Reprodução do pirá-brasília, Simpsonichthys boitonei Carvalho (Cyprinodontiformes, Rivulidae), e caracterização de seu habitat na Reserva Ecológica do Instituto Brasileiro de Geografia e Estatística, Brasília, Distrito Federal, Brasil

Abstract

O pirá-brasília, Simpsonichthys boitonei, é um peixe raro e endêmico do Distrito Federal, considerado como um "peixe-anual" por viver em poças temporárias e ter seu ciclo de vida completo em aproximadamente um ano. Os ovos dos peixes-anuais sobrevi-

The opportunistic feeding and reproduction strategies of the annual fish Cynopoecilus melanotaenia (Cyprinodontiformes: Rivulidae) inhabiting ephemeral habitats on southern Brazil

“…According to Winemiller & Rose (1992), fishes exhibiting the opportunistic strategy seem to be associated with very shallow habitats which are exposed to intense predation or unpredictable spatial and temporal variations. Moreover, the type of spawning of C. melanotaenia was fractional, also considered as a strategy to increase the chance of survival to prolonged depletions and stochastic water level (Shibatta, 2005), conditions commonly found in ephemeral habitats. Arenzon et al (1999Arenzon et al ( , 2001) also found this type of spawning in C. multipapillatus without a defined breeding season over a long period in accordance with environmental characteristics.…”

Reproductive strategy of a non-annual rivulid in a perennial wetland

“…This pattern of oocyte development was identified in A. riograndensis and registered for the annual Austrolebias toba Calviño, 2006, Austrolebias nigrofasciatus Costa & Cheffe, 2001, C. melanotaenia, C. multipapillatus and S. boitonei (Arenzon et al, 1999Calviño, 2006;Shibatta, 2005;Gonçalves et al, 2011;Volcan et al, 2011Volcan et al, , 2013) and the-non annual M. punctatus (Cassel et al, 2013). For fish of lentic habitats, multiple spawning during the reproductive period may reduce competition among larvae when they have a lower rate of dispersion (Godinho et al, 2010) and also represent an advantage in unstable environments regarding abiotic factors, since they allow for some batches of oocytes to be released in relatively better environmental conditions which increases the chances of survival for young offspring.…”

“…15. Number of oocytes in relation to their diameters in Atlantirivulus riograndensis (Costa & Lanés, 2009) (Shibatta, 2005;Laufer et al, 2009;Lanés et al, 2012Lanés et al, , 2013, more abundance male in Austrolebias luteoflammulatus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete, 1964) and Cynopoecilus melanotaenia (Regan, 1912) (Laufer et al, 2009;Gonçalves et al, 2011), or equal distribution, as in Austrolebias cheradophilus (VazFerreira, Sierra de Soriano & Scaglia de Paulete, 1964), C. melanotaenia (Laufer et al, 2009) and A. riograndensis, considering the population throughout the present study. Differences in the sex ratio may unbalance the population, increasing competition and agonistic behaviors especially in species with territorial males or those that present courtship behavior (Gonçalves et al, 2011).…”

“…The fecundity and oocyte size found for A. riograndensis meets other species of annual killifish, such as: Austrolebias toba presented an approximate fecundity of 57 oocytes per female per week with diameters ranging between 1.4 and 1.6 mm; A. nigrofasciatus apresentou 21.5 oocytes per female per week and an average diameter of 1.5 mm; C. melanotaenia averaged 19 oocytes in the reproductive period; C. multipapillatus presented fecundity varied between 49 and 219 oocytes with a mean diameter of 1.15 mm; S. boitonei was estimated at three oocytes per female for every day of spawning with an average diameter of 1.6mm (Arenzon et al, 1999;Calviño, 2006;Shibatta, 2005;Gonçalves et al, 2011;Volcan et al, 2011). Production rates (by number) and egg size, as registered by Moshgani & Van Dooren (2011) for Austrolebias nigripinnis (Regan 1912), can be influenced by environmental conditions or by the presence of males, such that the female-male interaction effect contributes to variation in the reproductive effort of these fish.…”

“…The reproductive success of these fish with annual cycle is associated with the ability to survive in unstable habitats, with elaborate courtship behaviors, complex processes of embryonic development, and the immersion of eggs into the substrate where they may remain in diapause until the next rainy season when larvae hatching occurs (Lowe-McConnell, 1999;Arenzon et al, 2001;Arezo et al, 2005;Costa, 2011). Other reproductive tactics presented by annual rivulids are rapid initial growth, early maturation, low fecundity, multiple spawning, long reproductive period during floods (Arenzon et al, 1999(Arenzon et al, , 2001(Arenzon et al, , 2002Shibatta, 2005;Volcan et al, 2011).…”