calcified segments (intergenicula). Many articulated and
upright crustose corallines can also form extensive twodimensional adherent crusts, allowing them to spread laterally, thereby providing those species with multiple
“bet-hedging” ecological survival strategies (called
heterotrichy; Littler and Kauker, 1984). The upright portions receive relatively more light and nutrients, and are
faster growing with increased fertility; whereas, horizontal
crusts are more resistant to physical forces such as grazing,
wave shearing, and sand scouring, while allowing the
plants to invade horizontal primary space.
Crustose (nongeniculate) corallines range in thickness
from a few micrometers to many centimeters (Figures 2
and 3). The thinner forms are faster-growing early colonizers and occur on all hard substrates and other marine
organisms. Crustose corallines span a spectrum of
morphotypes from thin sheet-like crusts to thick slowgrowing massive pavements to upright branched and
columnar coral-like heads that contribute to both cementation and bulk. On oceanic reefs, the highest part of the reef
is often a massive “algal ridge” of crustose corallines in the
reef’s breaker zone (Dawson, 1961) – see below. Thalli of
thicker forms often consist of three recognizable layers: an
attached lower hypothallus, a middle perithallus, and an
upper epithallus. Trichocytes (hair cells, megacells) occur
as horizontal plates within the epithallus layer in some
genera such as Porolithon. The meristematic (growing)
region is usually located as a layer beneath the uppermost
intercalary perithallus cells, a feature which is unusual in
the Rhodophyta, whose members (except also for
Delesseriaceae) typically show strictly apical cell growth.
Because of the upright branched head formers (Figure 3),
some specialists prefer the term nongeniculate over crustose; however, all have extensive crustose bases and
whether branched or simple they are still elaborations of
crusts.
Rhodoliths
In the absence of hard substrates, many nongeniculate species can propagate as free-living rhodolith nodules colonizing sedimentary seafloors (Figure 4). Some of the
attached crustose corallines break free and then continue
spherical growth as they are tumbled by wave action and
bioturbation to ultimately cover vast areas as free-living
rhodoliths (= nodules, rhodolites, maërl, red algal balls,
algaliths). Rhodolith beds have been found throughout
Algae, Coralline, Table 1 Classification (families, subfamilies,
genera, and authors) of the Order Corallinales (modified from
AlgaeBase.org, 2009)
Sporolithaceae (each cruciate tetrasporangium borne in a single
sorus)
Sporolithoideae
Sporolithon Heydrich
Heydrichia Townsend, Y.M. Chamberlain & Keats
Corallinaceae (multiple zonate tetrasporangia borne in unplugged
uniporate conceptacles)
Fosliella M.A. Howe
Goniolithon Foslie
Heteroderma Foslie
Litholepis Foslie
Porolithon Foslie
Pseudolithophyllum Lemoine
Lithophylloideae
Ezo Adey, Masaki, & Akioka
Lithophyllum Philippi
Paulsilvella Woelkerling, Sartoni, & Boddi
Tenarea Bory de Saint-Vincent
Titanoderma Nägeli
Mastophoroideae
Hydrolithon (Foslie) Foslie
Lesueuria Woelkerling & Ducker
Lithoporella (Foslie) Foslie
Mastophora Decaisne
Metamastophora Setchell
Neogoniolithon Setchell & Mason
Pneophyllum Kützing
Spongites Kützing
Amphiroideae
Amphiroa J.V. Lamouroux
Lithothrix J.E. Gray
Corallinoideae
Alatocladia (Yendo) Johansen
Arthrocardia Decaisne
Bossiella P.C. Silva
Calliarthron Manza
Chiharea Johansen
Cheilosporum (Decaisne) Zanardini
Corallina Linnaeus
Dermatolithon Foslie
Haliptilon (Decaisne) Lindley
Jania J.V. Lamouroux
Marginisporum (Yendo) Ganesan
Pachyarthron Manza
Rhizolamiella Scheveiko
Serraticardia (Yendo) P.C. Silva
Yamadaea Segawa
Metagoniolithoideae
Metagoniolithon Weber-van Bosse
Hapalidiaceae (multiple zonate tetrasporangia borne in plugged
multiporate conceptacles)
Austrolithoideae
Austrolithon A.S. Harvey & Woelkerling
Boreolithon A.S. Harvey & Woelkerling
Epulo R.A. Townsend & Huisman
Choreonematoidea
Choreonema F. Schmitz
Melobesioideae
Clathromorphum Foslie
Exilicrusta Y.M. Chamberlain
Kvaleya W.H. Adey & Sperapani
Algae, Coralline, Table 1 (Continued)
Leptophytum W.H. Adey
Lithothamnion Heydrich
Mastophoropsis Woelkerling
Melobesia J.V. Lamouroux
Mesophyllum Lemoine
Phymatolithon Foslie
Synarthrophyton Townsend
ALGAE, CORALLINE
21
upright crustose corallines can also form extensive twodimensional adherent crusts, allowing them to spread laterally, thereby providing those species with multiple
“bet-hedging” ecological survival strategies (called
heterotrichy; Littler and Kauker, 1984). The upright portions receive relatively more light and nutrients, and are
faster growing with increased fertility; whereas, horizontal
crusts are more resistant to physical forces such as grazing,
wave shearing, and sand scouring, while allowing the
plants to invade horizontal primary space.
Crustose (nongeniculate) corallines range in thickness
from a few micrometers to many centimeters (Figures 2
and 3). The thinner forms are faster-growing early colonizers and occur on all hard substrates and other marine
organisms. Crustose corallines span a spectrum of
morphotypes from thin sheet-like crusts to thick slowgrowing massive pavements to upright branched and
columnar coral-like heads that contribute to both cementation and bulk. On oceanic reefs, the highest part of the reef
is often a massive “algal ridge” of crustose corallines in the
reef’s breaker zone (Dawson, 1961) – see below. Thalli of
thicker forms often consist of three recognizable layers: an
attached lower hypothallus, a middle perithallus, and an
upper epithallus. Trichocytes (hair cells, megacells) occur
as horizontal plates within the epithallus layer in some
genera such as Porolithon. The meristematic (growing)
region is usually located as a layer beneath the uppermost
intercalary perithallus cells, a feature which is unusual in
the Rhodophyta, whose members (except also for
Delesseriaceae) typically show strictly apical cell growth.
Because of the upright branched head formers (Figure 3),
some specialists prefer the term nongeniculate over crustose; however, all have extensive crustose bases and
whether branched or simple they are still elaborations of
crusts.
Rhodoliths
In the absence of hard substrates, many nongeniculate species can propagate as free-living rhodolith nodules colonizing sedimentary seafloors (Figure 4). Some of the
attached crustose corallines break free and then continue
spherical growth as they are tumbled by wave action and
bioturbation to ultimately cover vast areas as free-living
rhodoliths (= nodules, rhodolites, maërl, red algal balls,
algaliths). Rhodolith beds have been found throughout
Algae, Coralline, Table 1 Classification (families, subfamilies,
genera, and authors) of the Order Corallinales (modified from
AlgaeBase.org, 2009)
Sporolithaceae (each cruciate tetrasporangium borne in a single
sorus)
Sporolithoideae
Sporolithon Heydrich
Heydrichia Townsend, Y.M. Chamberlain & Keats
Corallinaceae (multiple zonate tetrasporangia borne in unplugged
uniporate conceptacles)
Fosliella M.A. Howe
Goniolithon Foslie
Heteroderma Foslie
Litholepis Foslie
Porolithon Foslie
Pseudolithophyllum Lemoine
Lithophylloideae
Ezo Adey, Masaki, & Akioka
Lithophyllum Philippi
Paulsilvella Woelkerling, Sartoni, & Boddi
Tenarea Bory de Saint-Vincent
Titanoderma Nägeli
Mastophoroideae
Hydrolithon (Foslie) Foslie
Lesueuria Woelkerling & Ducker
Lithoporella (Foslie) Foslie
Mastophora Decaisne
Metamastophora Setchell
Neogoniolithon Setchell & Mason
Pneophyllum Kützing
Spongites Kützing
Amphiroideae
Amphiroa J.V. Lamouroux
Lithothrix J.E. Gray
Corallinoideae
Alatocladia (Yendo) Johansen
Arthrocardia Decaisne
Bossiella P.C. Silva
Calliarthron Manza
Chiharea Johansen
Cheilosporum (Decaisne) Zanardini
Corallina Linnaeus
Dermatolithon Foslie
Haliptilon (Decaisne) Lindley
Jania J.V. Lamouroux
Marginisporum (Yendo) Ganesan
Pachyarthron Manza
Rhizolamiella Scheveiko
Serraticardia (Yendo) P.C. Silva
Yamadaea Segawa
Metagoniolithoideae
Metagoniolithon Weber-van Bosse
Hapalidiaceae (multiple zonate tetrasporangia borne in plugged
multiporate conceptacles)
Austrolithoideae
Austrolithon A.S. Harvey & Woelkerling
Boreolithon A.S. Harvey & Woelkerling
Epulo R.A. Townsend & Huisman
Choreonematoidea
Choreonema F. Schmitz
Melobesioideae
Clathromorphum Foslie
Exilicrusta Y.M. Chamberlain
Kvaleya W.H. Adey & Sperapani
Algae, Coralline, Table 1 (Continued)
Leptophytum W.H. Adey
Lithothamnion Heydrich
Mastophoropsis Woelkerling
Melobesia J.V. Lamouroux
Mesophyllum Lemoine
Phymatolithon Foslie
Synarthrophyton Townsend
ALGAE, CORALLINE
21