Check-list of the Basque coast benthic algae ( North of Spain ) por

An annotated check-list of the marine benthic flora of the Spanish Basque coast, based on literature records and original data, is presented. According to the present taxonomy, the known list of algae totals 372 taxa (354 species and 18 infraspecific taxa), distributed as follows: 23 Cyanophyta, 221 Rhodophyta, 74 Heterokontophyta and 54 Chlorophyta. In addition, 16 taxa are considered as taxa inquirenda and 8 as taxa excludenda. For each taxon the vertical distribution, abundance estimation, and two first published records are given. Remarks on the most noteworthy features of the flora of the study area are included. The floristic character of Spanish Basque coast flora was compared with nearby regions applying Cheney’s ratio [(Rhodophyta+Chlorophyta)/Phaeophyta, or (R+C)/P]. The resulting high value (4,09) indicates its warm-water character, which was already noted at the end of the XIX century. From a physionomical point of view, Basque benthic vegetation resembles more closely that of southern regions (S Portugal, Morocco). The warming process of waters off the Basque coast during summer up to 22 oC is responsible for the absence or very rare occurrence of cold temperate species like large fucoids and kelps, which are common in Galicia and Brittany, and explains the abundance of numerous warm-temperate species as ceramiaceous algae.

The aim of the present work is to compile for the first time the marine algal flora (Cyanophyta, Rhodophyta, Heterokontophyta and Chlorophyta) of the Spanish Basque coast.For this purpose a critical review of all published records has been carried out and we have supplemented this information with 37 new records of our collections.This check-list contributes to increasing the understanding of the biogeographical characteristics of this Atlantic area and the knowledge about its biodiversity.

Material and Methods
The Spanish Basque coast is located in the northern part of the Iberian Peninsula, on the south-eastern corner of the Bay of Biscay (Fig. 1).It is mostly rocky with an exposed to very exposed shore and very few estuaries, all of them small.Following the coastline and including the estuaries, it extends over 300 km from Cape Higer (43º23'46''N; 1º47'24''W) in the East to Kobaron Point (43º21'01" N; 3º09'58" W) in the West.In political terms it comprises the Spanish provinces of Gipuzkoa and Bizkaia.The sea surface temperature ranges from 11 ºC to 22 ºC in February and August, respectively (Ibáñez, 1990;Borja & al., 2000).Biogeographically, it belongs to the warm temperate NE Atlantic sub-region (Hoek & Breeman, 1990).
The list of marine benthic algae (Cyanophyta, Rhodophyta, Heterokontophyta and Chlorophyta) was compiled after a careful review of all published records and supplemented by our own collections.Unpublished works such as M. Phil.Thesis, Ph.D. Doctoral Thesis and Technical Reports have not been considered.The data presented here date from Montagne (1842) to Díez & al. (2003).First and second records are given for each taxon.
The present taxonomic status and nomenclatural changes of the taxa concerned have been considered.The check-list includes the synonyms under which a specific or infraspecific taxon has been recorded.Records that need to be confirmed are included in a separate list as taxa inquirenda.Likewise, a list of taxa excludenda is also given with pertinent comments and references.Specimens of most of the species included in this check-list are deposited in the herbaria of the Basque Country University (BIO), the University of Barcelona (BCF) and the University of Santiago de Compostela (SANT).Information about the abundance estimation and vertical distribution of each species is given together with an indication of the provinces (Gipuzkoa and Bizkaia) from which they have been reported.

Results and Discussion
The known list of benthic marine algae from the Spanish Basque coast now totals 372 taxa (354 species and 18 infraspecific taxa): 23 Cyanophyta, 221 Rhodophyta, 74 Heterokontophyta and 54 Chlorophyta (Table 1).In addition, 16 taxa are considered as taxa inquirenda and 8 as taxa excludenda.
This flora includes several warm-temperate species which reach their northern limit of distribution in this area.Most of these species are rare or very rare on the Basque coast such as Bryopsis pennata, Pedobesia simplex, Hydroclathrus clathratus, Sargassum vulgare, Ceramium tenerrimum, Chrysymenia ventricosa, Haliptilon virgatum and Pleonosporium caribaeum.However, within this group there are frequently found species such as Colpomenia sinuosa, Spatoglossum solieri, Dasya rigidula and Peyssonnelia squamaria and seasonally abundant species such as Centroceras clavulatum and Hypnea musciformis.
The presence of Colpomenia sinuosa, Hydroclathrus clathratus, Sargassum vulgare, Spatoglossum solieri, Centroceras clavulatum and Halopithys incurva establishes interesting floristic differences with respect to the Northwest coast of Iberian Peninsula, where these species are absent.Likewise, among the benthic marine flora from the Basque coast should be emphasize the presence of an endemism, Fucus chalonii.There are only two known populations of this dwarf species of Fucus located at Andagorria inlet (French Basque coast) and at Ogeia inlet (Spanish Basque coast).
According to the literature consulted, the Cheney's ratio for the Basque coast (4.09) is high compared with nearby regions (Table 2), indicating its warm-water character and, after data compiled by Álvarez & al. (1988), significantly greater than for the Atlantic Iberian Peninsula considered as a whole (3.10).From a physionomical viewpoint, Basque benthic vegetation more closely resembles that of southern regions, due to the absence or very rare occurrence of large fucoids and kelps (in the intertidal and subtidal zones, respectively) and the presence of Gelidium corneum and Cystoseira baccata stands in the subtidal zone.
The present composition of seaweed floras at a worldwide scale is explained on the basis of species' temperature responses (in some cases in combination with photoperiod responses), and taking into account paleoclimatological aspects and the displacement of coastlines in geological periods (Athanasiadis, 1990;Hoek & al., 1990).The flora of the north coast of Spain falls within the warm temperate NE Atlantic subregion according to the phytogeographical scheme proposed by Hoek & Breeman (1990).However, on this coast, of similar latitude throughout, there are significant floristic differences between the western and eastern coasts, with the Basque coast flora showing fewer cold-temperate species and more Mediterranean species than that of Galicia.This 'southern character'of Basque coast flora may be explained by the fact that the surface water of this part of the Bay of Biscay is warmed in summer up to 22°C (August isotherm) in contrast to Galicia which only reaches 19°C.In addition, some areas of the northwest coast of Spain are affected by episodic upwelling events during summer.The warming process of waters off the Basque coast is the result of the entrainment of water masses in the southern corner of the Bay of Biscay due to the abatement of the winds and sea current regimes during summer (Borja & al., 1996).
Bornet (1892: footnote to pp. [167][168], who was apparently unfamiliar with the flora of Galicia, thought that the flora of Biarritz (French Basque coast) extended without much change along the coast of Spain, Portugal, and Morocco.Sauvageau (1897), after seeing specimens of cold-water Fucales collected by Durieu de Maisonneuve at Gijón (Asturias) in 1835, doubted about Bornet's conclusion and, to settle the matter, collected along the north coast of Spain as far west as A Coruña (Galicia).He concluded that the flora of the Basque coast was an interruption of the flora that was common to Brittany and Galicia.Similarly, Feldmann & Lami (1941) pointed out the southern character of the Basque coast, describing it as "une enclave très remarquable d'une végétation à nombreux élément subtropicaux au sein de la région boréale tempérée".On the basis of data gathered from literature and supplemented by personal observations, Hoek & Donze (1966, 1967) concluded that "floristically and as regards temperature-range of the surface-water, the Côte Basque finds its logical place in between Morocco and NW.Spain."Likewise, the same authors pointed out that the physionomical resemblance between the algal flora of the Basque coast and that of Morocco explains the stress placed by phycologists on the southern character of the algal flora of the Basque coast.Subsequently, Álvarez Cobelas & al. (1989), studing floristic data of Iberian Peninsula, found a great similarity between Gipuzkoa and the South of Portugal.As other works before, the results from our check-list emphasises the meridional character of this Atlantic coast.Anagnostidis & Komárek (1988) to Leptolyngbya, which resulted superfluous (Hoffman & Compère, 1990), so we have decided to maintain the name used in Geitler's treatment.4. The systematic position of this taxon is uncertain and probably does not belong to the Acrochaetiaceae.According to Pueschel (1989) it probably belongs to Gigartinales. 5. Guiry (1997) recommends a revision of the generic placement of this species.6.According to Silva & al. (1996) although the identity of Gelidium corneum has been ascertained by the examination of the type specimen (Dixon, 1967), most authors in the 20 th century have unjustifiably rejected the name as being ambiguous.Likewise, Silva & al. (1996) add that G. corneum should be applied to the species currently known in Europe as G. sesquipedale.7. We follow Fredriksen & al. (1994) in considering that Gelidium pulchellum and G. pusillum represent distinct entities at the species level.8.We follow Silva & al. (1996) in their proposal of Gelidium spinosum as a new combination with Gelidium latifolium as a synonym.9. See Silva & al. (1996) for the rejection of the nomenclatural authority of Gelidium latifolium.10.Hoek & Donze (1966) reported Gelidium latifolium and G. attenuatum as distinct entities.11.We follow Santelices & Hommersand (1997) (Jaasund, 1960).Its occurrence in the Basque coast should be confirmed since there is only one report (Borja & al., 1982) (1982).Its occurrence in the Basque coast should be confirmed since it mainly has a northerly distribution and there are no voucher specimens to confirm its presence in the Basque coast.On the other hand, the status of this taxon is in some way dubious and requires further investigation (Guiry & Dhonncha, 2003).

Fig. 1 .
Fig. 1.Map showing the location of the Spanish Basque Country and the regions with which its flora is compared.

Table 1 .
Check-list of the benthic marine algae of the Spanish Basque coast.

Table 2 .
Feldmann & Feldmann, 1953)a+Chlorophyta)/Phaeophyta] for the Spanish Basque coast and nearby areas (only taxa at species level).Notes1.After several works (e.g.,Feldmann & Feldmann, 1953)which concluded that Dermocarpa P. Crouan & H. Crouan and Xenococcus Thur.were indistinguishable, Komárek & Anagnostidis (1986) adopted Xenococcus, and subsequently the family Xenococcaceae Ercegovi ć as the names that have priority, because they considered the type species Dermocarpa violacea P. Crouan & H. Crouan to be taxonomically doubtful.However, Silva & al. (1996) pointed out that presently Dermocarpaceae and Dermocarpa are the correct names because no formal proposals have been submitted to reject them.2. This species was assigned by Anagnostidis & Komárek (1988) to genus Leptolyngbya.Hoffman & Compère (1990) pointed out that the name Leptolyngbya Anagnostidis & Komárek was initially superfluous since the genus to which it applied included Spirocoleus lagerheimii Möbius, the type of Spirocoleus.After that, Silva & al. (1996) assigned it to the genus Spirocoleus.3.This species was assigned by Hoek (1963))posal of Pterocladiella as a new genus.12.According toCremades & al. (1997a), most reports of Amphiroa rigida and Amphiroa beauvoisii J.V. Lamour.fromEuropeanAtlanticcoastshouldbereferred to A.van-bosseae.13.This species has been reported under the misapplied ephitet 'tortuosa', either as Tenarea tortuosa or as Lithophyllum tortuosum.According to Woelkerling (1988) the correct name for this alga is Lithophyllum byssoides.species,varietyorform.However, on the Basque coast there is a variety of F. spiralis of a reduced size with a morphology and habitat which does not fall under the description given for F. spiralis var.limitaneus.Seoane-Camba (1975) described this reduced variety of F. spiralis as "Type C", one of the four morphological types that he recognized at Cape Higer.Its thallus is 6 cm long, has long cylindrical receptacles without a sterile edge, and lives in the upper eulittoral level of very exposed wave areas.Further investigations are needed to determine the taxonomic status of this variety.52.The taxonomy of this green algae group originally assigned to the Chaetophoraceae is in a changeable state.We follow Silva & al. (1996), who adopted an arbitrary compromise with references to alternative opinions.53.Contrary to Gayral (1965), Golden & Garbary (1984) consider Ulvaria as a subgenus of Monostroma.In the check-list of the Mediterranean Chlorophyceae, Gallardo & al. (1993) retain Ulvaria as a genus, considering Monostroma oxyspermum as a synonym of U. oxysperma (Kütz.)Bliding.54.Recent works (Tan & al., 1999; Hayden & al., 2003) have provided evidences that Ulva and Enteromorpha are not distinct evolutionary entities, with Ulva being the oldest name.55.Bae & Lee (2001) have recently proposed Umbraulva as a new genus to which Ulva olivascens was assigned.56.In contrast to Burrows (1991) who considers that Chaetomorpha aerea is conspecific with C. linum, we followBlair (1983)in considering these species to be distinct.57.We followGallardo & al. (1993), who consider Chaetomorpha mediterranea a separate taxonomic identity from Rhizoclonium tortuosum, in contrast toSilva & al. (1996).58.This species includes Cladophora pseudopellucida(Hoek 1979).59.Hoek (1963)previously recorded this species floating on saltmarsh pools near Hondarribia (Gipuzkoa).60.We followSilva & al. (1996)in considering Rhizoclonium riparium and R. tortuosum as distinct species.Gallardo & al. (1993) however, consider them as synonyms.61.See Gallardo & al. (1993) in relation to the proposal of this new name for Bryopsis cupressoides Kütz.sensu J. Feldmann and B. cupressoides J.V. Lamour.sensu Kütz.62. Records of the gametophytic stage, known as Halicystis parvula Schmitz ex Murray, are included.Gorostiaga & Díez (1996) firstly reported this stage from the Basque coast.63.Pedobesia simplex is a new name for P. lamourouxii Wynne & Leliaert (2001).Polysiphonia foetidissima Cocks ex Bornet.-Thisspecies was reported only by Gorostiaga & Díez (1996), but there are no voucher specimens to confirm its presence in the Basque coast.Polysiphonia lanosa (L.) Tandy.-Angulo(1980) and Ibáñez & al. (1980) reported this species as Vertebrata lanosa (L.) T.A. Christensen from only one locality, and associated to Ascophyllum nodosum.Recent surveys in this locality have not confirmed the occurrence of P. lanosa.Rhodymenia coespitosella L'Hardy-Halos.-Gorostiaga & al. (1987) and Gorostiaga & Díez (1996) reported this taxon from the Basque coast, but its occurrence needs to be confirmed.After studying the R. coespitosella specimens kept at BIO, we conclude that all specimens should be referred to R. holmesii.Phaeophyceae Cystoseira barbata (Stackh.)C. Agardh.-Nofurther information was given for this Mediterranean taxon after Lázaro Ibiza (1893).Cystoseira foeniculacea (L.) Grev.-Colmeiro (1867) cited this species as C. abrotanifolia (L.) C. Agardh; no further information was given for this taxon.Cystoseira platyclada Sauv.-This taxon was reported by Casares (1989) and Casares & Seoane-Camba (1989).However, according to the morphology and habitat described by Casares (1987), we consider that is should be better referred to C. usneoides.Dictyota implexa J.V. Lamour.-Nofurther information was given for this meridional taxon after Colmeiro (1867).Probably, he referred to D. dichotoma var.implexa (Desf.)Gray, a taxonomic synonym of D. dichotoma var.intrincata.Elachista scutulata (Sm.)Duby.-Theonly record by Casares & Seoane-Camba (1989) corresponds to drift material.Isthmoplea sphaerophora (Carmichael) Kjellm.-Thetaxonomical position of Isthmoplea sphaerophora is unclear 15 Crouan & H. Crouan has not been reported.15.Silva & al. (1996)pointed out that the epithet commemorates Teede (the collector) and 'teedii' is corrected to 'teedei' in accordance with Rec.60C.1(a) and Art.60.11.16.This taxon includes the tetrasporophytic stage, Petrocelis cruenta J. Agardh for which the first record was given by Bárbara & al. (1995).Despite its late discovery, both stages are frequent in the Basque coast. of Agardh.-Thiscold-water taxon has been reported by Angulo (1980), Ibáñez & al. (1980) and Gorostiaga (1981), but no voucher specimens could be found until now.After studying the material kept at BIO, we conclude that all the specimens identified as G. patens are Ahnfeltiopsis devoniensis, thus the and no voucher specimens could be found.Sargassum acinarium (L.) Setch.-LázaroIbiza (1893) reported this meridional taxon as Sargassum linifolium C. Agardh.No further information was given.Chlorophyceae Codium effusum (Raf.)Delle Chiaje.-Fischer-Piette(1963) reported this taxon as C. difforme Kütz.; this species has a meridional distribution and no further information has been given for it, therefore its occurrence in the Basque coast should be confirmed.Urospora bangioides (Harv.)Holmes et Batters.-Thistaxon has been only reported by Fernández & al.