ULTRASTRUCTURE OF A NEW INTRACELLULAR SYMBIOTIC ALGA FOUND WITHIN PLANKTONIC FORAMINIFERA 1

ABSTRACT A small intracellular eukaryotic algal symbiont, 1.5–3.5 μm in diameter, occurs abundantly and persistently in nine planktonic Foraminifera host species. This alga is different from the dinoflagellate, from 8–12 μm in diameter, known to occur in the four spinose species Orbulina universa, G...

Full description

Bibliographic Details
Published in:Journal of Phycology
Main Author: Gastrich, Mary Downes
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1987
Subjects:
Online Access:http://dx.doi.org/10.1111/j.1529-8817.1987.tb04215.x
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1529-8817.1987.tb04215.x
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1529-8817.1987.tb04215.x
Description
Summary:ABSTRACT A small intracellular eukaryotic algal symbiont, 1.5–3.5 μm in diameter, occurs abundantly and persistently in nine planktonic Foraminifera host species. This alga is different from the dinoflagellate, from 8–12 μm in diameter, known to occur in the four spinose species Orbulina universa, Globigerinoides sacculifer, G. ruber, and G. conglobatus. Transmission and epifluorescent microscopy were used to confirm the presence cophyta. The evidence supporting this classification includes the presence of a chloroplastic endoplasmic reticulum surrounding the plastids and tubular cristae, as opposed to flattened cristae, in the mitochondria. Three classes of algae may be represented including the Chrysophyceae, Bacillariophyceae, and Prymnesiophyceae. Ultrastructural analysis indicated that the alga in the spinose Globigerinella aequilateralis resembles a prymnesiophyte because the chloroplasts lack a girdle lamella. The algae in the non‐spinose species and the short‐spined Globigerina cristata resemble endocytic chrysophytes or diatoms because of the presence of a girdle lamella. Ultrastructural characteristics of the chrysophycophycean alga present in planktonic Foraminifera are discussed and compared to those of non‐dinoflagellate symbiotic algae associated with other invertebrate hosts.