Taxonomic Reassessment of the Genus Padina (Dictyotales, Phaeophyta) from the Gulf of California

Riosmena-Rodriguez, Rafael,Paul-Chavez, Litzia,Hernandez-Carmona, Gustavo,Lopez-Vivas, Juan Manuel,Casas-Valdez, Margarita The Korean Society of Phycology 2009 ALGAE Vol.24 No.4

A monographic reassessment of Padina Adanson species from the Gulf of California was developed based on an exhaustive review of the character and characters states that have been used to delimit species in recent and historically valuable collections. Eight names (P. caulescens Thivy in Taylor, P. concrescens Thivy in Taylor, P. crispata Thivy in Taylor, P. durvillaei Bory Saint-Vincent, P. gymnospora [Kutzing] Sonder, P. mexicana Dawson, P. tetrastromatica Hauck and P. vickersiae Hoyt in Howe) were reported from the region. An analysis of 1,200 specimens led to the conclusion that only three species (P. durvillaei, P. concrescens and P. mexicana) can be recognized for the area based on four discriminating characters: presence of calcium carbonate in the cell wall; number of medullary cell layers in the basal area; number of medullary cell layers in the middle part and presence/absence of cortical cells. Comparative analysis of the species in the Gulf of California in relation to other recently evaluated species has shown a clear distinction among them suggesting Padina species were overestimated in our area.

Population Structure of Codium amplivesiculatum (Chlorophyta) Associated with Rhodolith Beds from the Southwestern Gulf of California

Riosmena-Rodriguez, Rafael,Holguin-Acosta, Elena The Korean Society of Phycology 2008 ALGAE Vol.23 No.2

Populations of Codium amplivesiculatum were found in association with rhodolith beds. We present population trends of C. amplivesiculatum from surveys conducted in the southwestern Gulf of California based on monthly sampling from June 1999 to August 2000. Surveys were conducted at 2 sites in the San Lorenzo Channel at depths of 8 - 12 m. The parameters measured were percent cover, biomass and structure in relation to size of the thalli. From each thallus the following measurements were taken: length and diameter, proportion of each thallus with reproductive structures and the degree of fragmentation (measured as number of small thalli). Mean biomass and cover varied seasonally with the maximum (1036.6 gm$^{-2}$ and 100% cover) present in June 2000 and the minimum in winter (0 gm$^{-2}$ and 0% cover). The longest fronds (3 m) occurred during July 1999 and August 2000, while the maximum diameters of 1.0 cm were present during October and November 1999. There were no significant linear relationships between length and diameter of the fronds, suggesting independent growth. Reproductive structures were common in June and July 1999 with monoic and dioic thalli present. Most fronds were monoic, and this is the first record of this feature for this species. Fragmentation occurred in September, and may be associated with stress from early gametangial reproduction and the combination of high temperatures and low nutrients. A hypothetical life cycle for the species is presented.

Population Structure and Reproduction of Padina concrescens Thivy(Dictyotales: Phaeophyta) in Southwest Baja California Peninsula, Mexico

Rafael, Riosmena-Rodriguez,Consuelo, Ortuno-Aginrre The Korean Society of Phycology 2009 ALGAE Vol.24 No.1

The brown algae padina concrescens is widely distributed in the northwestern Pacific Mexico. We described the population of P. concrescens based on population parameters such as cover, density and size structure and reproduc-tion at two levels tide at the intertidal area in the southwestern Baja. California Peninsula. Monthly visits from January to December 2003 were done. Both cover and density were measured in situ by quadrants method. Samples were collected to obtain size structure and percentage of reproductive fronds. Our results show there is sparial vari-ation in the population structure more than temporal. Thus, cover and density peak were at different months ineach tide level studied, the lower tide level shows the high values in cover as well as density. The frond develop-ment was observed in height/width ratio this relation was consistent only in the low tidal zone. Size class distribu-tion has consistently small size plants in both tide levels.Reproduction was seasonal in the tide channel but in both tide levels all the reproductive plants were tetrasporophyte. Our results suggest that this population is pseudopere-nial and it strongly as a consequence of the intense competition in the intertidal zone.

Taxonomic Reassessment of the Genus Padina (Dictyotales, Phaeophyta) from the Gulf of California

Rafael Riosmena-Rodriguez,Litzia Paul-Chavez,Gustavo Hernández-Carmona,Juan Manuel López-Vivas,Margarita Casas-Valdez 한국조류학회I 2009 ALGAE Vol.24 No.4

A monographic reassessment of Padina Adanson species from the Gulf of California was developed based on an exhaustive review of the character and characters states that have been used to delimit species in recent and historically valuable collections. Eight names (P. caulescens Thivy in Taylor, P. concrescens Thivy in Taylor, P. crispata Thivy in Taylor, P. durvillaei Bory Saint-Vincent, P. gymnospora [Kützing] Sonder, P. mexicana Dawson, P. tetrastromatica Hauck and P. vickersiae Hoyt in Howe) were reported from the region. An analysis of 1,200 specimens led to the conclusion that only three species (P. durvillaei, P. concrescens and P. mexicana) can be recognized for the area based on four discriminating characters: presence of calcium carbonate in the cell wall; number of medullary cell layers in the basal area; number of medullary cell layers in the middle part and presence/absence of cortical cells. Comparative analysis of the species in the Gulf of California in relation to other recently evaluated species has shown a clear distinction among them suggesting Padina species were overestimated in our area.

Lithothamnion steneckii sp. nov. and Pneophyllum conicum: new coralline red algae (Corallinales, Rhodophyta) for coral reefs of Brazil

Mariath, Rodrigo,Riosmena-Rodriguez, Rafael,Figueiredo, Marcia The Korean Society of Phycology 2012 ALGAE Vol.27 No.4

Nongeniculate coralline red algae are a common element of the Brazilian coastal zone, especially associated to coral reefs. During the course of ecological studies at Parque Municipal Marinho do Recife de Fora, two species of non-geniculate Corallinales were the major organisms covering the reef. Analyses of the vegetative and reproductive features of the species were analyzed; indicating that one new species of the genus Lithothamnion is proposed here based on the combination of several features associated with anatomy of the tetrasporangial conceptacles in relation to other species of the genus for which modern accounts are available. This new proposal along with other new species, new combinations and range extension of some species of the genus based in similar features clearly suggest that stability in species delimitation is possible. The second species found Pneophyllum conicum represents a range extension of more than 6,000 km from the Pacific in to the Atlantic Ocean suggesting that some nongeniculate species are widely distributed. The occurrence and abundance of these species supports and emphasizes the need for an extensive taxonomic reassessment of coralline red algae in the context of Brazilian coral reef biodiversity.

Morphometrics of Scinaia latifrons (Nemaliales, Rhodophyta) in the Southwestern Gulf of California, Mexico

Leon-Cisneros, Karla,Riosmena-Rodriguez, Rafael The Korean Society of Phycology 2005 ALGAE Vol.20 No.1

Scinaia latifrons Howe occurs in rhodolith beds between 9 to 27 m depths at San Lorenzo channel, Gulf of California, Mexico. As very little was known about the morphometrics of this normally temperate species in a subtropical area, we investigated the phenological changes from December 1998 to December 1999. The gametophytic phase of the species was present from late February to late May, which represented a shorter time period to other known species in the genus. Our results suggested that two gametophytic cohorts develop over winter and early spring based on the size class structure of the frond height. Thalli became reproductively mature at a small size (1-2 cm in height) and all the plants were monoecious. Scinaia latifrons at the study location underwent allometric growth, indicated by the lack of correlation between size, width of the plants, or branching patterns.

PHYLOGENETIC RELATIONSHIPS WITHIN THE GENUS <i>HYPNEA</i> (GIGARTINALES, RHODOPHYTA), WITH A DESCRIPTION OF <i>H. CAESPITOSA</i> SP. NOV.¹

Geraldino, Paul John L.,Riosmena-Rodriguez, Rafael,Liao, Lawrence M.,Boo, and Sung Min Blackwell Publishing Ltd 2010 Journal of phycology Vol.46 No.2

<P>Species discrimination within the gigartinalean red algal genus <I>Hypnea</I> has been controversial. To help resolve the controversy and explore phylogeny within the genus, we determined <I>rbc</I>L sequences from 30 specimens of 23 species within the genus, <I>cox</I>1 from 22 specimens of 10 species, and <I>psa</I>A from 16 species. We describe <I>H. caespitosa</I> as a new species characterized by a relatively slender main axis; a pulvinate growth habit with entangled, anastomosing, and subulate uppermost branches; and unilaterally borne tetrasporangial sori. The new species occurs in the warm waters of Malaysia, the Philippines, and Singapore. The phylogenetic trees of <I>rbc</I>L, <I>psa</I>A, and <I>cox</I>1 sequences showed a distant relationship of <I>H. caespitosa</I> to <I>H. pannosa</I> J. Agardh from Baja California and the marked differentiation from other similar species. The <I>rbc</I>L + <I>psa</I>A tree supported monophyly of the genus with high bootstrap values and posterior probabilities. The analysis revealed three clades within the genus, corresponding to three sections, namely, <I>Virgatae</I>, <I>Spinuligerae</I>, and <I>Pulvinatae</I> first recognized by J. G. Agardh. Exceptions were <I>H. japonica</I> T. Tanaka in <I>Pulvinatae</I> and <I>H. spinella</I> (C. Agardh) Kütz. in <I>Spinuligerae.</I></P>

Vegetative and reproductive anatomy of Sargassum lapazeanum (Fucales: Sargassaseae) in the south-western Gulf of California, Mexico

Sorcia, Gabriela Andrade,Rodriguez, Rafael Riosmena The Korean Society of Phycology 2011 ALGAE Vol.26 No.4

An analysis of the vegetative and reproductive anatomy of Sargassum lapazeanum was performed based on extensive sampling in three areas within its geographical range: a) San Juan de la Costa, b) Punta Calera, c) Punta Machos. Material was collected from low intertidal to subtidal populations and evaluated based on variations present within and between populations. Our goal was to comprehensively analyze the features of the vegetative and reproductive anatomy of this species. Our observations showed that this species has cauline, which is anatomically composed of three tissues layers. This species is dioic, with male and female conceptacles in the same receptacle but with different maturation times. The present study confirmed the presence of cauline in this species; this structure was previously described for some species in the Gulf of California, such as Sargassum horridum, and for several species in Japan. This structure could be responsible for the growth of primary branches and may also generate a new plant. This trend might explain the perennial nature of this species at the population level. Field and laboratory experiments could help to delimit the ecophysiological conditions under which this structure starts to develop.

Colpomenia wynnei sp. nov. (Scytosiphonaceae, Phaeophyceae): a new species of marine algae from Northeast Asia

Lee, K.M.,Riosmena-Rodriguez, R.,Kogame, K.,Boo, S.M. BLACKWELL SCIENTIFIC PUBLICATIONS 2014 Phycologia Vol.53 No.5

Morphological reassessment and molecular assessment of Sargassum (Fucales: Phaeophyceae) species from the Gulf of California, Mexico

ANDRADE-SORCIA, GABRIELA,RIOSMENA-RODRIGUEZ, RAFAEL,MUÑ,IZ-SALAZAR, RAQUEL,LÓ,PEZ-VIVAS, JUAN MANUEL,BOO, GA HUN,LEE, KYUNG MIN,BOO, SUNG MIN Magnolia Press 2014 Phytotaxa Vol.183 No.4

<P>Systematic molecular studies have not been performed on ecologically important brown algae (Sargassum) in the Gulf of California, Mexico, where 42 specific and infraspecific names have been recorded within this genus. We conducted phylogenetic analyses of nuclear ribosomal ITS and mitochondrial cox1 and cox3 sequences, along with detailed morphological observations of Sargassum collected in the Gulf of California. We confirmed the presence of six species, five previously described-S. herporhizum, S. horridum, S. johnstonii, S. lapazeanum, and S. sinicola, as well as the newly described Sargassum ulixei sp. nov. which is characterized by terete primary axes arising from the stipe, lanceolate to elliptical sessile ecostate blades with smooth margins, cryptostomata, ellipsoidal vesicles with a short mucron, and cylindrical to ellipsoidal receptacles. The individual analyses and subsequent phylogenetic analysis recognized two groups previously described by Dawson, one as Sargassum and other as Horridum. Our studies suggest that the Gulf of California is a region with endemic Sargassum species, and is clearly distinguished from the Pacific side of Baja California, where recently introduced species are common. Based on phylogenetic relationships, we propose two geographical origins for the Sargassum from the Gulf of California: a first group originating from the proto-Gulf, related to species from the northern hemisphere (including five species); and a second group, containing S. sinicola, introduced when the southern end opened at a later stage. </P>