Biology Reference
In-Depth Information
Fig. 12.3
(
a
)
Asparagopsis armata
on
Ulva
(photo by Stefan Kraan; (
b
) unidentified lineage of
Asparagopsis taxiformis
(photo by Mark JA Vermeij)
of
Asparagopsis
species. Although it is easy to identify the macroscopic
A. armata
gametophytes in the field, the identification of cryptic Falkenbergia isolates
and their assignment to
A. armata
populations is only feasible with molecular
tools or by inference when
Asparagopsis
gametophytes and
Falkenbergia
occur at
the same sites.
12.3.5 Case Study:
Asparagopsis Taxiformis
The warm temperate to tropical red seaweed
Asparagopsis taxiformis
(Delile)
Trevisan de Saint-L´on, 1845, (Fig.
12.3b
) consists of four genetically distinct
yet morphologically virtually identical mitochondrial lineages, detectable only by
molecular tools (the nuclear D1, D2, and D3 hyper-variable domains of the large
subunit rDNA gene, the plastid RUBISCO spacer, and the mitochondrial cox2-3
intergenic spacer). One of these, lineage two, is of Indo-Pacific origin and invaded
the Mediterranean basin from the Suez Canal (N´ Chual´in et al.
2004
; Andreakis
et al.
2004
,
2007a
,
b
). Phylogeographic patterns inferred from individuals of this
species-complex collected globally were suitable to delineate cryptic taxa, infer
lineage-specific distribution patterns, and elucidate single or multiple introduction
events worldwide. Most importantly, the phylogeographic approach was useful to
