Biological variables of Hypostomus francisci (Siluriformes: Loricariidae) from Itapecerica River, Minas Gerais State, Brazil

Abstract

Herein we determine for the first time the reproduction parameters and population structure of Hypostomus francisci in the Itapecerica River, São Francisco Basin. A total of 250 specimens was captured quarterly between March 2010 and February 2012. Body weight, total length and weight of the gonads were obtained in the laboratory. Gonad samples were submitted to histological and histochemical techniques. Females with spawning capable ovaries were used to determine the fecundity and relative fecundity. Sex ratio with 1:1.01 (female:male) was observed. Males were more numerous than females for individuals smaller than 170 mm, however the number of females was significantly greater for specimens larger than 330 mm. The length-weight relationship estimated for H. francisci indicates negative-allometric growth. Females spawning capable were observed mostly in November-December-January. Two cohorts of oocytes at a determined time evidencing the development type group-synchronic. The eggs reaching 3.4 mm and the fecundity ranged from 312-1,460 oocytes with an average of 585.81 ± 337.43 oocytes per female. The reproductive parameters and population structure of H. francisci from Itapecerica River suggested that this species showed singular reproductive tactics among congeners.

Oocyte growth, follicular complex formation and extracellular-matrix remodeling in ovarian maturation of the imperial zebra pleco fish Hypancistrus zebra

“…zebra vary in size (diameter 44.07–487.81 µm). The increase in the diameter of the oocytes is similar to that found in Siluriformes, including Loricariichthys platymetopon , Loricariichthys sp., Loricaria sp., Hypostomus ternetzi , Megalancistrus aculeatus 31 and Hypostomus francisci 32 . This size variation may be related to the reproductive strategy: numerous small eggs are common in migratory species, whereas non-migratory species tend to have fewer but large eggs.…”

Biological aspects of Hypostomus affinis (Siluriformes: Loricariidae) in Brazilian coastal rivers

“…We observed mature specimens along the whole studied period for both drainages, with the highest frequency seen at the beginning of the rainy period (October 2008 and2009). The reproduction in Hypostomus species seems to occur primarily in the rainy season (Mazzoni & Caramaschi, 1997;Sales et al, 2016), despite some exceptions (e.g., (Medeiros & Pompiani, 2009). A breeding peak in September to February was previously recorded for H. affinis from the Paraíba do Sul River (Mazzoni & Caramaschi, 1995), corroborating our observations.…”

“…Harboring about 150 species (Dias & Zawadzki, 2018;van der Laan & Fricke, 2021), the genus Hypostomus Lacepède, 1803 is the richness taxa within loricariids, and most of them are endemic to the Brazilian coastal drainages (Camelier & Zanata, 2015). This genus usually fed on detritus (Power, 1984;Salvador Junior et al, 2009) and shows great adaptability to different habitats, from clear running water with rocky-bed to muddy water with soft bottoms (Garavello & Garavello, 2004;Sales et al, 2016). For this reason, some Hypostomus species can withstand rivers damming, with a notorious adaptation of their life cycles to the reservoir environments (Duarte et al, 2011;Gomes et al, 2015).…”

“…The knowledge on the biological aspects of Hypostomus species is scarce, considering its diversity (Gomes et al, 2015). Until now, the existent studies regard few species, addressing: the breeding cycle (Galarça et al, 2014;Mazzoni & Caramaschi, 1997), spawning behavior (Menezes & Caramaschi, 1994), fecundity (Mazzoni & Caramaschi, 1997;Takahashi et al, 2008), growth pattern (Salvador et al, 2018(Salvador et al, , 2017, and general reproductive tactics (Gomes et al, 2015;Sales et al, 2016). Although the shortfall in knowledge, the pleco Hypostomus affinis (Steindachner, 1877) is one of the most studied taxa of this genus regarding its biology (Duarte et al, 2011;Duarte & Araújo, 2002;Mazzoni & Caramaschi, 1997).…”

When destruction comes first: Two new species of Hypostomus Lacépède, 1803 (Siluriformes: Loricariidae) from a deeply‐impacted river in the Rio São Francisco basin in Brazil

“…Recent efforts focusing on ecology (Garavello & Garavello, 2004), reproduction (Sales et al ., 2016) or taxonomy of Hypostomus have been undertaken in the Rio São Francisco Basin (Zawadzki et al ., 2017, 2019). Nonetheless, the taxonomic diversity of the genus and knowledge of its distribution and ecology are far from being fully known, resulting in Linnean, Wallacean and Eltonean shortfalls.…”