Palynological record (1483–1994) of Gymnodinium catenatum in Pescadero Basin, southern Gulf of California, Mexico

This paper presents the stratigraphic record of Gymnodinium catenatum during the last ~ 500 years, in Pescadero Basin, southern Gulf of California. Our aim is to help clarify the relation between abundances of cysts of G. catenatum and regional changes in the sea surface temperature and nutrient availability at a decadal scale. The record was obtained from core samples of laminated sediments dated with ¹⁴C, representing conditions in the area from 1483 to 1967 (PCM99-74C-5) and from 1907 to 1994 (PCM00-61C-4). Samples were treated with normal palynological processing, without oxidation, and using Lycopodium spores for quantification. The palynological assemblages observed contain varied and abundant terrestrial and marine components. However, we focus on the abundance of G. catenatum, due to its toxicity and the resulting impact in the area. This species is currently common in the area, and according to our results has been present there since ~ 1483. Cysts of G. catenatum are generally abundant in the 20th century, with maximum concentrations observed from 1888 to 1920, and from 1945 to 1965, but they show a steady decrease in the latter part of the century (1965–1994). Before 1830, abundances of G. catenatum were low because of increased upwelling conditions, probably related to a higher variability of the winter sea surface temperatures in the area. Both our data in the 20th century and the actual reports in the area, indicate a close relation with sea surface temperature. From 1907 to 1994 cyst abundances seem to increase during cool La Niña conditions in the area, and decrease during warmer El Niño events. They also show an evident decrease in cyst abundance from 1970 to 1994, while the sea surface temperature in the area increased during the same period. This inverse relation is also indicated by the low abundances of G. catenatum observed during red tide events, combined with high sea surface temperatures in Mazatlan. Additionally, our results do not show any relation of G. catenatum blooms and anthropogenic activity in the area.     

Paralytic shellfish toxin profile in strains of the dinoflagellate Gymnodinium catenatum Graham and the scallop Argopecten ventricosus G.B. Sowerby II from Bahía Concepción, Gulf of California, Mexico

Gymnodinium catenatum Graham is a paralytic shellfish poison (PSP) producer that was described for the first time from the Gulf of California in 1943. During the last decade, its distribution along the Mexican Pacific coastline has increased. In Bahía Concepción, a coastal lagoon on the western side of the Gulf of California, G. catenatum has been linked to significant PSP concentrations found in mollusks. In this study, we describe the saxitoxin profile of 16 strains of G. catenatum, and catarina scallops (Argopecten ventricosus) from Bahía Concepción. Toxins were analyzed by HPLC with post-column oxidation and fluorescence detection. The average toxicity of the G. catenatum strains was 26.0±6.0 pg and 28.0±18.0 pg STX eq/cell after 17 and 22 days of growth, respectively. Ten toxins were recorded, but only dcSTX, dcGTX2, dcGTX3, C1, and C2 were always present in all strains at both growth stages. Since toxin profiles in scallops were similar to the cultures, biotransformations are not significant in catarina scallop. NeoSTX, GTX2, GTX3, and B2 were present in some G. catenatum strains and their presence varied with the age of the culture. In scallop samples, dcSTX, dcGTX2, and dcGTX3 were the most abundant toxins, and from the C-toxin group, only C2 was found. This unique toxin profile can be used as a biomarker for this population, when compared with strains of G. catenatum from other geographic regions.     

A new species of Sanicula L. (Umbelliferae/Apiaceae) endemic to Baja California, Mexico

A new species of the genusSanicula (sect.Sanicoria) endemic to the southern Sierra Juárez of Baja California, Mexico, is described and illustrated.Sanicula moranii resemblesS. deserticola andS. bipinnatifida, but has thicker basal leaves, with broader petioles and rachises, and shorter fruit prickles that are confined to the apical part of the mericarps. The taxonomic relationships of these species are discussed, along with aspects of their distribution and habitat.

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Resumen  Una neuva especie del géneroSanicula (secciónSanicoria) endémica de la Sierra Juárez de Baja California, México, es descrita e ilustrada.Sanicula moranii presenta similitud conS. deserticola yS. bipinnatifida, no obstante tiene gruesas hojas basales con pecíolos y raquis anchos, y espínulas del fruto más cortas que se distribuyen únicamente en la parte apical de los mericarpos. Además, se comentan las relaciones taxonómicas de las tres especies, así como algunos aspectos de sus distribuciones y hábitats.

     

Samuraia tabularasa gen. nov., sp. nov. (Cnidaria,Hydrozoa, Hydrocorynidae), an intertidal hydroid from the Gulf of California,Mexico

Samuraia tabularasa, the samurai hydroid, a previously unreported genus and species of athecate hydrozoan, family Hydrocorynidae, is described, based upon field and laboratory observations. Colonies live attached to rocky substrates in the middle of the intertidal zone in the northern and central Gulf of California, Mexico. The principal characters that allow this species to be referred to a new genus are associated with its mode of sexual reproduction by eumedusoids that can remain attached to the colony, or be released as ephemeral, rudimentary structures. This is in contrast to the feeding, free medusae produced by the two species of the other genus, Hydrocoryne, in the family Hydrocorynidae.     

Brown algae (Phaeophyta) from Bahía de los Angeles,Gulf of California,México

Seven sites in Bahía de los Angeles, northern Gulf of California, were sampled seasonally over a three-year period. Five species of brown algae previously not recorded from this bay were identified: Ralfsia pacifica, Sporochnus balleanus, Hydroclathrus clathratus, Colpomenia sinuosa and Padina mexicana. Of these, H. clathratus also provided a new record for the northern Gulf of California. One species previously recorded from the bay, Dictyopteris undulata, was not observed. On a seasonal basis, temperature and biodiversity showed an inverse relationship: highest species numbers occurred in spring, when temperatures were lowest, and lowest species numbers occurred in autumn when temperatures were highest. Most species of brown algae in Baífa de los Angeles are annuals.     

Two new Marina (Leguminosae) from the southern Baja California peninsula, Mexico

Marina victoriae andM. brevis are newly described species from the southern Baja California peninsula, Mexico. The former is a perennial herb locally abundant in the eroded hillsides at the foothills of Sierra de la Victoria, where an oak woodland and a dry tropical forest meet. The latter is an elusive ephemeral inhabiting a narrow strip of land between the mangroves and the desert scrub on an island in the Gulf of California. These two new species belong to the seriesChrysorrhizae, a group native to the Gulf of California basin.     

Trophic level and overlap of sea lions (Zalophus californianus) in the Gulf of California, Mexico

Stable isotope and scat analyses were used in concert to determine trophic level and dietary overlap among California sea lions from different rookeries in the Gulf of California. Isotopic analysis of the fur of sea lion pups revealed differences in δ¹⁵N and δ¹³C values among rookeries during the breeding season. Mean δ¹⁵N and δ¹³C values varied from 20.2‰ to 22.4‰ and from −15.4‰ to −14.0‰, respectively. The pattern of differences among rookeries was similar between years in most cases. Isotopic variations among rookeries were associated with differences in prey consumption. There was a significant correlation between δ¹⁵N value and trophic level, as determined by scat analysis. Joint application of isotopic and scat analyses allowed us to identify how the feeding habits of sea lions vary with location. Our results suggest the presence of spatial structure in available prey as well as the localized use of prey by sea lions across the Gulf of California.     

A new genus of Cletopsyllidae (Copepoda,Harpacticoida) from Gulf of Mexico

A new genus and new species of the family Cletopsyllidae Huys & Willems, 1989 from deep-sea sediment in the Gulf of Mexico, are reported and fully described and illustrated. The new genus Pentacletopsyllus (type species: P. montagnisp. n.) can be distinguished from the four known genera of the family by antennule segmentation, length ratio of first and second endopodal segments of P1, and armature pattern on P5 exopod. It also differs from its sister genera by the rostrum being bifid at the tip, third segment of the female antennule having a smooth posterior margin, the baseoendopod of P5 with biarticulate outer setophore bearing basal seta, and female caudal rami without lobate expansion. A revised key to species of the family Cletopsyllidae Huys & Willems, 1989 is provided.     

Whale shark Rhincodon typus strandings in the Gulf of California,Mexico

The present study analyses whale shark Rhincodon typus stranding in the Gulf of California, Mexico, reported by the public, scientists, authorities and artisanal fishermen. A total of 14 strandings were documented during the period 2001–2018. The total length of R. typus ranged from 350–1,102 cm, with a sex ratio of 3.5:1 (males: females). This study highlights potential stranding areas, the need for better stranding protocols to assist R. typus recovery and the importance of samples from dead animals for scientific research.     

Monitoring Karenia brevis blooms in the Gulf of Mexico using satellite ocean color imagery and other data

Harmful algal blooms (HABs) of Karenia brevis are a recurrent problem in the Gulf of Mexico, with nearly annual occurrences on the Florida southwest coast, and fewer occurrences on the northwest Florida and Texas coasts. Beginning in 1999, the National Oceanic and Atmospheric Administration has issued the Gulf of Mexico HAB Bulletins to support state monitoring and management efforts. These bulletins involve analysis of satellite imagery with field and meteorological station data. The effort involves several components or models: (a) monitoring the movement of an algal bloom that has previously been identified as a HAB (type 1 forecast); (b) detecting new blooms as HAB or non-HAB (type 2); (c) predicting the movement of an identified HAB (type 3); (d) predicting conditions favorable for a HAB to occur where blooms have not yet been observed (type 4). The types 1 and 2 involve methods of bloom detection requiring routine remote sensing, especially satellite ocean color imagery and in situ data. Prediction (types 3 and 4) builds on the monitoring capability by using interpretative and numerical modeling. Successful forecasts cover more than 1000 km of coast and require routine input of remotely sensed and in situ data.The data sources used in this effort include ocean color imagery from the Sea-Viewing Wide Field-of-View Sensor/OrbView-2 satellite and processed using coastal-specific algorithms, wind data from coastal and offshore buoys, field observations of bloom location and intensity provided by state agencies, and forecasts from the National Weather Service. The HAB Bulletins began in coordination with the state of Florida in autumn of 1999 and included K. brevis bloom monitoring (type 1), with limited advisories on transport (type 3) and the detection of blooms in new areas (type 2). In autumn 2000, we improved both the transport forecasts and detection capabilities and began prediction of conditions favorable for bloom development (type 4). The HAB Bulletins have had several successes. The state of Florida was advised of the potential for a bloom to occur at the end of September 2000 (type 4), and the state was alerted to the position of blooms in January 2000 and October 2001 in areas that had not been previously sampled (type 3). These successful communications of HAB activity allowed Florida agencies responsible for shellfish management and public health to respond to a rapidly developing event in a timely, efficient manner.     

Morphology and toxicology of Prorocentrum arabianum sp. nov., (dinophyceae) a toxic planktonic dinoflagellate from the Gulf of Oman, Arabian Sea

A new species of planktonic dinoflagellate, Prorocentrum arabianum isolated from the Gulf of Oman, is described using both scanning electron microscopy (SEM) and light microscopy. This clonal isolate has the following morphological characteristics: (1) cell shape is asymmetric; (2) thecal surface is rugose, covered with small poroids; (3) periflagellar area is unornamented, and (4) intercalary band is horizontally striated. Analysis of P. arabianum confirms the production of one cytotoxic compound and one ichthyotoxic compound. P. arabianum is the second known toxic planktonic Prorocentroid dinoflagellate.     

Aggregata polibraxiona n. sp. (Apicomplexa: Aggregatidae) from Octopus bimaculatus Verrill, 1883 (Mollusca: Cephalopoda) from the Gulf of California,Mexico

The Apicomplexa Aggregata spp. are intracellular parasites of cephalopods that infect the intestinal tract of commercially important species such as Octopus bimaculatus, which sustains the octopus fishery in Baja California (B.C.), Mexico. In this study, Aggregata polibraxiona n. sp. was described from the cecum of O. bimaculatus collected from Bahia de Los Angeles, B. C. Light and electron microscopy revealed that oocysts and sporocysts were spherical to ovoid in shape. Sporulated oocysts (293–835 × 177–688 μm) contained 135–674 sporocysts (12–24 × 11–22 μm). The sporocyst wall was covered by tubular projections (0.55–2.19 μm in length) bifurcated in the top, unevenly distributed, covered by a thin membrane. Each sporocyst contains 11–13 sporozoites (16–26 × 1.20–3 μm). Three partial sequences of the 18S rDNA gene were obtained, and two phylogenetic approaches were performed according to Bayesian inference and Maximum Likelihood. In both phylogenetic reconstructions, the sequences of A. polibraxiona n. sp. were recovered as a monophyletic group within the genus Aggregata and placed as a sister group to Aggregata octopiana Lineage II. Aggregata polibraxiona n. sp. is the first Apicomplexa described from a cephalopod host from Mexico and extends the geographical range of Apicomplexa infecting cephalopods.     

A new species of Amphictene (Annelida,Pectinariidae) from the Gulf of Mexico,with a redescription of Amphictene guatemalensis (Nilsson, 1928)

The genus Amphictene is reported for the first time from Mexico. Previous records for America are restricted to Brazil (Amphictene catharinensis) (Grube, 1870), and Guatemala (Amphictene guatemalensis) (Nilsson, 1928). In this paper we describe a new species, Amphictene helenae sp. n., characterized by the presence of three pairs of tentacular cirri, while other species have only two pairs. The new species is closely similar to Amphictene catharinensis, and can be distinguished by the presence of a circular group of glandular papillae inserted between the lines of glandular cirri present from the second segment. Amphictene guatemalensis is redescribed based on type material; it differs from the new species in the presence of two pairs of tentacular cirri on segments 1 and 2, six pairs of glandular cirri on the third segment, and four glandular lobes fused in pairs on the fourth segment.     

Detecting Karenia brevis blooms and algal resuspension in the western Gulf of Mexico with satellite ocean color imagery

Blooms of the toxic dinoflagellate, Karenia brevis, have had detrimental impacts on the coastal Gulf of Mexico for decades. Detection of Karenia brevis blooms uses an ecological approach based on anomalies derived from ocean color imagery. The same anomaly product used in Florida produces frequent false positives on the Texas coast. These failures occurred during wind-driven resuspension events. During these events resuspension of benthic algae significantly increases chlorophyll concentrations in the water, resulting in confusion with normal water column phytoplankton, such as Karenia. A method was developed to separate the resuspended chlorophyll from the water column chlorophyll, decreasing the false positives used with the detection method.     

Cystobasidiopsis nirenbergiae, a new agaricostilbomycete (Pucciniomycotina)

A new genus, Cystobasidiopsis, and a new species, Cystobasidiopsis nirenbergiae, are described for a fungus isolated from an arable loess soil in Ahlum near Braunschweig, Niedersachsen, Germany. An integrated analysis of morphological, ecological, ultrastructural and molecular data indicates that the new species belongs to the Chionosphaeraceae within the Agaricostilbales. Relevant characteristics of the new species are discussed and compared with those of related taxa.     

Petroleum production platforms as sites for the expansion of ciguatera in the northwestern Gulf of Mexico

Ciguatera is a common human disease of tropical, coral reef ecosystems acquired by consuming finfish-containing ciguatoxins (CTX). There are few records of this disease in the northwestern Gulf of Mexico, a region characterized by soft muddy bottoms that are considered poor habitat for the CTX source dinoflagellate Gambierdiscus toxicus. However, the approximately 4000 petroleum production platforms and hundreds of state-sponsored artificial reefs located in the Gulf of Mexico provide hard substrate and often support coral and other components of the tropical benthos. In addition to their role in their resource extraction, these oil production platforms are also popular sites for recreational fishing and sport diving. We examined these platforms as potential substrate for G. toxicus and report a first record of this species in the NW Gulf of Mexico. All the platforms (n = 6) examined harbored the dinoflagellate as an epiphyte on the fouling community, with three finds of G. toxicus associated with the pelagic macroalga Sargassum. Only minor toxicity (<0.15 ppb) was noted in two of 20 great barracuda (Sphyraena barracuda) examined. Tagging data suggest trans-Gulf migrations by barracuda are common; thus, we cannot determine if the toxicity was acquired locally or transported in migrating fish.These platforms are a clear example of how human activity has altered the environment in a way that allows expansion of a HAB population. The rapid increase in production platforms since 1942 has provided novel substrate in a sandy/muddy bottom environment generally considered to be poor habitat for these benthic dinoflagellates. These platforms create a unique habitat in the upper euphotic zone and serve as intersection points for fishermen and potentially toxic fish. Many Gulf of Mexico states have active programs to turn non-producing platforms into artificial reefs. Our results suggest that the use of these platforms as fisheries enhancement structures could have unintended consequences for human health, particularly if projected rising sea-surface temperatures over the next century alter benthic distributions and fish migration patterns. These concerns also extend to mariculture operations around oil production rigs or offshore wind farms, both of which would also add substrate for epibenthic microalgae.     

The emergence of Cochlodinium along the California Coast (USA)

A sudden and nearly synchronous emergence of the red tide forming dinoflagellate Cochlodinium along more than 800 km of California coastline was initially observed in late summer 2004. Thereafter high cell concentrations have been detected on an annual basis. Here, we present quantitative and semi-quantitative data indicating that Cochlodinium was uncommon in the phytoplankton community in California prior to 2004 and is now persisting as a more regular component and one that seasonally can cause red tides. The quantitative portion of this study was primarily conducted in Monterey Bay, where cell densities reached at least 6 × 10⁴ cells L⁻¹ during the initial outbreak. A semi-quantitative comparison of California coastal counties by the California Department of Health Services (CDHS) was also made: of the 15 counties surveyed (most with multiple sites per county), cells were detected only from Los Angeles County in the south to San Mateo County in the central region (seven counties), but not in the northern part of the state (six counties). Two counties in the central region of the state, San Luis Obispo and Santa Cruz, displayed intense and frequent periods of elevated Cochlodinium cell abundances. Although not observed in the state-wide CDHS survey, we occasionally found cells in San Diego County with densities up to 2.7 × 10⁴ cells L⁻¹. Though these colonial dinoflagellates have been recognized in California for over 80 years, with several “blooms” recorded prior to 2004, the species’ geographic range and abundance in recent years suggest significant shifts in the nearshore phytoplankton community of this region of the eastern Pacific.     

A new sponge-inhabiting amphipod species (Crustacea, Gammaridea, Sebidae) from the Veracruz Coral Reef System, southwestern Gulf of Mexico

A new species of the genus Seba Bate (Amphipoda: Sebidae) is described from the Veracruz Coral Reef System, Veracruz, south-western Gulf of Mexico. The specimens were found in association with a sponge, Ircinia fistularis, at depths from 8 to 10 m. Seba alvarezi n. sp. can be distinguished from closely related species mainly by the presence of a short, two-articulated accessory flagellum, three apical setae on article 3 of the mandible palp, and by the absence of apical setae on the inner lobe of maxilla 1. The new species is compared to closely related species in the family, and an identification key to the species of Seba known from the Gulf of Mexico and the Caribbean Sea is given.