Comparative seasonal and spatial distribution of decapod larvae assemblages in three coastal zones off the south-western Iberian Peninsula

Plankton studies over the long southern coast of Iberian Peninsula are very scarce and restricted to a few specific taxonomic groups. In order to know the dynamic of decapod larvae coastal assemblages from south-western of Iberian Peninsula, three zones were studied: Guadalquivir Estuary, Cádiz Bay and Algeciras Bay. The three zones differ by their freshwater inflow and turbidity (highest in Guadalquivir Estuary), primary production (highest in Cádiz Bay) and nutrient concentrations (lowest in Algeciras Bay). The material is based upon plankton samples (250 μm mesh) collected monthly at eight stations distributed between these zones, during 1 year. Maximum values of abundance and diversity were found in Cádiz Bay, while the lowest were recorded in Algeciras Bay. Brachyura was the main abundant taxonomic group in larval decapod assemblages, while Dendrobranchiata, Palinura, Stenopodidea, and Astacidea were scarcely represented or absent. From the 69 taxa identified, 11 were considered rare and 12 taxa constituted 87% of the total larvae collected. Liocarcinus spp. was the most representative taxon, being present in all stations and showing high abundance and dominance values. The annual distribution was specifically studied for Liocarcinus spp., Carcinus maenas, Xantho spp., Ilia nucleus, Uca tangeri, Brachynotus spp., Hippolyte spp., Philocheras spp., Pisidia longicornis, Diogenes pugilator, Pilumnus spp. and Upogebia sp. Attending to the temporal distribution of dominant taxa, three abundance patterns are shown for decapod larvae at study zones: (i) species present in non-warm months; (ii) species present in warm months; (iii) species present through all year

Larval descriptions of the family Porcellanidae: A worldwide annotated compilation of the literature (Crustacea, Decapoda)

For most of the family Porcellanidae, which comprises 283 species, larval development remains to be described. Full development has been only described for 52 species, while part of the larval cycle has been described for 45 species. The importance of knowing the complete larval development of a species goes beyond allowing the identification of larval specimens collected in the plankton. Morphological larval data also constitute a support to cladistic techniques used in the establishment of the phylogenetic status (see Hiller et al. 2006, Marco-Herrero et al. 2013). Nevertheless, the literature on the larval development of this family is old and widely dispersed and in many cases it is difficult to collect the available information on a particular taxon. Towards the aim of facilitating future research, all information available on the larval development of porcellanids has been compiled. Following the taxonomic checklist of Porcellanidae proposed by Osawa and McLaughlin (2010), a checklist has been prepared that reflects the current knowledge about larval development of the group including larval stages and the method used to obtain the larvae, together with references. Those species for which the recognised names have been changed according to Osawa and McLaughlin (2010) are indicated

Equipo oceanográfico para la recogida de muestras de plancton aplicable a rosetas oceanográficas

Equipo oceanográfico para la recogida de muestras de plancton aplicable a rosetas oceanográficas. El equipo comprende una carcasa, una red de plancton y un colector. La carcasa protege la red, tiene una abertura superior y otra inferior. La abertura superior posee una tapa que puede abrirse o cerrarse por un mecanismo de muelles controlado por un cable tensor. La carcasa posee ventanas en el extremo superior y una tapa fija inferior con agujeros para permitir la evacuación del agua. La red de plancton se fija tanto al borde superior de la carcasa así como a la tapa fija inferior. El colector, cuya función es recoger el plancton filtrado, está fijado a la cara externa de la tapa fija inferior y presenta ventanas laterales para la evacuación del agua filtrada. En caso de que se deseen obtener muestras conservadas, dichas ventanas se localizarán en la mitad superior del colector

Illustrated keys for the identification of the Pleocyemata (Crustacea: Decapoda) zoeal stages, from the coastal region of south-western Europe

The identification keys of the zoeal stages of Pleocyemata decapod larvae from the coastal region of south-western Europe, based on both new and previously published descriptions and illustrations, are provided. The keys cover 127 taxa, most of them identified to genus and species level. These keys were mainly constructed upon external morphological characters, which are easy to observe under a stereomicroscope. Moreover, the presentation of detailed figures allows a non-specialist to make identifications more easily

Planktonic stages of Processa macrodactyla (Decapoda: Caridea: Processidae) reared in the laboratory

Two ovigerous females of the processid shrimp Processa macrodactyla were caught in April 1997 at 13 m depth in coastal waters of Rota, Cádiz Bay, south-western Spain (36°36′N 6°18′W). Rearing was terminated after nine zoeal stages, when larvae moulted to the first juvenile instar. Descriptions of the appendages of every instar have been made so as to: (1) compare the larval morphology with that of other previous described known species in the genus Processa (P. canaliculata, P. edulis, P. elegantula, P. modica, P. nouveli); and (2) with those larvae not ascribed to a certain species in order to facilitate the specific identification of unknown collected planktonic larvae. When describing P. macrodactyla some characters remained, with few exceptions, invariable in their setation form ZI to ZIV or ZV, to then change and maintain until the last zoeal stage. This can be due to intermediate moults, with the result that some larvae unite the characters of Stages ZIV and ZV and others those of ZV and ZVI

Morphology of first seven larval stages of the striped soldier shrimp, Plesionika edwardsii (Brandt, 1851) (Crustacea: Decapoda: Pandalidae) from laboratory reared material

With the idea of starting a research program for the biological study of Plesionika edwardsii, eight ovigerous females were collected with artisanal bottom traps at 220 m depth in the Southwest of Gran Canaria island, north-western Africa (27º43.864´N 15º47.822´W), for laboratory larval cultures. The first seven zoeal stages of Plesionika edwardsii were obtained for 20 days after hatching at 23.4 ± 0.4ºC, 10ºC above adult habitat temperature. The zoeal stages are described and illustrated, constituting the first detailed larval description of the genus Plesionika. The larval morphology is compared with previous larval descriptions attributed to Plesionika spp. collected in plankton tows and with descriptions of the first stage of development of Plesionika acanthonotus reared in laboratory

Muestreo de fitoplancton para extracción de PUA (Aldehídos Volatiles Poliinsaturados)

Metodología para obtener muestras de fitoplancton para posterior extracción, caracterización y cuantificación de Aldehídos volátiles insaturados

Description of the first five larval stages of Plesionika narval (Fabricius, 1787) (Crustacea, Decapoda, Pandalidae) obtained under laboratory conditions.

The first five zoeal stages of Plesionika narval were obtained from 15 days of laboratory culture. All larval stages are described and illustrated in detail. Zoeal characters are compared with the previous described larvae of Plesionika acanthonotus and Plesionika edwardsii and with undetermined zoeas of Pandalidae from plankton samples

Muestreo de microzooplancton profundo (> 2000 m)

Metodología para obtener muestras microzooplancton (20 – 200 mm) profundo en una estación de muestreo determinada, para estudios cualitativos o cuantitativos. Aunque el microzooplancton es muy abundante en aguas poco profundas de casi cualquier zona geográfica (ver Gifford y Caron, 2000) y no se necesita filtrar grandes volúmenes de agua para obtener una muestra representativa, no es así en aguas profundas (> 1000 m), donde probablemente pocos litros de agua pueden no ser suficientes para conseguir buenas estimas. Se hace pues necesaria la utilización de un muestreador que consiga filtrar un elevado volumen de agua por una malla de 20 mm

ROV's Video Recordings as a Tool to Estimate Variation in Megabenthic Epifauna Diversity and Community Composition in the Guaymas Basin

Patterns in benthic megafauna diversity in littoral and intertidal zones in the Gulf of California have been associated with both habitat heterogeneity and substrate type. Current knowledge of invertebrate communities in hard bottom habitats at depths > 200 m in the Gulf is poor due to the methodological limitations inherent in sampling deep habitats. Using video imagery of benthic habitats coupled with environmental data from the Remotely Operated Vehicle Doc Ricketts, we documented variation in the diversity and community composition of the benthos from 849 to 990 m depth in the NW limit of the Guaymas Basin, in relation to dissolved oxygen and substrate characteristics. This depth range overlaps an oxygen minimum zone where oxygen drops to levels < 0.5 ml L-1 and strong gradients in a narrow depth range occur. Dissolved oxygen varied along our benthic survey from 0.200 to 0.135 ml L-1. We observed high taxonomic richness across an area of rocky outcrops through the lower transition zone. This megafaunal pattern differs from reports from other oxygen minimum zones characterized by a great abundance of a few species. Taxonomic richness diminished at depths with reduced dissolved oxygen in the lower boundary of the oxygen minimum zone with increasing soft sediment cover. We found that rocky outcrops and structure-forming organisms such as corals, sponges, and oyster aggregations supported a higher diversity (H' = 0.8) than soft sediment (H' = 0.7) as have been observed in other habitats such as seamounts. Environmental variables that explained most of the megafaunal variation were substrate type (18.4%), depth (1.14%) and temperature (0.9%). Salinity (0.45%) and dissolved oxygen (0.3%) were less important factors to explain the megafaunal composition variance. Substrate type played a key role in the diversity and composition of benthic megafauna. These results broaden our understanding concerning the potential roles of substrate characteristics in the community composition of the deep-sea benthic megafaunal assemblages in the Gulf of California and oxygen minimum zones in general