Environmental and hormonal influences upon EOD waveform in gymnotiform pulse fish

Silva, Ana C.; Quintana, Laura; Ardanaz, José Luis; Macadar, O.

doi:10.1016/s0928-4257(03)00003-2

Cited by 34 publications

(44 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Caudal filaments depth Level 1 = from 0 to 1.5%; Level 2 = from 1.51% to 2.5%; Level 3 = from 2.51% to 3.50%. (Silva et al, 1999;Ardanaz et al, 2001;Silva et al, 2002;Quintana et al, 2004), in photoperiod (Giora & Fialho, 2009) or in both temperature and photoperiod (Silva et al, 2003;Cognato & Fialho, 2006). For the B. draco population from lagoa Verde, the male reproductive cycle showed a positive relation with temperature, but no relation was found for photoperiod.…”

Section: Discussionmentioning

confidence: 99%

Reproductive biology of the Neotropical electric fish Brachyhypopomus draco (Teleostei: Hypopomidae) from southern Brazil

2009

View full text Add to dashboard Cite

The reproductive biology of a population of the weakly electric fish Brachyhypopomus draco from southern Brazil is described. Information is provided on the establishment of the reproductive period in this species and its relations with environmental and feeding factors, as well as on the absolute and relative fecundities, spawning type, sex ratio and sexual dimorphism. The species exhibits a relatively long reproductive period, a relative fecundity of 0.173 oocytes per mg of female total weight, and fractional spawning. The sex ratio did not differ from 1:1 during all sampled months. Sexual dimorphism related to hypertrophy of the male's distal portion of caudal filament was observed and males grew to greater lengths than females. Male gonadosomatic index (GSI) was significantly related to water depth, oxygen saturation and temperature. Female GSI was significantly related to water depth and hepatosomatic index.Descreve-se a biologia reprodutiva de uma população do peixe elétrico Brachyhypopomus draco do sul do Brasil. São apresentadas informações a respeito do período reprodutivo estabelecido e suas relações com fatores ambientais e alimentares, bem como a fecundidade absoluta e relativa, tipo de desova, proporção sexual e dimorfismo sexual. A espécie apresentou um período reprodutivo relativamente longo, uma fecundidade relativa de 0,173 ovócitos por mg de peso total da fêmea e uma desova do tipo parcelada. A proporção sexual encontrada foi de 1:1 durante todos os meses amostrados. Dimorfismo sexual relacionado com a hipertrofia da porção distal do filamento caudal dos machos e com o tamanho total dos espécimes -machos atingindo tamanhos maiores do que as fêmeas -foi encontrado. O IGS dos machos foi significativamente relacionado com a profundidade da água, a saturação de oxigênio e a temperatura; o IGS das fêmeas foi significativamente relacionado com a profundidade da água e o índice hepatossomático.

show abstract

Section: Discussionmentioning

confidence: 99%

Reproductive biology of the Neotropical electric fish Brachyhypopomus draco (Teleostei: Hypopomidae) from southern Brazil

2009

View full text Add to dashboard Cite

show abstract

“…A wavelet 'signal space' representing features of the head to tail EOD waveform suggests that these species may recognise and discriminate each other on the basis of both frequency and temporal components of the electrocommunication carrier . Finally, seasonal control of EOD waveform by environmental and hormonal factors may result in carrier modulation and thus result in gender and dominance signs and/or signals (Bass and Hopkins, 1983;Hopkins et al, 1990;Silva et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Waveform diversity of electric organ discharges: the role of electric organ auto-excitability inGymnotusspp.

Rodríguez-Cattáneo

Caputi

2009

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARYThis article shows that differences in the waveforms of the electric organ discharges (EODs) from two taxa are due to the different responsiveness of their electric organs (EOs) to their previous activity (auto-excitability). We compared Gymnotus omarorum endemic to Uruguay (35°South, near a big estuary), which has four components in the head to tail electric field (V 1 to V 4 ), with Gymnotus sp. endemic to the south of Brazil, Paraguay and Argentinean Mesopotamia (25°South, inland), which shows a fifth component in addition to the others (V 5 ). We found that: (a) the innervation pattern of the electrocytes, (b) the three earlier, neurally driven, EOD components (V 1 to V 3 ), and (c) their remnants after curarisation were almost identical in the two taxa. The equivalent electromotive forces of late components (V 4 and V 5 ) increased consistently as a function of the external current associated with the preceding component and were abolished by partial curarisation in both taxa. Taken together these data suggest that these components are originated in the responses of the electrocytes to longitudinal currents through the EO. By using a differential load procedure we showed that V 4 in G. omarorum responded to experimental changes in its excitation current with larger amplitude variations than V 4 in Gymnotus sp. We conclude that the differences in the EOD phenotype of the two studied taxa are due to the different EO auto-excitability. This, in turn, is caused either by the different expression of a genetic repertoire of conductance in the electrocyte membrane or in the wall of the tubes forming the EO.

show abstract

“…Reproductive biology and life history: Detailed accounts of the reproductive ecology and life history of Brachyhypopomus are available for B. occidentalis from Panama (Hagedorn, 1986;, and for three species from southern subtropical systems: B. bombilla , B. draco (Schaan et al, 2009), and B. gauderio (Giora et al, 2014;Miranda et al, 2008;Quintana et al, 2004;Silva et al, 2007;Silva et al, 2002; (and see species descriptions herein). The reproductive ecology of Amazon and Orinoco species is largely undocumented, although Alves-Gomes (1997) noted spawning preceding seasonal flooding in the rio Branco system of Roraima, Brazil, and Crampton (1996a) observed spawning coincident with the rising-water period and high water period in species from Amazonian floodplains.…”

Section: Functional Biology and Ecology Specializations Associated Wmentioning

confidence: 99%

“…At extreme southern latitudes Brachyhypopomus exhibit several adaptations to the austral winter -including gonadal quiescence, a general reduction in activity and feeding, and an accompanying reduction of the EOD pulse-rate 2014;Schaan et al, 2009;Silva et al, 2002). Some species of Brachyhypopomus appear to live for only one year, with mortality following a terminal reproductive effort -including B. bennetti (Crampton, 1996a) (listed therein as 'B.…”

Section: Functional Biology and Ecology Specializations Associated Wmentioning

confidence: 99%

“…Males exhibit a wider spacing, and move less than females -consistent with a polygynous or polygynandrous mating strategy resembling exploded lek polygyny . During the austral winter B. gauderio exhibits gonadal quiescence, reduced activity and feeding, and a slower EOD rate (Giora et al, 2014;Silva et al, 2002;Silva et al, 2003). cites a personal communication from D. Stewart (State University of New York, Syracuse) reporting that five specimens from FMNH lot 86684 from the Pantanal of Mato Grosso, Brazil (listed below) were "found aestivating in dry soil".…”

Section: Population Variationmentioning

confidence: 99%

See 1 more Smart Citation

A taxonomic revision of the Neotropical electric fish genus Brachyhypopomus (Ostariophysi: Gymnotiformes: Hypopomidae), with descriptions of 15 new species

et al. 2016

View full text Add to dashboard Cite

The bluntnose knifefish genus Brachyhypopomus Mago-Leccia, 1994, is diagnosed from other Rhamphichthyoidea (Rhamphichthyidae + Hypopomidae) by the presence of a disk-like ossification in the anterior portion of the palatoquadrate, and by the following external characters: short snout, 18.7-32.6% of head length Gymnorhamphichthys, Iracema, and Rhamphichthys), absence of a paired accessory electric organ in the mental or humeral region (vs. presence in Hypopygus and Steatogenys), presence of 3-4 pectoral proximal radials (vs. 5 in Akawaio), presence of the antorbital + infraorbital, and the preopercular cephalic lateral line canal bones (vs. absence in Racenisia). Brachyhypopomus cannot be diagnosed unambiguously from Microsternarchus or from Procerusternarchus on the basis of external characters alone. Brachyhypopomus comprises 28 species. Here we describe 15 new species, and provide redescriptions of all 13 previously described species, based on meristic, morphometric, and other morphological characters. We include notes on ecology and natural history for each species, and provide regional dichotomous keys and distribution maps, based on the examination of 12,279 specimens from 2,787 museum lots. A lectotype is designated for Brachyhypopomus pinnicaudatus (Hopkins, Comfort, Bastian & Bass, 1990 Peixes elétricos do gênero Brachyhypopomus Mago-Leccia, 1994, são diagnosticados dos outros Rhamphichthyoidea (Rhamphichthyidae + Hypopomidae) pela presença de uma ossificação discóide na porção anterior do palatoquadrado, e pelos seguintes caracteres externos: focinho curto, 18,7-32,6% do comprimento da cabeça (vs. 33,3-68,6% em Hypopomus, Gymnorhamphichthys, Iracema e Rhamphichthys), ausência de um órgão elétrico acessório pareado na região mental ou humeral (vs. presença em Hypopygus e Steatogenys), presença de 3-4 proximais peitorais radiais (vs. 5 em Akawaio), presença do antiorbital + infraorbital, e dos canais ossificados da linha lateral da região cefálica do pré-opérculo (vs. ausência em Racenisia). Brachyhypopomus não pode ser diagnosticado de maneira não-ambígua de Microsternarchus ou Procerusternarchus, com base em caracteres de morfologia externa. Brachyhypopomus compreende 28 espécies válidas. Aqui nós descrevemos 15 espécies novas, e fornecemos a redescrição de 13 espécies previamente descritas, baseado em caracteres merísticos, morfométricos e outros caracteres morfológicos. Nós incluímos notas sobre à ecologia e história natural para cada uma das espécies, e fornecemos chaves dicotômicas regionais e mapas de distribuição baseado no exame de 12.279 espécimes de 2.787 lotes de museus. Um lectótipo é designado para Brachyhypopomus pinnicaudatus (Hopkins, Comfort, Bastian & Bass, 1990

show abstract

Environmental and hormonal influences upon EOD waveform in gymnotiform pulse fish

Cited by 34 publications

References 47 publications

Reproductive biology of the Neotropical electric fish Brachyhypopomus draco (Teleostei: Hypopomidae) from southern Brazil

Reproductive biology of the Neotropical electric fish Brachyhypopomus draco (Teleostei: Hypopomidae) from southern Brazil

Waveform diversity of electric organ discharges: the role of electric organ auto-excitability inGymnotusspp.

A taxonomic revision of the Neotropical electric fish genus Brachyhypopomus (Ostariophysi: Gymnotiformes: Hypopomidae), with descriptions of 15 new species

Contact Info

Product

Resources

About