scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Neuroethology and life history adaptations of the elasmobranch electric sense.

01 Sep 2002-Journal of Physiology-paris (Elsevier)-Vol. 96, Iss: 5, pp 379-389
TL;DR: It is argued that the ontogenetic and seasonal variation in electrosensory tuning represent an adaptive electrosENSory plasticity that may be common to many elasmobranchs to enhance an individual's fitness throughout its life history.
Abstract: The electric sense of elasmobranch fishes (sharks and rays) is an important sensory modality known to mediate the detection of bioelectric stimuli. Although the best known function for the use of the elasmobranch electric sense is prey detection, relatively few studies have investigated other possible biological functions. Here, we review recent studies that demonstrate the elasmobranch electrosensory system functions in a wide number of behavioral contexts including social, reproductive and anti-predator behaviors. Recent work on non-electrogenic stingrays demonstrates that the electric sense is used during reproduction and courtship for conspecific detection and localization. Electrogenic skates may use their electrosensory encoding capabilities and electric organ discharges for communication during social and reproductive interactions. The electric sense may also be used to detect and avoid predators during early life history stages in many elasmobranch species. Embryonic clearnose skates demonstrate a ventilatory freeze response when a weak low-frequency electric field is imposed upon the egg capsule. Peak frequency sensitivity of the peripheral electrosensory system in embryonic skates matches the low frequencies of phasic electric stimuli produced by natural fish egg-predators. Neurophysiology experiments reveal that electrosensory tuning changes across the life history of a species and also seasonally due to steroid hormone changes during the reproductive season. We argue that the ontogenetic and seasonal variation in electrosensory tuning represent an adaptive electrosensory plasticity that may be common to many elasmobranchs to enhance an individual's fitness throughout its life history.

Content maybe subject to copyright    Report

Citations
More filters
Journal ArticleDOI
TL;DR: The reduction of bioelectric fields created by the freeze-simulating stimulus resulted in a possible decrease in shark predation risk by reducing detectability and the freeze response may also facilitate other non-visual cryptic mechanisms to lowerpredation risk from a wide range of predator types.
Abstract: Cephalopods, and in particular the cuttlefish Sepia officinalis, are common models for studies of camouflage and predator avoidance behaviour. Preventing detection by predators is especially important to this group of animals, most of which are soft-bodied, lack physical defences, and are subject to both visually and non-visually mediated detection. Here, we report a novel cryptic mechanism in S. officinalis in which bioelectric cues are reduced via a behavioural freeze response to a predator stimulus. The reduction of bioelectric fields created by the freeze-simulating stimulus resulted in a possible decrease in shark predation risk by reducing detectability. The freeze response may also facilitate other non-visual cryptic mechanisms to lower predation risk from a wide range of predator types.

31 citations

Book ChapterDOI
01 Jan 2004
TL;DR: The electrosense response properties are seasonally modified by the periodic expression of gonadal steroids and may serve important modulation of sensory function during reproductive behaviors and are proposed to reflect ontogenetic adaptations to their changing environments.
Abstract: Sharks and rays have a long evolutionary history as major predators in marine ecosystems, but the biological functions and selective pressures that shape the evolution of their ampullary electrosensory system are poorly known. The ampulla of Lorenzini is the functional electrosensory unit that consists of a small subdermal ampulla and a canal that projects to a surface pore on the head or pectoral fins. The sensory epithelium of the ampulla wall detects differences between the potential at the skin pore and internal potential of the animal, and stimulates neural transmission of information about the physical features of an external field to the brain. Natural weak electric stimuli include polar fields from bioelectric sources and induced fields from physical sources in the environment. Neurophysiological studies show that the ampullary electrosense responds to electric field gradients as low as 20 nV/cm, and behav- ioral studies show responses to gradients of 1-5 nV/cm. Elasmobranch fishes show behavioral responses to bioelectric stimuli produced by natural prey, mates, consexuals and potential predators. Numerous models exist for electrosensory navigation, but they remain to be rigorously tested. Recent work shows age-dependent changes in the response properties of the electrosense among embryo, juvenile and adult stages and are proposed to reflect ontogenetic adaptations to their changing environments. In addition, the electrosense response properties are seasonally modified by the periodic expression of gonadal steroids and may serve important modulation of sensory function during reproductive behaviors. Future work should continue to investigate different biological contexts in which the electrosense is used by elasmobranch fishes, and to test the selective forces that may have shaped the evolution of this remark- able sensory system.

29 citations

Book ChapterDOI
Carl Hopkins1
01 Jan 2005

25 citations


Cites background from "Neuroethology and life history adap..."

  • ...Elasmobranchs that produce electric signals locate their mates using electrosensory cues (Tricas et al. 1995; Sisneros et al. 1998; Sisneros and Tricas 2002a, b)....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the authors used routine, incidentally-collected ROV (n = 73) and commercial diver(n = 9) video recordings spanning 1998-2019 globally to provide an account of marine megafauna presence and potential feeding behaviour in the near visible vicinity of subsea anthropogenic structures.
Abstract: In oceans and seas worldwide, an increasing number of end-of-life anthropogenic offshore structures (e.g. platforms, pipelines, manifolds, windfarms, etc.) are facing full or partial removal. As part of the decommissioning process, studies on potential importance of subsea infrastructure to marine megafauna (defined as: cetaceans, pinnipeds, sirenians, large fish – such as sharks, rays, billfishes, and tuna, as well as marine reptiles, and seabirds) are lacking. Dedicated scientific Remotely Operated Vehicle (ROV) surveys around offshore installations are rare, but there is a wealth of archived industrial data and noteworthy species sightings posted publicly on various social media platforms. This study used routine, incidentally-collected ROV (n = 73) and commercial diver (n = 9) video recordings spanning 1998–2019 globally. Data were gathered directly from industrial partners (n = 36) and the public domain (YouTube; n = 46) to provide an account of marine megafauna presence and potential feeding behaviour in the near visible vicinity of subsea anthropogenic structures. A total of 79 video clips and 3 still images of marine megafauna near offshore structures were examined, resulting in 67 individual sightings and 16 sub-sightings (in which an individual was recorded within the same day). At least 178 individuals were identified to a minimum of 17 species of marine megafauna, amounting to a total (combined) sighting duration of 01:09:35 (hh:mm:ss). Results demonstrated proximate presence of marine megafauna (many of which are threatened species) to anthropogenic structures, with most animals displaying foraging or interaction behaviours with the structures. Observations included the deepest (2,779 m) confirmed record of a sleeper shark (Somniosus spp.) and the first confirmed visual evidence of seals following pipelines. These ROV observations demonstrate a latent source of easily-accessible information that can expand understanding of marine megafauna interactions with offshore anthropogenic infrastructure. Consequently, other workers in this field should be encouraged to re-analyse archived datasets, commence further collaborative research projects with industrial partners, and/or expand Internet search terms to additional species assemblages, in a bid to quantitatively elucidate relationships between offshore infrastructure and marine species.

25 citations


Cites background from "Neuroethology and life history adap..."

  • ..., 2013), mates (Tricas et al., 1995; Sisneros and Tricas, 2002), and potentially navigate on large global scales (Klimley, 1993; Klimley et al....

    [...]

Journal ArticleDOI
TL;DR: Detailed morphological data are presented to allow a complete interpretation of the functional significance of the sexual dimorphism found in the ALLN, which may result in improved sensitivity of the electrosensory system and may facilitate mate identification for reproduction.
Abstract: Quantitative studies of sensory axons provide invaluable insights into the functional significance and relative importance of a particular sensory modality. Despite the important role electroreception plays in the behaviour of elasmobranchs, to date, there have been no studies that have assessed the number of electrosensory axons that project from the peripheral ampullae to the central nervous system (CNS). The complex arrangement and morphology of the peripheral electrosensory system has a significant influence on its function. However, it is not sufficient to base conclusions about function on the peripheral system alone. To fully appreciate the function of the electrosensory system, it is essential to also assess the neural network that connects the peripheral system to the CNS. Using stereological techniques, unbiased estimates of the total number of axons were obtained for both the electrosensory bundles exiting individual ampullary organs and those entering the CNS (via the dorsal root of the anterior lateral line nerve, ALLN) in males and females of different sizes. The dorsal root of the ALLN consists solely of myelinated electrosensory axons and shows both ontogenetic and sexual dimorphism. In particular, females exhibit a greater abundance of electrosensory axons, which may result in improved sensitivity of the electrosensory system and may facilitate mate identification for reproduction. Also presented are detailed morphological data on the peripheral electrosensory system to allow a complete interpretation of the functional significance of the sexual dimorphism found in the ALLN.

23 citations


Cites background from "Neuroethology and life history adap..."

  • ...If we consider the fact that it is only the males that make the approach to waiting females for reproduction [Sisneros and Tricas, 2002], then males may not require the ability to differentiate between approaching females and predators, so any detection of an approaching stimulus could be…...

    [...]

  • ...In addition, the use of electroreception for mate location has previously been observed in other elasmobranch species [Bratton and Ayers, 1987; Tricas et al., 1995, Sisneros and Tricas, 2002]....

    [...]

  • ...It is possible that individuals can locate conspecifics from their species-specific electrical output [Sisneros and Tricas, 2002]....

    [...]

  • ..., 2012], predator avoidance [Sisneros and Tricas, 2002; Kempster et al., 2013], navigation [Kalmijn, 1979] and communication [Tricas et al....

    [...]

  • ...If we consider the fact that it is only the males that make the approach to waiting females for reproduction [Sisneros and Tricas, 2002], then males may not require the ability to differentiate between approaching females and predators, so any detection of an approaching stimulus could be interpreted as dangerous (predator)....

    [...]

References
More filters
Journal Article
TL;DR: This is a comprehensive identification guide encompassing all shallow marine fishes within California waters, and many of the family keys have been revised to incorporate recent taxonomic changes and to clarify previously ambiguous terminology.
Abstract: This is a comprehensive identification guide encompassing all shallow marine fishes within California waters. Geographic range limits, maximum size, depth range, a brief color description, and some meristic counts including, if available: fin ray counts, lateral line pores, lateral line scales, gill rakers, and vertebrae are given. Body proportions and shapes are used in the keys and a statement concerning the rarity or commonness in California is given for each species. In all, 554 species are described. Three of these have not been recorded or confirmed as occurring in California waters but are included since they are apt to appear. The remainder have been recorded as occurring in an area between the Mexican and Oregon borders and offshore to at least 50 miles. Five of California species as yet have not been named or described, and ichthyologists studying these new forms have given information on identification to enable inclusion here. A dichotomous key to 144 families includes an outline figure of a representative for all but two families. Keys are presented for all larger families, and diagnostic features are pointed out on most of the figures. Illustrations are presented for all but eight species. of the 554 species, 439 are found primarily in depths less than 400 ft., 48 are meso- or bathypelagic species, and 67 are deepwater bottom dwelling forms rarely taken in less than 400 ft. depth. The deepwater forms included are those taken in commercial trawling gear or that occasionally occur near the surface. An illustrated glossary is included to facilitate use of the identification keys and species descriptions. A comments section presents in detail reasons for certain taxonomic choices and to acknowledge personal communications. Original data presented include a ventral sensory pore pattern key for the skates, 170 geographic range limit extensions, and several depth range and maximum size records. Many of the family keys have been revised to incorporate recent taxonomic changes and to clarify previously ambiguous terminology.

667 citations

BookDOI
01 Jan 1988-Copeia
TL;DR: This volume constitutes a series of invited chapters based on presentations given at an International Conference on the Sensory Biology of Aquatic Animals held June 24-28, 1985 at the Mote Marine Laboratory in Sarasota, Florida.
Abstract: This volume constitutes a series of invited chapters based on presentations given at an International Conference on the Sensory Biology of Aquatic Animals held June 24-28, 1985 at the Mote Marine Laboratory in Sarasota, Florida. The immediate purpose of the conference was to spark an exchange of ideas, concepts, and techniques among investigators concerned with the different sensory modalities employed by a wide variety of animal species in extracting information from the aquatic environment. By necessity, most investigators of sensory biology are specialists in one sensory system: different stimulus modalities require different methods of stimulus control and, generally, different animal models. Yet, it is clear that all sensory systems have principles in common, such as stimulus filtering by peripheral structures, tuning of receptor cells, signal-to-noise ratios, adaption and disadaptation, and effective dynamic range. Other features, such as hormonal and efferent neural control, circadian reorganization, and receptor recycling are known in some and not in other senses. The conference afforded an increased awareness of new discoveries in other sensory systems that has effectively inspired a fresh look by the various participants at their own area of specialization to see whether or not similar principles apply. This inspiration was found not only in theoretical issues, but equally in techniques and methods of approach. The myopy of sensory specialization was broken in one unexpected way by showing limitations of individual sense organs and their integration within each organism. For instance, studying vision, one generally chooses a visual animal as a model.

664 citations