Cytological Observations on Two Planktonic Foraminifera, Globigerina bulloides d'Orbigny, 1826, and Globigerinoides ruber (d'Orbigny, 1839) Cushman, 1927* † ‡

• Published in: The Journal of Protozoology
• Main Authors: LEE, JOHN J., FREUDENTHAL, HUGO D., KOSSOY, VICTOR, BÉ, ALLAN
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1965
• Subjects: Bouquet; North Atlantic; Planktonic foraminifera
• Online Access: http://dx.doi.org/10.1111/j.1550-7408.1965.tb03253.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1550-7408.1965.tb03253.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1550-7408.1965.tb03253.x

SYNOPSIS. Globigerina bulloides and Globigerinoides ruber , two pelagic foraminifera from the North Atlantic, were fixed in modified Zenker or Bouin solutions directly after collection and studied cytochemically. They have two unusual organelles: a vesicular system and an organelle provisionally named a “cryptosome.” The vesicular system occurs chiefly in the newest formed chambers and consists of a pair of intertwined tubules with helical fine structure which terminate in a bouquet of approximately 20 vesicles or loops. The function of this system is unknown. The detailed morphology of the vesicular system is different in each species. The cryptosome is a structure which varies greatly in its morphology. It is better developed in G. bulloides than it is in G. ruber. At times a cryptosome may occupy up to 2/3 of the protoplasm of a chamber. In Himes‐Moriber‐stained preparations crypto‐somes stain with naphthol yellow S and contain within them an azure A‐Schiff staining spongy reticulum. Both of the pelagic foraminifera studied are heterokaryotic. Agamonts of G. ruber may have a graded series of nuclear sizes but those of G. bulloides typically have a single somatic nucleus. The zooxanthellae of G. ruber are similar to Symbiodinium microadriaticum and may collectively occupy almost 4/5 the volume of a chamber.