• ALGAE
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• v.18 no.1
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• pp.59-63
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• 2003

• ALGAE
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• v.20 no.1
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• pp.31-36
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• 2005

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.

• Ocean Science Journal
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• v.41 no.3
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• pp.191-193
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• 2006

Two specimens of Lutjanus inermis, the most unusual species of the genus in the tropical eastern Pacific region, were collected at La Ventana, Baja California Sur, Mexico in November 2005, 400 km northward from the type locality. The golden snapper can be recognized by its long anal fin, and its yellowish peduncle and caudal fin that sometimes present a reddish phase. Present it record is the first documented and verified report supported by voucher specimens of L. inermis inside the Gulf of California since its original description in the last quarter of the nineteenth century, setting the northern geographic limit to the Cortes Province.

• ALGAE
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• v.37 no.3
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• pp.185-204
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• 2022

The genus Coolia A. Meunier 1919 has a global distribution and is a common member of epiphytic dinoflagellate assemblages in neritic ecosystems. Coolia monotis is the type species of the genus and was the only known species for 76 years. Over the past few decades, molecular characterization has unveiled two species complexes that group morphologically very similar species, so their limits are often unclear. To provide new knowledge on the biogeography and species composition of the genus Coolia, 16 strains were isolated from Bahía de La Paz, Gulf of California. The species were identified by applying morphological and molecular approaches. The morphometric characteristics of all isolated Coolia species were consistent with the original taxa descriptions. Phylogenetic analyses (large subunit [LSU] rDNA D1 / D2 and internal transcribed spacer [ITS] 1 / 5.8S / ITS2) revealed a species assemblage comprising Coolia malayensis, C. palmyrensis, C. tropicalis, and the C. cf. canariensis lineage. This is the first report of Coolia palmyrensis and C. cf. canariensis in Mexico and C. tropicalis in the Gulf of California. Our results strengthen the biogeographical understanding of these potentially harmful epiphytic dinoflagellate species.

• ALGAE
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• v.24 no.4
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• pp.213-229
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• 2009

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.

• ALGAE
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• v.23 no.2
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• pp.141-150
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• 2008

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.

• ALGAE
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• v.33 no.3
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• pp.231-241
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• 2018

Genetic continuity of Digenea simplex outside the Atlantic waters remains less studied, despite its long exposure to oriental folk medicine and wide distribution in tropical waters. Mitochondrial COI-5P and plastid rbcL sequences and morphology were investigated for plants from Mexico and additional specimens from Japan. Two new species, Digenea mexicana and Digenea rafaelii, are described for plants that would previously have been recognized as D. simplex in Mexico. D. mexicana grows to 10.5 cm tall and has cylindrical axes, irregular or di-, trichotomous branches, simple to branched determinate branchlets with eight pericentral cells, and tetrasporangia on inflated upper parts of determinate branchlets. It occurs intertidally in Quintana Roo, Yucatan Peninsula. D. rafaelii grows to 5 cm tall and has cylindrical axes, irregular or di-, trichotomous branches, and simple determinate branchlets with ten pericentral cells. It occurs intertidally in the Gulf of California. Both COI-5P and rbcL sequences revealed the genetic discontinuity between D. mexicana and D. rafaelii.

• Structural Engineering and Mechanics
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• v.44 no.4
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• pp.501-519
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• 2012

Truss weight is one of the most important factors in the cost of construction that should be reduced. Different methods have been proposed to optimize the weight of trusses. The artificial bee colony algorithm has been proposed recently. This algorithm selects the lightest section from a list of available profiles that satisfy the existing provisions in the design codes and specifications. An important issue in optimization algorithms is how to impose constraints. In this paper, the artificial bee colony algorithm is used for the discrete optimization of trusses. The fly-back mechanism is chosen to impose constraints. Finally, with some basic examples that have been introduced in similar articles, the performance of this algorithm is tested using the fly-back mechanism. The results indicate that the rate of convergence and the accuracy are optimized in comparison with other methods.

• ALGAE
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• v.26 no.4
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• pp.327-331
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• 2011

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.

• Ocean Science Journal
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• v.43 no.3
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• pp.161-164
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• 2008

One specimen of Pteraclis aesticola was collected off San Jose del Cabo, Baja California Sur, Mexico ($22^{\circ}54'N$, $109^{\circ}45'W$), in March 2007. Present record is the first reported occurrence of the species in the Tropical Eastern Pacific biogeographic region (Gulf of California to southern Ecuadorian waters). Its large fan-like anal and dorsal fins and its counts of fin rays and vertebrae can distinguish the Pacific fanfish from the other species in the genus. This fish may have not yet been recorded in the region because its presence has been overlooked in the past because of rarity and lack of commercial value.