Topographical variation in lipid content and morphological structure of the blubber in the striped dolphin

We investigate stratification patterns and topographical variations in the blubber of the striped dolphin (Stenella coeruleoalba) to gain insights into its regionally-specific functions. We collected blubber from 10 stranded striped dolphins (5 females and 5 males) from the eastern coast of Spain in 2007-2009, at 11 body positions. Histological measurements (adipocyte number and area) and blubber lipid content were analysed for each position. Histological measurements revealed stratification of blubber into outer, middle, and inner layers. Both the adipocyte number and area were largest in the middle layer. The adipocyte number was higher in the outer than the inner layer, whereas the adipocyte area was higher in the inner than the outer layer. The ventral anterior position did not follow this pattern, likely due to its proximity to the acoustic blubber, which is known to have a different biochemical composition. The stratification in morphological blubber characteristics most likely reflects functional differences. The outer layer may provide structural support and act as a mechanical barrier with a minor role in energy storage. The middle layer may be responsible for thermoregulation, and the inner layer could be responsible for energy mobilization, which is favoured by its proximity to the body core and a higher vascularization. In addition, an increasing gradient from dorsal to ventral positions was observed in the mean number of adipocytes and lipid content, with the exception of the caudal region. Although both ventral and dorsal blubber can have insulator and buoyancy functions, the ventral blubber may mainly serve as an energy reserve

Estructura morfológica y variación topográfica del contenido lipídico en la grasa del delfín listado

We investigate stratification patterns and topographical variations in the blubber of the striped dolphin (Stenella coeruleoalba) to gain insights into its regionally-specific functions. We collected blubber from 10 stranded striped dolphins (5 females and 5 males) from the eastern coast of Spain in 2007-2009, at 11 body positions. Histological measurements (adipocyte number and area) and blubber lipid content were analysed for each position. Histological measurements revealed stratification of blubber into outer, middle, and inner layers. Both the adipocyte number and area were largest in the middle layer. The adipocyte number was higher in the outer than the inner layer, whereas the adipocyte area was higher in the inner than the outer layer. The ventral anterior position did not follow this pattern, likely due to its proximity to the acoustic blubber, which is known to have a different biochemical composition. The stratification in morphological blubber characteristics most likely reflects functional differences. The outer layer may provide structural support and act as a mechanical barrier with a minor role in energy storage. The middle layer may be responsible for thermoregulation, and the inner layer could be responsible for energy mobilization, which is favoured by its proximity to the body core and a higher vascularization. In addition, an increasing gradient from dorsal to ventral positions was observed in the mean number of adipocytes and lipid content, with the exception of the caudal region. Although both ventral and dorsal blubber can have insulator and buoyancy functions, the ventral blubber may mainly serve as an energy reserve.En el presente estudio se investigaron los patrones de estratificación así como las variaciones topográficas en la grasa del delfín listado (Stenella coeruleoalba) con el fin de conocer mejor las posibles funciones regionales de este tejido. Se recolectaron muestras de grasa en 11 posiciones corporales diferentes de 10 delfines listados (5 hembras y 5 machos) varados en la costa este de España entre los años 2007 y 2009. Las medidas histológicas (número de adipocitos y área de los mismos) y el contenido lipídico se analizaron en cada una de las posiciones. Las medidas histológicas mostraron que la grasa se estratificaba en 3 capas: externa, media e interna. Tanto el número de adipocitos como su área eran mayores en la capa media. El número de adipocitos era superior en la capa externa que en la interna, mientras que el área de los adipocitos era mayor en la capa interna que en la externa. Sin embargo, la región ventral anterior no seguía este patrón, probablemente esto sea debido a que esta región se encuentra muy próxima a la grasa acústica, que es conocida por presentar una composición bioquímica diferente al resto de grasa corporal. La estratificación morfológica observada en la grasa probablemente esté reflejando una diferenciación funcional. La capa más externa podría dar soporte estructural y actuar como barrera mecánica, con un papel menos importante como almacén de reservas energéticas. La capa media podría ser responsable de la termorregulación, mientras que en la capa interna se produciría la movilización energética, lo cual se vería favorecido por su elevada vascularización y por estar en contacto con el interior del cuerpo. Además, se observó que tanto el número de adipocitos como el contenido lipídico seguían un gradiente creciente desde las posiciones dorsales a las ventrales, a excepción de la región caudal. Aunque tanto la grasa de la región dorsal como la de la ventral pueden presentar funciones de flotabilidad y aislamiento térmico, la grasa de la región ventral podría estar actuando principalmente como región de reserva energética

Isotopic evidence of limited exchange between Mediterranean and eastern North Atlantic fin whales

RATIONALE The relationship between stocks of fin whales inhabiting the temperate eastern North Atlantic and the Mediterranean Sea is subject to controversy. The use of chemical markers facilitates an alternative insight into population structure and potential borders between stocks because the two areas present dissimilar isotopic baselines. METHODS Baleen plates, composed of inert tissue that keeps a permanent chronological record of the isotopic value of body circulating fluids, were used to investigate connectivity and boundaries between the stocks. Values were determined by continuous flow isotope ratio mass spectrometry. RESULTS Stable isotopes confirm that, while the two subpopulations generally forage in well-differentiated grounds, some individuals with characteristic Atlantic values do penetrate into the Mediterranean Sea up to the northernmost latitudes of the region. As a consequence, the border between the two putative subpopulations may be not as definite as previous acoustic investigations suggested. The discriminant function obtained in this study may assist researchers to use baleen plate isotopic data to assign the origin of fin whales of uncertain provenance. CONCLUSIONS This study strengthens the stock subdivision currently accepted for management and conservation while recognizes a low level of exchange between the Mediterranean and temperate eastern North Atlantic subdivisions. Copyright © 2013 John Wiley & Sons, Ltd.Peer Reviewe

Perfluoroalkyl substances in striped dolphins (Stenella coeruleoalba) from the NW Mediterranean Sea: Biomagnification and temporal trends (1990-2021)

Poly- and Perfluoroalkyl Substances (PFAS) are widely recognized as a class of pollutants known for their ability to bioaccumulate and biomagnify in the environment. In this study, the objective is to determine the biomagnification rates of PFAS in sexually mature striped dolphins and assess the temporal trends of PFAS concentrations over the past three decades (1990-2021) in the North-Western Mediterranean Sea. Thirteen out of the 19 targeted PFAS compounds were detected in the digestive content of the dolphins, while all 17 PFAS compounds were detected in the liver samples. Concentrations of PFAS in the digestive content ranged from 50 to 1611 ng/g, while the liver samples showed concentrations ranging from 268 to 7014 ng/g. The most prevalent compounds found in both types of samples were linear perfluorooctanesulfonic acid (n-PFOS) and perfluorooctanesulfonamide (FOSA), which were present in all samples. Additionally, perfluoroundecanoic acid (PFUnDA), perfluorotridecanoic acid (PFTrDA), and perfluorononanoic acid (PFNA) were also detected in significant quantities. Interestingly, the study found that long-chain PFAS compounds exhibited greater biomagnification rates compared to short-chain PFAS compounds in striped dolphins. This suggests a potential impact on the health of these marine mammals due to the accumulation of long-chain PFAS in their systems. The analysis of the samples indicated that half of the digestive content samples exceeded the Environmental Quality Standards (EQS) concentrations, indicating that the consumption of polluted prey may pose health risks for striped dolphins. When examining the temporal trends, the concentrations of most long-chain PFAS compounds showed an increase from 1990 to 2004-2009. However, concentrations appeared to stabilize during the period of 2014-2021, potentially reflecting the impact of country regulations and industry initiatives aimed at reducing PFAS pollution. These findings underscore the persistent presence of banned PFAS compounds in the marine ecosystem and highlight the need for ecological risk assessments and the development of management strategies to mitigate PFAS pollution in marine environments. In conclusion, this study provides valuable insights into the biomagnification rates of PFAS in striped dolphins and highlights the persistent nature of these pollutants in the North-Western Mediterranean Sea. The identification of specific PFAS compounds and their temporal trends contribute to the understanding of PFAS pollution and support future efforts in assessing ecological risks and implementing effective management strategies in marine ecosystems

High incidence of clinical fragility fractures in postmenopausal women with rheumatoid arthritis. A case-control study.

Objectives: To estimate the incidence of clinical fragility fractures in postmenopausal women with rheumatoid arthritis (RA) and analyze risk factors for fracture. Methods: Incidence of clinical fragility fractures in 330 postmenopausal women with RA was compared to that of a control population of 660 age-matched postmenopausal Spanish women. Clinical fractures during the previous five years were recorded. We analyzed associations with risk factors for fracture in both populations and with disease-related variables in RA patients. Results: Median age of RA patients was 64 years; median RA duration was eight years. Sixty-nine percent were in remission or on low activity. Eighty-five percent had received glucocorticoids (GCs); 85 %, methotrexate; and 40 %, ≥1 biologic DMARD. Fifty-four patients and 47 controls had ≥1 major osteoporotic fracture (MOF). Incidence of MOFs was 3.55 per 100 patient-year in patients and 0.72 in controls (HR: 2.6). Risk factors for MOFs in RA patients were age, previous fracture, parental hip fracture, years since menopause, BMD, erosions, disease activity and disability, and cumulative dose of GCs. Previous fracture in RA patients was a strong risk for MOFs (HR: 10.37). Conclusion: Of every 100 postmenopausal Spanish women with RA, 3-4 have a MOF per year. This is more than double that of the general population. A previous fracture poses a high risk for a new fracture. Other classic risk factors for fracture, RA disease activity and disability, and the cumulative dose of GCs are associated with fracture development

Fin whale (Balaenoptera physalus) mitogenomics: A cautionary tale of defining sub-species from mitochondrial sequence monophyly

© The Authors, 2019. This article is distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 4.0 International License. The definitive version was published in Molecular Phylogenetics and Evolution (2019), doi:10.1016/j.ympev.2019.02.003.The advent of massive parallel sequencing technologies has resulted in an increase of studies based upon complete mitochondrial genome DNA sequences that revisit the taxonomic status within and among species. Spatially distinct monophyly in such mitogenomic genealogies, i.e., the sharing of a recent common ancestor among con-specific samples collected in the same region has been viewed as evidence for subspecies. Several recent studies in cetaceans have employed this criterion to suggest subsequent intraspecific taxonomic revisions. We reason that employing intra-specific, spatially distinct monophyly at non-recombining, clonally inherited genomes is an unsatisfactory criterion for defining subspecies based upon theoretical (genetic drift) and practical (sampling effort) arguments. This point was illustrated by a re-analysis of a global mitogenomic assessment of fin whales, Balaenoptera physalus spp., published by Archer et al. (2013), which proposed to further subdivide the Northern Hemisphere fin whale subspecies, B. p. physalus. The proposed revision was based upon the detection of spatially distinct monophyly among North Atlantic and North Pacific fin whales in a genealogy based upon complete mitochondrial genome DNA sequences. The extended analysis conducted in this study (1,676 mitochondrial control region, 162 complete mitochondrial genome DNA sequences and 20 microsatellite loci genotyped in 358 samples) revealed that the apparent monophyly among North Atlantic fin whales reported by Archer et al. (2013) to be due to low sample sizes. In conclusion, defining sub-species from monophyly (i.e., the absence of para- or polyphyly) can lead to erroneous conclusions due to relatively “trivial” aspects, such as sampling. Basic population genetic processes (i.e., genetic drift and migration) also affect the time to the most recent common ancestor and hence the probability that individuals in a sample are monophyletic.We are grateful to Hanne Jørgensen, Anna Sellas, Mary Beth Rew and Christina Færch-Jensen for technical assistance. We thank Drs. P. E. Rosel and K. D. Mullin (U.S. National Marine Fisheries Service Southeast Fisheries Science Center) and members of the U.S. Northeast and Southeast Region Marine Mammal Stranding Network and its response teams, including the International Fund for Animal Welfare, the Marine Mammal Stranding Center, Mystic Aquarium, the Riverhead Foundation for Marine Research and Preservation (K. Durham) and the Marine Mammal Stranding Program of the University of North Carolina Wilmington for access to fin whale samples from the western North Atlantic. We thank Gisli Vikingsson for providing samples. We are indebted to Dr. Eduardo Secchi for facilitating data sharing. Data collection in the Southern Ocean was conducted under research projects Baleias (CNPq grants 557064/2009-0 and 408096/2013-6), INTERBIOTA (CNPq 407889/2013-2) and INCT-APA (CNPq 574018/2008-5), of the Brazilian Antarctic Program and a contribution by the research consortium ‘Ecology and Conservation of Marine Megafauna – EcoMega-CNPq’. MAS was supported through a FCT Investigator contract funded by POPH, QREN European Social Fund, and Portuguese Ministry for Science and Education. Data collection in the Azores was funded by TRACE-PTDC/MAR/74071/2006 and MAPCET-M2.1.2/F/012/2011 [FEDER, COMPETE, QREN European Social Fund, and Proconvergencia Açores/EU Program]. Fin whale illustration herein is used with the permission of Frédérique Lucas. We acknowledge the Center for Information Technology of the University of Groningen for IT support and access to the Peregrine high performance-computing cluster

Tissue distribution of retinoids in common dolphins Delphinus delphis

Exposure to organochlorines induces retinoid deficiency in mammals; hence, retinoids are potential biomarkers of the impact of these pollutants. Appropriate target tissues to monitor retinoids in cetaceans have not been properly identified because of a lack of information on the contribution of each tissue to total body retinoids. Therefore, we have addressed this issue by studying the contribution of the main body tissues to retinoids in 21 common dolphins obtained from incidental catches and in apparent good health and nutritive condition. Although concentrations in the liver were highest, those in blubber were also high and accounted for 43% of the total retinoid load of the compartments examined. As blubber can be obtained using non-invasive biopsy techniques, this tissue is proposed as a reliable indicator of retinoid status in cetaceans. However, blubber topographical variation in structure and composition requires standardization of sampling sites. Retinoid concentrations did not differ significantly between sexes or with body size for any of the tissues, but the lipid content of blubber strongly influenced these concentrations. Biopsies from healthy, free-ranging individuals are preferred to samples from stranded animals. Further research on the influence of factors (age, sex, reproductive condition, diet) that potentially affect retinoid levels is required to implement the use of retinoids as biomarkers of pollutant exposure in cetaceans

Retinoid and lipid patterns in the blubber of common dolphins (Delphinus delphis): implications for monitoring vitamin A status

We determined retinoid concentrations in various body positions of the blubber of 25 common dolphins (Delphinus delphis) to study topographical variation in concentrations. Specimens were obtained from incidental catches and were apparently healthy. We found concentrations to be high and therefore conclude that blubber represents a significant contribution to total retinoid body load. Consequently, blubber is proposed as a tissue of choice for monitoring retinoid status in this species. Anterior-ventral blubber had the highest vitamin A concentration and posterior-dorsal the lowest. Therefore, when assessing retinoid status, topographical variation should be taken into account to ensure consistent sampling. This pattern appeared to be explained by a parallel variation in lipid content. Thus, the dynamics and body distribution of retinoids appear to be basically governed by the lipophilicity of the molecules. The highest lipid richness found in the anterior-ventral region might indicate that this region is comparatively more important for insulation and lipid storage than the dorsal posterior region. Retinoid levels did not appear to vary according to sex, but they did vary with lipid content. This should be taken into account when designing sampling protocols; for monitoring purposes, biopsies from healthy, free-ranging individuals should be preferred to samples from stranded animals

Temporal trends of halogenated and organophosphate contaminants in striped dolphins from the Mediterranean Sea

PBDEs, HBCD, novel DBDPE, PBEB and HBB, dechloranes, OPFRs and natural MeO-PBDEs were monitored in muscle of striped dolphins (Stenella coeruleoalba) from the Mediterranean Sea collected in three time periods (1990, 2004–2009 and 2014–2018). PBDEs levels decreased about 60% in under three decades, from 5067 ± 2210 to 2068 ± 2642 ng g−1 lw, evidencing the success of their ban. Most PBDEs were found in all the samples, with BDE-47, -99, -154, -100 and -153 as the main contributors. Found in 71.4% of the samples, α-HBCD was stable through time and usually <LOQ. DBDPE concentrations decreased by 89% from 1990 to 2004–2009 and have remained stable since. HBB occurred rarely and decreased by 94% to a current few ng g−1 lw. Dec 602 was the main dechlorane with stable concentrations around 1200 ng g−1 lw, but a declining trend might have started in the last years. OPFRs concentrations were stable and showed the highest concentrations of all FRs in 2014–2018: 6253 ± 11,293 ng g−1 lw. TBOEP and TNBP contributed to most of the OPFR concentration, the former with decreasing levels by 96%. MeO-PBDEs showed mean concentrations between 600 and 700 ng g−1 lw in all periods. Non-targeted analysis allowed the identification and semi-quantification of additional chlorinated pollutants, such as polychlorinated terphenyls (PCTs) (levels decreasing by 81% to a current 770 ng g−1 lw mean) and polychlorinated diphenyl ethers (PCDEs) (decreasing by 83% to a current 3200 ng g−1 lw) in Mediterranean marine mammals for the first time.This work has been financially supported by the European project Synergising International research Studies into the environmental Fate and Behaviour of Toxic Organic Chemicals in the Waste Stream (INTERWASTE, ID 734522, H2020-MSCA-RISE/0253), by the Spanish Ministry of Science and Innovation (Project CEX2018-000794-S) and the Generalitat de Catalunya (Consolidated Research Group 2017 SGR 1404 – Water and Soil Quality Unit). Biotage is acknowledged for providing SPE cartridges. The samples were provided by the Departament de Biologia Animal, Universitat de Barcelona.Peer reviewe