Fin Size Research Articles

Heat transfer enhancement of rectangular fins with circular perforations

Heat transfer augmentation devices like fins have been around for quite long time. Because of the increased demand for lightweight, thin, and cost-effective fins, fin size optimization is important. As a result, fins must be designed to extract the most heat with the least amount of material while keeping the fin’s ease of manufacture in consideration. The enhancement in heat transfer coefficient is related to the resetting of the thermal boundary layer for each disturbance. Perforated plates in fins are examples of surface disturbance. The aim of this research is to analyze the temperature reduction over a variety of circular perforations. Numerical simulation (ANSYS Fluent code) is employed to examine fins with perforations. A FVM code is used to solve turbulent air flow and heat transfer equations across fins. Over a continuum of circular perforation counts, other variables such as heat flux and thermal gradient are compared. It was observed that there was a significant temperature drop as well as an improvement in heat transfer. The results can be extended to the design of rectangular fin heat exchangers.

A Parametric Study of Wind Pressure Distribution on Façades Using Computational Fluid Dynamics

This paper uses Computational Fluid Dynamics (CFD) to determine wind pressures on façades for the purpose of efficient design of these elements. An outstand fin arrangement was modeled where local brackets are used to protrude the fins from the building. A parametric study, for both changes in the length of the bracket and the fin, was derived from CFD simulations with 1-in-50-year storm conditions adopted throughout. Further simulations are performed for revised wind directions that ensure all fins are equally exposed to oncoming winds. In total, 15 models are created to act as a representative sample of the total number of possible configurations. Peak values for pressure are used to calculate forces and moments on the fins. These wind loading results were then used to interpolate the values for the remaining façade geometries. From interpreting the trends that are apparent in the relationship of fin size and bracket length to efficient loading, a set of design criteria is established. The optimal façade design is defined, based on placing equal importance onto minimizing the force along the fin’s length and the moment acting at the fin-bracket connection. The performance of some façade elements is shown to worsen the effects of the wind, relative to other designs, with the potential for very negative consequences. Wind direction is shown to have a significant effect on loading, with the magnitude of wind pressures reduced considerably for the worst affected fin, if the sheltering effect is absent between the fins.

Using statolith shape analysis to identify five commercial Loliginidae squid species in Chinese waters

Identification of squids in the family Loliginidae is a time-consuming exercise because of the highly overlapping distributions of species and their overall similarity (fin shape and size, sucker ring dentition, and color). Identifying squid based on statolith morphology is considered more accurate than identifying species based on beaks or gladius morphology. We report and compare the statolith shape of five commercially Loliginidae squid (Uroteuthis (Photololigo) duvaucelii, U. edulis, U. chinensis, Loliolus beka, L. japonica) to determine how well these structures discriminate species. Based on statolith morphology, variation in the lateral and dorsal domes enables an 84.8% success rate at classifying species. Environmental factors correlate with statolith shape, and for vertically migrating squid, statolith relative size decreases with increased depth of habitation. Statolith morphology can be used to effectively and accurately identify species of Loliginidae squid occurring in Chinese waters, and may prove valuable for identifying and managing squid resources.

ХАРАКТЕРИСТИКА РАЗМЕРНЫХ ПАРАМЕТРОВ МОЛОДИ СТЕРЛЯДИ (ACIPENSER RUTHENUS L. 1758) РЕКИ ИРТЫШ (УВАТСКИЙ РАЙОН)

The article gives the description of dimensional parameters (absolute length, body weight, plastic characters) of young sterlet in the Irtysh River (the Tyumen region, Uvat district). The state of the population was assessed according to the description and a comparative analysis 
 of data obtained by measuring individuals of sterlet from other reservoirs and water areas. Characteristics of young sterlet growth at the age of 1+ and 2+ were also given. It has been stated that starlet juveniles in the Irtysh River are exposed to the local environmental conditions (water temperature, adequate food reserve), which is expressed in a significant variability of the species growth rates in each age group. The results of the analysis of the mass values of sterlet species from different water areas and habitats confirm that sterlet is a plastic species. When analyzing the plastic features of sterlet juveniles, there has been observed the uneven growth of body parts, which can be seen in the variability of parts of the head, size of fins and body weight, followed by the growth of fish and its transition to older age groups. It is noted that significant differences between species from different water areas do not tend to be distributed in latitude or longitude, and sterlet grown under aquaculture conditions does not prevail in all parameters over wild individuals, which suggests the presence of any influence on the growth rate of sterlet by almost the entire habitat including the studied sterlet population.

Experimental and Numerical Investigation of Heat Transfer Enhancement Using Circular Perforated Fins

Experiments were done to investigate the natural and forced convection of heat transfer along a flat surface equipped with various types of rectangular aluminum fins (solid and perforated). Fins selected with dimensions of(30mm height ×30 mm width ×lmm thickness). Perforated fins have various distributed holes(2 mm dia. for 9 holes and 4 mm dia. for 5 holes). For forced convection, the air flow channel selected with a cross section area of (100×100 mm2)for (1000 mm) length. Nine Thermocouples used to recorded the temperature distributed from the fin base to its tip. Flow pattern included laminar and the air flow towards the fin lateral area of (30 mm × 30 mm). The effect of number, size and arrangement of perforated fins was studied. higher heat transfer rates observed with increasing the number of circular holes also the effectiveness were increased due to the reduction into fin’s weight. Also a numerical study was done to investigate these temperature distribution used (SOLDWORKS) simulation program. Good agreements were noted when compared between experimental and theoretical works.

Revalidation of the Argentinian pouched lamprey Geotria macrostoma (Burmeister, 1868) with molecular and morphological evidence.

BackgroundThe Argentinian pouched lamprey, classified as Petromyzon macrostomus Burmeister, 1868 was first described in 1867 in De La Plata River, in Buenos Aires, Argentina, and subsequently recorded in several rivers from Patagonia. Since its original description, the validity of P. macrostomus was questioned by several ichthyologists and 36 years after its original discovery it was considered a junior synonym of Geotria australis Gray, 1851. For a long time, the taxonomic status of G. australis has been uncertain, largely due to the misinterpretations of the morphological alterations that occur during sexual maturation, including the arrangement of teeth, size and position of fins and cloaca, and the development of an exceptionally large gular pouch in males. In this study, the taxonomic status of Geotria from across the “species” range was evaluated using both molecular analysis and examination of morphological characteristics.Methodology/principal findingsPhylogenetic and species delimitation analyses based on mitochondrial DNA sequences of Cytochrome b (Cyt b) and Cytochrome C Oxidase Subunit 1 (COI) genes, along with morphological analysis of diagnostic characters reported in the original descriptions of the species were used to assess genetic and morphological variation within Geotria and to determine the specific status of the Argentinian lamprey. These analyses revealed that Geotria from Argentina constitutes a well differentiated lineage from Chilean and Australasian populations. The position of the cloaca and the distance between the second dorsal and caudal fins in sub-adult individuals, and at previous life stages, can be used to distinguish between the two species. In addition, the genetic distance between G. macrostoma and G. australis for the COI and Cyt b mitochondrial genes is higher than both intra- and inter-specific distances reported for other Petromyzontiformes.Conclusions/significanceOur results indicate that the Argentinian pouched lamprey, found along a broad latitudinal gradient on the south-west Atlantic coast of South America, should be named as Geotria macrostoma (Burmeister, 1868) and not as G. australis Gray 1851, returning to its earliest valid designation in Argentina. Geotria macrostoma can now be considered as the single lamprey species inhabiting Argentinian Patagonia, with distinct local adaptations and evolutionary potential. It is essential that this distinctiveness is recognized in order to guide future conservation and management actions against imminent threats posed by human actions in the major basins of Patagonia.

Optimization of Fin Parameters to Reduce Entropy Generation and Melting Time of a Latent Heat Storage Unit

Abstract One of the challenges in the design and development of a latent heat storage unit (LHSU) is to increase the charging and discharging rates which are inherently low because of low thermal conductivity of phase change materials (PCM). Out of various heat transfer enhancement techniques, employing annular fins is very simple, efficient and no fabrication complexity is involved. Fin parameters (fin size and number of fins) significantly influence the enhancement in heat transfer rate. Hence, optimization of fin parameters is necessary for the efficient design of an LHSU. While designing an LHSU along with heat transfer rate, entropy generation should also be considered in order to make it exergetically efficient. Therefore, the present study is aimed at multi-objective optimization of annular fin parameters to minimize the melting time and entropy generation. Fin diameter and the number of fins are taken as the variables. The influence of these two variables on the melting time, average Nusselt number, energy stored, and distribution of entropy is presented. The melting rate is increased, and global entropy generation decreased by increasing the number of fins up to 15. An increase in the fin diameter reduced the melting time while entropy generation got increased. For the multi-objective optimization, the multi-objective optimization based on ratio analysis (MOORA) technique is chosen and the optimized values of fin diameter and number of fins are observed to be 80 mm and 15 respectively. Finally, optimized parameters are represented in non-dimensional form to make them applicable for any size of the LHSU.

Taxonomic research on Deania calcea and Deania profundorum (Family: Centrophoridae) in the Cantabrian Sea (Northeast Atlantic) with comments on Deania hystricosa

Three elasmobranch species of the genus Deania are currently reported in NE Atlantic waters: D. calcea, D. hystricosa and D. profundorum; however, in north Spanish waters (NE Atlantic), only D. calcea and D. profundorum have been caught. Among the criteria used to discriminate Deania species one is dermal denticle length and body colour. In this study the authors explore the feasibility of these criteria and examine other morphological characters to investigate if sexual or ontogenic features had relevance for the distinction of the species particularly those sampled in this study, D. calcea and D. profundorum. Molecular analyses were conducted to validate these results.In D. calcea, dermal denticle length ranged from 340μm to 1400μm (763.2μm± 180.4 s.d.); in D. profundorum, dermal denticle length ranged from 195μm to 650μm (372.3μm± 111.7 s.d.). In both Deania species, a significant positive correlation was found between shark total length and dermal denticle length. Dermal denticles varied in size and shape along the shark body. These differences were significant both intra- and inter-specifically.A multivariate analysis based on morphological characters was used to test differences between D. calcea and D. profundorum. The hierarchical analysis clearly identified three groups; two groups corresponded to each species, and a third group discriminated between small and large individuals of D. profundorum. The morphometric characters that contributed most to the divergence between both species were mainly related to the size of the dorsal fins, the inter-dorsal distance and the distances from the snout to the origin of each dorsal fin. Based on morphological characters, no sexual dimorphism was observed.The phylogenetic tree was reconstructed with molecular COI sequences available on BOLD and those obtained in this study. The output tree discriminate D. calcea from D. profundorum, however could not separate molecularly D. calcea and D. hystricosa.

Effects of helical fins with semi-circular in cross-section on the performance characteristics of novel finned-cyclone separators

Separation of particles (solid) from hot gases were carried out with the help of cyclone separators in most of the power generation industries (fluidized bed boilers) and process industries. Present research focuses on improving the performances of such devices by modifying the geometry. Conventional 2D2D Lapple type cyclone separator geometry was modified by attaching semi-circular cross-section helical fins along the height of barrel wall to make it as finned-cyclone separators. Semi-circular helical fins attached on the barrel wall varies (six-sets) with size (5 mm, 7.5 mm, and 10 mm) and pitch (30 mm and 50 mm). 3D computational fluid dynamics simulations were carried out using ANSYS 15.0 tool and validation were performed with experimental data available in the literature for conventional 2D2D Lapple type cyclone separator before proceeding towards simulations of semi-circular finned-cyclone separators. Improved performance was noticed from all selected six cyclone separators with semi-circular fins (cswf) when compared to conventional cyclone separators while studying the fluid mechanics characteristics, which directly influences on collection-efficiency of cyclone separators. Among selected cyclone separators, the cswf with size of fin 7.5 mm and fin-pitch 50 mm was noted to be performing improved collection efficiency for the particles size <3 µm. Around 5%–11% improved collection efficiency when compared to conventional cyclone separators were observed in the study by fixing the semi-circular fins along the height of barrel wall without disturbing the main role of cyclone separator, which is separating the very fine particles, which would otherwise causes pollution.

Influence of Hydrophobic Fin Configuration in Thermal System in Relation to Electronic Device Cooling Applications

In this study, heat and flow analysis of the cooling system incorporating fins with hydrophilic and hydrophobic wetting surfaces has been considered in relation to electronic cooling applications. Temperature and velocity fields in the solution domain are simulated for various fin numbers and sizes. A temperature parameter is introduced to assess the thermal performance of the system. Fin count is introduced to formulate the number of fins in the solution domain. The Nusselt number and pressure drop between the inlet and exit ports due to different fin configurations of the cooling system for various fin counts are presented. It is found that the temperature parameter attains high values for large sizes and small fin counts, which is more pronounced for low Reynolds numbers. Increasing number of fins results in almost uniform flow distribution among the fin, which is more pronounced for the hydrophobic fin configuration. The Nusselt number attains larger values for the hydrophilic fin configuration than that corresponding to the hydrophobic fin, and it attains a peak value for certain arrangement of fin count, which differs with the Reynolds number. The pressure drop between the inlet and exit ports reduces for hydrophobic fin; hence the slip velocity introduced for hydrophobic fin improves the pressure drop by 6% to 16% depending on the fin counts in the cooling system.

Integrated analysis of bioelectric signaling in regulation of proportion.

We are proportionate entities: the mechanical and physiological function of our bodies is dependent on allometric scaling between tissues and organs. How such scaling is genetically and developmentally regulated remains a long lasting question and requires knowledge at many levels and across disciplines. Using unbiased forward genetic screens in the zebrafish, we identify mutations in potassium channels that lead to increase in relative fin size. We assess how these mutations affect electrophysiological properties of the encoded potassium channels in Xenopus oocytes. Using the zebrafish fin as an experimental platform we detail key regulation of bioelectric signaling and its control of coordinated growth during development and regeneration. Complementing these experimental approaches, we extend our investigation through a broad scale phylogenomic analysis capitalizing on natural variation in fin length in evolution as well in clinical cases of coordinated overgrowth of extremities. The combination of approaches provides mechanistic insight into bioelectric regulation of coordinated growth during development and regeneration and the prevalence of bioelectric signaling in regulating form.Support or Funding InformationNIH R01HD084985

Semi-analytical thermal modeling of transverse and longitudinal fins in a cylindrical phase change energy storage system

Inclusion of fins in phase change energy storage systems has been widely investigated for improving the rate of energy storage. Despite significant past experimental research in this direction, there is a lack of comprehensive theoretical models for fin-based enhancement in energy storage, particularly for cylindrical geometries. This is a considerably challenging, non-linear problem. This paper presents a semi-analytical model for temperature distribution and energy storage in an annular phase change material (PCM) material around a hot cylinder in the presence of transverse and longitudinal fins extending into the PCM. Two distinct pathways for heat transfer into the PCM are analyzed separately and expressions for total heat flux into the PCM are determined for both fin types. The perturbation method is used for analyzing the non-linear phase change problem and determining the heat flux into the PCM through the fin. The dependence of total energy stored on fin thermal properties and geometrical parameters is determined. Results indicate key similarities and differences between cylindrical fins and recently-reported Cartesian fins. It is shown that even a thin fin results in considerable heat transfer enhancement. Results also indicate diminishing results when the fin size is further increased. Theoretical modeling presented in this paper improves the fundamental understanding of an important heat transfer enhancement strategy for phase change based energy storage systems. Results discussed here may help improve the practical design of finned, cylindrical phase change energy storage systems that are commonly used for harnessing renewable energy.

BMP Signaling Gradient Scaling in the Zebrafish Pectoral Fin

SummarySecreted growth factors can act as morphogens that form spatial concentration gradients in developing organs, thereby controlling growth and patterning. For some morphogens, adaptation of the gradients to tissue size allows morphological patterns to remain proportioned as the organs grow. In the zebrafish pectoral fin, we found that BMP signaling forms a two-dimensional gradient. The length of the gradient scales with tissue length and its amplitude increases with fin size according to a power-law. Gradient scaling and amplitude power-laws are signatures of growth control by time derivatives of morphogenetic signaling: cell division correlates with the fold change over time of the cellular signaling levels. We show that Smoc1 regulates BMP gradient scaling and growth in the fin. Smoc1 scales the gradient by means of a feedback loop: Smoc1 is a BMP agonist and BMP signaling represses Smoc1 expression. Our work uncovers a layer of morphogen regulation during vertebrate appendage development.

Studies on Separation Efficiency and Energy Conservation Through Novel Finned Cyclone Separator

Abstract In the present study, cylindrical portion of conventional (nonfinned) cyclone separator was reshaped by fixing triangular, semicircular, and rectangular cross section helical fins in order to make it as water wall having fin size 7 mm with fin pitch of 40 mm to improve its separation efficiency and to utilize the cyclone separator as heat exchanger. Fluid dynamic characteristics like axial velocity, tangential velocity, pressure drops were studied by varying the fin geometry (triangular/semicircular/rectangular). For the particles' size less than 3 μm, proposed cyclone separator with triangular helical fin was giving comparatively improved collection efficiency than other selected cyclone separators. Improvement in the collection efficiency of triangular fin-based cyclone separators was perceived from 5% to 10% over the conventional cyclone separator. Hence, helical fins with triangular in cross section were selected further for heat transfer and scale-up studies. It was observed that for the small barrel wall height (h = 400 mm) water temperature was enhanced by 4 °C, and with scale-up (making h = 800 mm) it was increased considerably around 15 °C. Thus based on improved separation efficiency to capture very-fine particulate matter (PM 2.5, which otherwise causes serious health issues) and considerable temperature gain of water noted at lab level scale-up study, triangular helical fins may be to fixed on the inner surface of barrel wall of conventional (nonfinned) cyclone separators in order to use them as heat exchanger for energy conservation in industrial applications.

Hydrodynamic characteristics of a 2D2D cyclone separator with a finned cylindrical body

Cyclone separators used for separating solid particles from the gases mainly employed in electricity generating units having fluidized bed boilers and in other industries such as cement industries. In the present study, cylindrical portion of the nonfinned (conventional) cyclone separator (nfcs) was reshaped by fixing triangular helical fins in order to improve its performance in terms of collection efficiency. Fluid dynamic characteristics like axial velocity, tangential velocity, pressure drops etc. were studied which influences the collection efficiency by varying the fin size (fs) such as 5.0 mm, 7.5 mm and 10.0 mm and also by varying fin pitch (fp) as 50.0 mm and 30.0 mm. With available experimental work, validation was accomplished for the nfsc before proceeding computational study on the novel triangular finned cyclone separators (fcs). For the particles' size less than 3 μm, comparatively proposed triangular fin with fs & fp as 7.5 mm & 30.0 mm respectively was giving improved collection efficiency than other selected separators. Improvement in the collection efficiency of triangular finned cyclone separators (fcs) was perceived from 5% to 10% over the conventional cyclone separator (nfcs). Main role of the cyclone separators is to separate the particles from gases which was unruffled after by inclusion of fins. Rather fin inclusion has played a dominant role in minimizing very fine particulate matter emissions which otherwise leads to severe health problems.

Effects of Span Length and Additional Structure on Flow-Induced Transverse Vibration Characteristic of a Cantilevered Rectangular Prism

We consider the effects of the aspect ratio L/H (where L is the length of a prism, and H is the height of a prism normal to the flow direction) and the size of additional structures (which are a plate and a fin on the surface of a prism) on a vibration characteristic of a cantilevered rectangular prism. The present research is intended to support the analysis of energy harvesting research on the flow-induced vibration in water flow using a magnetostrictive phenomenon. The prisms are constructed from stainless steel and mounted elastically to a plate spring attached to the ceiling wall of the water tunnel. The prisms with aspect ratios of L/H ≥ 5 have reasonably identical vibration characteristics. However, the difference in the vibration characteristic appears distinctly on a rectangular prism with an aspect ratio of L/H = 2.5. The rectangular prism with an aspect ratio of L/H = 10 and a side ratio of D/H = 0.2 has a stable and large response amplitude and oscillates with a lower velocity. The length of the added plate and the size of the added fin influence the velocity of vibration onset. If the length of the added plate and fin size on the rectangular prism with D/H = 0.2 becomes large, the curve of the response amplitude shifts to that of the rectangular prism with D/H= 0.5. The response amplitude of the rectangular prism with/without plate or fin is found to be related to the second moment of area of the prism.

Fin Length and Total Length Relationships of Silky Shark Carcharhinus falciformis Landed at Tanjung Luar Fish Landing Port, West Nusa Tenggara, Indonesia

Shark fins are a very valuable product for international trade. This study aims to obtain the equations describing the relationship between fin length and the total length of silky shark. Using the total length at sexual maturity (Lm), the equation is then used to estimate the fin length associated with this Lm, which can then be included in the recommendation for international shark fin trades. Data collection was carried out from March 2018 to February 2019 at Tanjung Luar Fish Landing Port, West Nusa Tenggara. All data were collected from 2,837 individuals of silky sharks, consisting of 1,416 females and 1,421 males. The total length of silky shark ranges from 61 to 282 cm for females and 18-283 cm for males. The relationships of first dorsal fin length and total length is DFL=2.0151+0.1243 TL (both sexes). Furthermore, the relationships of pectoral fin length and total length were found to be PFL=-8.0098+0.2127 TL (both sexes). The first dorsal fin length and pectoral fin length at the time the silky shark sexually matures were 23 cm and 35 cm, respectively. This fin-total length relationship can be used by the fisheries authority to determine the allowed minimum size of silky shark fins for export.

Design, modeling, and experimental validation of a concave‐shape pectoral fin of labriform‐mode swimming robot

The pectoral fin shape, size, and speed are the three main parameters for the proposed design. The influence of the geometrical shape of pectoral fin in labriform‐mode swimming mechanism is evaluated with the aid of computational fluid dynamics (CFD) method, which could be considered as a first step before building the complete robot prototype. The simulated results obtained are then validated experimentally. Two concave‐shape fins were designed with high precision, and each one of them is attached to a servomotor arm, which is, in turn, connected to a servomotor that is sliding on a pair of parallel shafts fixed at the center of a pool. The mathematical model of the proposed design is derived and then simulated by SolidWorks software. A different number of fin oscillating angles are tested with different power‐to‐recovery ratios. The generated thrust and drag force components under different working conditions are investigated, and hence, the drag coefficient is obtained experimentally. Body velocity and motor torque are calculated and compared with theoretical analysis. The results indicate that for each angle of rotation, there exists an optimal ratio that produces a maximum thrust during power stroke and maintains a minimum drag during recovery stroke.

Optimum Arrangement of Fins in a Free Convection-Based Solar Air Heater

Abstract In this paper, the details of a numerical study performed for the optimum fin arrangement in a solar air heater with a rectangular fin array attached to the bottom side of the absorber plate have been presented. Results have been presented for various fin sizes and spacing between the fins, while the heat transfer and fluid flow are directed by natural convection. An inclined rectangular channel similar to the dimensions of a typical solar air heater has been considered. Three different fin configurations, namely, continuous long fins for the whole length of the channel, in-line interrupted and staggered interrupted arrangements of fins, have been studied. The present analysis aims to identify the optimum configuration of the fin array for enhanced heat transfer. The spacing between the fins and the height of the fins are varied to obtain an optimum configuration. The numerical simulations are performed for heat flux (q″) ranging from 250 to 750 W/m2 on the absorber plate. The inclination angles of the channel (θ) have been maintained at 15 deg, 30 deg, and 45 deg from the horizontal plane. The results show that with the spacing between fins, S = 5.4 cm performs better in the case of longitudinal continuous fin arrangement. However, a fin spacing of 4.75 cm shows a higher heat transfer in the case of staggered fin configuration. In comparison with nine long uninterrupted fins, using the staggered arrangement with 15 × 10 fins saves up to 33% of fin material.

Negative allometric growth during ontogeny in the large pelagic filter-feeding basking shark

Many pelagic shark species change body and fin shape isometrically or by positive allometry during ontogeny. But some large apex predators such as the white shark Carcharodon carcharias or the tiger shark Galeocerdo cuvier show distinct negative allometry, especially in traits related to feeding (head) or propulsion (caudal fin). In particular, changes in propulsion are attributed to a shift in swimming mode. The more heterocercal caudal fin of younger individuals with its large caudal fin span seemingly aids in hunting small, agile prey. In contrast, the less heterocercal caudal fin with a larger fin area in larger individuals aids a long-distance slow swimming mode. We were interested if negative allometric effects can be observed in a planktivorous shark, the basking shark Cetorhinus maximus, a large species adapted to long-distance slow swimming. To address this question, we compared three size classes, specifically < 260 cm (juveniles), 299–490 cm (subadults), and from adults > 541 cm total length. Comparing literature data, we found negative allometric growth of the head and of the caudal fin, but a more rapid decrease of relative caudal fin size than of relative head length. Hereby, we provide the first evidence for early negative allometric growth of the caudal fin in a large pelagic filter-feeding shark. Our study further demonstrates that ecomorphological approaches may add valuable insight into the life history of animals that are challenging to study in their natural habitat, including large roving sharks such as the basking shark.