Marine algal flora of French Polynesia III. Rhodophyta, with additions to the Phaeophyceae and

217 Pages·2008·14.08 MB·English

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Cryptogamie,Bryologie,2010,31(1):3-205
©2010Adac.Tousdroitsréservés
Marine algal flora of French Polynesia III. Rhodophyta,
with additions to the Phaeophyceae and Chlorophyta
AntoineD.R.N’Yeurta*&ClaudeE.Payria,b
aUMR7138,Systématique,Adaptation,Evolution,EquipeBiodiversitéMarine
Tropicale,IRD-Nouméa-BPA5,98848Nouméacedex,NewCaledonia
bLaboratoireTerre-Océan,UniversitédelaPolynésiefrançaise,B.P.6570Faa’a
98702,Tahiti,FrenchPolynesia
(Received8October2009,Accepted23December2009)
Abstract—ThisthirdpaperinamonographicseriesonthemarinemacroalgaeofFrench
PolynesiagivesadetailedcoverageofthespeciesofRhodophytaoccurringintheseislands.
Atotalof197taxaarepresented(195Rhodophyceae,1Phaeophyceaeand1Chlorophyta;
ofthese,84(or43%)representnewrecordsfortheflora,while7(or3.6%)arenewspecies.
The new combination Jania subulata (J. Ellis et Solander) N’Yeurt et Payri is made for
Haliptilon subulatum (J. Ellis et Solander) W. H. Johansen. Padina stipitata Tanaka et
Nozawa (Phaeophyceae) and Codium saccatum Okamura (Chlorophyceae) are notable
additionstotheflorafromdeepwaterhabitatsinthesouthernAustrals;56taxa(or28.7%)
occuronlyintheAustralarchipelago.TheflorahasmostaffinitieswiththatoftheHawaiian
Islands(SørensenIndex=0.30),followedbytheCookIslandsandSamoa(SI=0.26each)
and the Solomon Islands (SI = 0.25). There are some disjunct distribution patterns for
severalsubtropicaltotemperatespecies,possiblysuggestingspecialoceaniccurrentroutes
betweenthesouthernAustrals,HawaiiandtheSouthernAustralianregion.
algae / biogeography / distribution / floristics / French Polynesia / Rhodophyceae / new
records/taxonomy
Résumé — Ce troisième volet d’une étude sur la flore marine de la Polynésie française
donneunedistributiondétailléedesespècesdeRhodophycéesquisontprésentesdansces
îles. Un total de 197 taxons sont présentés (195 Rhodophycées, 1 Phaeophycée et
1Chlorophycée), dont 84 (soit 43 %) sont nouveaux pour la flore, et 7 (soit 3,6 %)
représentent des nouvelles espèces. La nouvelle combinaison Jania subulata (J. Ellis et
Solander) N’Yeurtet Payri est faite pourHaliptilon subulatum(J. Elliset Solander) W.H.
Johansen. Padina stipitata Tanaka et Nozawa (Phaeophyceae) et Codium saccatum
Okamura (Chlorophyta) sont nouveaux pour la flore, provenant d’habitats profonds dans
les îles les plus sud des Australes; 56 taxons (ou 28,7 %) ont été trouvés seulement dans
l’archipel des Australes. La flore a le plus d’affinités avec l’archipel Hawaiien (Index de
Sørensen de 0,30), suivi par les îles Cook et Samoa (SI = 0,26 chaque) puis par les îles
Salomon(SI=0,25).Unerépartitiondisjointepourunnombred’espècessous-tropicalesà
tempérées suggèrerai un lien particulier par les courants océaniques entre l’archipel des
Australesdusud,l’archipelHawaiienetlarégionsud-australienne.
algae / biogéographie / distribution / floristique / Polynésie Française / Rhodophyceae /
nouveauxreports/taxonomie
* Correspondenceandreprints:[email protected]
Communicatingeditor:FrederikLeliaert
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INTRODUCTION
ThisstudygivesadetailedoverviewofthemarinespeciesofRhodophyta
(along with two new records of Phaeophyceae and Chlorophyta) occurring in
French Polynesia, and supplements and revises the taxa previously reported by
Setchell, (1926), Payri & Meinesz (1985a, b), Payri & N’Yeurt (1997), Payri et al.
(2000) and Conte & Payri (2002, 2006). The Phaeophyceae and Chlorophyta of
French Polynesia, as well as the history of early phycological collecting in these
islands,weretreatedinPayri&N’Yeurt(1997)andN’Yeurt&Payri(2006,2007).
MATERIALSANDMETHODS
All material was collected using SCUBA, dredging, snorkelling or reef-
walking. Herbarium specimens were pressed using standard techniques, and
representative parts of thalli and turf algae stored in 4% buffered formalin in
sealed plastic bags packed in a light-proof container for shipment and later
anatomical examination in the laboratory. Herbarium specimens were
photographed using a bench-mounted digital camera (NIKON Coolpix 995).
Photomicrographs were obtained using OLYMPUS C-4040Z or C-5050Z digital
cameras fitted on an OLYMPUS BH2 microscope. Voucher specimens are
housed at the Phycological Herbarium of the Université de la Polynésie française
in Tahiti (UPF), with ‘S’ referring to slide collections, and can also be viewed
online at the following Internet address: http://biodiv.upf.pf/base (link at times
subject to outages). ‘IFR’ refers to holdings in the herbarium of the French
Institute of Research on Coral Reef Environment (IFRECOR) in Bora Bora,
French Polynesia (curated by Mr. Denis Schneider). Where necessary, available
FrenchPolynesianherbariumrecordsinUPFhavebeenre-verifiedinthelightof
newtaxonomicinformation,andsomebyWilliamSetchellandH.E.Parksaswell
as other early collections in BM (British Museum, London), PC (Museum
National d’Histoire Naturelle, Paris), SAP (Hokkaido University, Sapporo) and
UC(UniversityofCalifornia,Berkeley)examinedeitheronsiteoronloanbythe
first author. Unfortunately, some voucher specimens of species from Moorea
listed in Payri (1987), which contain some taxa not held at UPF, could not be
located and are presumed lost. Consequently, only those records which could be
confirmed on the basis of existing collections, either in UPF or elsewhere, have
been included in this study. Recent new records from a deepwater survey by the
authors of the island of Moorea in the context of a genetic barcoding program by
the University of California Gump Research Station, have been included in this
publication. The taxonomy generally follows that of Silva et al., (1987; 1996),
Reviers(2003),andisupdatedwithothersourceswherenecessaryasstatedinthe
text.Foreachtaxon,basionymandtypelocalityinformationisprovided,followed
byrelevantsynonymsandbibliographicreferences(mostlyrestrictedtothosethat
are regional, tropical or contain pertinent diagnostic figures). Asterisks (*)
indicate new records for French Polynesia.
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MarinealgalfloraofFrenchPolynesiaIII.Rhodophyta, 5
withadditionstothePhaeophyceaeandChlorophyta
RESULTSANDOBSERVATIONS
Key to the genera of French Polynesian Rhodophyta
1a. Thallus internally calcified, even lightly so (bubbles when tested with weak
acid) .............................................................2
1b. Thallustotallyuncalcified ..........................................19
2a. Thallussegmented ...............................................3
2b. Thallusunsegmented.............................................8
3a. Thalluscalcifiedatsegmentjoints ..........................Tricleocarpa
3b. Thallusuncalcifiedatsegmentjoints ..................................4
4a. Axescompressedtoflattened;segmentswithupward-curvinglobes .....5
4b. Axestereteorcompressed;segmentsnotcurvingupward..............7
5a. Thallusdichotomouslybranched,axesflattened,1-6mmwide .. Jania(inpart)
5b. Thalluspinnatelybranched,axescompressed,0.3-1mmwide.............6
6a. Intergenicula 0.3-0.5 mm wide, main axes percurrent, less than 9 tiered
medullarycellsperintergenicula ....................... Jania(inpart)
6b. Intergenicula 0.5-1 mm wide, main axes not percurrent, more than 10
tieredmedullarycellsperintergenicula.......................Corallina
7a. Axes usually terete, less than 150µm in diameter; conceptacles located at
nodesjustbelowdichotomies ............................ Jania(inpart)
7b. Axes compressed to terete, more than 500µm in diameter; conceptacles
scatteredoninternodesurface ...............................Amphiroa
8a. Thallusflabellate,withskin-liketexture...................Titanophora
8b. Thallusnotasabove..............................................9
9a. Thalluswithringsofverticillatehairsaroundbranches........ Actinotrichia
9b. Thalluswithoutverticillateringsofhairsaroundbranches. ..............10
10a. Tipsofultimatebranchesuncalcified...............................13
10b. Thalluscalcifiedthroughout,includingtips .........................11
11a. Thallusstone-likeorcrustose ...................... Corallinales(inpart)
11b. Thallusnotstone-likeorcrustose....................................12
12a. Axesrigid,sometimesvillous,to3mmwide ........................18
12b. Axessoftandgelatinous,glabrous,to10mmwide............ Renouxia
13a. Cortical cells distinctly inflated or club-shaped; carpogonial branch straight,
3-celled,calcificationannulate ............................. Yamadaella
13b. Cortical cells not distinctly inflated or clavate; carpogonial branch curved,
3-6-celled,calcificationsmoothorpowdery,notannulate................14
14a. Calcification clearly restricted to axial core, surrounded by mucus;
spermatangiainwhorlsonsubapicalcells,neverterminal;sterilefilaments
issued from base of carpogonial branch making dense, non-involucral
clustersbelowcystocarp ................................ Trichogloea
14b. Calcification diffuse, not restricted to axial core or covered by mucus;
spermatangia usually terminal, not in subapical whorls; sterile filaments
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from carpogonium either absent or making long involucres around
cystocarp...................................................... 15
15a. Medullaryfilamentslessthan30µmindiameter,carpogonialbrancheslateral
on subterminal cortical cells; cystocarps with long involucres of sterile
filamentsissuedfromcarpogonialbranch;spermatangiasingle,inclustersor
innon-dendroidpairs ............................................. 16
15b. Medullary filaments more than 40µm in diameter; carpogonial branches on
filaments at base of cortical fascicles; cystocarps lacking long involucres of
sterilefilaments;spermatangiaindenseelongate-ovoidheads....Ganonema
16a. Axeslackingshortlateralbranchlets;outercorticalfilamentsunbranched;
gonimoblastobconical;spermatangiaindenseclusters......Titanophycus
16b. Axes with or without short lateral branchlets; outer cortical filaments
profusely branched; gonimoblast spherical; spermatangia on outermost
corticalfilaments.......................................... Liagora
17a. Thalluscrustose,withmoreorlesspronouncedhypobasalcalcification.....
....................................................... Peyssonnelia
17b. Thallusnotcrustoseandlackinganyhypobasalcalcification ............ 18
18a. Tetrasporangiaterminalonelongatefilaments;pericarpabsent...Galaxaura
18b. Tetrasporangialateralorterminalonstalkcells;pericarppersistent .....
.................................................... Dichotomaria
19a. Thallusconsistingofasinglerowofcells. ............................ 20
19b. Thallusconsistingofmorethanonerowofcells. ...................... 23
20a. Thalluslessthan5mmhigh,ofsubquadratecells ................... 22
20b. Thallusmorethan5mmhigh,cellsnotsubquadrate................. 21
21a. Cellssubcylindrical .......................................Anotrichum
21b. Cellsoval ................................................ Griffithsia
22a. Thalluslessthan500µmhigh,entirelyuniseriate,unbranched ..........
.................................................... Erythrotrichia
22b. Thallus1-5mmhigh,multiseriateinolderparts,irregularlybranched
....................................................... Stylonema
23a. Innerstructurefilamentousorsemi-filamentous...................... 25
23b. Innerstructurecellular,orcellularwithsparsehyphae................. 24
24a. Thallushollow,vesicle-likeorseptatewithregulardiaphragms. ....... 36
24b. Thallussolidthroughout ........................................ 41
25a. Axeslessthan2mmindiameter,growinginestuariesandrivermouths .. 26
25b. Axesover4mmindiameter,notgrowinginestuariesandrivermouths .. 27
26a. Filamentsconfinedtocenterofaxis;branchingregularlydichotomouswith
unconstrictedbranchbase;tetrasporangiazonatelydivided....Sarconema
26b. Filaments not confined to center of axis; branching irregular with
constrictionsatbaseofbranches;tetrasporangiacruciatelydivided ......
......................................................Grateloupia
27a. Thallusformingclumpsofcrisp,roundedrosettes10-15mmwide..........
....................................................... Cryptonemia
27b. Thallusnotinclumpsorformingrosettes ............................ 28
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28a. Thallusprocumbent,withmultipleattachmentpoints .......Meristotheca
28b. Thalluserect,withasinglebasalholdfast...........................29
29a. Thallusterete.....................................................35
29b. Thallusstrap-shaped,blade-likeorglobose ...........................30
30a. Thallusblade-like...............................................31
30b. Thallusstrap-shapedorglobose,notformingblades .................32
31a. Atleastsomeanticlinal(cortextocortex)filamentspresent ..... Halymenia
31b. Anticlinalfilamentsabsent;thallususuallyperforate ...........Kallymenia
32a. Axesstrap-shaped,complanate,3-4mmwide,withroundedapices. ......
.....................................................Corynocystis
32b. Thallusglobose,notcomplanate ..................................33
33a. Holdfastdiscoidorcartilaginous;tetrasporangiacruciate,lateralonterminal
cellsofcorticalfilaments ...................................Gibsmithia
33a. Holdfastnevercartilaginous ........................................34
34a. Corticalcellsrectilinear;sphericalnutritivecellspresentbelowcystocarp .
.........................................................Predaea
34b. Corticalcellsovoid;nutritivecellsabsentbelowcystocarps...... Platoma
35a. Main axis percurrent; higher-order branches spindle-shaped; cells of
carpogonial branch subrectangular, without a thick mucilaginous coating;
carposporangialmassfullyencirclingauxiliary-cellfilament ... Peleophycus
35b. Main axis not percurrent; higher-order branches not spindle-shaped; cells of
carpogonial branch sub-moniliform with a thick mucilaginous coating;
carposporangialmassincompletelyencirclingauxiliary-cellfilament........
........................................................ Dudresnaya
36a. Thallus regularly segmented; diaphragms present; cells barrel-shaped,
irregularlybranchedandfree...............................Champia
36b. Thallus not regularly segmented; diaphragms absent; cells vesicle-like;
simplesaccateordichotomouslybranchedandlaterallyfused .........37
37a. Thallusdifferentiatedintoacreepingstolon,stipeandovoidvesicles .......
........................................................Botryocladia
37b. Thallusnotdifferentiatedintoacreepingstolon,stipeandvesicles .......38
38a. Thallusovoid,consistingoffreeorfusedvesicles ....................40
38b. Thallusterete,consistingofwiryorarcuateaxes. ....................39
39a. Thalluslessthan5mmhigh,creeping;branchesarcuateandpinkish........
.........................................................Lomentaria
39b. Thallusto40mmhigh,erect;branchesstraightandiridescentblue... Coelothrix
40a. Thallusdichotomouslybranched;vesiclesovoid,fusedlaterally. .........
................................................... Chamaebotrys
40b. Thallussaccate,simpletofurcate,spindle-shaped,notfusedlaterally.....
.................................................... Gloiosaccion
41a. Ultimatebranchesflattenedorleaf-like ..............................42
41b. Ultimatebranchesnotflattenedorleaf-like...........................53
42a. Thallus forming rosettes, differentiated into a rigid naked stem and leaf-
likeultimatebranchletswithamidribandinrolledtips .........Amansia
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42b. Thallus not forming rosettes or differentiated into a rigid stem and leaf-
likeultimatebranchletswithinrolledtips .......................... 43
43a. Thallusconsistingoffelt-likelobesandanetworkoffilaments ..Haloplegma
43b. Thallusnotfelt-likeorcomposedofanetworkoffilaments............. 44
44a. Thallusstrap-shapedorcompressed............................... 48
44b. Thallusfolioseorblade-like ..................................... 45
45a. Thallusprocumbentanddorsiventral,withacentralkeel-likeregion.......
...................................................Dasya palmatifida
45b. Thallusnotasabove .............................................. 46
46a. Thallusiridescent,flabelliformandanastomosing,withacentralstipe.. 47
46b. Thallus not iridescent, flabelliform or anastomosing; stipe basal or
marginal ...................................................... 49
47a. Thallusfoliose;tetrasporangiaterminal,carpogonialbranch3-celled.......
.........................................................Halichrysis
47b. Thalluspeltate;tetrasporangiaintercalary;carpogonialbranch4-celled.....
................................................Asteromenia (inpart)
48a. Thallusstrap-like;axes1-2mmwide;medullarycells60-150µmwide ....
..............................................Asteromenia (inpart)
48b. Thalluscompressed;axesto150µmwide;medullarycells10-18µmwide .
.....................................................Caulacanthus
49a. Thallusdelicateandthin,membranous(atleastinpart)................ 50
49b. Thallus thick and blade-like and/or subdichotomously branched, cells
rounded................................................ Rhodymenia
50a. Midribpresent;pluristromaticandbranchedatthemidrib.. Hypoglossum
50b. Midribabsent.................................................. 51
51a. Thallusmonostromaticthroughout;ofunbranchedlobes...... Nitophyllum
51b. Thalluspluristromatic. ............................................ 52
52a. Branchingirregularlyalternatefrommargins;tetrasporangiainsori .....
....................................................Myriogramme
52a. Branching pinnate to subdichotomous; tetrasporangia in whorls on side
branchlets....................................Acanthophorapacifica
53a. Thallusplumose,withapinkishnakedcreepingstolonanderectaxes ......
.......................................................Asparagopsis
53b. Thallusnotplumose .............................................. 54
54a. Thallusterete(includingturf-likeminuteforms).................... 56
54b. Thalluscompressedtoflattened,notturf-like ...................... 55
55a. Thallus erect and lubricous, alternately branched; tetrasporangia zonate, in
elongatestichidia;noparticularlypungentodourwhenfresh.... Plocamium
55b. Thallusprostrate,notlubricous;bilaterallybranched;tetrasporangiacruciate
tozonate,innemathecia;pungentodourwhenfresh..............Portieria
56a. Thallus2-20cmhigh,erectandnon-epiphytic ...................... 57
56b. Thalluslessthan2cmhigh,oftencreepingorepiphytic.............. 74
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57a. Thallus unbranched in lower portions but irregularly branched above; side
branchletsshortandtruncate,alternatelytoradiallyarranged ...........58
57b. Thallusnotasabove...............................................61
58a. Incross-section,axialcellsurroundedclearlyby5largepericentralcells ..
....................................................... Chondria
58b. Incross-section,axialcellnotclearlysurroundedby5pericentralcells. 59
59a. Axialcellwithonly2pericentralcells;axesbroadandflattened............
.....................................................Chondrophycus
59b. Axialcellwith4pericentralcells;axesteretetocompressed............ 60
60a. Apicalcellsunkeninapicalpit;centralaxisunclearexceptatapex .......
........................................................ Palisada
60b. Apicalcellnotsunkeninapicalpit;centralaxisrelativelyclear....Laurencia
61a. Thalluscomposedofwiryaxes,moreorlessrigid ......................62
61b. Thallusnotwiryorparticularlyrigid .................................64
62a. Thallus greenish-yellow, tough and wiry with oppositely-branched axes,
formingdecumbentclumpsonthereefcrest ..........Gelidiella(inpart)
62b. Thallusnotdecumbentorasabove................................63
63a. Axes400-500µmindiameter;mostlybranchedatapices,whichturnyellow. .
....................................................... Ahnfeltiopsis
63b. Axes150-300µmindiameter;unbranchedatapices,notturningyellow .....
...................................................... Wurdemannia
64a. Thallus flexible; axes terete or compressed and distally palmate;
tetrasporangiainterminalbulb-likeswellings ...............Gelidiopsis
64b. Thallusnotasabove.............................................65
65a. Thallus reddish-brown; ultimate branches strap-shaped or terete; internal
rhizinespresent;apicalcellconspicuousandexserted...................66
65b. Thalluswithoutinternalrhizinesorconspicuousapicalcell..............67
66a. Branchingalternatetoopposite;branchapextruncateorblunt ..........
....................................................Pterocladiella
66b. Branchingpinnate;branchapextaperedandfiliform,pointed ...Gelidium
67a. Thallus of sparsely and alternately branched axes issued from a creeping
base;growingasadensetuftoncoraldebris...........................68
67b. Thallusnotasabove...............................................69
68a. Axial and periaxial cells in clear transverse rows; sporangia in sparse,
regularlyarrangedrows.................................Parviphycus
68b. Axial and periaxial cells irregularly disposed; sporangia not arranged in
regularrows......................................Gelidiella(inpart)
69a. Thallus terete and brittle, uniformly covered with short knobby spine-like
branchlets..................................... Acanthophora(inpart)
69b. Thallusnotasabove...............................................70
70a. Thallusfurry,withaxescoveredwithfinefilamentoussidebranchlets...71
70b. Thallusnotfurry................................................72
71a. Filamentoussidebranchletsregularlycorticatedatthenodesonly;tetrasporangia
non-involucrateandprotrudingonsidesofbranchlets................ Spyridia
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71b. Filamentous side branchlets uncorticated; tetrasporangia involucrate and
occurringinspecializedfusiformstichidia ................. Dasya(inpart)
72a. Thallusregularlydichotomouslybranched,tree-like,withabasalstipe...
......................................................Dermonema
72b. Thallusnotasabove............................................ 73
73a. Branches terete or flattened, arcuate or straight; proliferous side branchlets
absent;tetrasporangiacruciateandscatteredinoutercortex......Gracilaria
73b. Branches terete or flattened; always arcuate; proliferous side branchlets
sometimespresent;tetrasporangiazonateandoccurringinsaddle-shapedsori
ontheundersideofbranchlets..................................Hypnea
74a. Thallus soft and rubbery, composed of compressed, elongate lobes with
short, irregularly distichous side branchlets and strap-like rhizoids issued
fromventralsurfaceofblades............................ Gloiocladia
74b. Thallusnotasabove............................................ 75
75a. Mainaxislackingpericentralcellsaroundaxialcell.................... 76
75b. Mainaxiswithfourormorepericentralcellsaroundaxialcell........... 77
76a. Erect axes sparsely branched, covered with three whorls of upwardly-
curvedsidebranchletsperaxialcell......................... Crouania
76b. Erect axes alternately to radially branched; whorls of side branchlets
absent ................................................. Seirospora
77a. Main axes partially or fully covered with small cortical cells 8-10µm in
diameter;terminalandlateraltrichoblastsneverpresent ............... 78
77b. Main axes never covered with small cortical cells; terminal and lateral
trichoblastsoftenpresent.......................................... 82
78a. Axesfullycorticated............................................ 79
78b. Axescorticatedatthenodesonly. ................................ 81
79a. Thallusminute,lessthan2mmhigh,epiphyticonlyonLobophora.........
........................................................ Phaeocolax
79bThallusmorethan3mmhigh,notepiphyticonlyonLobophora.......... 80
80a. Tipofaxespointed;nodalspinesabsent .................. Corallophila
80b. Tipofaxesclaw-likeorforcipate;nodalwhorlsofspinespresent. .......
...................................................... Centroceras
81a. Basipetalcellsdistinctlyelongate ..............................Gayliella
81a. Basipetalcellsangular,notelongate.......................... Ceramium
82a. Axeswithterminaland/orlateraltrichoblasts...................... 84
82b. Axeswithoutterminalorlateraltrichoblasts ....................... 83
83a. Thallus erect and irregularly dichotomously branched, with dichotomously
branchedsidebranchletsissuedfromeveryothersegment... Heterosiphonia
83b. Thalluscreeping,witherectunbranchedaxes...................... Ditria
84a. Thallus composed of a creeping, often incurved main axis from which are
issuedseveralerectsimplebranchlets .................. Herposiphonia
84b. Thallus mostly erect and irregularly branched, never with an incurved
mainaxis. ..................................................... 85
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85a. Rhizoids separated by a cross-wall from the supporting pericentral cells;
tetrasporangiainspiraledseries;spermatangialbrancheswithasterilelateral
........................................................Neosiphonia
85b. Rhizoids in open connection with the pericentral cells; tetrasporangia in
straightseries;spermatangialbrancheslackingasterilelateral . Polysiphonia
RHODOPHYTA R. Wettstein
StylonematalesK.M.Drew
StylonemataceaeK.M.Drew
StylonemaReinsch
The taxonomy of this and other related red algal genera was recently
revisedbySaunders&Hommersand(2004),takingintoaccountrecentmolecular
data.
*Stylonema alsidii (Zanardini) K.M. Drew, 1956: 72. Indian Ocean: Silva et al.,
1996:87;HawaiianIslands:Abbott,1999a:44,fig.1B-C;Oman:Wynne,1999:189;
Samoa:Skelton&South,2002a:137,fig.3A-B;2007:12,figs9-10;PacificIslands:
Zucarelloetal.,2008:390. (Figs1-2)
Basionym:BangiaalsidiiZanardini,1840:136(typelocality:Trieste,Italy).
Homotypicsynonym:Goniotrichumalsidii(Zanardini)M.Howe1914:75.Tristan
da Cunha: Baardseth, 1942: 33, fig. 13A-B; Venezuela: Díaz-Piferrer, 1970: 170,
fig.22.
Materialexamined:Rapa,Australs,10Oct.2000,leg.V.Clouard,UPF3253RPS57.
Thallus to 5 mm high and 12-15µm in diameter, filamentous and basally
uniseriate, with some older parts multiseriate. Branching simple or irregular.
Remarks: Epiphytic on Fernandosiphonia sp.; to date in French Polynesia only
reported from a single collection from the island of Rapa, southern Australs.
RecentphylogeneticstudiesbyZucarelloetal.(2008)haveshownS.alsidiitobea
trulyubiquitousspecies.
Erythropeltidales Garbary et al.
ErythrotrichiaceaeG.M.Smith
ErythrotrichiaAreschoug
*Erythrotrichia carnea (Dillwyn) J. Agardh, 1883: 15. Indian Ocean: Silva et al.,
1996: 88; Rotuma Island: N’Yeurt, 1996: 406, figs 109, 118; Hawaiian Islands:
Abbott, 1999a: 45, fig. 1E; Fiji: N’Yeurt, 2001: 746, fig. 106; Samoa: Skelton &
South,2007:11,fig.8. (Figs3-4)
Basionym: Conferva carnea Dillwyn, 1807: pl. 84 (type locality: Glamorgan,
Wales).
Material examined: Taapuna, Tahiti, 15 Sep. 1995, leg. A. D. R. N’Yeurt, UPF 438 S52;
Rapa,Australs,4Nov.2002,leg.C.E.Payri,UPF3421RPS203.
Thallus entirely uniseriate, to 500µm long and 10-25µm in diameter,
composed of cells isodiametric to cylindrical at the base, gradually becoming
longerandbroaderupwards.Attachedtothesubstratumbyacharacteristiclobed
extension of the basal cell.
Remarks: Epiphytic on Padina (lagoon, Tahiti) or on Sargassum (rocky shelves,
Rapa). This species can be differentiated from Stylonema alsidii by its entirely
uniseriatethallusattachedviaalobedextensionofthebasalcell.
N_YEURT.fm Page12 Mercredi,3.février2010 5:0517
12A. D.R.N’Yeurt&C.E.Payri
Figs 1-6. 1. Stylonema alsidii: habit of irregularly branched thallus (UPF 3253). Scale = 15µm.
2.Stylonema alsidii: detail of cells of filament (UPF 3253). Scale = 15µm. 3. Erythrotrichia
carnea:habit(UPF3421). Scale=20µm.4.Erythrotrichiacarnea:detailofrectangularcellsof
upper thallus (UPF 3421). Scale = 15µm. 5. Acrochaetium barbadense: habit, showing adaxial
monosporangia (arrow) (UPF 3425). Scale = 70µm. 6. Acrochaetium microscopicum: habit on
Polysiphoniahost(UPF3424).Scale=25µm.