Effects of snout dimensions on the hydrodynamics of suction feeding in juvenile and adult seahorses

Seahorses give birth to juveniles having a fully functional feeding apparatus, and juvenile feeding behaviour shows striking similarities to that of adults. However, a significant allometric growth of the snout is observed during which the snout shape changes from relatively short and broad in juveniles to relatively long and slender in adults. Since the shape of the buccal cavity is a critical determinant of the suction performance, this snout allometry will inevitably affect the suction feeding ability. To test whether the snout is optimised for suction feeding throughout an ontogeny, we simulated the expansion of different snout shapes varying from extremely long and slender to short and broad for juvenile and adult snout sizes, using computational fluid dynamic models. Our results showed that the snout diameter at the start of the simulations is involved in a trade-off between the realizable suction volume and expansion time on the one hand (improving with larger initial diameters), and maximal flow velocity on the other hand (improving with smaller initial diameters). Moreover suction performance (suction volume as well as maximal attainable flow velocity) increased with decreasing snout length. However, an increase in snout length decreases the time to reach the prey by the cranial rotation, which may explain the prevalence of long snouts among syngnathid fishes despite the reduced suction performance. Thus, the design of the seahorse snout revolves around a trade-off between the ability to generate high-volume suction versus minimisation of the time needed to reach the prey by the cranial rotation.     

Parametric studies on bioengineering effects of tree root-based suction on ground behaviour

Using native vegetation to improve soil stiffness, stabilise slopes and control erosion is a rapidly evolving process. A theoretical model previously developed by the authors for the rate of tree root water uptake together with an associated numerical simulation is used to study the effects of a wide range of soil, tree, and atmospheric parameters on partially saturated ground. The influence of different parameters on the maximum initial rate of root water uptake is investigated through parametric and sensitivity analyses. Field measurements taken from previously published literature are compared with numerical predictions for validation. The rate of selected parameters such as potential transpiration and its distribution, suction at wilting point, the coefficient of permeability and the distribution of root length density are studied in detail. The analysis shows that the rate of potential transpiration increases the soil matric suction and ground settlement, while the potential transpiration rate has an insignificant effect on the distribution of soil suction. Root density distribution factors affect the size of the influence zone. Suction at the wilting point increases the soil matric suction and ground settlement, whereas the saturation permeability decreases the maximum soil matric suction generated. The analysis confirms that the most sensitive parameters, including the coefficients of the tree root system, the transpiration rate, the permeability of the soil and its suction at the wilting point should be measured or estimated accurately for an acceptable prediction of ground conditions in the vicinity of trees.     

改良式吸痰装置的设计与临床应用

目的探讨改良式吸痰装置在儿科吸痰的应用效果。方法利用纳入、排除标准的抽样方法选取我院儿科2014年3月~2015年3月收治的138例肺炎患儿为研究对象,随机分为对照组68例和观察组70例。对照组采用常规吸痰装置进行吸痰,观察组采用改良的吸痰装置吸痰,观察比较两组患儿吸痰时鼻腔黏膜的出血情况、吸痰所需时间和护士满意度。结果观察组鼻腔黏膜出血2例,对照组15例,两组比较差异有统计学意义(P0.05);观察组有效吸痰时间为51.3s,明显低于对照组的103.5s,差异具有统计学意义(P0.05)。观察组的护士满意度为92.8%显著高于对照组的50%,两组比较差异具有统计学意义(P0.05)。结论改良式吸痰装置能缩短操作时间,降低鼻腔黏膜损伤,有利于护士快速有效解除患儿痰液堵塞,提高护士及家属满意度。     

Adhesion and Suction Functions of the Tip Region of a Nectar-drinking Butterfly Proboscis

In this study,we investigated the dynamic functions of the tip region of the butterfly proboscis through which liquid is sucked during liquid feeding.The microstructures and flow patterns in the tip region of the proboscis were in vivo analyzed.The tip region can be divided into two functional sections:namely adhesion and suction sections.The liquid adheres to the adhesion section during liquid suction.Although the tip region has numerous slits connected to food canal of the proboscis,liquid is mainly sucked through the suction section,which section is submerged in the fluid pulled by the adhesion section and then successfully imbibes liquid.To check the dynamic functions of the tip region,we fabricated a suction tip model having adhesion and suction parts.The in vitro model experiments show that the hydrophilicity of the adhesion part and the existence of the suction inlet improve the liquid uptake driven by a suction pump.This study may provide insights for the biomimetic design of nectar-feeding butterflies.     

Pressure Effects on Membrane Potentials of Mesophyll Cell Protoplasts and Epidermal Cell Protoplasts of Commelina communis L.

Pantoja, O. and Willmer, C. M. 1986. Pressure effects on membranepotentials of mesophyll cell protoplasts and epidermal cellprotoplasts of Commelina communis L.—J. exp. Bot. 37:315–320. Membrane potentials of epidermal cell protoplasts and mesophyllcell protopiasts of Comnelina communis were measured when theprotoplasts were immobilized in a suction micropipette. Whenzero suction was employed, membrane potentials of both protoplasttypes were near to zero. As suction pressure was increased,membrane potentials became increasingly more negative with gradientsof 14·3 mV/kPa and 10·5 mV/kPa for mesophyll cellprotoplasts and epidermal cell protoplasts, respectively. Theplasma membrane is stretched when suction pressure is appliedto protoplasts and it is considered that this simulates cellturgor pressure which is associated with negative membrane potentialsof intact cells. The results help to explain why some investigatorsobtain positive membrane potentials for protoplasts while othersobtain negative values. The results also indicate that considerablecaution is needed in the interpretation of ion flux data whenprotoplasts are used. Key words: Commelina communis, membrane potentials, pressure, protoplasts     

Comparative anatomy and evolutionary history of suction feeding in cetaceans

Some odontocetes possess unique features of the hyolingual apparatus that are involved in suction feeding. The hyoid bone and associated musculature generates rapid, piston‐like retraction, and depression of the hyoid and tongue. “Capture” suction feeders (e.g., Globicephala) use suction for capturing and swallowing prey. “Combination” feeders (i.e., Lagenorhynchus) use both raptorial feeding (to capture prey) and suction (to ingest prey). In “capture” suction feeders, features of the hyoid and skull have been attributed to creating suction (i.e., large surface area and mandibular bluntness). In addition to odontocetes, a mysticete, the gray whale (Eschrichtius robustus), is considered a benthic suction feeder. However, anatomical studies of purported suction‐feeding structures of the gray whale are lacking. In addition, few studies have utilized evolutionary approaches to understand the history of suction feeding in cetaceans. This study incorporates quantitative and qualitative hyoid and cranial data from 35 extant and 14 extinct cetacean species into a multivariate principal component analysis and comparative phylogenetic analyses. Conclusions from these analyses are that some commonly attributed features (i.e., ventral throat grooves and mandibular bluntness) and one principal component are significantly correlated with suction feeding. Finally, ancestral state reconstructions indicate that suction feeding likely evolved once, early in cetacean evolutionary history.     

Effects of lower body negative pressure on cardiac and vascular responses to carotid baroreflex stimulation

The aim of this study was to assess carotid baroreflex responses during graded lower body negative pressure (LBNP). In 12 healthy subjects (age 29+/-4 years) we applied sinusoidal neck suction (0 to -30 mmHg) at 0.1 Hz to examine the sympathetic modulation of the heart and blood vessels and at 0.2 Hz to assess the effect of parasympathetic stimulation on the heart. Responses to neck suction were determined as the change in spectral power of RR-interval and blood pressure from baseline values. Measurements were carried out during progressive applications (0 to -50 mmHg) of LBNP. Responses to 0.1 and 0.2 Hz carotid baroreceptor stimulations during low levels of LBNP (-10 mmHg) were not significantly different from those measured during baseline. At higher levels of LBNP, blood pressure responses to 0.1 Hz neck suction were significantly enhanced, but with no significant change in the RR-interval response. LBNP at all levels had no effect on the RR-interval response to 0.2 Hz neck suction. The unchanged responses of RR-interval and blood pressure to neck suction during low level LBNP at -10 mmHg suggest no effect of cardiopulmonary receptor unloading on the carotid arterial baroreflex, since this LBNP level is considered to stimulate cardiopulmonary but not arterial baroreflexes. Enhanced blood pressure responses to neck suction during higher levels of LBNP are not necessarily the result of a reflex interaction but may serve to protect the circulation from fluctuations in blood pressure while standing.     

Theoretical study on two-dimensional aerodynamic characteristics of unsteady wings

A simple computing method based on a potential theory is developed for two-dimensional steady and unsteady deflected wings. This method of theoretical analysis is essentially related to thin and angular airfoils. Thus, the method is very simple but is effective to forecast aerodynamic forces for deflected or angular airfoils with a small camber operating in high Reynolds number flow, specifically in unsteady motion. The suction force acting on the leading edge of steady airfoils is theoretically obtained by using the Blasius formula. By Polhamus's leading edge suction analogy, the suction force is considered to be directed upward in partially separated flow for real thin airfoil with sharp leading edge. The theory can also be applied to obtain the aerodynamic characteristics of thin airfoils operating on low Reynolds number flow under some degree of approximation. This is very useful for the unsteady aerodynamic analysis because the Navier-Stokes equation can be solved by neither analytical nor numerical method for the thin and angular airfoils, which are common in the insect wing.     

Large variation of suction sampling efficiency depending on arthropod groups,species traits,and habitat properties

Suction sampling is widely used to estimate arthropod abundance and diversity. To test the reliability of abundance data derived from suction sampling, we examined sampling efficiency across a wide range of arthropod groups and tested for effects of species traits, vegetation density, and differences between sites. Suction sampling efficiency was quantified by vacuuming an enclosed meadow area and subsequent removal of the turf, which was treated with heat extraction to collect the remaining arthropods. We obtained 250 pairs of suction and turf samples from seven grasslands with variable vegetation density. High suction sampling efficiencies between 49 and 86% were obtained for Auchenorrhyncha, Heteroptera, Araneida, Curculionoidea, Hymenoptera, and Diptera. In contrast, efficiencies were below 30% for Aphidae, Thysanoptera, Staphylinidae and other Coleoptera, and for soil arthropods such as Collembola, Isopoda, Diplopoda, and Formicidae. Efficiency varied significantly among habitats (sites) for most groups, often more than two‐fold. Surprisingly, sampling efficiency for Hymenoptera, Diplopoda, and Collembola increased with vegetation density, probably because aboveground activity of these taxa was higher in dense vegetation. Suction sampling was nearly twice as efficient for spiders living in the vegetation than for spiders living near the soil surface, and cursorial and large‐bodied spider species were more efficiently sampled than web‐builders and small species. Depending on the sampling effort, suction sampling missed between 49% (one sample) and 31% (250 samples) of the spider species present. Suction sampling efficiency varied more strongly among sites and among arthropod groups than previously recognized. Abundance data derived from suction sampling are strongly underestimated, especially for arthropods living near the soil surface. Thus, comparisons of abundance and diversity between sites should be restricted to vegetation‐dwelling species of the most efficiently sampled groups. The positive relationship of sampling efficiency with vegetation density demonstrates that variation in efficiency is mediated by arthropod behaviour.     

Effects of negative upper airway pressure on pattern of breathing in sleeping infants

Negative upper airway (UAW) pressure inhibits diaphragm inspiratory activity in animals, but there is no direct evidence of this reflex in humans. Also, little is known regarding reflex latency or effects of varying time of stimulation during the breathing cycle. We studied effects of UAW negative pressure on inspiratory airflow and respiratory timing in seven tracheostomized infants during quiet sleep with a face mask and syringe used to produce UAW suction without changing lower airway pressure. Suction trials lasted 2-3 s. During UAW suction, mean and peak inspiratory airflow as well as tidal volume was markedly reduced (16-68%) regardless of whether stimulation occurred in inspiration or expiration. Reflex latency was 42 +/- 3 ms. When suction was applied during inspiration or late expiration, the inspiration and the following expiration were shortened. In contrast, suction applied during midexpiration prolonged expiration and tended to prolong inspiration. The changes in flow, tidal volume, and timing indicate a marked inhibitory effect of UAW suction on thoracic inspiratory muscles. Such a reflex mechanism may function in preventing pharyngeal collapse by inspiratory suction pressure.     

Suction feeding mechanics, performance, and diversity in fishes

Despite almost 50 years of research on the functional morphologyand biomechanics of suction feeding, no consensus has emergedon how to characterize suction-feeding performance, or its morphologicalbasis. We argue that this lack of unity in the literature isdue to an unusually indirect and complex linkage between themuscle contractions that power suction feeding, the skeletalmovements that underlie buccal expansion, the sharp drop inbuccal suction pressure that occurs during expansion, the flowof water that enters the mouth to eliminate the pressure gradient,and the forces that are ultimately exerted on the prey by thisflow. This complexity has led various researchers to focus individuallyon suction pressure, flow velocity, or the distance the preymoves as metrics of suction-feeding performance. We attemptto integrate a mechanistic view of the ability of fish to performthese components of suction feeding. We first discuss a modelthat successfully relates aspects of cranial morphology to thecapacity to generate suction pressure in the buccal cavity.This model is a particularly valuable tool for studying theevolution of the feeding mechanism. Second, we illustrate themultidimensional nature of suction-feeding performance in acomparison of bluegill, Lepomis macrochirus, and largemouthbass, Micropterus salmoides, two species that represent oppositeends of the spectrum of performance in suction feeding. As anticipated,bluegills had greater accuracy, lower peak flux into the mouth,and higher flow velocity and acceleration of flow than did bass.While the differences between species in accuracy of strikeand peak water flux were substantial, peak suction velocityand acceleration were only about 50% higher in bluegill, a relativelymodest difference. However, a hydrodynamic model of the forcesthat suction feeders exert on their prey shows that this differencein velocity is amplified by a positive effect of the smallermouth aperture of bluegill on force exerted on the prey. Ourmodel indicates that the pressure gradient in front of a fishthat is feeding by suction, associated with the gradient inwater velocity, results in a force on the prey that is largerthan drag or acceleration reaction. A smaller mouth apertureresults in a steeper pressure gradient that exerts a greaterforce on the prey, even when other features of the suction floware held constant. Our work shows that some aspects of suction-feedingperformance can be determined from morphology, but that thecomplexity of the behavior requires a diversity of perspectivesto be used in order to adequately characterize performance.     

Functional morphology of the feeding apparatus,feeding constraints,and suction performance in the nurse shark Ginglymostoma cirratum

The nurse shark, Ginglymostoma cirratum, is an obligate suction feeder that preys on benthic invertebrates and fish. Its cranial morphology exhibits a suite of structural and functional modifications that facilitate this mode of prey capture. During suction‐feeding, subambient pressure is generated by the ventral expansion of the hyoid apparatus and the floor of its buccopharyngeal cavity. As in suction‐feeding bony fishes, the nurse shark exhibits expansive, compressive, and recovery kinematic phases that produce posterior‐directed water flow through the buccopharyngeal cavity. However, there is generally neither a preparatory phase nor cranial elevation. Suction is generated by the rapid depression of the buccopharyngeal floor by the coracoarcualis, coracohyoideus, and coracobranchiales muscles. Because the hyoid arch of G. cirratum is loosely connected to the mandible, contraction of the rectus cervicis muscle group can greatly depress the floor of the buccopharyngeal cavity below the depressed mandible, resulting in large volumetric expansion. Suction pressures in the nurse shark vary greatly, but include the greatest subambient pressures reported for an aquatic‐feeding vertebrate. Maximum suction pressure does not appear to be related to shark size, but is correlated with the rate of buccopharyngeal expansion. As in suction‐feeding bony fishes, suction in the nurse shark is only effective within approximately 3 cm in front of the mouth. The foraging behavior of this shark is most likely constrained to ambushing or stalking due to the exponential decay of effective suction in front of the mouth. Prey capture may be facilitated by foraging within reef confines and close to the substrate, which can enhance the effective suction distance, or by foraging at night when it can more closely approach prey. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.     

Tumescent and dry liposuction of lower extremities: differences in lymph vessel injury

Lipectomy is a standard procedure in plastic surgery. Until now, however, there was no definite information about the influence of different liposuction techniques (tumescent versus dry liposuction) on the integrity of lymph collectors during this procedure. To study the effect of these liposuction techniques on the incidence of lymph vessel injury, postmortem lymphatic preparations were done in nine human cadavers (18 lower extremities). Conventional liposuction with a blunt 4-mm cannula in the dry technique (n = 29 regions) was compared with the tumescent technique (n = 26). Liposuction was performed in parallel to the superficial lymph vessels (longitudinal suction) or transversally in an 80-degree to 90-degree angle to the extremity (vertical suction). Careful surgical preparation of different regions followed. A specific macroscopic lymph vessel injury score was applied to differentiate three degrees of lymph vessel lesions according to the extravasation of patent blue. In all lower extremities, postmortem lymph flow occurred as indicated by patent blue staining of the lymph vessels. Injection of fluid that is obligatory during tumescent suction did not result in grade 2 injury. On the contrary, tumescent suction overall produced significantly fewer lymph vessel lesions when compared with the dry technique (p < 0.05). Longitudinal liposuction produced significantly less injury when compared with vertical suction (p < 0.05). Tumescent suction and dry suction were equally effective in removing adipose aspirates, as verified by circumference measurements. In addition, tumescent liposuction is unlikely to cause major lesions of epifascial lymph vessels during suction procedures vertical to the extremity axis. Therefore, in this respect, this technique is superior to dry suction.     

Linking cranial kinematics,buccal pressure,and suction feeding performance in largemouth bass

The rate and magnitude of buccal expansion are thought to determine the pattern of water flow and the change in buccal pressure during suction feeding. Feeding events that generate higher flow rates should induce stronger suction pressure and allow predators to draw prey from further away. We tested these expectations by measuring the effects of prey capture kinematics on suction pressure and the effects of the latter on the distance from which prey were drawn-termed suction distance. We simultaneously, but not synchronously, recorded 500-Hz video and buccal pressure from 199 sequences of four largemouth bass, Micropterus salmoides, feeding on goldfish. From the video, we quantified several kinematic variables associated with the head and jaws of the feeding bass that were hypothesized to affect pressure. In a multiple regression, kinematic data accounted for 79.7% of the variation among strikes in minimum pressure. Faster mouth opening and hyoid depression were correlated with lower pressures, a larger area under the pressure curve, and a faster rate of pressure reduction. In contrast, buccal pressure variables explained only 16.5% of the variation in suction distance, and no single pressure variable had a significant relationship with suction distance. Thus, although expected relationships between head kinematics and buccal pressure were confirmed, suction distance was only weakly related to buccal pressure. Three explanations are considered. First, bass may not attempt to maximize the distance from which prey are drawn. Second, the response of prey items to suction-induced flow depends on prey behavior and orientation and is, therefore, subject to considerable variation. Third, previous theoretical work indicates that water velocity decays exponentially with distance from the predator's mouth, indicating that variation among strikes in flow at the mouth opening is compressed away from the mouth. These findings are consistent with other recent data and suggest that suction distance is a poor metric of suction feeding performance.     

种皮对海棠种子的保护作用机理研究

目的:研究海棠种子种皮对海棠种子保护作用机理。方法:通过种子水势、吸水膨胀、种子化学染色、红外光谱分析和显微形貌观察考察海棠种子结构和成分对种子的影响。结果和结论:表面油脂起着防水作用,但是在一定的条件下易分解;种皮表层红色短纤物结构致密使种子具有防水透湿的作用,种皮内层是生物高分子,在吸水初期表现出高的吸水力(包括溶胀吸水力、保持力、荷重下的吸收力),后期由水分引起的相关生物反应产生的某种物质使其表现刚性而开裂。三者共同作用保护种子使其长时间在自然环境下仍然保持生物活性。     

Dependence of the root suction force on the soil water content

The suction force of active roots ofFraxinus excelsior L. was estimated by the refractometric compensation method (compensation in a sucrose solution) and its dependence on the water content of soil was determined. Where differences in the soil humidity were excluded within the root system, the dependence could be expressed by a curve resembling the dependence of the suction force of soil on its water content. This dependence was valid both for the minimal gradients of suction forces between the over-and underground parts of the plant (pot experiments), as well as when transpiration and hence gradients were present (under field conditions). Where differences in soil humidity were formed within the root system, the dependence did not correspond to this basic curve, due to the compensation of root suction forces within the root system.     

Effect of healthy aging on left ventricular relaxation and diastolic suction

Doppler ultrasound measures of left ventricular (LV) active relaxation and diastolic suction are slowed with healthy aging. It is unclear to what extent these changes are related to alterations in intrinsic LV properties and/or cardiovascular loading conditions. Seventy carefully screened individuals (38 female, 32 male) aged 21-77 were recruited into four age groups (young: <35; early middle age: 35-49; late middle age: 50-64 and seniors: ≥65 yr). Pulmonary capillary wedge pressure (PCWP), stroke volume, LV end-diastolic volume, and Doppler measures of LV diastolic filling were collected at multiple loading conditions, including supine baseline, lower body negative pressure to reduce LV filling, and saline infusion to increase LV filling. LV mass, supine PCWP, and heart rate were not affected significantly by aging. Measures of LV relaxation, including isovolumic relaxation time and the time constant of isovolumic pressure decay increased progressively, whereas peak early mitral annular longitudinal velocity decreased with advancing age (P < 0.001). The propagation velocity of early mitral inflow, a noninvasive measure of LV suction, decreased with aging with the greatest reduction in seniors (P < 0.001). Age-related differences in LV relaxation and diastolic suction were not attenuated significantly when PCWP was increased in older subjects or reduced in the younger subjects. There is an early slowing of LV relaxation and diastolic suction beginning in early middle age, with the greatest reduction observed in seniors. Because age-related differences in LV dynamic diastolic filling parameters were not diminished significantly with significant changes in LV loading conditions, a decline in ventricular relaxation is likely responsible for the alterations in LV diastolic filling with senescence.     

Extravasation injuries and emergency suction as treatment

To evaluate the efficiency of emergency suction in extravasation injuries of contrast medium, records of 11 patients treated for extravasation injuries with a combination of suction and saline washout were reviewed. All of the patients were treated in the first 2 hours after injury. The mean extravasated volume was 55 cc. There were no surgery-related complications, and all the patients experienced a relief of their preoperative pain. Except for two patients with blisters at admission, none of them suffered skin or soft-tissue necrosis. Mean time to complete healing was 9 days. Emergency suction therapy is safe and effective in preventing the skin and soft-tissue necrosis associated with extravasation injuries of hyperosmolar contrast medium.     

Suction lipectomy: complications and results by survey

In October of 1983, we sent a questionnaire on suction lipectomy to 2524 U.S. and Canadian members of the American Society of Plastic and Reconstructive Surgeons. Six-hundred and twelve plastic surgeons returned questionnaires (24.2 percent response rate). One-hundred and seven responding surgeons reported 1573 operations in which suction lipectomy with or without skin excision was used for 2685 procedures on various parts of the body. In the subset of 1249 operations in which suction lipectomy only was used to treat 2261 anatomic areas, surgeons reported greater than 80 percent good or excellent aesthetic results. The overall complication rate was 9.3 percent. The most frequent complications were persistent hypesthesia (2.6 percent), seroma (1.6 percent), and persistent edema (1.4 percent). Skin pigmentation, pain, hematoma, infection, and slough each occurred with an incidence of 1.0 percent or less. Based on the results of this survey, suction lipectomy is a valuable new modality for surgical improvement of body contour.     

Absence of Suction Feeding Ichthyosaurs and Its Implications for Triassic Mesopelagic Paleoecology

Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were ‘ram-feeders’, without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the establishment of modern-style mesopelagic animal communities in the Triassic. This new interpretation matches the fossil record of coleoids, which indicates the absence of soft-bodied deepwater species in the Triassic.