Environmental DNA (eDNA) for monitoring marine mammals: Challenges and opportunities

Monitoring marine mammal populations is essential to permit assessment of population status as required by both national and international legislation. Traditional monitoring methods often rely on visual and/or acoustic detections from vessels and aircraft, but limitations including cost, errors in the detection of some species and dependence on taxonomic expertise, as well as good weather and visibility conditions often limit the temporal and spatial scale of effective, long-term monitoring programs. In recent years, environmental DNA (eDNA) has emerged as a revolutionary tool for cost-effective, sensitive, noninvasive species monitoring in both terrestrial and aquatic realms. eDNA is a rapidly developing field and a growing number of studies have successfully implemented this approach for the detection and identification of marine mammals. Here, we review 21 studies published between 2012 and 2021 that employed eDNA for marine mammal monitoring including single species detection, biodiversity assessment and genetic characterization. eDNA has successfully been used to infer species presence (especially useful for rare, elusive or threatened species) and to characterize the population genetic structure, although additional research is needed to support the interpretation of non-detections. Finally, we discuss the challenges and the opportunities that eDNA could bring to marine mammal monitoring as a complementary tool to support visual and acoustic methods

Comparación de la incidencia de malformaciones morfológicas y esqueléticas entre rodaballos (Scophthalmus maximus l.) diploides y triploides

Triploid fish are sterile and can be grown to the desired size without the problems related to reproduction. This is an interesting option for the marketing of large fish. Triploidy in some species is associated with morphological and skeletal deformations causing changes in the appearance of the fish and therefore also in their commercial value. This study compared the incidence of morphological and skeletal malformations in two groups of triploid turbot and diploid controls at 6 and 12 months of age. Morphological alterations were determined from measurements on external photographs of the upper side of the fish, and skeleton alterations were studied through X-ray photographs. The incidences of morphological and skeletal malformations were not significantly different (p>0.05) between ploidy in either of the two groups analyzed. These results suggest that triploidy per se does not induce malformations in turbot, although, it is possible that in some cases the induction treatment can cause these effects

Pth4, an ancient parathyroid hormone lost in eutherian mammals, reveals a new brain-to-bone signaling pathway

Regulation of bone development, growth, and remodeling traditionally has been thought to depend on endocrine and autocrine/paracrine modulators. Recently, however, brain-derived signals have emerged as key regulators of bone metabolism, although their mechanisms of action have been poorly understood. We reveal the existence of an ancient parathyroid hormone (Pth)4 in zebrafish that was secondarily lost in the eutherian mammals' lineage, including humans, and that is specifically expressed in neurons of the hypothalamus and appears to be a central neural regulator of bone development and mineral homeostasis. Transgenic fish lines enabled mapping of axonal projections leading from the hypothalamus to the brainstem and spinal cord. Targeted laser ablation demonstrated an essential role for of pth4-expressing neurons in larval bone mineralization. Moreover, we show that Runx2 is a direct regulator of pth4 expression and that Pth4 can activate cAMP signaling mediated by Pth receptors. Finally, gain-of-function experiments show that Pth4 can alter calcium/phosphorus levels and affect expression of genes involved in phosphate homeostasis. Based on our discovery and characterization of Pth4, we propose a model for evolution of bone homeostasis in the context of the vertebrate transition from an aquatic to a terrestrial lifestyle.Spanish Economy and Competitiveness Ministry Project [ALG2011-23581, AGL2014-52473R]; Portuguese Foundation for Science and Technology [PTDC/BIA-ANM/4225/2012-phos-fate]; U. S. National Institutes of Health/Office of the Director Grant [R01OD011116, R01 RR020833]; Generalitat de Catalunya [SGR2014-290]; Spanish Economy and Competitiveness Ministry [BFU2010-14875]; Science and Innovation Ministry [AGL2010-22247-C03-01]; Campus do Mar Ph.D. grant; Xunta de Galicia (Santiago, Spain) [AGL2014-52473R]info:eu-repo/semantics/publishedVersio

Our waves in the ocean: Projects for marine conservation and sustainable fisheries

Poster.-- Close Encounters IIM (2nd Kind) Virtual Conference, 26th February 2021N

Nuevas tecnologías moleculares y de control remoto para la evaluación de las poblaciones de cetáceos (Proyecto NuTec)

Poster.-- Encontros IIM Primeira fase, 12 de decembro de 2019Peer reviewe

Climate change and finfish aquaculture: insights from zebrafish

II International Symposium in Marine Sciences = II Simposio internacional de Ciencias del Mar, Vigo, 27-30 abril 2009N

Morphological and Molecular Characterization of Dietary-Induced Pseudo-Albinism during Post-Embryonic Development of Solea senegalensis (Kaup, 1858)

16 páginas, 5 tablas, 8 figurasThe appearance of the pseudo-albino phenotype was investigated in developing Senegalese sole (Solea senegalensis, Kaup 1858) larvae at morphological and molecular levels. In order to induce the development of pseudo-albinos, Senegalese sole larvae were fed Artemia enriched with high levels of arachidonic acid (ARA). The development of their skin pigmentation was compared to that of a control group fed Artemia enriched with a reference commercial product. The relative amount of skin melanophores, xanthophores and iridophores revealed that larval pigmentation developed similarly in both groups. However, results from different relative proportions, allocation patterns, shapes and sizes of skin chromatophores revealed changes in the pigmentation pattern between ARA and control groups from 33 days post hatching onwards. The new populations of chromatophores that should appear at post-metamorphosis were not formed in the ARA group. Further, spatial patterns of distribution between the already present larval xanthophores and melanophores were suggestive of short-range interaction that seemed to be implicated in the degradation of these chromatophores, leading to the appearance of the pseudo-albino phenotype. The expression profile of several key pigmentation-related genes revealed that melanophore development was promoted in pseudo-albinos without a sufficient degree of terminal differentiation, thus preventing melanogenesis. Present results suggest the potential roles of asip1 and slc24a5 genes on the down-regulation of trp1 expression, leading to defects in melanin production. Moreover, gene expression data supports the involvement of pax3, mitf and asip1 genes in the developmental disruption of the new post-metamorphic populations of melanophores, xanthophores and iridophores.This work was funded by the Ministry of Science and Innovation (MICIIN) of the Spanish Government (project AGL2008-03897-C04-01/ACU). MD was supported by a Juan de la Cierva post-doctoral contract (MICIIN, Spain)Peer reviewe

Brains in metamorphosis: Temporal transcriptome dynamics in hatchery-reared flatfishes

Metamorphosis is a captivating process of change during which the morphology of the larva is completely reshaped to face the new challenges of adult life. In the case of fish, this process initiated in the brain has traditionally been considered to be a critical rearing point and despite the pioneering molecular work carried out in other flatfishes, the underlying molecular basis is still relatively poorly characterized. Turbot brain transcriptome of three developmental stages (pre-metamorphic, climax of metamorphosis and post-metamorphic) were analyzed to study the gene expression dynamics throughout the metamorphic process. A total of 1570 genes were differentially expressed in the three developmental stages and we found a specific pattern of gene expression at each stage. Unexpectedly, at the climax stage of metamorphosis, we found highly expressed genes related to the immune response, while the biological pathway enrichment analysis in pre-metamorphic and post-metamorphic were related to cell differentiation and oxygen carrier activity, respectively. In addition, our results confirm the importance of thyroid stimulating hormone, increasing its expression during metamorphosis. Based on our findings, we assume that immune system activation during the climax of metamorphosis stage could be related to processes of larval tissue inflammation, resorption and replacement, as occurs in other vertebrates.Fil: Guerrero Peña, Laura. Spanish National Research Council. Institute of Marine Research. Aquatic Biotechnology Lab; Spain.Fil: Suarez Bregua, Paula. Spanish National Research Council. Institute of Marine Research. Aquatic Biotechnology Lab; Spain.Fil: Méndez Martínez, Luis. Spanish National Research Council. Institute of Marine Research. Aquatic Biotechnology Lab; Spain.Fil: García Fernández, Pablo. Nueva Pescanova Biomarine Center; Spain.Fil: Tur, Ricardo. Nueva Pescanova Biomarine Center; Spain.Fil: Rubiolo, Juan Andrés. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro Científico y Tecnológico Acuario del Río Paraná; Argentina.Fil: Rubiolo, Juan Andrés. Universidad de Santiago de Compostela. Facultad de Veterinaria. Departamento de Genética; Spain.Fil: Tena, Juan J. Universidad Pablo de Olavide. Centro Andaluz de Biología del Desarrollo (CABD); Spain.Fil: Rotllant, Josep. Spanish National Research Council. Institute of Marine Research. Aquatic Biotechnology Lab; Spain

Identification of cetacean species in multi-purpose surveys using environmental DNA metabarcoding and visual monitoring

34th European Cetacean Society Conference, O Grove, 16-20 April 2023Environmental DNA (eDNA) metabarcoding has recently emerged as a promising method to study the diversity of aquatic vertebrates in marine environments supporting the traditional monitoring. However, only a handful of eDNA studies have evaluated the detection of marine mammal species and compared information obtained from eDNA and visual monitoring methods. In this work, we used eDNA isolated from water samples and MarVer3 metabarcoding primers previously published by Valsecchi et al. (2020) to detect and identify cetacean species. A total of 77 water samples were collected during the PELACUS 2021 survey along the continental shelf waters of the northern and northwestern Iberian Peninsula. Water sampling was conducted every approximately 20 nmi (nautical miles) along the line-transect while marine mammal sightings were recorded with the distance sampling methodology. The results showed that four cetacean species (bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus delphis), minke whale (Balaenoptera acutorostrata) and Cuvier‟s beaked whale (Ziphius cavirostris) were identified by eDNA and visual methods. In addition, eDNA samples revealed the presence of fin whale (Balaenoptera physalus), which was overlooked by visual monitoring. However, long-finned pilot whale (Globicephala melas) and striped dolphin (Stenella coeruleoalba) were only sighted by observers. These findings support the eDNA analysis as a complementary tool to traditional visual surveys, which are currently the primary method for monitoring the health status of cetacean populationsN

Possible role of central the melanocortin system in the control of circadian locomotor activity rhythms

Trabajo presentado en el 11º Congreso de la Asociación Ibérica de Endocrinología Comparada (AIEC), celebrado en Vigo (España), del 13 al 15 de julio de 2017The melanocortin system integrates peptides derived from proopiomelanocortin that show melanocortinic and/or corticotropic activity. Endogenous melanocortin antagonists, agouti-signaling protein (ASIP) and agouti-related protein (AGRP) compete with melanocortin peptide for binding to five different melanocortin receptors (MC1RMC5R). In zebrafish, AGRP and MC5R are duplicated. AGRP1 is specifically expressed in the hypothalamus but AGRP2 is expressed in the pineal. AGPR2 modulates the expression of the melanin-concentrating hormone (MCH) that is involved in the background adaptation. The expression of AGRP2 in the zebrafish pineal gland suggests the involvement of the melanocortin system in the regulation of circadian rhythms. We use a zebrafish transgenic strain overexpressing ASIP (Ag zebrafish) to study the role of melanocortin antagonist in the circadian structure of fish. We demonstrate that both diurnal and nocturnal melatonin levels in Ag zebrafish are statistically similar. Accordingly, comparison of brain transcriptome between Ag and wild type (WT) zebrafish revealed a significant enrichment of tryptophan and circadian rhythms go terms. Finally, the analysis of daily locomotor activity exhibited significant differences between Ag and WT fish further supporting a role for melanocortin system in the activity rhythms of zebrafish.Peer reviewe