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Species Description:
The genus Bostrychia is a
widespread Rhodophycean species, found from tropical to cool-temperate areas,
but is most often associated with mangroves (Smith and Norris 1988). Eight
species are known in the tropical and subtropical western Atlantic. Branches are
bilateral and feathery in appearance, with curled tips. Lower branches have very
few branchlets (Littler and Littler 1989). The color of B. montagnei is
generally a dark purple to blackish that, when dry, becomes a pale yellow color.
This species grows to 8 cm, but is generally shorter. It is usually found
growing in tufts on the prop roots of mangroves in the sheltered upper
intertidal zone, although it occasionally is found on rocks, pilings, and
seawalls.
The taxonomy of the genus Bostrychia is
based almost solely on vegetative, rather than reproductive structures. This is
primarily due to the fact that it is somewhat rare to collect male or female
gametophytes in nature. However, reproductive structures are important taxonomic
traits within this genus and can be used to assess the relationships between
members of the genus. An examination of these structures is given in Smith and
Norris (1988a; 1988b), who used the structural simplicity of reproductive
tissues in this genus to support the idea that Bostrychia is indeed one
of the more primitive genera in the Rhodomelaceae.
II. HABITAT AND
DISTRIBUTION
Regional Occurrence:
B. montagnei is widely
distributed throughout the tropics and subtropics, and is typically found in
Florida, the Caribbean and along the west coast of Africa. It has limited
distribution in cool-temperate zones. IRL Distribution:
In the Indian River Lagoon, B. montagnei
occurs almost solely on the prop roots of the red mangrove, Rhizophora mangle.
It has also been collected from the Florida Keys and along the east coast of
central Florida.
III. LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan:
Generally grows to less than 8 cm. Abundance:
B. montagnei is considered to
be relatively abundant in Florida, though not always seen year-round. In the
Indian River Lagoon, it is most prevalent in late summer and fall. Reproduction:
Development of the cystocarp, a female
reproductive structure which releases meiotic spores, appears to be
developmentally regulated such that only a single cystocarp will mature per
branch, despite the fact that as many as 20 procarps (precursors to the
cystocarp) may initially be present (Smith and Norris 1988). Male thalli of this
species produce spermatangia continuously over a fertile branch.
IV. PHYSICAL TOLERANCES
V. COMMUNITY ECOLOGY
Trophic Mode:
Autotrophic Competitors:
B. montagnei is likely to
compete with other epiphytic species which colonize mangrove prop roots. Habitat:
Most commonly found in the sheltered upper intertidal zone, though it can
also utilize higher energy habitats. Associated Species:
In the Indian River Lagoon, B. montagnei is generally found growing
on the prop roots of the red mangrove, Rhizophora mangle. VI. SPECIAL STATUS Special Status:
None Economic Importance:
None
Report by: K. Hill,
Smithsonian Marine Station
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irl_webmaster@si.edu
Page last updated: July 25, 2001
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