State of the art of identification of eggs and larvae of freshwater fish in Brazil

Abstract

Aim This study aimed to assist in guiding research with eggs and larvae of continental fish in Brazil, mainly in the knowledge of the early development, as well as to present the state of the art and to point out the gaps and future directions for the development of researches in the area. Methods The literature review was carried out in the electronic platforms and studies were examined to investigate whether any addressed morphological description of fish eggs and/or larvae. Results We found 121 studies, including scientific articles, theses, dissertations, chapters of books and books. This bibliographic production characterized 140 species, representing only 4.1% of the total species present in the Brazilian basins. Most of the species studied belong to the orders Characiformes and Siluriformes, which are of commercial interest and native to the Paraná, Amazon, Paraguay and Uruguay basins. For some very species-rich families in the Brazilian rivers, such as Characidae and Loricariidade, only a fraction of their species was characterized for the early development (2.6% and 0.7% of the total, respectively) and 56% of the families did not present any study addressing the early ontogeny. Regarding the content of the descriptions, for 73 species, there is characterization of the embryonic period and for 62, there is description of the whole larval period. For only 41 species there were complete descriptions (embryonic and larval) of the early development. All of these studies were conducted mainly with material derived from induced spawning and material obtained in the field (regressive series). Conclusions The characterization of eggs and larvae, still presents few studies, limited mainly to species from the rivers of the Plata and Amazon basins, to studies of fish of commercial importance and the incompleteness of most of these studies is still outstanding.

Early development of the Neotropical fish known as long sardine Triportheus auritus (Valenciennes 1850) (Characiformes, Triportheidae)

“…However, work on describing the early stages of the fish life cycle has grown in this region (Machado‐Allison et al., 2020; Nakatani et al., 2001; Orsi et al., 2016; Ponton & Mérigoux, 2001). In Brazil, studies of this nature they can be considered incipient, as they encompass approximately 4% of valid species, and are often incomplete and/or do not include details of the different stages of development (Orsi et al., 2016; Reynalte‐Tataje et al., 2020; Zacardi, Santos, et al., 2020).…”

Larval development of the freshwater croaker Pachypops fourcroi (La Cépède 1802) (Perciformes: Sciaenidae)

“…This information on the characterization of P. fourcroi larval ontogeny will be important to assist in its correct identification and evaluation of its initial stocks, given the urgency and relevance of the development of research on early life history ecology and fishery biology (Reynalte‐Tataje et al ., 2020). Furthermore, it will be a useful tool in the effective detection of nursery and growth areas of the studied species, fostering proposals for management and conservation of this fishery resource of the Amazon basin.…”

Early development ofProchilodus nigricansSpix & Agassiz 1829 (Characiformes: Prochilodontidae) in captivity

“…However, little is known about the life history, biology and ecology of this species, especially during the early stages of development (Zacardi et al, 2017). The absence of studies of this nature is associated with the lack of literature that helps the correct identification of fish eggs and larvae in the natural environment (Reynalte‐Tataje et al, 2020). It is emphasized that although the Amazon region has the greatest fish biodiversity in the world, there are still few studies that address the description of the early ontogeny of fish species (Zacardi et al, 2020).…”

“…The studies describing the early stages of prochilodontids is limited to species occurring in other basins, such as Paraná (Abdo et al, 2015; Nakatani et al, 2001; Ninhaus‐Silveira et al, 2006; Reynalte‐Tataje et al, 2020; Souza et al, 2015). Only S. insignis has the early life cycle described (Araújo‐Lima, 1985).…”