Spatial distribution of juvenile fish species in nursery grounds of a tropical coastal area of the south-western Atlantic

Abstract

Background. Assessing patterns in habitat utilization and changes in the composition of biont assemblages is a key tool for efficient ecosystem conservation planning and management. Nevertheless, habitat use patterns by juvenile fish still need more comprehension. Therefore, the presently reported study investigated relations between the type of nursery ground and the structure of juvenile fish assemblages in a tropical coastal area of the south-western Atlantic. Materials and methods. From December 2009 to November 2010, we conducted monthly sampling of ichthyofauna in two habitat types (mangrove and sandy beach) used as nursery grounds by juvenile fish of the south-western Atlantic. Species richness and abundance were used to identify spatial and temporal patterns in the distribution of fish assemblages throughout habitats' dynamics. Results. A total of 845 fishes representing 16 families and 34 species were found during the presently reported study: Albula vulpes (Linnaeus, 1758); Atherinella brasiliensis (Quoy et Gaimard, 1825) Ginsburg, 1933; Sphyraena barracuda (Edwards, 1771); Sphoeroides testudineus (Linnaeus, 1758). No significant differences in species richness and total abundance were found between habitats and seasons. Nevertheless, our analyses showed that distinct sets of species use these areas. Moreover, we identified a strong relation between the rainfall and the species turnover in both habitats studied. Conclusion. Diversity of nursery grounds in coastal areas not only increases fish diversity but also plays an important role in the sustaining fish stocks.

Integrative taxonomy reveals extreme morphological conservatism in sympatricMugilspecies from the Tropical Southwestern Atlantic

“…Recent studies have pointed to the presence of six taxonomically recognized Mugil species in the Coral Coast MPA: Mugil brevirostris , M. curema , M. curvidens , M. incilis , M. liza , M. rubrioculus (da Silva, Teixeira, Batista, & Fabré, 2017, 2018; Torres et al., 2008), although the distribution of M. incilis has been contested (Menezes et al., 2015). Our study used 11 morphological traits to test whether the individuals identified as belonging to these six species are morphologically different.…”

Trophic ecology of the juveniles of two jack species (Caranx latus and C. hippos) in contrasted tropical estuaries

“…Their stomach contents were assessed under a stereomicroscope until 70 non-empty stomachs per species and estuary could be gathered. As densities for the two jack species are rather low in estuaries during the wetter months of the year (Vilar et al, 2011;Silva-Júnior et al, 2017;da Silva et al, 2018), fish from different years had to be pooled to reach a minimum number of 10 non-empty stomachs for both the dry (September to March) and the rainy (April to August) seasons in the area (CPRH, 2003;2003a), and a maximum of 30 individuals per year for each estuary. Prey items in all stomachs were identified to the lowest taxonomic level possible, depending on their degree of digestion.…”

“…In estuaries, physico-chemical gradients (e.g. in salinity) drive food web structure and determine habitat suitability for fish (Barletta et al, 2008;da Silva et al, 2018). However, food abundance also modulates interactions between potential competitors (Sánchez-Hernández et al, 2017;Costa-Pereira et al, 2019).…”

Desempenho Dos Diferentes Métodos De Amostragem Na Caracterização Da Ictiofauna Associada Ao Manguezal Da Praia De Arpoeiras Em Acaraú, Ceará

“…Com base no período de amostragem, não foi possível determinar épocas de desova. No entanto, estudos anteriores revelaram que peixes do gênero Lutjanus, L. jocu e L. alexandrei são endêmicas e dependentes de áreas costeiras, como manguezais e recifes, principalmente durante seu período reprodutivo (Osório;Godinho & Lotufo, 2011;Pinheiro & Farias, 2016;Aschenbrenner;Hackradt & Ferreira, 2016), assim como os membros da família Gerreidae coletados nesse estudo, D. Auratus e E. Argenteus (Viana et al, 2016;Pereira & Pessanha, 2017;Silva et al, 2018). A ausência de organismos adultos na área amostrada possivelmente indica que os indivíduos coletados não completam seu ciclo de vida no mangue (Pinheiro & Goitein, 2014), utilizando-o apenas como berçário e zona de alimentação.…”