Reproductive strategies of two Curimatidae species in a Mogi Guaçu impoundment, upper Paraná River basin, São Paulo, Brazil

Abstract

Considering that reproduction studies are fundamental to understand the life cycle of organisms, this study aimed to investigate the reproductive strategies of saguirus Cyphocharax nagelii and Steindachnerina insculpta in a dam of Mogi Guaçu River, (SP). Specimens were collected between August 2005 and July 2006 using gillnets with mesh sizes ranging from 1.5 to 5.0 cm between adjacent knots. Reproductive dynamics, body condition, reproductive period, spawning type and fecundity were analyzed in both species. The body condition reflected the reproductive dynamics, and differed significantly between the wet and dry seasons. During the dry season, the feeding activity and the accumulation of fat in the visceral cavity were higher. The reproductive period of both species covered the months between August and February, with peaks in October and December, and the distribution of the diameters of oocytes allowed to classify them as total spawners. The fecundity increased with weight and length, reaching 28,800 and 27,906 oocytes per female for C. nagelii and S. insculpta, respectively, whereas the amplitude of oocyte diameters varied between 50-1025 µm for the former and 75-975 µm for the later species. Taking into account that species with different reproductive strategies also respond differently to environmental impacts, our findings provide important information to subsidize management plans for these curimatid species.Considerando que o conhecimento da reprodução é fundamental para a compreensão do ciclo de vida dos organismos, este trabalho buscou avaliar as estratégias reprodutivas dos saguirus Cyphocharax nagelii e Steindachnerina insculpta em um represamento no rio Mogi Guaçu (SP). Os exemplares foram coletados entre agosto de 2005 e julho de 2006 com redes-de-espera (com tamanhos de malha variando entre 1,5 e 5,0 cm entre nós adjacentes). A dinâmica reprodutiva, a condição corporal, o período reprodutivo, o tipo de desova e a fecundidade foram os parâmetros reprodutivos analisados nas duas espécies. A condição corpórea refletiu a dinâmica reprodutiva, sendo significativamente diferente entre os períodos seco e chuvoso. Durante o período seco, a atividade alimentar e o acúmulo de gordura na cavidade visceral foram maiores. O período reprodutivo das duas espécies abrangeu os meses entre agosto e fevereiro, com picos em outubro e dezembro, e a distribuição dos diâmetros de ovócitos permitiu classificá-las como desovadoras totais. A fecundidade aumentou com o peso e com o comprimento, atingindo em média 28.800 e 27.906 ovócitos por fêmea, para C. nagelii e S. insculpta, respectivamente, ao passo que a amplitude de diâmetros ovocitários variou de 50 a 1.025 µm para a primeira e de 75 a 975 µm para a segunda espécie. Considerando que espécies com estratégias reprodutivas diferentes também respondem de modos diferentes aos impactos ambientais, as informações obtidas são importantes subsídios para nortear medidas de manejo para essas espécies de curimatídeos.

Tácticas reproductivas para optimizan la supervivencia de la descendencia de Cichlasoma orientale (Perciformes: Cichlidae)

“…However, no such correlation was observed in the present study, matching reports for other species of cichlids (Rana, 1988;Coward & Bromage, 1999) and for some species of teleosts (Rodrigues & Macchi, 2010;Peressin et al, 2012). Within a given population, egg size may be influenced by detrimental habitat changes (Hainfellner, Souza, Moreira, Makaghi, & Batlouni, 2012) or by the number of previous spawns in the reproductive cycle (oocytes tend to be larger in the first spawns) (Kjesbu, 1989).…”

“…The positive correlation between batch fecundity and standard length among females of C. orientale has been observed for other fish species (Mazzoni & Iglesias-Rios, 2002;Ortega-Salas, Cortés, & Reyes-Bustamante, 2009;Rodrigues & Macchi, 2010;Serezli et al, 2010;Araújo et al, 2012;Peressin et al, 2012;Reid & Chaput, 2012). The correlation may be explained by the fact that larger individuals have more energy available for the production of oocytes (Patimar & Mohammadzadeh, 2011) and larger females have more space in the abdominal cavity, providing greater fecundity.…”

On the relation amongst limnological factors and fish abundance in reservoirs at semiarid region

“…In addition, Cichla and Cichlasoma, both of which are common in coastal regions (Oliveira et al, 2005;Beltrão et al, 2009), also become less abundant in the dry season. In contrast, non-predator species generally displayed no seasonal patterns, although migrating species such as Leporinus spp., P. brevis and Curimatidae tend to become more abundant in the rainy season during the annual spawning season (Gurgel et al, 2012;Peressin et al, 2012;Silva Filho et al, 2012;Araújo et al, 2013). The low abundance of these species in PS and EQ may be associated with isolation from adjacent water courses due to the absence fish ladders in the dams (Antonio et al, 2007).…”

Short-term changes in energy allocation by Hemiodontidae fish after the construction of a large reservoir (Lajeado Dam, Tocantins River)

“…Depending on life-history strategies or life cycle phases, fish can prioritize a particular process (i.e., growth, when immature) or allocate energy to different processes (i.e., maintenance and reproduction, when adults). As many South American species present seasonal reproductive dynamics, it is common to observe temporal variations in the use of energy, including periods of accumulation (i.e., tissue formation) followed by periods of gamete production (Bailly et al, 2008;Santos et al, 2010;Peressin et al, 2012). Changes in such use are expected when rivers are dammed (Abujanra et al, 2009), since reservoirs change the availability of food resources (Mérona et al, 2003;Loureiro-Crippa & Hahn, 2006;Luz-Agostinho et al, 2006) and environmental triggers and conditions (e.g., duration and timing of floods, water flow, conductivity, and transparency) that stimulate and allow reproductive dynamics (Agostinho et al, 2004).…”