Ocean for Future

Ultima Clock Widget

  • :
  • :

che tempo che fa

Per sapere che tempo fa

Per sapere che tempo fa clicca sull'immagine
dati costantemente aggiornati

OCEAN4FUTURE

La conoscenza ti rende libero

su Amazon puoi trovare molti libri sulla storia del mare (ma non solo) e sulla sua cultura :) clicca sull'immagine ed entra in un nuovo mondo :)

i 100 libri da non perdere

NO PLASTIC AT SEA

NO PLASTIC AT SEA

Petizione OCEAN4FUTURE

Titolo : Impariamo a ridurre le plastiche in mare

Salve a tutti. Noi crediamo che l'educazione ambientale in tutte le scuole di ogni ordine e grado sia un processo irrinunciabile e che l'esempio valga più di mille parole. Siamo arrivati a oltre 4000 firme ma continuiamo a raccoglierle con la speranza che la classe politica al di là delle promesse comprenda realmente l'emergenza che viviamo, ed agisca,speriamo, con maggiore coscienza
seguite il LINK per firmare la petizione

Ultimi articoli

  Address: OCEAN4FUTURE

New record of Carcharhinus leucas (Valenciennes, 1839) in an equatorial river system

Reading Time: 7 minutes

A Bull shark, Carcharhinus leucas (Valenciennes, 1839), has been spotted  in an equatorial river
article by Leonardo Manir Feitosa, Ana Paula Barbosa Martins and Jorge Luiz Silva Nunes

Marine Biodiversity Records 20169:87

DOI: 10.1186/s41200-016-0094-6

Abstract

squalo-toroBull sharks are a cosmopolitan shark species frequently found in shallow shelf ocean waters and, occasionally, in several tropical river systems around the world. Due to bull shark’s capability to enter riverine systems, the documentation of its occurrence is essential for future fisheries inspections and studies. In this way, this study aims to report the presence of a medium sized specimen of C. leucas in an equatorial river system. The specimen was caught by fishermen at Mearim River, located in Northern Brazil and well known for the occurrence of tidal bores during the highest spring tides of the dry season. The event coincided with the occurrence of one of the strongest spring tides of 2015. The captured female specimen measured approximately 1300 mm and weighted 35 kg. The occurrence of this species was not known in this river basin until now. We recommend and support future ichthyologic studies in the Mearim River basin in order to provide data for the delimitation of the territory used by C. leucas in Maranhão State, specially looking into its age, growth, diet, spatial, and temporal movement patterns in this area.

Keywords
Euryhaline shark Elasmobranch North Brazil

Introduction
Bull sharks are a coastal cosmopolitan species frequently found in shallow shelf waters, present in all of the world’s oceans, occasionally entering warm river systems (Cervigón & Alcalá, 1999; Compagno et al., 2005). It has been known to occur in several other rivers in all continents (Ballantyne & Fraser, 2013). Its presence is known in the Amazon basin since the early 1900s (Thorson, 1972), where specimens were caught about 4200 km into the river (Carvalho and McEachran 2003). This species has also been registered 1200 km into the Mississippi River (Moss, 1984); in Matawan Creek, New Jersey (Klimley, 2013); 175 km into the San Juan River, as well as in other rivers and lakes of Mexico (Helfman et al., 2009); in the Iquitos and Ucayali rivers, both in Peru, among other freshwater systems (Carvalho and McEachran 2003). Furthermore, it is also known to give birth in estuaries and rivers and to move towards coastal ecosystems when reaches a larger size (Compagno et al., 2005). This behavior is displayed by several other coastal shark species, and is believed to be related to a lower predation risk for the young in these areas (Grubbs, 2010). This study aims to report the presence of a medium sized specimen of C. leucas in the Mearim River basin, Maranhão State, Brazil, extending the number of elasmobranchs listed for this area.

squalo-toro-2

Materials and methods
Mearim River is located in central Maranhão State, geographically considered as Northern Brazil by Programa Revizee (2006) (Fig. 1). It extends for 930 km until its mouth located in the meridional edge of Ilha dos Caranguejos (Soares, 2005). Its final portion is known for slow currents, leading to turbid waters and concentration of nutrients and muddy sediments. Perhaps its most unique feature is the occurrence of tidal bores, locally known as pororoca, during the highest spring tides of the dry season (August to December). The effect of the high tide can be seen until 256 km into the river basin (Soares, 2005) and causes a mixture between the salty and freshwaters, as well as fine sediments (Chanson, 2005). According to Kjerfve & Ferreira (1993), the Mearim River tidal bore, whose effects gradually decrease upstream, causes an increase in salinity up to 18 % and a small decrease in water temperature, reaching its furthest extent in Arari city.

https://static-content.springer.com/image/art%3A10.1186%2Fs41200-016-0094-6/MediaObjects/41200_2016_94_Fig1_HTML.gif

Fig. 1   Middle and lower portions of the Mearim River basin, with the river’s mouth (a) and the location where the specimen of C. leucas was captured (b)

On 3 September of 2015 a juvenile female Carcharhinus leucas was caught by local fishermen in the municipality of Arari (3°23′14″S and 44°49′55″W), Maranhão State, on the margin of the Mearim River, located approximately 80 km far from the river’s mouth. According to the fishermen, the shark tried to attack a dog on the margin and got stranded due to the low depth. The event coincided with the occurrence of one of the strongest spring tides of the year in the Maranhão State, which has one of the largest tidal variations in Brazil, reaching up to 7 m.

Results
One female specimen of Carcharhinus leucas measuring approximately 1300 mm in total length (TL) and weighing 35 kg was caught by local fishermen (Fig. 2). Its identification was carried out following Compagno et al. (2005). It was not possible to analyze the specimen before the fishermen processed it. However, based on studies of Compagno et al. (2005) and Cruz-Martinez et al. (2005) female individuals mature between 1800 mm and 2300 mm TL. Taking this into account, the approximate TL or this specimen suggests that it was not yet mature.

https://static-content.springer.com/image/art%3A10.1186%2Fs41200-016-0094-6/MediaObjects/41200_2016_94_Fig2_HTML.gif

Fig. 2 Different views of the juvenile C. leucas specimen captured and processed by fishermen in Arari city

Discussion
Only 5 % of all elasmobranchs can tolerate some sort of salinity range during their lifetime (Helfman et al., 1997). The tolerance level varies according to the age class and specific features of habitat use by each individuals and/or species (Cervigón & Alcalá, 1999; Compagno et al., 2005; Ballantyne & Fraser, 2013). In Maranhão State, several marine species of elasmobranchs have been captured in estuarine areas, such as Isogomphodon oxyrhynchus, Carcharhinus porosus, Sphyrna tiburo, Rhizoprionodon porosus (Lessa, 1997; Almeida & Vieira, 2000) and a juvenile specimen of Pristis pristis [see Faria et al. (2013) for updated taxonomic nomenclature] measuring weighing 20 kg was incidentally caught in the same area in 1999 (Soares, 2005).

img_3237

The ability that C. leucas has to enter riverine systems further than any other shark species is related to its osmotic acclimation to salinity gradients (Klimley, 2013; Pillans & Franklin, 2004). It is believed to be related to the rectal gland activity plasticity (Pillans et al., 2005), urea and trimethylamine oxide (TMAO) reabsorption by the kidney (Pillans et al., 2008), and ion uptake by the gills (Ballantyne & Robinson, 2010), which is enhanced when in freshwater. With all this put together, according to these authors, C. leucas can maintain its body hyperosmotic in freshwater environments, but loses much more water and ions due to large amounts of urine produced.

This record is important to direct future more thorough ichthyologic studies in the Mearim River basin that look into the spatial and temporal scales in which these animals can be found, their size range in the river, diet, age, growth, spatial, and temporal movements to provide useful ecological and biological data for the assessment of distribution of bull shark individuals in the Mearim River.

Declarations

Acknowledgements
We would like to thank the officials from Arari city’s environmental agency Secretaria de Meio Ambiente e Recursos Naturais (SEMA) for contacting us about the shark specimen capture. Also, we would like to thank Taissa Caroline Silva Rodrigues, Clarisse Mendes Éleres de Figueiredo, and Osmann Cid Conde Oliveira for the help with the figures presented in this report.

Authors’ contributions
JLSN and LMF gathered the data presented in this study. LMF, APBM and JLSN participated in the conception and elaboration of the manuscript. All of them have read and approved the final version of this paper and agree to be accountable for all aspects of the work.

Competing interests
The authors declare that they have no competing interests.

Open Access
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

References

  1. Almeida ZS, Vieira HCP. Distribuição e abundância de elasmobrânquios no litoral maranhense, Brasil. Pesquisa em Foco. 2000;8(11):89–104.Google Scholar
  2. Ballantyne JS, Robinson JW. Freshwater elasmobranchs: a review of their physiology and biochemistry. J Comp Physiol B. 2010. doi:10.1007/s00360-010-0447-0.Google Scholar
  3. Ballantyne JS, Fraser DI. Euryhaline elasmobranchs. In: McCormick SD, Farrell AP, Brauner CJ, editors. Fish Physiology: Euryhaline Fishes: Fish Physiology. New York: Academic Press; 2013. p. 125–98.
  4. Carvalho MR, McEachran J. Family Carcharhinidae (Requiem Sharks). In: Reis RE, Kullander SO, Ferraris CJ, editors. Checklist of the freshwater fishes of South and Central America. Porto Alegre: EDIPUCRS; 2003. p. 13–7.Google Scholar
  5. Cervigón F, Alcalá A. Los peces marinos de Venezuela: Tiburones y rayas. Estado Nueva Esparta, Venezuela: Fundación Museo del Mar; 1999.Google Scholar
  6. Chanson H. Tidal Bore, Aegir, Pororoca, Mascaret. What? Where? When? How? Why? La Houille Blanche. 2005. doi:10.1051/lhb:200503014.Google Scholar
  7. Compagno LV, Dando M, Fowler S. A Field Guide to the Sharks of the World. London. Princeton Field Guide: Harper Collins Publishers Ltd.; 2005.Google Scholar
  8. Cruz-Martinez A, Chiappa-Carrara X, Arenas-Fuentes V. Age and growth of the bull shark, Carcharhinus leucas, from southern Gulf of Mexico. Journal of Northwest Atlantic Fisheries Science. 2005. doi:10.2960/J.v35.m481.Google Scholar
  9. Faria VV, McDavitt MT, Charvet P, Wiley TR, Simpfendorfer CA, Naylor GJP. Species delineation and global population structure of critically endangered sawfishes (Pristidae). Zool J Linnean Soc. 2013. doi:10.1111/j.1096-3642.2012.00872.x.Google Scholar
  10. Grubbs RD. Ontogenetic shifts in movements and habitat use. In: Carrier JC, Musick JA, Heithaus MR, editors. Sharks and their relatives II: Biodiversity, adaptive physiology, and conservation. Boca Raton: CRC Press; 2010. p. 319–50.View ArticleGoogle Scholar
  11. Helfman GS, Collette BB, Facey DE. The Diversity of Fishes. 3rd ed. Malden: MA: Blackwell Science; 1997. p. 528.Google Scholar
  12. Helfman GS, Collete BB, Facey DE, Bowen BW. The diversity of fishes: Biology, Evolution, and Ecology. West Sussex: Wiley Blackwell; 2009. p. 720.Google Scholar
  13. Kjerfve B, Ferreira HO. Tidal bores: first ever measurements. Ciência e Cultura. 1993;45:135–7.Google Scholar
  14. Klimley AP. The biology of sharks and rays. Chicago: The University of Chicago Press; 2013.View ArticleGoogle Scholar
  15. Lessa R. Sinopse dos estudos sobre elasmobrânquios da costa do Maranhão. Boletim Laboratório de Hidrobiologia. 1997;10:19–36.Google Scholar
  16. Moss SA. Sharks: an introduction for the amateur naturalist. Englewood Cliffs, New Jersey: Prentice Hall; 1984.Google Scholar
  17. Pillans RD, Franklin CE. Plasma osmolyte concentrations and rectal gland mass of bull sharks Carcharhinus leucas, captured along a salinity gradient. Comp Biochem Physiol A Mol Integr Physiol. 2004. doi:10.1016/j.cbpb.2004.05.006.Google Scholar
  18. Pillans RD, Good JP, Anderson WG, Hazon N, Franklin CE. Freshwater to seawater acclimation of juvenile bull sharks (Carcharhinus leucas): plasma osmolytes and Na+/K + − ATPase activity in gill, rectal gland, kidney and intestine. J Comp Physiol B. 2005. doi:10.1007/s00360-004-0460-2.Google Scholar
  19. Pillans RD, Good JP, Anderson WG, Hazon N, Franklin CE. Rectal gland morphology of freshwater and seawater acclimated bull sharks Carcharhinus leucas. J Fish Biol. 2008. doi:10.1111/j.1095-8649.2008.01765.x.Google Scholar
  20. Programa Revizee. Relatório Executivo: Avaliação do Potencial Sustentável de Recursos Vivos na Zona Econômica Exclusiva. Brasília/DF: MMA/SQA/PGT/GERCOM; 2006.Google Scholar
  21. Soares EC. Peixes do Mearim. São Luís: Instituto Geia; 2005. 131.Google Scholar
  22. Thorson TB. The status of the bull shark, Carcharhinus leucas. Amazon River: Copeia; 1972. p. 601–5.Google Scholar

Copyright

© The Author(s) 2016
print
(Visited 194 times, 1 visits today)
Share

Lascia un commento

Il tuo indirizzo email non sarà pubblicato. I campi obbligatori sono contrassegnati *

Legenda

Legenda

livello elementare articoli per tutti

livello medio articoli che richiedono conoscenze avanzate

livello difficile articoli specialistici

Traduzione

La traduzione dei testi è fornita da Google translator in 42 lingue diverse. Non si assumono responsabilità sulla qualità della traduzione

La riproduzione, anche parziale, a fini di lucro, e la pubblicazione per qualunque utilizzo degli articoli e delle immagini pubblicate è sempre soggetta ad autorizzazione da parte dell’autore degli stessi che può essere contattato tramite la seguente email: infoocean4future@gmail.com


If You Save the Ocean
You Save Your Future

OCEAN4FUTURE

Salve a tutti. Permettetemi di presentare in breve questo sito. OCEAN4FUTURE è un portale, non giornalistico, che pubblica articoli e post di professionisti e accademici che hanno aderito ad un progetto molto ambizioso: condividere la cultura del mare in tutte le sue forme per farne comprendere la sua importanza.

Affrontiamo ogni giorno tematiche diverse che vanno dalla storia alle scienze, dalla letteratura alle arti.
Gli articoli e post pubblicati rappresentano l’opinione dei nostri autori e autrici (non necessariamente quella della nostra redazione), sempre nel pieno rispetto della libertà di opinione di tutti.
La redazione, al momento della ricezione degli stessi, si riserva di NON pubblicare eventuale materiale ritenuto da un punto di vista qualitativo non adeguato e/o non in linea per gli scopi del portale. Grazie di continuare a seguirci e condividere i nostri articoli sulla rete.

Andrea Mucedola
Direttore OCEAN4FUTURE

Chi c'é online

13 visitatori online

Ricerca multipla

Generic selectors
Exact matches only
Search in title
Search in content
Filter by Categories
Archeologia
Associazioni per la cultura del mare
Astronomia e Astrofisica
Biologia
Cartografia e nautica
Chi siamo
Climatologia
Conoscere il mare
Didattica
Didattica a distanza
disclaimer
Ecologia
Emergenze ambientali
Fotografia
Geologia
geopolitica
Gli uomini dei record
I protagonisti del mare
Il mondo della vela
L'immersione scientifica
La pesca
La pirateria
La subacquea ricreativa
Lavoro subacqueo - OTS
Le plastiche
Letteratura del mare
Malacologia
Marina mercantile
Marine militari
Materiali
Medicina
Medicina subacquea
Meteorologia e stato del mare
nautica e navigazione
Normative
Ocean for future
OCEANO
Oceanografia
per conoscerci
Personaggi
Pesca non compatibile
Programmi
Prove
Recensioni
Reportage
SAVE THE OCEAN BY OCEANDIVER campaign 4th edition
Scienze del mare
Sicurezza marittima
Storia della subacquea
Storia della Terra
Storia Navale
Storia navale del Medioevo (post 476 d.C. - 1492)
Storia Navale dell'età antica (3.000 a.C. - 476 d.C,)
Storia navale dell'età moderna (post 1492 - oggi)
Storia navale della prima guerra mondiale (1914-1918)
Storia navale della seconda guerra mondiale (1939 - 1945)
Storia navale Romana
Subacquea
Subacquei militari
Sviluppi della scienza
Sviluppo compatibile
Tecnica
Uomini di mare
Video

I più letti di oggi

 i nodi fondamentali

I nodi fanno parte della cultura dei marinai ... su Amazon puoi trovare molti libri sul mare e sulla sua cultura :) clicca sull'immagine ed entra in un nuovo mondo :)

Follow me on Twitter – Seguimi su Twitter

Tutela della privacy – Quello che dovete sapere

> Per contatti di collaborazione inviate la vostra richiesta a infoocean4future@gmail.com specificando la vostra area di interesse
Share
Translate »