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Plastogamy in Foraminifera: Glabratella ornatissima (Cushman)
Author(s) -
LIPPS JERE H.,
ERSKIAN MALCOLM G.
Publication year - 1969
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1969.tb02292.x
Subject(s) - foraminifera , zygote , brood , gamete , biology , membrane , microbiology and biotechnology , embryo , anatomy , zoology , human fertilization , ecology , biochemistry , embryogenesis , benthic zone
SYNOPSIS. The foraminiferan Glabratella ornatissima (Cushman) undergoes plastogamy during reproduction. In this process, 2 (or rarely more) individuals join together by their apertural sides to mutually exchange gametes. The apertural sides and internal septa are dissolved, forming a single large brood chamber. After the zygotes grow to a 2‐ or 3‐chambered stage, the young foraminifera are liberated from the enclosing parent tests. Scanning electron micrographs and histochemically stained thin sections indicate that the reproductively mature individuals are firmly united by an organic membrane during plastogamy. This membrane is monolamellar, less than 1 μ thick and has minute lumps on its surface. Biochemically it contains a nonsulfated acid mucopolysaccharide, which is unlike the membranes associated with CaCO 3 deposition lining the interior of foraminiferal tests. The young foraminifera liberate themselves by secretion of an enzyme which degrades the membrane. The mechanism of plastogamy is interpreted to be an adaptation to life in turbulent waters that would decrease the chance of gamete union or zygote survival were the gametes released and fertilized freely.