scholarly journals Electroreception in the Guiana dolphin ( Sotalia guianensis )

2011 ◽  
Vol 279 (1729) ◽  
pp. 663-668 ◽  
Author(s):  
Nicole U. Czech-Damal ◽  
Alexander Liebschner ◽  
Lars Miersch ◽  
Gertrud Klauer ◽  
Frederike D. Hanke ◽  
...  
Keyword(s):  
Electric Fields ◽  
Lateral Line ◽  
Detection Threshold ◽  
Sotalia Guianensis ◽  
Trigeminal Nerves ◽  
Sensory Ability ◽  
Guiana Dolphin

Passive electroreception is a widespread sense in fishes and amphibians, but in mammals this sensory ability has previously only been shown in monotremes. While the electroreceptors in fish and amphibians evolved from mechanosensory lateral line organs, those of monotremes are based on cutaneous glands innervated by trigeminal nerves. Electroreceptors evolved from other structures or in other taxa were unknown to date. Here we show that the hairless vibrissal crypts on the rostrum of the Guiana dolphin ( Sotalia guianensis ), structures originally associated with the mammalian whiskers, serve as electroreceptors. Histological investigations revealed that the vibrissal crypts possess a well-innervated ampullary structure reminiscent of ampullary electroreceptors in other species. Psychophysical experiments with a male Guiana dolphin determined a sensory detection threshold for weak electric fields of 4.6 µV cm −1 , which is comparable to the sensitivity of electroreceptors in platypuses. Our results show that electroreceptors can evolve from a mechanosensory organ that nearly all mammals possess and suggest the discovery of this kind of electroreception in more species, especially those with an aquatic or semi-aquatic lifestyle.

Rostrum Contact Behaviors by the Guiana Dolphin (Sotalia guianensis) in Ilhéus, Brazil

2016 ◽  
Vol 42 (2) ◽  
pp. 203-209
Author(s):  
Flavia B. Izidoro ◽  
Yvonnick Le Pendu
Keyword(s):  
Sotalia Guianensis ◽  
Guiana Dolphin

scholarly journals Feeding Strategies of the Guiana Dolphin Sotalia guianensis

2009 ◽  
Vol 3 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Marcos R. Rossi-Santos ◽  
Paulo A.C. Flores
Keyword(s):  
Feeding Strategies ◽  
Sotalia Guianensis ◽  
Guiana Dolphin

scholarly journals Quem são e o que pensam os condutores de embarcações turísticas para observação de botos-cinza?

2018 ◽  
Vol 11 (4) ◽  
Author(s):  
Josivânia Emanuelly Azevedo Dos Santos ◽  
Vitor de Oliveira Lunardi ◽  
Diana Carvalho de Freitas ◽  
Maria Mayara dos Santos Silva ◽  
Diana Gonçalves Lunardi
Keyword(s):  
Cultural Awareness ◽  
Environmental Planning ◽  
Codes Of Conduct ◽  
Rio Grande ◽  
The Sustainable Development ◽  
Sotalia Guianensis ◽  
Relevant Role ◽  
Social Environmental ◽  
Guiana Dolphin ◽  
Dolphin Watching

Condutores turísticos podem exercer um papel relevante para o desenvolvimento sustentável do ecoturismo, sendo responsáveis pela condução dos turistas durante a visitação, promoção da sensibilização ambiental e cultural e contribuição no monitoramento de impactos socioambientais no local de visitação. Este estudo teve como objetivo descrever quem são e o que pensam os condutores de embarcações turísticas para observação de botos-cinza (Sotalia guianensis). Para tanto, foi registrada a interação entre condutores turísticos e turistas durante 22 passeios de observação de botos-cinza realizados entre 2014 e 2018 na Reserva de Fauna Costeira de Tibau do Sul (REFAUTS), Rio Grande do Norte, Brasil. Adicionalmente, 22 questionários foram aplicados aos condutores de embarcações turísticas na REFAUTS, em maio de 2017 e julho de 2018. Durante os 22 passeios monitorados, os turistas não receberam qualquer informação sobre a REFAUTS ou receberam informação insuficiente sobre a biologia e ecologia de botos-cinza. De acordo com as respostas obtidas nos questionários, condutores turísticos da REFAUTS são predominantemente jovens, com nível de escolaridade fundamental e têm esta atividade como principal fonte de renda. Estes condutores declararam trabalhar na REFAUTS há pelo menos sete anos e ter conhecimento insuficiente sobre a existência desta Reserva. Uma parte significativa destes profissionais também declarou desconhecer a Lei Municipal nº 349/2007, que regulamenta o transporte marítimo na REFAUTS. Contudo, estes condutores declararam reconhecer a importância dos seguintes aspectos ambientais para a REFAUTS: boto-cinza, ambiente marinho protegido, normas de conduta, programa de fiscalização e cobrança da taxa turística para a REFAUTS. Os resultados deste estudo poderão subsidiar programas de educação ambiental voltados para os condutores turísticos, tornando-os importantes aliados na conservação de botos-cinza e agentes multiplicadores no processo de sensibilização ambiental de turistas na REFAUTS. Who are and what think the guiana dolphin-watching operators? Tour operators can play a relevant role in the sustainable development of ecotourism, being responsible for driving tourists during the visitation, promoting environmental and cultural awareness and contributing to the monitoring of social-environmental impacts in the place of visitation. This study aimed to describe who are and what think the Guiana dolphin-watching operators. We recorded the interaction between dolphin-watching operators and tourists during 22 tours conducted between 2014 and 2018 in the Coastal Wildlife Reserve of Tibau do Sul (REFAUTS), Rio Grande do Norte State, Brazil. In addition, 22 questionnaires were applied to dolphin-watching operators at the REFAUTS in May 2017 and July 2018. During the 22 tours monitored, tourists did not receive any information about the REFAUTS or received insufficient information about the biology and ecology of Guiana dophin (Sotalia guianensis). According to the answers obtained in the questionnaires, dolphin-watching operators are predominantly young, with elementary scholarly and have this activity as the main source of income. These dolphin-watching operators reported that they have worked in the REFAUTS for at least seven years and that they have insufficient knowledge about the existence of this Reserve. A significant number of these professionals also reported that they do not know the Municipal Law no 349/2007, which regulates maritime transport at the REFAUTS. However, these dolphin-watching operators reported that they recognize the importance of the following environmental aspects for the REFAUTS: Guiana dolphin, protected marine area, codes of conduct, inspection program and tourist tax for the REFAUTS. The results of this study may subsidize environmental education programs for dolphin-watching operators, making them important partners in the conservation of Guiana dolphin and multipliers in the process of environmental awareness of tourists in the REFAUTS. KEYWORDS: Dolphin; Environmental Perception; Environmental Planning; Pipa Beach; Dolphin-Watching.

Flowing water decreases hydrodynamic signal detection in a fish with an epidermal lateral-line system

2006 ◽  
Vol 57 (6) ◽  
pp. 611 ◽  
Author(s):  
Daniel K. Bassett ◽  
Alexander G. Carton ◽  
John C. Montgomery
Keyword(s):  
Lateral Line ◽  
Detection Threshold ◽  
Low Noise ◽  
Detection Sensitivity ◽  
Lateral Line System ◽  
Flowing Water ◽  
Background Flow ◽  
Line System ◽  
Water Conditions ◽  
The Common

The lateral-line system of the common bully, Gobiomorphus cotidianus, is unusual in that it possesses an extensive array of superficial neuromasts. Fish were trained to orientate to a small vibrating bead (50 Hz). By manipulating the amplitude of vibration to determine the threshold level for the behaviour, the hydrodynamic detection capabilities of the common bully were characterised in both still- and flowing-water. In still water, the common bully attained a detection threshold (calculated as the amplitude of water particle displacement at the snout) of 3.3 × 10−5 cm at 50 Hz. Successive elevations in the background flow caused a 10-fold decrease in detection sensitivity. At a background flow of 4.5 cm s–1 the detection threshold increased to 3 × 10−4 cm. These findings demonstrate that a lateral-line system that lacks sub-surface canal neuromasts is most sensitive in still-water conditions (low-noise). However, this system is compromised under flowing-water conditions such that sensitivity is reduced at current velocities >1.5 cm s–1.

scholarly journals On the feeding habit of the Guiana Dolphin Sotalia guianensis (van Bénedèn, 1864) (Mammalia: Cetartiodactyla: Delphinidae) in southeastern Brazil (~220S): has there been any change in more than two decades?

2017 ◽  
Vol 9 (2) ◽  
pp. 9840 ◽  
Author(s):  
Ana Paula Madeira Di Beneditto ◽  
Clara Da Cruz Vidart Badia ◽  
Salvatore Siciliano
Keyword(s):  
Prey Species ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Southeastern Brazil ◽  
Feeding Preferences ◽  
Sotalia Guianensis ◽  
The North ◽  
Trichiurus Lepturus ◽  
Janeiro State ◽  
Guiana Dolphin

Along the north and central coast of Rio de Janeiro State (22025’S–23000’S), southeastern Brazil, the Guiana Dolphin Sotalia guianensis forages on neritic prey, mainly fish.  From the analysis of the dolphin’s stomach contents and the identification of partially digested prey, it was verified that the most frequent prey species were young specimens of Trichiurus lepturus.  Comparing our results with previous studies on the feeding habits of Guiana Dolphin in the same region, we noticed the maintenance of its feeding preferences during more than two decades, indicating little or no change in the use of prey by this top predator. 

scholarly journals Subcellular Cadmium, Lead and Mercury Compartmentalization in Guiana Dolphins (Sotalia guianensis) From Southeastern Brazil

2020 ◽  
Vol 7 ◽  
Author(s):  
Rachel Ann Hauser-Davis ◽  
Lívia Figueiredo ◽  
Leila Lemos ◽  
Jailson Fulgêncio de Moura ◽  
Rafael C. C. Rocha ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Marine Mammals ◽  
Insoluble Fraction ◽  
Southeastern Brazil ◽  
Chemical Contamination ◽  
Inductively Coupled ◽  
Sotalia Guianensis ◽  
Subcellular Compartmentalization ◽  
Cadmium Lead ◽  
Guiana Dolphin

Marine mammals are considered excellent ocean health sentinels and are ubiquitously exposed to chemical contaminants worldwide. The Guiana dolphin (Sotalia guianensis) is a near-threatened dolphin species from Brazil with unknown population size data. This indicates the need for assessments regarding deleterious effects that may arise from exposure to chemical contamination, especially metals. After entry in the organism, these compounds are subject to internal subcellular compartmentalization, which in turn alters their bioavailability. However, almost no assessments regarding subcellular metal contents in marine mammals are available. In this context, metal compartmentalization was determined in three subcellular fractions for three toxic elements, Cd, Hg and Pb, by inductively coupled plasma mass spectrometry (ICP-MS) in Guiana dolphin kidney and liver samples from Southeastern Brazil. Differential metal-detoxification mechanisms were observed for the three elements, where metallothionein (MT) detoxification was postulated for only for Pb, while Cd and Hg were poorly associated to MT, and mostly present in the insoluble fraction, indicating low bioavailability. This is the first report on subcellular metal compartmentalization in Guiana dolphins and indicates that critical biochemical detoxification data is obtained through subcellular fraction analyses in marine mammals. This indicates an emerging study field for this type of assessment, which may, in turn, aid in conservation efforts.

Real-Time Record of Entanglement of a Guiana Dolphin (Sotalia guianensis) in Recreational Fishing Ge

2017 ◽  
Vol 43 (3) ◽  
pp. 320-323
Author(s):  
Salvatore Siciliano ◽  
Leandro G. Corrêa ◽  
Ana Paula M. Di Beneditto
Keyword(s):  
Real Time ◽  
Recreational Fishing ◽  
Sotalia Guianensis ◽  
Time Record ◽  
Guiana Dolphin
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