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Species within the dinoflagellate genus Dinophysis can produce okadiac acid and dinophysistoxins leading to diarrhetic shellfish poisoning. Since the first report of D. ovum from the Gulf of Mexico in 2008, reports of other Dinophysis species across US have increased. Members of the D. cf. acuminata complex (D. acuminata, D. acuta, D. ovum, D. sacculus) are difficult to differentiate due to their morphological similarities. Dinophysis feeds on and steals the chloroplasts from the ciliate, Mesodinium rubrum, which in turn has fed on and captured the chloroplasts of its prey, the cryptophyte Teleaulax amphioxeia. The objective of this study was to generate de novo transcriptomes for new isolates of these mixotrophic organisms. The transcriptomes obtained will serve as a reference for future experiments to assess the effect of different abiotic and biotic conditions and will also provide a useful resource for screening potential marker genes to differentiate among the closely related species within the D. cf. acuminata-complex. The complete comprehensive detailed workflow and links to obtain the transcriptome data are provided. [ABSTRACT FROM AUTHOR]

Tropical cyclones impose tremendous impacts on microplankton communities. When Hurricane Harvey struck Texas in August 2017, delivering record rainfall, the resulting historically large freshwater plume provided an opportunity to identify how the coastal microplankton community responded to such a drastic shift in hydrography. Two cruises were conducted along the Texas coast one week apart to assess the impact of the low-salinity plume moving downcoast. The spatial–temporal variability and recovery of the microplankton community was compared with microplankton community changes during and after 13 other tropical storm/cyclone events observed during the decade-long record from the Texas Observatory for Algal Succession Timeseries (TOAST). Results revealed an unprecedented ciliate-dominated community developed in the weeks following Hurricane Harvey. TOAST data revealed diatoms dominated during upwelling and water column mixing. Moderate downwelling conditions favored dinoflagellates while strong downwelling and reduced salinity following Hurricane Harvey resulted in a ciliate-dominated community. The unexpectedly large biomass of ciliates and low diatom biomass observed during the response cruise indicated that the microplankton community had not yet recovered. Intensification of future hurricanes may produce brief blooms of diatoms, while dinoflagellates or ciliates dominate following high freshwater discharge. These drastic shifts in microplankton communities pose important implications for biogeochemical cycling, trophic interactions and commercial fisheries. [ABSTRACT FROM AUTHOR]

Identification of marine invertebrate larvae using morphological characters is laborious and complicated by phenotypic plasticity. Balanus amphitrite is a dominant barnacle, important in the context of intertidal ecology and biofouling of manmade structures. Morphological identification of barnacle larval forms in a mixed population is difficult because of their intricacy and similarity in size, shape and developmental stages. We report the development and application of a nucleic acid-based Polymerase Chain Reaction (PCR) method for the specific identification of the barnacle, B. amphitrite, from the heterogeneous zooplankton sample. This method is reliable and accurate thereby overcoming taxonomic ambiguity. Sequence alignment of the 18S rRNA gene region of selected species of barnacles allowed the design of B. amphitrite-specific PCR primers. Assay specificity was evaluated by screening DNA obtained from selected species of barnacles. The oligonucleotide primers used in the study flanked a 1600 bp region within the 18S rRNA gene. The primer is specific and can detect as few as 10 individuals of B. amphitrite larvae spiked in a background of ~186 mg of zooplankton. This technique facilitates accurate identification and the primer can be used as a marker for enumeration of B. amphitrite larvae in the plankton. [ABSTRACT FROM PUBLISHER]

Studies on the settlement and the subsequent recruitment of intertidal organisms are crucial steps in understanding their population structure in a particular bioregion. However, studying the recruitment of intertidal organisms such as barnacles, with two-phase life cycle, and understanding the determinants of recruitment is a complex problem. Many processes which operate during the pelagic pre-settlement phase and benthic post-settlement phase at different spatial and temporal scales can determine the fate of barnacle populations. In this study, observations were carried out on settlement and recruitment of the intertidal barnacle Balanus amphitrite from a tropical environment influenced by monsoons at spatial and temporal scales. Settlement and recruitment both showed significant temporal variations. In general, settlement and recruitment was lower during the monsoon season except during monsoon breaks. Consistency in settlement and recruitment was mostly observed during the pre-monsoon season, and it coincided with peaks in larval abundance observed during the same season. In general, settlement remained more or less similar on different types of substrata, whereas recruitment differed significantly. Temporal variations observed in settlement and recruitment of barnacles could be due to the influence of monsoons in this region, which leads to seasonal fluctuations in physical factors such as local hydrodynamics, that influence the retention and dispersal of larvae in the adult habitats, and could also be due to variations in the availability of food for the larvae and the settled populations. [ABSTRACT FROM PUBLISHER]