The Variety and Abundance of Zooplankton in the Coastal Waters of Puerto Rico

During 1973-1974 a total of 160 zooplankton samples were collected in the uppermost 3 m at seven locations within 1 km of the coast of Puerto Rico. Total zooplankton densities ranged from 41 to 7568 organisms/m3. Copepods formed 65-84% of all zooplankton caught; meroplankton constituted 2-17%. Larger densities (2-21X) of zooplankton tended to be caught at night. Regional differences in the abundance of meroplankton were related to water circulation patterns, community development of benthic organisms, and recruitment from an embayment. The total abundance of zooplankton around Puerto Rico was similar to densities of zooplankton near other Caribbean Islands

Editorial: Deep Pelagic Ecosystem Dynamics in a Highly Impacted Water Column: The Gulf of Mexico After Deepwater Horizon

The intermediate-sized midwater fauna (fishes, shrimps, and cephalopods; “micronekton” collectively) are dominant components of the pelagic ocean, which is by far the largest ecosystem type on Earth by several metrics (volume, organismal numbers, biomass, and productivity). Deep-pelagic micronekton, those animals residing in the water column below 200 m depth during the day, are the direct link between plankton and oceanic top predators, and through the linked processes of feeding and daily vertical migration facilitate one of Earth\u27s most important ecosystem services to humans, carbon sequestration. Despite increasing recognition of this importance, a disconnect exists between stewardship and human impact; only a miniscule fraction of the deep-pelagic ocean has been studied in detail, while anthropogenic threats to that system are increasing rapidly. Perhaps nowhere on Earth is that dichotomy more demonstrable than the Gulf of Mexico (Gulf hereafter), a complex, high-diversity ecosystem under intense human usage and subjected to arguably the worst marine pollution event in human history. Assessment of the impacts of the Deepwater Horizon disaster to the deep-pelagic biota was impeded from the start by the lack of pre-event information, both in terms of baselines (faunal composition, abundance, and distribution) and in terms of understanding natural variability, against which impacts of anthropogenic disturbance could be detected and quantified. In this Research Topic, we present a description of three interlinked research programs (ONSAP, DEEPEND, and DEEPEND|RESTORE, described below) that began in 2010 and continue as of this writing. These programs were designed to investigate key aspects of the Gulf pelagic ecosystem, including its faunal structure, biophysical drivers of that structure, organismal and community ecology, natural variability, and potential resilience to disturbance. The contributed papers are grouped below by major themes, indicated in the conceptual model (Figure 1) of DEEPEND (Deep Pelagic Nekton Dynamics; www.deependconsortium.org), the largest of the three aforementioned research programs

Fatty acid trophic markers and trophic links among seston, crustacean zooplankton and the siphonophore Nanomia cara in Georges Basin and Oceanographer Canyon (NW Atlantic)

A grant to MJY from the National Science Foundation (NSF-0002493), and USDa CRIS Project FLA-FAS-03978 supported this work. This is contribution no. 1696 to the Harbor Branch Oceanographic Institution.Fatty acid concentrations expressed as percentages of total fatty acid pools in seston, stage V copepodites of Calanus finmarchicus, adults of the euphausiid Meganyctiphanes norvegica, and the physonect siphonophore Nanomia cara were used to elucidate trophic links in Georges Basin and Oceanographer Canyon in September 2003. Seston at both locations was refractory and comprised mainly of saturated fatty acids. Phytoplankton did not contribute significantly to the fatty acid composition of seston or higher trophic levels. Only four fatty acids, i.e. 14:0, 16:0, 16:1 (n-7) and 18:1 (n-7), were transferred from seston to C. finmarchicus or M. norvegica, which suggested weak trophic interactions. Fatty acids transferred from the two species of crustaceans to N. cara included the same four fatty acids, along with three polyunsaturated fatty acids found in relatively high concentrations in both crustaceans, i.e. 20:3 (n-6), 20:5 (n-3) and 22:6 (n-3). In addition, 18:1 (n-9), which occurred in relatively high concentrations only in M. norvegica, and 18:0 and 18:2 (n-6), which were found in low concentrations in both crustaceans, also appeared to be transferred to N. cara. Overall, fatty acid trophic markers proved useful for identifying trophic links to N. cara.En este estudio se utilizaron las concentraciones de ácidos grasos (expresadas como porcentajes) para identificar posibles relaciones tróficas entre el seston, el estadio V (copepoditos) de Calanus finmarchicus, los adultos del eufáusido Meganyctiphanes norvegica, y el sifonóforo fisonecto Nanomia cara en Georges Basin y el cañón submarino Oceanographer durante Septiembre de 2003. En ambos lugares el seston era muy refractario y compuesto básicamente por ácidos grasos saturados. El fitoplancton no contribuyó de forma significativa a la composición de ácidos grasos del seston o de niveles tróficos superiores. Sólo cuatro ácidos grasos [14:0, 16:0, 16:1 (n-7) y 18:1 (n-7)] se transfirieron potencialmente del seston a C. finmarchicus o M. norvegica, lo que sugiere una débil conexión trófica entre estos eslabones de la cadena. Los ácidos grasos transferidos de las dos especies de zooplancton crustáceo a N. cara incluyen los mismos descritos más arriba y otros tres ácidos grasos poliinsaturados [20:3 (n-6), 20:5 (n-3) y 22:6 (n-3)] encontrados en concentraciones relativamente elevadas en ambos crustáceos. Además, tanto el 18:1 (n-9) (encontrado en elevadas concentraciones en M. norvegica) y los 18:0 y 18:2 (n-6) (encontrados en bajas concentraciones en ambas especies de crustáceos) se transfieren a N. cara. Los ácidos grasos demuestran ser una herramienta útil para identificar conexiones tróficas en N. cara

High abundance of the epibenthic trachymedusa Ptychogastria polaris Allman, 1878 (Trachylina, Hydrozoa) in subpolar fjords along the West Antarctic Peninsula

http://www.godac.jamstec.go.jp/darwin/cruise/yokosuka/yk07-15/

Zooplancton gelationoso recogido con redes en el golfo de Maine con descripciones de un nuevo sifonóforo, una nueva antomedusa y diagnosis de la nueva familia Jeanbouillonidae

A systematic account is provided of the siphonophores, medusae, ctenophores, molluscs and salps net-collected in basins of the Gulf of Maine and adjacent canyons during three cruises carried out in September 2002, 2003 and 2004. We describe the siphonophore Lensia quadriculata sp. nov. and the hydroidomedusae Jeanbouillonia maserati gen. nov. et sp. nov., the latter is the first member of the new family Jeanbouilloniidae. New observations are made about the morphology and/or systematics of the siphonophore Gilia reticulata and the hydroidomedusae Bougainvillia platygaster, Bougainvillia principis, Modeeria rotunda, Clytia hemisphaerica, Orchistoma collapsum and Dichotomia cannoides. Parasites associated with the ctenophores Pleurobrachia pileus (a cestode) and Beroe sp. (a hyperid amphipod) are reported.Se presenta un directorio sistemático de los sifonóforos, medusas, ctenóforos, moluscos y salpas recogidos con redes en las cuencas del golfo de Maine y cañones submarinos adyacentes durante tres cruceros realizados en septiembre de 2002, 2003 y 2004. El sifonóforo Lensia quadriculata sp. nov. y la hidroidomedusa Jeanbouillonia maserati gen. nov. et sp. nov. son descritos, ésta última especie es el primer miembro de la nueva familia Jeanbouilloniidae. Se aportan nuevas observaciones sobre la morfología y/o posición sistemática del sifonóforo Gilia reticulata y de las hidroidomedusas Bougainvillia platygaster, Bougainvillia principis, Modeeria rotunda, Clytia hemisphaerica, Orchistoma collapsum y Dichotomia cannoides. Se registran algunos parásitos asociados a los ctenóforos Beroe sp. (un anfípodo hipérido) y Pleurobrachia pileus (un céstodo).

High Abundance of the Epibenthic Trachymedusa Ptychogastria polaris Allman, 1878 (Hydrozoa, Trachylina) in Subpolar Fjords Along the West Antarctic Peninsula

http://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt01-07_leg2/ehttp://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr12-07/

Vertical distribution (0–1000 m) of gelatinous zooplankton and particulate matter (60ìm<<5mm) along the Mid Atlantic ridge in the North Atlantic. Potential impact of appendicularians on particle aggregation

The vertical distribution (0-1000 m depth) of macrozooplankton along the northern portion of the Mid-Atlantic Ridge (59°58N, 25°53W to 41°29N, 28°19W) was investigated during the MARECO program (June and July 2004) using the Underwater Video Profiler (UVP). Twelve relatively large (> 1 cm) groups were selected from the recorded images: sarcodines (with two sub-groups), crustaceans (excluding copepods), chaetognaths, ctenophores (with two sub-groups cydippids and lobates), siphonophores, medusae (with three subgroups Aeginura grimaldii, Aglantha spp. and all other medusae), appendicularians, and thaliaceans. The numerically dominant groups over the whole area were crustaceans (26%), medusae (20%) and appendicularians (17%). The gelatinous fauna were consistently most numerous between 400-900 m. Appendicularians, ctenophores and A. grimaldii occurred mostly below 300 m (maximum concentrations of 75, 58, and 30 individuals 100m-3, respectively). The macrozooplankton community below 200 m varied with the spatial distribution of the four regions defined by the temperature and salinity profiles. The results suggest that the Sub-Polar Front restricts the mixing of macrozooplankton communities down to 1000 m depth. The observed relationship between appendicularians and biovolume and size of particles is investigated in the four oceanic regions. Keywords: Gelatinous zooplankton, mesopelagic zooplankton, Sub Polar Front, North Atlantic, Underwater Video Profiler, MARECO

DNA Barcoding the Medusozoa using mtCOI

Special issue Species Diversity of Marine Zooplankton.-- 9 pages, 4 figures, 3 tablesThe Medusozoa are a clade within the Cnidaria comprising the classes Hydrozoa, Scyphozoa, and Cubozoa. Identification of medusozoan species is challenging, even for taxonomic experts, due to their fragile forms and complex, morphologically-distinct life history stages. In this study 231 sequences for a portion of the mitochondrial Cytochrome Oxidase I (mtCOI) gene were obtained from 95 species of Medusozoans including; 84 hydrozoans (61 siphonophores, eight anthomedusae, four leptomedusae, seven trachymedusae, and four narcomedusae), 10 scyphozoans (three coronatae, four semaeostomae, two rhizostomae, and one stauromedusae), and one cubozoan. This region of mtCOI has been used as a DNA barcode (i.e., a molecular character for species recognition and discrimination) for a diverse array of taxa, including some Cnidaria. Kimura 2-parameter (K2P) genetic distances between sequence variants within species ranged from 0 to 0.057 (mean 0.013). Within the 13 genera for which multiple species were available, K2P distance between congeneric species ranged from 0.056 to 0.381. A cluster diagram generated by Neighbor Joining (NJ) using K2P distances reliably clustered all barcodes of the same species with ≥99% bootstrap support, ensuring accurate identification of species. Intra- and inter-specific variation of the mtCOI gene for the Medusozoa are appropriate for this gene to be used as a DNA barcode for species-level identification, but not for phylogenetic analysis or taxonomic classification of unknown sequences at higher taxonomic levels. This study provides a set of molecular tools that can be used to address questions of speciation, biodiversity, life-history, and population boundaries in the MedusozoaThis work was supported by the National Science Foundation (Award Number 0002493) to M.J.Y. Programmatic support was provided by the Alfred P. Sloan Foundation. The authors acknowledge two anonymous reviewers who enhanced this manuscript. This study is a contribution from the Census of Marine Zooplankton (CMarZ, see www.CMarZ.org), a Census of Marine Life (CoML) field projectPeer Reviewe