No abstract

An annotated checklist of about 605 principally free-living dinoflagellate species and infraspecific taxa from 91 genera reported from the Mexican Pacific is presented on the basis of published literature, some theses, unpublished reports, and original data. Literature references from 1878 to 2005 (in total, 311) are included in the bibliography, and taxonomic notes in regard to some taxa are given, where appropriate. The presence of illustrations divided into three categories (line drawings, light micrographs and scanning electronic micrographs) in the cited works is indicated as well as the known distribution of the taxa in the Mexican Pacific. The nomenclature is brought up to date, and 193 species and infraspecific taxa are accompanied with original comments. Four new combinations are proposed: Histioneis pieltainii (B. F. Osorio) Okolodkov comb. nov., Latifascia subantarctica (Balech) Okolodkov comb. nov., Peridiniella globosa (P. A. Dang.) Okolodkov comb. nov. and Protoperidinium curtipes (Jörg.) Balech f. asymmetricum (Matzen.) Okolodkov comb. nov. Twentynine nomina nuda were revealed. The leading genera are Protoperidinium (111 species), Ceratium (63) Dinophysis (41), Gonyaulax (25), Oxytoxum (22), Gymnodinium (22), Prorocentrum (21), Alexandrium (17) Ornithocercus (12) and Amphidinium (12). To discover the true dinoflagellate species diversity in the Mexican Pacific, more studies on the athecate Gymnodiniales species, benthic and epiphytic dinoflagellates, the ''Diplopsalis group'', the genus Protoperidinium and recently described genera of the family Podolampadaceae, are needed.

This review presents a detailed analysis of the state of knowledge of studies done in Mexico related to the dinoflagellate Gymnodinium catenatum, a paralytic toxin producer. This species was first reported in the Gulf of California in 1939; since then most studies in Mexico have focused on local blooms and seasonal variations. G. catenatum is most abundant during March and April, usually associated with water temperatures between 18 and 25 ºC and an increase in nutrients. In vitro studies of G. catenatum strains from different bays along the Pacific coast of Mexico show that this species can grow in wide ranges of salinities, temperatures, and N:P ratios. Latitudinal differences are observed in the toxicity and toxin profile, but the presence of dcSTX, dcGTX2-3, C1, and C2 are usual components. A common characteristic of the toxin profile found in shellfish, when G. catenatum is present in the coastal environment, is the detection of dcGTX2-3, dcSTX, C1, and C2. Few bioassay studies have reported effects in mollusks and lethal effects in mice, and shrimp; however no adverse effects have been observed in the copepod Acartia clausi. Interestingly, genetic sequencing of D1-D2 LSU rDNA revealed that it differs only in one base pair, compared with strains from other regions.

No abstract

In vitro experiments were performed with Gymnodinium catenatum Graham strains isolated from three locations in the Gulf of California to determine the variability in toxicity and toxin profiles. Strains were cultivated in GSe at 201 C AE 11 C, 150 lmol photons . m À 2 . s À 1 (12:12 light:dark cycle), and harvested during different growth phases. Growth rates were higher than in previous studies, varying between 0.70 and 0.82 day À 1 . The highest cell yields were reached at 16 and 19 days, with maximum densities between 1090 and 3393 cells . mL À 1 . Bahía de La Paz (BAPAZ) and Bahía de Mazatlán (BAMAZ) were the most toxic (101 pg STXeq . cell À 1 ), whereas strains from Bahía Concepción (BACO) were the least toxic (13 pg STXeq . cell À 1 ). A strain isolated from cyst germination was one of the least toxic strains. No significant changes in toxin content with culture age were observed (0.2 and 0.6 pmol paralytic shellfish poisoning . cell À 1 ). All strains contained neosaxitoxin (NEOSTX), decarbamoyl-saxitoxin (dcSTX), decarbamoyl-gonyautoxin-2,-3, (dcGTX2-3), N-sulfocarbamoylsaxitoxin (B1), N-sulfo-carbamoylneosaxitoxin (B2), and N-sulfo-carbamoylgonyautoxin-2,-3 (C1-2). Bahía Concepción strains had the highest content of C1; BAPAZ and BAMAZ strains had a higher percentage of NEOSTX. Differences in toxin composition with culture age were observed only in BAMAZ and BAPAZ strains. Cultures with a higher percentage of long chains had more NEOSTX, while those with a higher proportion of short chains had a lower content of NE-OSTX. Gulf of California strains are characterized by a high proportion of NEOSTX, and seem to have evolved particular physiological responses to their environment that are reflected in the toxin profile, suggesting different populations.