Reproductive cycle of the Amazonian planktivorous catfish Hypophthalmus marginatus (Siluriformes, Pimelodidae)

Abstract

We evaluated the annual process of oocyte and ovarian development of the planktivorous Amazonian catfish, the mapará (Hypophthalmus marginatus), aiming to support captive reproduction for domestication. A total of 149 females were captured from the Tocantins River at the Tucuruí Dam (3°49'55"S, 49°39'9"W) in 13 sampling events. For each individual, we evaluated ovary histology and plasma steroid concentrations. Two annual reproductive cycles, with similar characteristics, including a long period of rest, a short vitellogenic stage and a well‐defined spawning season from November to March, were described. A 17β‐estradiol (E2) rise and a 17α,20β‐dihydroxy‐4‐pregnen‐3‐one (DHP) peak were associated with vitellogenesis and spawning season, respectively, in the first cycle but not in the second reproductive cycle. In conclusion, the studied species presents a reproductive cycle similar to that of other migratory total spawners; however, unusually for this group of fish, there were three (but not two) batches of vitellogenic oocytes in “in maturation” and “mature” stage ovaries, pointing to the possibility of more than one spawn during the spawning season.

Wild Leporinus friderici induced spawning with different dose of mGnRHa and metoclopramide or carp pituitary extract

“…In this context, one of the bottlenecks for the consolidation of its production in captivity, for aquaculture and preservation purposes, is the attainment of viable embryos through hormonal induction. When kept in captivity, ovarian and testicular maturation takes place, reaching more advanced stages of maturation between November and February (rainy season in Brazil) and, as well as the majority of tropical reophilic fish, hormonal stimulation is required for spawning (Borella et al, 2019;Hainfellner et al, 2019).…”

The environmental licensing of hydroelectrics and the interface with migratory fish and aquaculture in Brazil

“…While the curimbatá was among the migratory species most affected by the fact that the closure of the river prevents its upward reproductive migration and limits its recolonization in the downstream from upstream, the same reason cannot be attributed to the reduction in the abundance of mapará, as it carried out its entire migratory cycle in the downstream area, so it is very likely that there was also a decrease in plankton production due to a degradation of the aquatic environment (Mérona et al, 2010). Still concerning maparás, a fish that we studied due to its high potential for integrated aquaculture purposes for being planktivorous, in the same area reported by Mérona et al (2010), we published a study in 2019 where maparás were observed upstream and downstream the dam, but in the immediate downstream portion very close to the dam, spawned individuals were not found, and only mature females were observed (absence of spawning) (Hainfellner et al, 2019). We also observed that some females found downstream from the dam, however at a slightly greater distance, indeed had postovulatory follicles, indicating that they had spawned in those areas, but not in the dam area (Hainfellner et al, 2019).…”

“…Still concerning maparás, a fish that we studied due to its high potential for integrated aquaculture purposes for being planktivorous, in the same area reported by Mérona et al (2010), we published a study in 2019 where maparás were observed upstream and downstream the dam, but in the immediate downstream portion very close to the dam, spawned individuals were not found, and only mature females were observed (absence of spawning) (Hainfellner et al, 2019). We also observed that some females found downstream from the dam, however at a slightly greater distance, indeed had postovulatory follicles, indicating that they had spawned in those areas, but not in the dam area (Hainfellner et al, 2019).…”

“…Below we cite some examples, especially in cases where we have developed some studies, as in the case of the Tucuruí Dam (Hainfellner et al, 2019), where many particularities are observed in each case, which involve numerous variables: type of dam, rainfall, climate, local social contexts, and mainly the migratory stretches of the river that each species occupy. An important topic to be addressed is the momentary abundance of species that is frequently observed after the installation of hydroelectric plants.…”

Lunar cycle and reproductive activity of Redbelly yellowtail fusilier, Caesio cuning in Karimunjawa National Park, Indonesia

“…The VSI peak (Figure 5) occurs twice at full moon. The reduction in VSI during spawning was also studied by Hainfellner et al (2019) in Amazonian planktivorous catfish, Hypophthalmus marginatus. This species continues to feed and increases the VSI to a maximum (3%) when entering the spawning season, the VSI will decrease.…”