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  • Author or Editor: Carlos Esse x
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Abstract

The deep-water rose shrimp, Parapenaeus longirostris (H. Lucas, 1846), is the most dominant shrimp species on the Algerian west coast. In that area, the diet of P. longirostris was studied between July 2020 and June 2021. This approach to the diet of the rose shrimp was based on analysis of the stomach contents and determination of the ingested prey. A seasonal sampling was carried out in the main fishing ports (Béni Saf, Bouzedjar, Oran and Mostaganem). The results obtained showed that the shrimp feed intensively in spring and increasingly less in winter and summer. Crustaceans, foraminiferans, polychaetes, and molluscs constituted the most frequent preys in the diet, with respective frequencies of 58.85, 55.95, 36.63 and 32.04%. Small microplancton and mesoplancton prey (radiolarians, copepods, and various larvae) were less important in the diet of P. longirostris. Fish and echinoderms constitute accidental prey, of which the frequency is less than 10%.

In: Crustaceana

Abstract

Antofagasta Bay is characterized by having a high primary productivity due to the presence of the cold Humboldt Stream. However, due to the current global climate change, also the previously generated biodiversity patterns are changing. The aim of the present study was analysing Antofagasta Bay in order to determine the existence of correlations between optical, i.e., spectral, properties recorded through remote sensing on the one hand, and the presence of dinoflagellates and zooplankton, on the other. The studies were done during two periods, i.e., in February 2019 and February 2020. The results revealed the existence of three main groups of sites: a first group comprising sites sampled in February 2019, with high Band 3 and Band 4 reflectance, high chlorophyl values, and high abundances of Dinophysis and copepods; a second group combining four sites visited in February 2019, with high Gymnodinium and Ceratium, high reflectance in Band 1, Band 2, Band 5, Band 6 and Band 7, and low zooplankton abundance; and finally a third group encompassing all sites sampled in 2020, with high Prorocentrum abundance, and low zooplankton abundance, as well as low reflectance. A similar situation with regard to zooplankton and optical properties was earlier reported for Chilean Patagonian lakes.

In: Crustaceana

Abstract

Antofagasta Bay is characterized by a high primary productivity due to the presence of the cold Humboldt Stream that is associated with a high diversity in flora and fauna in the benthic and pelagial environments of the Chilean west coast. Nevertheless, due to the global climate changes, the existing biodiversity patterns change as well. The aim of the present study was to analyse Antofagasta Bay for determining the existence of patterns between optical properties of the water, and the phytoplankton and zooplankton. The results show that one site had high chlorophyll concentrations, high reflectance, a high abundance of the dinoflagellate genus Dinophysis, and a high abundance of copepodites, whereas five sites had low chlorophyll concentrations, a low reflectance value, low copepodite abundances, and high abundances of dinoflagellates of the genera Ceratium, Gymnodinium and Prorocentrum. These results are similar to earlier observations for the coastal waters along northern Chile.

In: Crustaceana

Abstract

The Chilean north Patagonian lakes are characterized by their marked oligotrophic or oligomesotrophic status and low abundance of zooplankton species; many of the lakes with oligomesotrophic status are associated with human intervention due to towns on their shores. The aim of the present study was to determine the relations between spectral properties (LANDSAT OLI), chlorophyll and plankton abundances in two north Patagonian lakes: Villarrica, which has two towns on its shores, and Lake Caburgua, which has native forest on its shores. The results revealed that Lake Villarrica has high reflectance in the near infrared, red and green bands, high concentrations of chlorophyll a, the absence of mixotrophic protozoa, and a high abundance of bacterial and plankton, mainly phytoplankton (Chlophyceae and diatoms) and zooplankton. Lake Caburgua, on the other hand, has low reflectance in the same bands, and low chlorophyll concentrations, low bacterial and zooplankton abundances, with the exception of high mixotrophic ciliates and small phytoplankton, and Volvox colonies. The obtained results agree with limnological observations on both lakes, and observations agrees with similar observations of the spectral properties of glacial north Patagonian lakes and of the zooplankton community, and in this scenario, the use of remote-sensing techniques would be a good tool to predict the plankton community in Patagonian lakes.

In: Animal Biology

Abstract

The intertidal invertebrate community on rocky shores in northern Chile is characterised by a high species richness resulting from the high productivity of this ecosystem. The present study aims to do the first characterisation of invertebrate communities on rocky shores in Antofagasta town and surroundings (23°S), using species co-occurrence and niche-sharing null models, analysis of similarities (ANOSIM) and nonmetric multidimensional scaling (NMDS). The null model results revealed that species associations are not structured, that the existing species do not have the same ecology, which would result in many repeated species by site, and that specificity in their ecological niches exists. The ANOSIM and NMDS revealed the absence of significant differences between sites with human intervention and without human intervention. The obtained results agree with the literature for northern and central Chilean and southern Peruvian rocky shores, and other coastal marine ecosystems with high productivity.

In: Animal Biology