Biology and reproductive processes of the larger foraminiferan Cycloclypeus carpenteri (Protozoa, Nummulitidae)

Krüger, Ralph; Röttger, R.; Lietz, Ruth; Hoheneggerz, Johann

doi:10.1016/s0003-9365(97)80057-7

Cited by 26 publications

(19 citation statements)

References 19 publications

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“…The spreading of reticulopodia from the main part of cytoplasm comprises the main mechanism with which foraminifera interact with their environment [6]. The main functions of reticulopodia include food capture [7], motility and attachment [8–9], test construction [6, 10–11], and, possibly, some aspects of reproduction [12–13]. These cellular functions of reticulopodia have been revealed mainly by using scanning and transmission electron microscopy.…”

Section: Introductionmentioning

confidence: 99%

Cytological Observations of the Large Symbiotic Foraminifer Amphisorus kudakajimensis Using Calcein Acetoxymethyl Ester

et al. 2016

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Large benthic foraminifera are unicellular calcifying reef organisms that can form symbiotic relationships with a range of different microalgae. However, the cellular functions, such as symbiosis and calcification, and other aspects of cellular physiology in large benthic foraminifera are not fully understood. Amphisorus kudakajimensis was used as a model to determine the detailed cellular characteristics of large benthic foraminifera. We used calcein acetoxymethyl ester (calcein AM) as a fluorescent indicator for live confocal imaging. We demonstrated that calcein AM is a useful fluorescent indicator to stain the fine network of reticulopodia and the cytoplasm in living A. kudakajimensis. We showed that at least two types of reticulopodia exist in A. kudakajimensis: the straight bundle of reticulopodia that spreads from the aperture and the fine reticulopodia along the surface of the aperture and chamber walls. The cytoplasm in outer chambers was highly branched and contained a few dinoflagellates. In contrast, the inner chamberlets contained condensed cytoplasm and many dinoflagellates, suggesting that the cytoplasm of A. kudakajimensis performs different functions based on its location within the large test. Our confocal detailed image analysis provides real-time cellular morphology and cell physiology of living foraminifera.

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Section: Introductionmentioning

confidence: 99%

Cytological Observations of the Large Symbiotic Foraminifer Amphisorus kudakajimensis Using Calcein Acetoxymethyl Ester

et al. 2016

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“…Because of the size‐dependent changes in velocities that are necessary for traction, these dependencies must also be fitted by non‐linear regressions. As a non‐dimensional foraminiferal test ( d = 0) cannot be entrained (velocity → ∞) and as the smallest tests consisting of two or three chambers after release from the parental test or sheet exceed 100 μ m (Röttger & Spindler, 1976; Dettmering, 1997; Krüger et al. , 1997), polynomial regressions based on the logarithm of diameters with the minimum at 0·1 mm were calculated as follows: fulfilling the conditions above.…”

Section: Methodsmentioning

confidence: 99%

Studies on settling, traction and entrainment of larger benthic foraminiferal tests: implications for accumulation in shallow marine sediments

Yordanova

Hohenegger

2007

Sedimentology

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Settling and traction velocities were measured on optimally preserved tests of larger foraminifera using a settling tube and flume tank. Within larger foraminifera with porcelaneous tests, the peneroplids, Peneroplis antillarum, P. planatus, P. pertusus and Dendritina cf. D. zhengae, are distinguished by low test densities (ca 1AE2) that do not change with growth. Buoyancy is high because of low Reynolds numbers and increases in large individuals because of the allometric change of test shape. The fusiform Alveolinella quoyi, with test densities ca 1AE6, is characterized by high Reynolds numbers, inducing the weakest buoyancy within porcelaneous larger foraminifera. The highest buoyancy was recorded for the three soritids, Parasorites orbitolitoides, Sorites orbiculus and Amphisorus hemprichii, because of their low test densities (ca 1AE25) and the extremely flat, biconcave, plate-like shape. Flat tests, however, reduce traction and entrainment from smooth surfaces. Within hyaline larger foraminiferat, the amphisteginids show thick-lenticular (Amphistegina lobifera, A. radiata) to thin-lenticular tests (A. bicirculata, A. papillosa), influencing buoyancy. Here, high test densities (ca 1AE8) decrease with growth in A. lobifera, A. lessonii and A. bicirculata, and remain constant in A. radiata and A. papillosa. Minimum velocities required for entrainment are lower for thick-lenticular tests and higher for thin-lenticular tests. Test densities remain constant with growth in the calcarinid Baculogypsina sphaerulata (q $ 1AE78) and decrease slightly in Calcarina gaudichaudii and Neorotalia calcar (starting at q $ 1AE85), all living under extreme hydrodynamic conditions. Density decreases the most in Baculogypsinoides spinosus (starting at q $ 1AE8), resulting in higher buoyancy through low Reynolds numbers. Traction is promoted in spherical tests of Baculogypsina and Baculogypsinoides.Within nummulitids, the thick-lenticular Palaeonummulites venosus (test density decreasing with size; starting at 1AE78) is less buoyant, expressed in high Reynolds numbers, but easily entrained. Thick-lenticular juveniles and extremely flat adults distinguish Operculinella cumingii, Heterostegina depressa and the giant Cycloclypeus carpenteri. Test densities increase during growth, starting from ca 1AE6 and attaining a maximum of 1AE8. Buoyancy is low in small tests and high in large tests, while entrainment velocities are reduced as the tests flatten. High buoyancy is also a characteristic of the entirely flat tests in Operculina ammonoides (from deeper regions) and Planostegina operculinoides, which is expressed in the lowest Reynolds numbers within larger foraminifera.

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“…Reduced chamber volumes induced by weak disturbance (e.g., starvation) are compensated by reducing septal distances and thus retaining the spiral outline 17 . Repair mechanisms after stronger disturbance such as fractioning also help attain the ‘normal’ test form in many nummulitid foraminifera, but often via a large number of ‘deformed’ repair chambers 16,51 .…”

Section: Discussionmentioning

confidence: 99%

Lunar cycles and rainy seasons drive growth and reproduction in nummulitid foraminifera, important producers of carbonate buildups

Hohenegger

Kinoshita

Briguglio

et al. 2019

Sci Rep

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Representatives of the foraminifer Nummulites are important in Earth history for timing Cenozoic shallow-water carbonates. Taphonomic complexity explains the construction of carbonate buildups, but reproduction and life span of the constructing individuals are unknown. During the 15-month investigation period, asexually reproduced schizonts and gamonts showed equal proportions in the first half of this period, whereas gamonts predominated in the second half. Oscillations in cell growth are mainly caused by light intensities during chamber construction when minor differences in water depth increase the photosynthetic rate of endosymbiotic diatoms during neap tides. The continuous reproduction rate of N . venosus throughout the year is increased in subtropical calms by higher summer temperatures and the marginal input of inorganic nutrients during rainy seasons. The expected life span of both gamonts and schizonts are 18 months.

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Biology and reproductive processes of the larger foraminiferan Cycloclypeus carpenteri (Protozoa, Nummulitidae)

Cited by 26 publications

References 19 publications

Cytological Observations of the Large Symbiotic Foraminifer Amphisorus kudakajimensis Using Calcein Acetoxymethyl Ester

Cytological Observations of the Large Symbiotic Foraminifer Amphisorus kudakajimensis Using Calcein Acetoxymethyl Ester

Studies on settling, traction and entrainment of larger benthic foraminiferal tests: implications for accumulation in shallow marine sediments

Lunar cycles and rainy seasons drive growth and reproduction in nummulitid foraminifera, important producers of carbonate buildups

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