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

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

Influence of reproduction on stable isotope ratios: nitrogen and carbon isotope discrimination between mothers, foetuses, and milk in the fin whale, a capital breeder

In mammals, the influence of gestation and lactation on the tissue stable-isotope ratios of females, fetuses, and milk remains poorly understood. Here we investigate the incidence of these events on δ13C and δ15N values in fin whales sampled off northwestern Spain between 1983 and 1985. The effect of gestation on tissue stable-isotope ratios was examined in the muscle of pregnant females (n = 13) and their fetuses (n = 10) and that of lactation in the muscle of nursing females (n = 21) and their milk (n = 25). Results suggest that fetuses are enriched compared to their mothers in both 15N (Δ15N = 1.5 ) and 13C (Δ13C =1.1 ), while, compared to muscle, milk is enriched in 15N (Δ15N = 0.3 ) but depleted in 13C (Δ13C = −0.62 ). This pattern is consistent with that previously observed for other species that, like the fin whale, rely on endogenous energy during reproduction, and it substantiates a general difference in the physiological processing of nitrogen and carbon balances between income and capital breeders. These findings are relevant to the understanding of the energetic balance of mammals during gestation and lactation and are central when inferences on trophic ecology are drawn from isotopic values of reproductive females

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

Multifocal Granulomatous Panniculitis with Ceroid Pigment in Two Mediterranean Striped Dolphins (Stenella coeruleoalba)

Two striped dolphins (Stenella coeruleoalba) were found stranded on the Catalonian Spanish coast. The main pathologic finding in both animals was the existence of multiple granulomatous lesions in the blubber, microscopically composed of macrophages and multinucleated cells containing vacuolar material. This material was identified as ceroid pigment due to its ultrastructural morphology, autofluorescence, and positive staining with periodic acid-Schiff and Ziehl-Neelsen techniques. The special stains and electron microscopy did not reveal any microorganisms associated with the lesions. These findings are very suggestive of ''nutritional panniculitis,'' a welldefined entity associated with vitamin E deficiency that has been rarely described in free-living species

Design and validation of the INCUE questionnaire: Assessment of primary healthcare Nurses’ basic training needs in palliative care

Many instruments have been created to measure knowledge and attitudes in palliative care. However, not only is it important to acquire knowledge, but also that this knowledge should reach patients and their relatives through application in clinical practice. This study aimed to develop and psychometrically test the INCUE questionnaire (Investigación Cuidados Enfermeros/Investigation into Nurses’ Care Understanding of End-of-Life) to assess the basic training needs of primary or home healthcare nurses in palliative care. A questionnaire was developed based on the classical theory of tests and factor analysis models. Initially, 18 experts developed 67 items in two blocks and determined content validity by two rounds of expert panels. Exploratory factor analysis and reliability testing were conducted with a non-probabilistic sample of 370 nurses. Some items were observed to have very low homogeneity indices or presented convergence problems and were eliminated. Questionnaire reliability was 0.700 in the theoretical block (KR20 Index) and 0.941 in the practical block (Cronbach’s alpha). The model converges and shows an adequate fit, specifically CFI = 0.977, TLI = 0.977 and RMSEA = 0.05. The correlation between the two factors in the model is ρ = 0.63. The questionnaire objectively evaluates primary or home healthcare nurses’ knowledge of palliative care and its practical application, thereby facilitating more efficient training plans.This questionnaire is being developed as part of a project to pinpoint the training needs of primary care nurses in the field of palliative care at the Dr Peset Health Department in Valencia (Project EAPCP19-V01)This project has received funding under the first Call for R + D Grants in Nursing 2019 (UGP-19-258), from the Fundació per al Foment de la Investigació Sanitària i Bioèdica de la Comunitat Valenciana (Fisabio).Enfermerí