Search results for " Invertebrates"

Parasite community diversity in two Mediterranean labrid fishes Symphodus tinea and Labrus merula

1994

Examination of 111 peacock wrasse [Symphodus tinea (L.)] and 97 brown wrasse (Labrus merula L.) from the Valencian coast (Spain) yielded 24 metazoan parasite species (11 Digenea, three Cestoda, four Nematoda. one Acanlhocephala, five Crustacea). Eighteen species were from 5. tinea and 17 from L. merula; 11 of the 24 species were common to both hosts. Brillouin's diversity index, was applied to fully censused parasite infracommunities. This is the first time that all the metazoan parasites (internal and external) in any position in the host have been analysed for diversity. High values of prevalence, intensity, and diversity parameters indicate that these labrid fishes support diverse parasi…

Poor nutritional quality of primary producers and zooplankton driven by eutrophication is mitigated at upper trophic levels

2022

Eutrophication and rising water temperature in freshwaters may increase the total production of a lake while simultaneously reducing the nutritional quality of food web components. We evaluated how cyanobacteria blooms, driven by agricultural eutrophication (in eutrophic Lake Köyliöjärvi) or global warming (in mesotrophic Lake Pyhäjärvi), influence the biomass and structure of phytoplankton, zooplankton, and fish communities. In terms of the nutritional value of food web components, we evaluated changes in the ω-3 and ω-6 polyunsaturated fatty acids (PUFA) of phytoplankton and consumers at different trophic levels. Meanwhile, the lakes did not differ in their biomasses of phytoplankton, zoo…

Polymorphism in Developmental Mode and Its Effect on Population Genetic Structure of a Spionid Polychaete, Pygospio elegans

2012

Population genetic structure of sedentary marine species is expected to be shaped mainly by the dispersal ability of their larvae. Long-lived planktonic larvae can connect populations through migration and gene flow, whereas species with nondispersive benthic or direct-developing larvae are expected to have genetically differentiated populations. Poecilogonous species producing different larval types are ideal when studying the effect of developmental mode on population genetic structure and connectivity. In the spionid polychaete Pygospio elegans, different larval types have been observed between, and sometimes also within, populations. We used microsatellite markers to study population st…

Invertebrate Models in Innate Immunity and Tissue Remodeling Research

2022

The aim of this Special Issue is to highlight the close functional and highly conserved link between innate immunity, homeostasis maintenance, inflammation, tissue remodeling and regeneration [...]

Introduction to Symposium: Poecilogony--A Window on Larval Evolutionary Transitions in Marine Invertebrates

2012

Poecilogony is the intraspecific variation in developmental mode that has been described in some marine invertebrates. Poecilogonous species produce different larval forms (e.g., free-swimming planktotrophic larvae as well as brooded lecithotrophic or adelphophagic larvae). Poecilogony can be a controversial topic, since it is difficult to identify and characterize the phenomenon with certainty. It has been challenging to determine whether poecilogony represents developmental polymorphism with a genetic basis or developmental polyphenism reflecting plastic responses to environmental cues. Other outstanding questions include whether common mechanisms underlie the developmental variation we o…

Cytotoxic Activity of Tunicate Hemocytes

1996

Tunicates (protochordates) are filter-feeding marine invertebrates with a worldwide distribution. In their larval form, they exhibit many of the features characteristic of the vertebrates. The larva, with a tail, notochord, and dorsal neural tube, upon settlement undergoes a remarkable metamorphosis in which it loses most of its chordate characteristics and becomes a sessile invertebrate adult. Thus, due to these characteristics, tunicates are considered to be the most primitive members of the phylum Chordata. Owing to their position in the phylogenetic line leading to the vertebrates, they have attained importance as experimental organisms and have been examined by researchers from a varie…

Insight into the role of cetaceans in the life cycle of the tetraphyllideans (Platyhelminthes: Cestoda)

2007

Abstract Four types of tetraphyllidean larvae infect cetaceans worldwide: two plerocercoids differing in size, ‘small’ (SP) and ‘large’ (LP), and two merocercoids referred to as Phyllobothrium delphini and Monorygma grimaldii . The latter merocercoid larvae parasitize marine mammals exclusively and exhibit a specialised cystic structure. Adult stages are unknown for any of the larvae and thus the role of cetaceans in the life cycle of these species has been a long-standing problem. The SP and LP forms are thought to be earlier stages of P. delphini and M. grimaldii that are presumed to infect large pelagic sharks that feed on cetaceans. A molecular analysis of the D2 variable region of the …

GHOST NETS AS SUBSTRATE FOR MARINE INVERTEBRATES

Marine molecular biology : An emerging field of biological sciences

2007

An appreciation of the potential applications of molecular biology is of growing importance in many areas of life sciences, including marine biology. During the past two decades, the development of sophisticated molecular technologies and instruments for biomedical research has resulted in significant advances in the biological sciences. However, the value of molecular techniques for addressing problems in marine biology has only recently begun to be cherished. It has been proven that the exploitation of molecular biological techniques will allow difficult research questions about marine organisms and ocean processes to be addressed. Marine molecular biology is a discipline, which strives t…

Evaluating anthropogenic impacts on naturally stressed ecosystems: Revisiting river classifications and biomonitoring metrics along salinity gradients

2019

Naturally stressed ecosystems hold a unique fraction of biodiversity. However, they have been largely ignored in biomonitoring and conservation programmes, such as the EU Water Framework Directive, while global change pressures are threatening their singular values. Here we present a framework to classify and evaluate the ecological quality of naturally stressed rivers along a water salinity gradient. We gathered datasets, including aquatic macroinvertebrate assemblages and environmental information, for 243 river locations across the western Mediterranean to: a) gauge the role of natural stressors (salinity) in driving aquatic community richness and composition; b) make river classificatio…