Morard et al 2019 S2 C319.jpg
Morard et al 2019 S2 C208.jpg
Morard et al 2019 S2 C281.jpg
Morard et al 2019 S2 C329.jpg
This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.
Morard et al 2019 S2 C319.jpg
Morard et al 2019 S2 C208.jpg
Morard et al 2019 S2 C281.jpg
Morard et al 2019 S2 C329.jpgCurrent identification/main database link: Globigerinoides ruber subsp. albus Morard et al. 2019
Original Description
Diagnosis: Differs from G. ruber ruber by the absence of reddish color of the shell, by the presence of a distinct sequence motive in the SSU rDNA gene, by its seasonality and depth habitat in the modern Atlantic and its presence in the Indopacific throughout the last 120 ka. The two subspecies cannot be distinguished prior to 750 ka due to the fading of the color with time and both are then captured as G. ruber well into the Neogene.
Description. The new subspecies largely overlaps with G. ruber ruber in test morphology, but differs in the color of the test, which develops during the neanic stage (Brummer et al 1987). The morphology of the species and its changes during the ontogeny have been described in detail by Brummer et al. (1987) and is formalized accordingly below. The holotype has been selected such that the test shows all key features of the species, but lacks color and because it yielded a SSU rDNA sequence of genetic type G. ruber albus n.subsp. Ia (Voucher C319).
Prolocular stage. Proloculus small, 12.5 ± 1.5 μm (10–16 μm), wall imperforate, smooth and non-spinose; aperture interiomarginal, circular with thickened rim, in multi-chambered tests larger than deuteroconch and truncated by flat wall shared with deuteroconch.
Juvenile stage. Starting with deuteroconch, test lobate, umbilico-convex, umbilicus open, wide, narrowing after completion of initial whorl; chambers hemispherical, 7–12 (9.3 ± 1.2) added in ± 1.5 whorls of near planispire, with 5–6 in initial whorl, totaling 8–13 (9.7 ± 1.2) chambers in tests 54–76 (65.3 ± 5.8) μm in diameter. Aperture interiomarginal-marginal, a small, low arch with marked rim. Spines sparse, thin, flexible; microspines present; pores sparse, exclusively along sutures on spiral side; wall texture spinose, non-cancellate. No preferential shell coiling direction; algal symbionts acquired.
Neanic stage. Test rapidly changing towards adult morphology, becoming sphaeroidal with umbilicus closing; chambers globose, 3–4 in half to complete whorl of low trochospire, decreasing to 3 in last whorl, totaling 12–16 (14 ± 1.3) chambers in tests 120–190 (140 ± 25) μm in diameter. Aperture widening to a wide, high arch and migrating to the umbilicus. Spines and pores becoming numerous and evenly distributed; spines becoming thicker and more rigid; spine bases, inter-spine ridges and pore pits develop; wall becoming coarsely perforate and cancellate.
Adult stage. Test sphaeroidal to elongate with reddish color, chambers globose in a lowmedium trochospire, at least 1, usually 2 to 3, up to 4 chambers are added, totaling 14–18 chambers in test >180, up to 510 μm in diameter, until reproduction (gametogenesis). Secondary aperture(s) develop. Wall texture cancellate-spinose and macroperforate. Terminal stage. Usually one, occasionally two normalform and/or diminutive (kummerform) chambers are added, rarely one or two bullate chambers capping the secondary apertures. Spines progressively shed, wall coarsely perforate, smooth to coarsely cancellate. Loss of algal symbionts, loss of buoyancy. Terminal shells 230–560 μm in diameter with 15–19 chambers in 3–4 whorls of low to medium trochospire.
Brummer, G-J, Hemleben, C & Spindler, M. (1987). Ontogeny of extant spinose planktonic foraminifera (Globigerinidae): A concept exemplified by Globigerinoides sacculifer (Brady) and G. ruber (d’Orbigny). Marine Micropaleontology. 12: 357-381. gs Morard, R. et al. (2019). Genetic and morphological divergence in the warm-water planktonic foraminifera genus Globigerinoides. PLoS One. 14(12): 1-30. gs V OReferences:
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Globigerinoides ruber albus compiled by the pforams@mikrotax project team viewed: 18-4-2021
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