Algal-foraminiferal symbiosis in the planktonic foraminifer Globigerinella aequilateralia; I, Occurrence and stability of two mutually exclusive chrysophyte endosymbionts and their ultrastructure

Faber, Walter W.; Anderson, O. Roger; Lindsey, J. L.; Caron, David A.

doi:10.2113/gsjfr.18.4.334

Cited by 67 publications

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“…8A,B,D,E). Thus, we do not consider Parker's two morphogroups of G. siphonifera as having the same biological meaning as the Type I and II forms recognized by Faber et al (1988Faber et al ( , 1989. It is likely that Parker's Group I and n forms are ecophenotypes since she found latitudinal differences in their distribution.…”

Section: ^Lmentioning

confidence: 93%

“…These observations were based on study of Recent samples from tropical Pacific cores rather than on living specimens. On the other hand, Faber et al (1988Faber et al ( , 1989 could easily identify the Type I and II morphologies among living SCUBAcoUected specimens, but could not detect differences between the shells after the Type I and II specimens had died. Our observations suggest that while Type I shells tend to attain a larger size, the only feature that can be consistently used for light-microscopic discrimination of Type I from Tj^e II forms is shell pore size, whereby adult chambers of Type I forms have much larger pore diameters than do the adult chambers of Type II ( Fig.…”

Section: ^Lmentioning

confidence: 98%

“…We focus on this species because previous studies have demonstrated distinct biological differences between two living forms (identified as Type I and Type II), but no consistent differences between their empty shells (Faber et al 1988(Faber et al , 1989. Our principal goals are to (1) discuss the biological evidence for distinguishing G. siphonifera Types I and II as distinct species, on the basis of observations of living specimens and results from laboratory culture, pigment analysis, stable isotopic analysis, and DNA sequencing; (2) qualitatively compare the progressive changes in Type I and II shell morphology at different ontogenetic growth stages; (3) describe the metrics used to characterize the empty shell morphologies of Types I and II; and (4) discuss speciation mechanisms that may have led to cladogenesis in G. siphonifera.…”

Section: Introductionmentioning

confidence: 99%

“…Nor can we ascertain whether the intracellular differences between the Type I and II symbionts observed by Faber et al (1988) result from growth of genetically identical symbiont cells in genetically different hosts, or if the symbionts themselves are in fact genetically different. DNA sequencing of the Type I and 11 symbionts (K. Darling et alunpublished) should help to clarify this uncertainty.…”

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confidence: 99%

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Cryptic speciation in the living planktonic foraminiferGlobigerinella siphonifera(d'Orbigny)

1997

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Abstract.-Two living forms of Globigerinella siphonifera (d'Orbigny), presently identified as Type I and Type II, can easily be distinguished and collected by SCUBA divers because of differences in appearance, arrangement of the rhizopodial network, and the presence or absence of commensals. Additional biological differences are apparent from laboratory culture experiments; Type I individuals survive significantly longer than Type II under conditions of darkness and starvation and have significantly slower chamber formation rates. Stable isotopic analyses of Types I and II also reveal notable differences, with Type I consistently yielding more negative S'^O and 8"C values. Results of Mg / Ca ratio analyses indicate that Type II specimens precipitated their shells in slightly cooler (deeper) surface waters than Type I specimens. These observations and results from DNA sequencing unequivocally demonstrate that G. siphonifera Types I and II should be regarded as biological sister species.Contrarily, biometric analysis of the empty shells reveals few significant differences between G. siphonifera Types I and II. Of all the features measured from X-ray and SEM images of serially dissected specimens, only shell porosity yields readily discernible differences, with Type I adult chambers averaging 10-20% porosity and Type II adult chambers averaging 4-7% porosity. Statistically significant differences between Type I and II populations are revealed in maximum test diameter (Type I is typically larger) and coiling (Type I is typically more evolute), but these differences do not justify species level distinction of Types I and II using traditional paleontological species concepts.On the basis of the above evidence, and since all specimens were collected at the same location at ~ 3-8 m water depth, we conclude that G. siphonifera Types I and II are living examples of cryptic speciation, whereby biological speciation has occurred in the absence of discernable change in shell morphology. However, it is not clear when or where this speciation took place. Preliminary study of deep-sea cores from the Caribbean and Pacific sides of the Isthmus of Panama reveals a predominance of specimens with Type II porosity values, with rare occurrence of specimens yielding Type I porosity values. Systematic downcore measurement of shell porosity and tightness of coiling needs to be extended back to the middle Miocene, when G. siphonifera first appeared, to determine the timing of the Type I and II morphological divergence.Postulated mechanisms for reproductive isolation and speciation of Types I and II include alloparapatric, depth parapatric, and sympatric speciation. These models could be tested if further analysis of fossil G. siphonifera shells allows determination of the timing of speciation, the preferred depth distribution, and the history of geographic distribution of Types I and II.

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Section: ^Lmentioning

confidence: 93%

Section: ^Lmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

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Cryptic speciation in the living planktonic foraminiferGlobigerinella siphonifera(d'Orbigny)

1997

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“…Because temperature have a similar effect among species on respiration and photosynthesis, parameters R (T 1 ), T Ap and T Ar are directly issued from Lombard et al (2009a) and are assumed to be the same for all species. Symbiont number (s nb ) for a 250 µm size for O. universa and G. siphonifera were estimated in Spero and Parker (1985) and Faber et al (1988), respectively. As O. universa, G. sacculifer and G. ruber have the same symbiont type (Hemleben et al, 1989), they are assumed to produce photosynthesis in the same way.…”

Section: Data From Culture Experiments and Growth Model Calibrationmentioning

confidence: 99%

Modelling planktic foraminifer growth and distribution using an ecophysiological multi-species approach

et al. 2011

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Abstract. We present an eco-physiological model reproducing the growth of eight foraminifer species (Neogloboquadrina pachyderma, Neogloboquadrina incompta, Neogloboquadrina dutertrei, Globigerina bulloides, Globigerinoides ruber, Globigerinoides sacculifer, Globigerinella siphonifera and Orbulina universa). By using the main physiological rates of foraminifers (nutrition, respiration, symbiotic photosynthesis), this model estimates their growth as a function of temperature, light availability, and food concentration. Model parameters are directly derived or calibrated from experimental observations and only the influence of food concentration (estimated via Chlorophyll-a concentration) was calibrated against field observations. Growth rates estimated from the model show positive correlation with observed abundance from plankton net data suggesting close coupling between individual growth and population abundance. This observation was used to directly estimate potential abundance from the model-derived growth. Using satellite data, the model simulate the dominant foraminifer species with a 70.5% efficiency when compared to a data set of 576 field observations worldwide. Using outputs of a biogeochemical model of the global ocean (PISCES) instead of satellite images as forcing variables gives also good results, but with lower efficiency (58.9%). Compared to core tops observations, the model also correctly reproduces the relative worldwide abundance and the diversity of the eight species when using either satellite data either PISCES Correspondence to: F. Lombard (lombardfa@gmail.com) results. This model allows prediction of the season and water depth at which each species has its maximum abundance potential. This offers promising perspectives for both an improved quantification of paleoceanographic reconstructions and for a better understanding of the foraminiferal role in the marine carbon cycle.

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Thirteen thousand years of southeastern Mediterranean climate variability inferred from an integrative planktic foraminiferal‐based approach

et al. 2015

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Over the past 13 ka, the hydrology for the southeastern Mediterranean was mainly regulated by Nile River runoff, which in turn was controlled by climate forcing. Being affected by orbital forcing, and the position of the Intertropical Convergence Zone (ITCZ), planktic foraminiferal data (assemblages, stable isotopes, and size properties) indicate three major periods. (1) From 13.0 to 11.5 ka, the upper water column was well-mixed, cold, and productive. (2) From 11.5 to 6.4 ka, hydrology and foraminifers were affected by intensified monsoonal circulation. The enhanced size of Globigerinoides ruber is interpreted as a response to environmental stress caused by low-saline waters. (3) After 6.4 ka, the southward retreat of the ITCZ caused a decrease in freshwater discharge and hence a return to ecological equilibrium. A drop in foraminifer diversity from 2.9 to 1.1 ka was related to more arid conditions, and limited supply of nutrients from the Nile River. We suggest a link to a negative North Atlantic Oscillation (NAO) marking the Roman Humid Period in the western Mediterranean, and in anti-phase with the southeastern Mediterranean aridity. Because Nile River runoff exerted major control on surface hydrology, a connection to Indian and Pacific climate systems partially controlling precipitation over the Nile catchment area is hypothesized. From 1.1 to 0.54 ka, high foraminifer diversity indicates humid conditions synchronous to the Medieval Climate Anomaly under a positive NAO state. Over the past 0.54 ka encompassing the Little Ice Age, another arid period is indicated by a drop in foraminifer diversity.Riverine mud belt deposits capture short-term climate variability, bearing continuous and expanded sedimentary successions and retaining both continental and marine environmental signals at high resolution through high sedimentation rates. The range of temporal variability in these archives spans from decadal to millennial scales, MOJTAHID ET AL.

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Algal-foraminiferal symbiosis in the planktonic foraminifer Globigerinella aequilateralia; I, Occurrence and stability of two mutually exclusive chrysophyte endosymbionts and their ultrastructure

Cited by 67 publications

References 0 publications

Cryptic speciation in the living planktonic foraminiferGlobigerinella siphonifera(d'Orbigny)

Cryptic speciation in the living planktonic foraminiferGlobigerinella siphonifera(d'Orbigny)

Modelling planktic foraminifer growth and distribution using an ecophysiological multi-species approach

Thirteen thousand years of southeastern Mediterranean climate variability inferred from an integrative planktic foraminiferal‐based approach

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