Hydrodynamic reception

Last updated
Arthropods like these northern prawn, and some mammals, detect water movement with sensory hairs such as whiskers, bristles or antennae Woda-6 ubt.jpeg
Arthropods like these northern prawn, and some mammals, detect water movement with sensory hairs such as whiskers, bristles or antennae

In animal physiology, hydrodynamic reception refers to the ability of some animals to sense water movements generated by biotic (conspecifics, predators, or prey) or abiotic sources. This form of mechanoreception is useful for orientation, hunting, predator avoidance, and schooling. [1] [2] Frequent encounters with conditions of low visibility can prevent vision from being a reliable information source for navigation and sensing objects or organisms in the environment. Sensing water movements is one resolution to this problem. [3]

Contents

This sense is common in aquatic animals, the most cited example being the lateral line system, the array of hydrodynamic receptors found in fish and aquatic amphibians. [4] Arthropods (including crayfish and lobsters) and some mammals (including pinnipeds and manatees) can use sensory hairs to detect water movements. Systems that detect hydrodynamic stimuli are also used for sensing other stimuli. For example, sensory hairs are also used for the tactile sense, detecting objects and organisms up close rather than via water disturbances from afar. [5] Relative to other sensory systems, our knowledge of hydrodynamic sensing is rather limited. [6] This could be because humans do not have hydrodynamic receptors, which makes it difficult for us to understand the importance of such a system. Generating and measuring a complex hydrodynamic stimulus can also be difficult.

Overview of hydrodynamic stimuli

Definition

“Hydrodynamic” refers to the motion of water against an object that causes a force to be exerted upon it. [7] A hydrodynamic stimulus is therefore a detectable disturbance caused by objects moving in a fluid. The geometry of the disturbance depends on properties of the object (shape, size, velocity) and also on properties of the fluid, such as viscosity and velocity. [8] [9] These water movements are not only relevant to animals that can detect them, but constitute a branch of physics, fluid dynamics, that has importance in areas such as meteorology, engineering, and astronomy.

A frequent hydrodynamic stimulus is a wake, consisting of eddies and vortices that an organism leaves behind as it swims, affected by the animal's size, swimming pattern, and speed. [10] Although the strength of a wake decreases over time as it moves away from its source, vortex structure of a goldfish's wake can remain for about thirty seconds, and increased water velocity can be detected several minutes after production. [11]

Uses of hydrodynamic stimuli

Since movement of an object through water inevitably creates movement of the water itself, and this resulting water motion persists and travels, the detection of hydrodynamic stimuli is useful for sensing conspecifics, predators, and prey. Many studies are based upon the question of how an aquatic organism can capture prey despite darkness or apparent lack of visual or other sensory systems and find that the sensing of hydrodynamic stimuli left by prey is probably responsible. [12] [13] [14] [15] As for detection of conspecifics, harbor seal pups will enter the water with their mother, but eventually ascend to obtain oxygen, and then dive again to rejoin the mother. [2] Observations suggest that the tracking of water movements produced by the mother and other pups allows this rejoining to occur. Through these trips and the following of conspecifics, pups might learn routes to avoid predators and good places to find food, showing the possible significance of hydrodynamic detection to these seals.

Hydrodynamic stimuli also function in exploration of the environment. For example, blind cave fish create disturbances in the water and use distortions of this self-generated field to complete spatial tasks, such as avoiding surrounding obstacles. [16]

Visualizing hydrodynamic stimuli

Since water movements are difficult for humans to observe, researchers can visualize the hydrodynamic stimuli that animals detect via particle image velocimetry (PIV). This technique tracks fluid motions by particles put into the water that can be more easily imaged compared to the water itself. The direction and speed of water movement can be defined quantitatively. [10] This technique assumes that the particles will follow the flow of the water.

Invertebrates

To detect water movement, many invertebrates have sensory cells with cilia that project from the body surface and make direct contact with surrounding water. [17] Typically, the cilia include one kinocilium surrounded by a group of shorter stereocilia. Deflection of stereocilia toward the kinocilium by movement of water around the animal stimulates some sensory cells and inhibits others. Water velocity is thus related to the amount of deflection of certain stereocilia, and sensory cells send information about this deflection to the brain via firing rates of afferent nerves. Cephalopods, including the squid Loligo vulgaris and cuttlefish Sepia officinalis , have ciliated sensory cells arranged in lines at different locations on the body. [18] Although these cephalopods have only kinocilia and no stereocilia, the sensory cells and their arrangement are analogous to the hair cells and lateral line in vertebrates, indicating convergent evolution.

Arthropods are different from other invertebrates as they use surface receptors in the form of mechanosensory setae to function in both touch and hydrodynamic sensing. These receptors can also be deflected by solid objects or water flow. [1] They are located on different body regions depending on the animal, such as on the tail for crayfish and lobsters. [9] [19] Neural excitation occurs when setae are moved in one direction, while inhibition occurs with movement in the opposite direction.

Fish

Lateral line on an Atlantic cod Atlantic cod.jpg
Lateral line on an Atlantic cod

Fish and some aquatic amphibians detect hydrodynamic stimuli via their lateral line organs. This system consists of an array of sensors called neuromasts arranged along the length of the fish's body. [4] Neuromasts can be free-standing (superficial neuromasts) or within fluid-filled canals (canal neuromasts). The sensory cells within neuromasts are polarized hair cells within a gelatinous cupula. [1] The cupula, and the stereocilia within, are moved a certain amount depending on the movement of the surrounding water. Afferent nerve fibers are excited or inhibited depending on whether the hair cells they arise from are deflected in the preferred or opposite direction. Lateral line receptors form somatotopic maps within the brain informing the fish of amplitude and direction of flow at different points along the body. These maps are located in the medial octavolateral nucleus (MON) of the medulla and in higher areas such as the torus semicircularis. [20]

Mammals

Detection of hydrodynamic stimuli in mammals typically occurs through use of hairs (vibrissae) or “push-rod” mechanoreceptors, as in platypuses. When hairs are used, they are often in the form of whiskers and contain a follicle-sinus complex (F-SC), making them different from the hairs with which humans are most familiar. [21] [22] [23]

Pinnipeds

Pinnipeds, including sea lions and seals, use their mystacial vibrissae (whiskers) for active touch, including size and shape discrimination, and texture discrimination in seals. [13] [24] When used for touch, these vibrissae are moved to the forward position and kept still while the head moves, thus moving the vibrissae on the surface of an object. This is in contrast to rodents, which move the whiskers themselves to explore objects. [24] More recently, research has been done to see if pinnipeds can use these same whiskers to detect hydrodynamic stimuli in addition to tactile stimuli. While this ability has been verified behaviorally, the specific neural circuits involved have not yet been determined.

Seals

Research on the ability of pinnipeds to detect hydrodynamic stimuli was first done on harbor seals (Phoca vitulina). [13] It had been unclear how seals could find food in dark waters. It was found that a harbor seal that could use only its whiskers for sensory information (due to being blindfolded and wearing headphones), could respond to weak hydrodynamic stimuli produced by an oscillating sphere within the range of frequencies that fish would generate. As with active touch, whiskers are not moved during sensing, but are projected forward and remain in that position.

To find whether seals could actually follow hydrodynamic stimuli using their vibrissae rather than just detect them, a blindfolded harbor seal with headphones can be released into a tank in which a toy submarine has left a hydrodynamic trail. [3] After protracting its vibrissae to the most forward position and making lateral head movements, the seal can locate and follow a trail of 40 meters even when sharp turns to the trail are added. When whisker movements are prevented with a mask covering the muzzle, the seal cannot locate and follow the trail, indicating use of information obtained by the whiskers.

Trails produced by live animals are more complex than that produced by a toy submarine, so the ability of seals to follow trails produced by other seals can also be tested. [2] A seal is capable of following this center of this trail, either following the direct path of the trail or using an undulatory pattern involving crossing the trail repeatedly. This latter pattern might allow the seal to track a fish swimming in a zigzagging motion, or assist with tracking weak trails by comparing the surrounding water with the prospective trail. [25]

Other studies have shown that the harbor seal can distinguish between the hydrodynamic trails left by paddles of different sizes and shapes, a finding in agreement with what the lateral line in goldfish is capable of doing. [8] Discrimination between different fish species might have adaptive value if it allows seals to capture those with highest energy content. Seals can also detect a hydrodynamic trail produced by a fin-like paddle up to 35 seconds old with an accuracy rate greater than chance. [26] Accuracy diminishes as the trail becomes older.

Sea lions

The California sea lion (Zalophus californianus) have mystacial vibrissae that differ from those of seals, but it can detect and follow a trail made by a small toy submarine. [25] Sea lions use an undulatory pattern of tracking similar to that in seals, [2] but do not perform as well with increased delay before they are allowed to swim and locate the trail.

Species differences in vibrissae

Studies raise the question of how detection of hydrodynamic stimuli in these animals is possible given the movement of the vibrissae due to water flow during swimming. Whiskers vibrate with a certain frequency based on swim speed and properties of the whisker. [3] Detection of the water disturbance caused by this vibrissal movement should overshadow any stimulus produced by a distant fish due to its proximity. For seals, one proposal is that they might sense changes in the baseline frequency of vibration to detect hydrodynamic stimuli produced by another source. However, a more recent study shows that the morphology of the seal's vibrissae actually prevents vortices produced by the whiskers from creating excessive water disturbances. [27]

In harbor seals, the structure of the vibrissal shaft is undulated (wavy) and flattened. [27] This specialization is also found in most true seals. [24] In contrast, the whiskers of the California sea lion are circular or elliptical in cross-section and are smooth.

When seals swim with their vibrissae projected forward, the flattened, undulated structure prevents the vibrissae from bending backward or vibrating to produce water disturbances. [27] Thus, the seal prevents noise from the whiskers by a unique whisker structure. However, sea lions appear to monitor modulations of the characteristic frequency of the whiskers to obtain information about hydrodynamic stimuli. [24] This different mechanism might be responsible for the sea lion's worse performance in tracking an aging hydrodynamic trail. [25] Since the whiskers of the sea lion must recover its characteristic frequency after the frequency is altered by a hydrodynamic stimulus, this could reduce the whisker's temporal resolution. [24]

Manatees

Similar to the vibrissae of seals and sea lions, Florida manatees also use hairs for detecting tactile and hydrodynamic stimuli. However, manatees are unique since these tactile hairs are located over the whole post-cranial body in addition to the face. [15] These hairs have different densities at different locations of the body, with higher density on the dorsal side and density decreasing ventrally. The effect of this distribution in spatial resolution is unknown. This system, distributed over the whole body, could localize water movements analogous to a lateral line.

Research is currently being done to test detection of hydrodynamic stimuli in manatees. While the anatomy of the follicle-sinus complexes of manatees have been well studied, [23] there is much to learn about the neural circuits involved if such detection is possible and the way in which the hairs encode information about strength and location of a stimulus via timing differences in firing.

Platypuses

In contrast to the sinus hairs that other mammals use to detect water movements, evidence indicates that platypuses use specialized mechanoreceptors on the bill called “push-rods”. [14] These look like small domes on the surface, which are the ends of rods that are attached at the base but can move freely otherwise.

Using these push-rods in combination with electroreceptors, also on the bill, allows the platypus to find prey with its eyes closed. [14] While researchers initially believed that the push-rods could only function when something is in contact with the bill (implicating their use for a tactile sense), it is now believed that they can also be used at a distance to detect hydrodynamic stimuli. The information from push-rods and electroreceptors combine in the somatosensory cortex in a structure with stripes similar to the ocular dominance columns for vision. In the third layer of this structure, sensory inputs from push-rods and electroreceptors may combine so that the platypus can use the time difference between arrival of each type of signal at the bill (with hydrodynamic stimuli arriving after electrical signals) to determine the location of prey. That is, different cortical neurons could encode the delay between detection of electrical and hydrodynamic stimuli. However, a specific neural mechanism for this is not yet known.

Other mammals

The family Talpidae includes the moles, shrew moles, and desmans. Most members of this family have Eimer's organs, touch-sensitive structures on the snout. The desmans are semi-aquatic and have small sensory hairs that have been compared to the neuromasts of the lateral line. These hairs are termed “microvibrissae” due to their small size, ranging from 100 to 200 micrometers. They are located with the Eimer's organs on the snout and might sense water movements. [28]

Soricidae, a sister family of Talpidae, contains the American water shrew. This animal can obtain prey during the night despite the darkness. To discover how this is possible, a study controlling for use of electroreception, sonar, or echolocation showed that this water shrew is capable of detecting water disturbances made by potential prey. [12] This species probably uses its vibrissae for hydrodynamic (and tactile) sensing based on behavioral observations and their large cortical representation.

While not well studied, the Rakali (Australian water rat) may also be able to detect water movements with its vibrissae as these have a large amount of innervation, though further behavioral studies are needed to confirm this. [21]

While tying the presence of whiskers to hydrodynamic reception has allowed the list of mammals with this special sense to grow, more research still needs to be done on the specific neural circuits involved.

Related Research Articles

<span class="mw-page-title-main">Pinniped</span> Infraorder of mammals

Pinnipeds, commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae, Otariidae, and Phocidae. There are 34 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage. Pinnipeds belong to the order Carnivora; their closest living relatives are musteloids, having diverged about 50 million years ago.

<span class="mw-page-title-main">Sense of balance</span> Physiological sense regarding posture

The sense of balance or equilibrioception is the perception of balance and spatial orientation. It helps prevent humans and nonhuman animals from falling over when standing or moving. Equilibrioception is the result of a number of sensory systems working together; the eyes, the inner ears, and the body's sense of where it is in space (proprioception) ideally need to be intact.

<span class="mw-page-title-main">Whiskers</span> Type of animal hair used for sensing

Vibrissae, more generally called whiskers, are a type of stiff, functional hair used by mammals to sense their environment. These hairs are finely specialised for this purpose, whereas other types of hair are coarser as tactile sensors. Although whiskers are specifically those found around the face, vibrissae are known to grow in clusters at various places around the body. Most mammals have them, including all non-human primates and especially nocturnal mammals.

<span class="mw-page-title-main">Lateral line</span> Sensory system in fish

The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial cells, known as hair cells, which respond to displacement caused by motion and transduce these signals into electrical impulses via excitatory synapses. Lateral lines serve an important role in schooling behavior, predation, and orientation.

Stimulus modality, also called sensory modality, is one aspect of a stimulus or what is perceived after a stimulus. For example, the temperature modality is registered after heat or cold stimulate a receptor. Some sensory modalities include: light, sound, temperature, taste, pressure, and smell. The type and location of the sensory receptor activated by the stimulus plays the primary role in coding the sensation. All sensory modalities work together to heighten stimuli sensation when necessary.

A mechanoreceptor, also called mechanoceptor, is a sensory receptor that responds to mechanical pressure or distortion. Mechanoreceptors are innervated by sensory neurons that convert mechanical pressure into electrical signals that, in animals, are sent to the central nervous system.

<span class="mw-page-title-main">Electroreception and electrogenesis</span> Biological electricity-related abilities

Electroreception and electrogenesis are the closely-related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes to stun prey. The capabilities are found almost exclusively in aquatic or amphibious animals, since water is a much better conductor of electricity than air. In passive electrolocation, objects such as prey are detected by sensing the electric fields they create. In active electrolocation, fish generate a weak electric field and sense the different distortions of that field created by objects that conduct or resist electricity. Active electrolocation is practised by two groups of weakly electric fish, the Gymnotiformes (knifefishes) and the Mormyridae (elephantfishes), and by Gymnarchus niloticus, the African knifefish. An electric fish generates an electric field using an electric organ, modified from muscles in its tail. The field is called weak if it is only enough to detect prey, and strong if it is powerful enough to stun or kill. The field may be in brief pulses, as in the elephantfishes, or a continuous wave, as in the knifefishes. Some strongly electric fish, such as the electric eel, locate prey by generating a weak electric field, and then discharge their electric organs strongly to stun the prey; other strongly electric fish, such as the electric ray, electrolocate passively. The stargazers are unique in being strongly electric but not using electrolocation.

<span class="mw-page-title-main">West Indian manatee</span> The largest living sirenian in the world

The West Indian manatee, also known as the North American manatee, is a large, aquatic mammal native to warm coastal areas of the Caribbean, from the eastern US to northern Brazil. Living alone or in herds, it feeds on underwater plants and uses its whiskers to navigate. It is divided into two endangered subspecies, the Florida manatee in the US and the Antillean manatee in the Caribbean, both of which face pressure from habitat loss, pollution, and other human activity. The West Indian manatee is the largest of the sirenians, a group of large aquatic mammals that includes the dugong, other manatees, and the extinct Steller's sea cow.

Sensory substitution is a change of the characteristics of one sensory modality into stimuli of another sensory modality.

<i>Hydrophis curtus</i> Species of snake

Hydrophis curtus, also known as Shaw's Sea Snake, short sea snake, but often includes Hydrophis hardwickii is a species of sea snake. Like most Hydrophiinae sea snakes, it is a viviparous, fully marine, and front fanged elapid that is highly venomous. It is collected for a variety of purposes including human and animal food, for medicinal purposes and for their skin.

<span class="mw-page-title-main">Cat senses</span>

Cat senses are adaptations that allow cats to be highly efficient predators. Cats are good at detecting movement in low light, have an acute sense of hearing and smell, and their sense of touch is enhanced by long whiskers that protrude from their heads and bodies. These senses evolved to allow cats to hunt effectively at dawn and dusk.

Active sensory systems are sensory receptors that are activated by probing the environment with self-generated energy. Examples include echolocation of bats and dolphins and insect antennae. Using self-generated energy allows more control over signal intensity, direction, timing and spectral characteristics. By contrast, passive sensory systems involve activation by ambient energy. For example, human vision relies on using light from the environment.

A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of stimuli. Although traditionally five human senses were identified as such, it is now recognized that there are many more. Senses used by non-human organisms are even greater in variety and number. During sensation, sense organs collect various stimuli for transduction, meaning transformation into a form that can be understood by the brain. Sensation and perception are fundamental to nearly every aspect of an organism's cognition, behavior and thought.

Feature detection is a process by which the nervous system sorts or filters complex natural stimuli in order to extract behaviorally relevant cues that have a high probability of being associated with important objects or organisms in their environment, as opposed to irrelevant background or noise.

<span class="mw-page-title-main">Harbor seal</span> Species of mammal

The harborseal, also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere. The most widely distributed species of pinniped, they are found in coastal waters of the northern Atlantic, Pacific Oceans, Baltic and North Seas.

Robotic sensing is a subarea of robotics science intended to provide sensing capabilities to robots. Robotic sensing provides robots with the ability to sense their environments and is typically used as feedback to enable robots to adjust their behavior based on sensed input. Robot sensing includes the ability to see, touch, hear and move and associated algorithms to process and make use of environmental feedback and sensory data. Robot sensing is important in applications such as vehicular automation, robotic prosthetics, and for industrial, medical, entertainment and educational robots.

<span class="mw-page-title-main">Surface wave detection by animals</span>

Surface wave detection by animals is the process by which animals, such as surface-feeding fish are able to sense and localize prey and other objects on the surface of a body of water by analyzing features of the ripples generated by objects' movement at the surface. Features analyzed include waveform properties such as frequency, change in frequency, and amplitude, and the curvature of the wavefront. A number of different species are proficient in surface wave detection, including some aquatic insects and toads, though most research is done on the topminnow/surface killifish Aplocheilus lineatus. The fish and other animals with this ability spend large amounts of time near the water surface, some just to feed and others their entire lives.

Most fish possess highly developed sense organs. Nearly all daylight fish have color vision that is at least as good as a human's. Many fish also have chemoreceptors that are responsible for extraordinary senses of taste and smell. Although they have ears, many fish may not hear very well. Most fish have sensitive receptors that form the lateral line system, which detects gentle currents and vibrations, and senses the motion of nearby fish and prey. Sharks can sense frequencies in the range of 25 to 50 Hz through their lateral line.

<span class="mw-page-title-main">Communication in aquatic animals</span>

Communication occurs when an animal produces a signal and uses it to influences the behaviour of another animal. A signal can be any behavioural, structural or physiological trait that has evolved specifically to carry information about the sender and/or the external environment and to stimulate the sensory system of the receiver to change their behaviour. A signal is different from a cue in that cues are informational traits that have not been selected for communication purposes. For example, if an alerted bird gives a warning call to a predator and causes the predator to give up the hunt, the bird is using the sound as a signal to communicate its awareness to the predator. On the other hand, if a rat forages in the leaves and makes a sound that attracts a predator, the sound itself is a cue and the interaction is not considered a communication attempt.

An Artificial Lateral Line (ALL) is a biomimetic lateral line system. A lateral line is a system of sensory organs in aquatic animals such as fish, that serves to detect movement, vibration, and pressure gradients in their environment. An artificial lateral line is an artificial biomimetic array of distinct mechanosensory transducers that, similarly, permits the formation of a spatial-temporal image of the sources in immediate vicinity based on hydrodynamic signatures; the purpose is to assist in obstacle avoidance and object tracking. The biomimetic lateral line system has the potential to improve navigation in underwater vehicles when vision is partially or fully compromised. Underwater navigation is challenging due to the rapid attenuation of radio frequency and Global Positioning System signals. In addition, ALL systems can overcome some of the drawbacks in traditional localization techniques like SONAR and optical imaging.

References

  1. 1 2 3 Herring, Peter. The Biology of the Deep Ocean. New York: Oxford, 2002.
  2. 1 2 3 4 Schulte-Pelkum, N, S Wieskotten, W Hanke, G Dehnhardt, and B Mauck. “Tracking of biogenic hydrodynamic trails in harbour seals (Phoca vitulina).” Journal of Experimental Biology 210, no. 5 (2007): 781-7. doi : 10.1242/jeb.02708. PMID   17297138.
  3. 1 2 3 Dehnhardt, G, B Mauck, W Hanke, and H Bleckmann. “Hydrodynamic trail-following in harbor seals (Phoca vitulina).” Science 293, no. 5527 (2001): 102-4. doi : 10.1126/science.1060514. PMID   11441183.
  4. 1 2 Bleckmann, H, and R Zelick. “Lateral line system of fish.” Integrative Zoology 4 (2009): 13-25. doi : 10.1111/j.1749-4877.2008.00131.x.
  5. ↑ Dehnhardt, G, and A. Kaminski. “Sensitivity of the mystacial vibrissae of harbour seals (Phoca vitulina) for size differences of actively touched objects.” Journal of Experimental Biology 198, no. 11 (1995): 2317-23. PMID   7490570.
  6. ↑ Bleckmann, Horst. "Reception of Hydrodynamic Stimuli in Aquatic and Semiaquatic Animals." In Progress in Zoology, Vol. 41, edited by W. Rathmayer, 1-115. Stuttgart, Jena, New York: Gustav Fischer, 1994.
  7. ↑ Merriam-Webster.com, s.v. “Hydrodynamics," http://www.merriam-webster.com/dictionary.
  8. 1 2 Wieskotten, S, B Mauck, L Miersch, G Dehnhardt, and W Hanke. “Hydrodynamic discrimination of wakes caused by objects of different size or shape in a harbour seal (Phoca vitulina).” Journal of Experimental Biology 214, no. 11 (2011): 1922-30. doi : 10.1242/jeb.053926. PMID   21562180.
  9. 1 2 Bradbury, Jack W., and Sandra L. Vehrencamp. Principles of Animal Communication, Second Edition. Sunderland: Sinauer, 2011. 249-257.
  10. 1 2 Videler, J J, U K Muller, and E J Stamhuis. “Aquatic vertebrate locomotion: wakes from body waves.” Journal of Experimental Biology 202, no. 23 (1999): 3423-30. PMID   10562525.
  11. ↑ Hanke, W, C Brucker, and H Bleckmann. “The ageing of the low-frequency water disturbances caused by swimming goldfish and its possible relevance to prey detection.” Journal of Experimental Biology 203, no. 7 (2000): 1193-200. PMID   10708639.
  12. 1 2 Catania, K C, J F Hare, K L Campbell. “Water shrews detect movement, shape, and smell to find prey underwater.” PNAS 105, no. 2 (2008): 571-76. doi : 10.1073/pnas.0709534104.
  13. 1 2 3 Dehnhardt, G, B Mauck, and H Bleckmann. “Seal whiskers detect water movements.” Nature 394, no. 6690 (1998): 235-6.
  14. 1 2 3 Pettigrew, J D, P R Manger, and S L Fine. “The sensory world of the platypus.” Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 353, no. 1372 (1998): 1199-210. doi : 10.1098/rstb.1998.0276. PMID   9720115.
  15. 1 2 Reep, R L, C D Marshall, and M L Stoll. “Tactile hairs on the postcranial body in Florida manatees: a Mammalian lateral line?” Brain, Behavior and Evolution 59, no. 3 (2002): 141-54. PMID   12119533.
  16. ↑ Windsor, S P, D Tan, and J C Montgomery. “Swimming kinematics and hydrodynamic imaging in the blind Mexican cave fish (Astyanax fasciatus). Journal of Experimental Biology 211, no. 18 (2008), 2950-9. doi : 10.1242/jeb.020453. PMID   18775932.
  17. ↑ Budelmann, Bernd-Ulrich. "Hydrodynamic Receptor Systems in Invertebrates." In The Mechanosensory Lateral Line. Neurobiology and Evolution, edited by S Coombs, P Gorner, H Munz, 607-632. New York: Springer, 1989.
  18. ↑ Budelmann, B U, and H Bleckmann. “A lateral line analogue in cephalopods: water waves generate microphonic potentials in the epidermal head lines of Sepia and Lolliguncula.” Journal of Comparative Physiology A 164 (1988): 1-5.
  19. ↑ Douglass, J K, and L A Wilkens. “Directional selectivities of near-field filiform hair mechanoreceptors on the crayfish tailfan (Crustacea: Decapoda).” Journal of Comparative Physiology A 183 (1998): 23-34.
  20. ↑ Plachta, D T T, W Hanke, and H Bleckmann. “A hydrodynamic topographic map in the midbrain of goldfish Carassius auratus.” Journal of Experimental Biology 206, no. 19 (2003): 3479-86. doi : 10.1242/jeb.00582.
  21. 1 2 Dehnhardt, G, H Hyvärinen, A Palviainen, and G Klauer. “Structure and innervation of the vibrissal follicle-sinus complex in the Australian water rat, Hydromys chrysogaster.” The Journal of Comparative Neurology 411, no. 4 (1999): 550-62. PMID   10421867.
  22. ↑ Marshall, C D, H Amin, K M Kovacs, and C Lydersen. “Microstructure and innervation of the mystacial vibrissal follicle-sinus complex in bearded seals, Erignathus barbatus (Pinnipedia: Phocidae). The Anatomical Record Part A 288, no. 1 (2006): 13-25. doi : 10.1002/ar.a.20273. PMID   16342212.
  23. 1 2 Sarko, D K, R L Reep, J E Mazurkiewicz, and F L Rice. “Adaptations in the Structure and Innervation of Follicle-Sinus Complexes to an Aquatic Environment as Seen in the Florida Manatee (Trichechus manatus latirostris).” Journal of Comparative Neurology 504 (2007): 217-37. doi : 10.1002/cne.
  24. 1 2 3 4 5 Miersch, L, W Hanke, S Wieskotten, F D Hanke, J Oeffner, A Leder, M Brede, M Witte, and G Dehnhardt. “Flow sensing by pinniped whiskers.” Philosophical Transactions of the Royal Society of London B 366, no. 1581 (2011): 3077-84. doi : 10.1098/rstb.2011.0155. PMID   21969689.
  25. 1 2 3 Gläser, N, S Wieskotten, C Otter, G Dehnhardt, and W Hanke. “Hydrodynamic trail following in a California sea lion (Zalophus californianus).” Journal of Comparative Physiology A 197, no. 2 (2011): 141-51. doi : 10.1007/s00359-010-0594-5. PMID   20959994.
  26. ↑ Wieskotten, S, G Dehnhardt, B Mauck, L Miersch, and W Hanke. “Hydrodynamic determination of the moving direction of an artificial fin by a harbour seal (Phoca vitulina).” The Journal of Experimental Biology 213, no. 13 (2010): 2194-200. doi : 10.1242/jeb.041699. PMID   20543117.
  27. 1 2 3 Hanke, W, M Witte, L Miersch, M Brede, J Oeffner, M Michael, F Hanke, A Leder, and G Dehnhardt. “Harbor seal vibrissa morphology suppresses vortex-induced vibrations.” Journal of Experimental Biology 213, no. 15 (2010): 2665-72. doi : 10.1242/jeb.043216. PMID   20639428.
  28. ↑ Catania, K C. “Epidermal Sensory Organs of Moles, Shrew Moles, and Desmans: A Study of the Family Talpidae with Comments on the Function and Evolution of Eimer’s Organ.” Brain, Behavior and Evolution 56, no. 3 (2000): 146-174. doi : 10.1159/000047201.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.