Caption: Golden riffleshell "glochidia
", or tiny immature young, reveal themselves with the aid of a microscope.
Studies of a suitable fish plasma for in vitro culture of glochidia
Hyriopsis myersiana (Lea, 1856).
Transportation of glochidia
by a host fish enables them to reach the upper regions of a river or stream, and an even wider distribution may occur if birds or other animals feed on the host fish.
A museum voucher of this species from the Calamus Reservoir in the Loup Basin probably represents a recent colonization via glochidia
Although the underlying basis for host specificity and host resistance to glochidia
are largely unknown, local tissue reactions of the host are likely important in mediating these responses (Arey, 1921; Meyers and Millemann, 1977; Fustish and Millemann, 1978; Meyers et al., 1980; Rogers-Lowery and Dimock, 2006).
Each female will produce around three million glochidia
each year but even in ideal conditions only 0.01% will survive.
The odds against any one individual glochidium surviving are extremely large--thousands or millions of glochidia
may be produced, but the vast majority never encounter a fish.
Rhizosperma is characterized by the presence of papillae all over the vegetative body, the presence of nine megaspore floats, and the presence of simple glochidia
; whereas sect.
In our samples, all individuals with a marsupium also carried glochidia
Freshwater mussels (Unionidiae or unionids) are dependent on a host fish for dispersal during an early parasitic life stage known as a glochidia
. Most unionid species are dioecious and can exhibit sexual dimorphism in which females often develop a large mantle tissue flap to attract a host fish.
The 24-h CF LC50 estimates for glochidia
of multiple species vary widely, ranging from 113 to 3,257 mg/L (Bringolf et al.
Descriptions of some of the glochidia
of the Unionidae (Mollusca: Bivalvia).