton interference is significant when phytoplankton standing stocks are low.

A study of reproduction and other life cycle phenomena in planktonic protists using an acridine orange fluorescence technique

The percentage of dividing individuals and temporal reproductive patterns were determined for natural populations of several planktonic protists including five species of tintinnids, a dinoflagellate, and a diatom. To obtain these data, a method was used in which the nuclei of planktonic ciliates and phytoplankters can be fluorescently stained with acridine orange at the time of collection and fixation. The technique is simple and can be used routinely in studies of reproduction or other life cycle phenomena of natural protistan populations. For the tintinnids, often more than half of the individuals were in some recognizable stage of fission; periodicity in the division process was only observed once and apparently followed a pulse of conjugation in the population. With the diatom Ditylum brightwellii the fluorescent staining technique yielded data on the extent and timing of division which were consistent with, but more complete than, previous enumerations of paired cells.

Effects of Olisthodiscus luteus on the growth and abundance of Tintinnids

The effects of the red tide flagellate Olisthodiscus luteus Carter on the growth of two tintinnid species, Tintinnopsis lubulosoides Meunier and Favella sp. (Clap. & Lach.) Jorg., were measured in batch culture. T. tubulosoides and Favella sp. grew at rates equivalent to 1.2 (10°C) and 2.0 (20°C) population doublings per day, respectively, when offered nutritionally adequate phytoplankton species. The growth rates of both tintinnid species were reduced in the presence of 102–103O. luteus cells · ml-1 in multialgal treatments. Growth rate inhibition was proportionately greater at higher O. luteus densities. Lethal effects were observed for both tintinnid species at O. luteus concentrations of 5x103 cells · ml-1 in multi-algal treatments. T. tubulosoides mortality occurred at all O. luteus concentrations in unialgal culture. O. luteus-conditioned medium did not substantially inhibit tintinnid growth when combined with acceptable food species, suggesting that toxicity is induced by ingestion or direct contact with O. luteus cells, or by exposure to a short-lived exudate. In agreement with these results, an inverse relationship between O. luteus concentration and tintinnid abundance was observed in Narragansett Bay, Rhode Island, over a two year period. The small lorica diameter of the species apparently inhibited by these O. luteus blooms suggests a detrimental effect independent of cell ingestion. In addition to the absolute concentration of O. luteus cells, the availability of nutritionally adequate algal food may be an important factor determining the impact of O. luteus blooms on tintinnid populations.

Studies on the functional role of tintinnids in the Southern California Bight. III. Grazing impact of natural assemblages

Tintinnids were identified and enumerated in samples from 100 stations in the Southern California Bight. Spring and summer samples were collected at weekly intervals at 3 locations off La Jolla, California (USA) in 1967. Samples were also taken at considerably wider spatial and temporal intervals during 4 cruises in the fall and winter of 1974–1975. Ninety-one species of tintinnids were identified, comprising assemblages ranging in density to over 18x106 tintinnids m-3. Previously published accounts of the feeding rates and behavior of tintinnids were then applied to this tintinnid assemblage in order to estimate their impact on the flow of carbon through the planktonic food web. Generally, for both surveys, less than 4% of the daily primary production was consumed by the observed tintinnid stocks, although at 14 stations calculated ingestion by tintinnids exceeded 10% and at 4 stations it exceeded 20% of the measured daily primary production. Other ciliates in the 1967 samples were, combined, approximately as abundant as the tintinnids; if their grazing rates were comparable, the consumption by the total ciliate assemblage would be double that of the tintinnids alone. The high tintinnid growth efficiencies previously observed (Heinbokel, 1978a) and the relatively high efficiency with which tintinnids can be grazed by larger consumers suggest that relatively little of the energy and material fixed by the nanno-phytoplankton may be lost to the larger consumers by the insertion of a ciliate “extra link” into the food chain.

Further studies on tintinnids (Protozoa: ciliata)

Summary The occurrence of 14 more interesting tintinnid species from Porto Novo (Coromandel coast, Bay of Bengal) is reported. Amongst them, 6 species (Tintinnopsis butchlii Daday , Coxliella annulata Daday , C. ampla Jorgensem , Metacylis jorgensenii Kofoid and Campbell , Favella brevis Kofoid and Campbell , Tintinnopsis uruguayensis Balech , plus the new species Dictyocysta seshaiyai are known for the first time from India. Further the presence of at least 4 species unknown for the Indian ocean so far (T. lohmani Laackmann , T. bermudensis Brandt , Helicostomella longa Brandt, T. uruguayensis Balech ) and the temperate water species T. beroidea Stein are reported. The significance of their occurrence is discussed.

Studies on the functional role of tintinnids in the Southern California Bight. I. Grazing and growth rates in laboratory cultures

Five species of tintinnids, Amphorella quadrilineata (Claparede and Lachmann, 1858), Tintinnopsis cf. beroidea Stein (1867), T. cf. acuminata Daday (1887), Eutintinnus pectinis (Kofoid and Campbell, 1929), and Helicostomella subulata (Ehrenberg, 1833), were isolated from Southern California coastal waters and maintained in laboratory cultures which were used to investigate, several aspects of the feeding dynamics and population growth rates of this group of planktonic ciliates. Data are most complete for the latter three species. Both E. pectinis and H. subulata displayed ingestion and growth rates which increased with increasing food concentration until a maximum rate was obtained which then remained essentially constant as food levels increased further. Maximum hourly ingestion was equivalent to approximately 10 to 20% of the body weight of the tintinnids. T. cf. acuminata showed no such maximum ingestion rate, as ingestion rates increased throughout the entire range of food concentrations used. The dependence of growth rate of T. cf. acuminata on food concentration also differed from the other species, being characterized by a broad region of maximum growth at intermediate food levels with reduced growth at both lower and higher food concentrations. Maximum observed growth rates represented doubling times of approximately 12 h for both E. pectinis and T. cf. acuminata and 24 h for H. subulata. The data suggested gross growth efficiencies exceeding 50% over much of the range of food concentrations used. No strong evidence supporting the existence of feeding thresholds or “switching” behavior was collected during these experiments, although apparently selective feeding was observed in one experiment with E. pectinis.

Microplankton of the Gulf of Elat: Aspects of seasonal and bathymetric distribution

The components of 4 major groups of microplankton were identified and their numerical abundance determined in net samples collected at depth intervals down to 600 m at a permanent station off the H. Steinitz Marine Biological Laboratory, Elat. The samples analyzed were collected once a fortnight over a period of 1 year beginning in June 1974. The groups studied were the Cyanophyta, Bacillariophyta and Pyrrhophyta of the phytoplankton and the Tintinnina of the microzooplankton. The pattern of vertical distribution of the phytoplankton as a whole showed a general decrease in cell numbers with increasing depth. The blue-green algae, consisting mainly of Trichodesmium sp. trichomes, were confined primarily to the upper 100 m. The diatoms were unevenly distributed, with one species, a minute centric diatom, Thalassiosira subtilis, associated with a massive bloom during March 1975 between 300 and 400 m. The peridinians, the group with the largest number of species, included forms which were evenly distributed throughout the whole water column and forms limited either to the upper or deeper water strata in accordance with their light intensity preferences. The mass occurrence of newly-emerged dinoflagellate cysts of Pyrophacus horologicum, a weakly-armoured dinoflagellate, in the 200 to 300 m depth interval during April 1975, suggests that reproductive processes in dinoflagellates may also be light-controlled. The tintinnids, like the phytoplankton groups, were most abundant in the upper 100 m with a gradual decrease in numbers of individuals, though not in species, in the deeper water strata. The overall yearly pattern of microplankton distribution indicates 3 peaks: late fall and early summer peaks consisting primarily of blue-green algae and one in early spring consisting of several species of diatoms and peridinians and of species of tintinnids which thrive in the same niches as the phytoplankton. Both phytoplankton and tintinnid production was lowest during the summer months.